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Sample records for gev monoenergetic ion

  1. Monoenergetic and GeV ion acceleration from the laser breakout afterburner using ultrathin targets

    SciTech Connect

    Yin, L.; Albright, B. J.; Hegelich, B. M.; Bowers, K. J.; Flippo, K. A.; Kwan, T. J. T.; Fernandez, J. C.

    2007-05-15

    A new laser-driven ion acceleration mechanism using ultrathin targets has been identified from particle-in-cell simulations. After a brief period of target normal sheath acceleration (TNSA) [S. P. Hatchett et al., Phys. Plasmas 7, 2076 (2000)], two distinct stages follow: first, a period of enhanced TNSA during which the cold electron background converts entirely to hot electrons, and second, the ''laser breakout afterburner'' (BOA) when the laser penetrates to the rear of the target where a localized longitudinal electric field is generated with the location of the peak field co-moving with the ions. During this process, a relativistic electron beam is produced by the ponderomotive drive of the laser. This beam is unstable to a relativistic Buneman instability, which rapidly converts the electron energy into ion energy. This mechanism accelerates ions to much higher energies using laser intensities comparable to earlier TNSA experiments. At a laser intensity of 10{sup 21} W/cm{sup 2}, the carbon ions accelerate as a quasimonoenergetic bunch to 100 s of MeV in the early stages of the BOA with conversion efficiency of order a few percent. Both are an order of magnitude higher than those realized from TNSA in recent experiments [Hegelich et al., Nature 441, 439 (2006)]. The laser-plasma interaction then evolves to produce a quasithermal energy distribution with maximum energy of {approx}2 GeV.

  2. Relativistically Induced Transparency Acceleration (RITA) - laser-plasma accelerated quasi-monoenergetic GeV ion-beams with existing lasers?

    NASA Astrophysics Data System (ADS)

    Sahai, Aakash A.

    2013-10-01

    Laser-plasma ion accelerators have the potential to produce beams with unprecedented characteristics of ultra-short bunch lengths (100s of fs) and high bunch-charge (1010 particles) over acceleration length of about 100 microns. However, creating and controlling mono-energetic bunches while accelerating to high-energies has been a challenge. If high-energy mono-energetic beams can be demonstrated with minimal post-processing, laser (ω0)-plasma (ωpe) ion accelerators may be used in a wide-range of applications such as cancer hadron-therapy, medical isotope production, neutron generation, radiography and high-energy density science. Here we demonstrate using analysis and simulations that using relativistic intensity laser-pulses and heavy-ion (Mi ×me) targets doped with a proton (or light-ion) species (mp ×me) of trace density (at least an order of magnitude below the cold critical density) we can scale up the energy of quasi-mono-energetically accelerated proton (or light-ion) beams while controlling their energy, charge and energy spectrum. This is achieved by controlling the laser propagation into an overdense (ω0 <ωpeγ = 1) increasing plasma density gradient by incrementally inducing relativistic electron quiver and thereby rendering them transparent to the laser while the heavy-ions are immobile. Ions do not directly interact with ultra-short laser that is much shorter in duration than their characteristic time-scale (τp <<√{mp} /ω0 <<√{Mi} /ω0). For a rising laser intensity envelope, increasing relativistic quiver controls laser propagation beyond the cold critical density. For increasing plasma density (ωpe2 (x)), laser penetrates into higher density and is shielded, stopped and reflected where ωpe2 (x) / γ (x , t) =ω02 . In addition to the laser quivering the electrons, it also ponderomotively drives (Fp 1/γ∇za2) them forward longitudinally, creating a constriction of snowplowed e-s. The resulting longitudinal e--displacement from

  3. Laser-driven shock acceleration of monoenergetic ion beams.

    PubMed

    Fiuza, F; Stockem, A; Boella, E; Fonseca, R A; Silva, L O; Haberberger, D; Tochitsky, S; Gong, C; Mori, W B; Joshi, C

    2012-11-21

    We show that monoenergetic ion beams can be accelerated by moderate Mach number collisionless, electrostatic shocks propagating in a long scale-length exponentially decaying plasma profile. Strong plasma heating and density steepening produced by an intense laser pulse near the critical density can launch such shocks that propagate in the extended plasma at high velocities. The generation of a monoenergetic ion beam is possible due to the small and constant sheath electric field associated with the slowly decreasing density profile. The conditions for the acceleration of high-quality, energetic ion beams are identified through theory and multidimensional particle-in-cell simulations. The scaling of the ion energy with laser intensity shows that it is possible to generate ~200 MeV proton beams with state-of-the-art 100 TW class laser systems.

  4. Multistaged acceleration of ions by circularly polarized laser pulse: Monoenergetic ion beam generation

    SciTech Connect

    Zhang Xiaomei; Shen Baifei; Li Xuemei; Jin Zhangying; Wang Fengchao

    2007-07-15

    A multiple-staged ion acceleration mechanism in the interaction of a circularly polarized laser pulse with a solid target is studied by one-dimensional particle-in-cell simulation. The ions are accelerated from rest to several MeV monoenergetically at the front surface of the target. After all the plasma ions are accelerated, the acceleration process is repeated on the resulting monoenergetic ions. Under suitable conditions multiple repetitions can be realized and a high-energy quasi-monoenergetic ion beam can be obtained.

  5. Generation of monoenergetic ion beams via ionization dynamics (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Lin, Chen; Kim, I. Jong; Yu, Jinqing; Choi, Il Woo; Ma, Wenjun; Yan, Xueqing; Nam, Chang Hee

    2017-05-01

    The research on ion acceleration driven by high intensity laser pulse has attracted significant interests in recent decades due to the developments of laser technology. The intensive study of energetic ion bunches is particularly stimulated by wide applications in nuclear fusion, medical treatment, warm dense matter production and high energy density physics. However, to implement such compact accelerators, challenges are still existing in terms of beam quality and stability, especially in applications that require higher energy and narrow bandwidth spectra ion beams. We report on the acceleration of quasi-mono-energetic ion beams via ionization dynamics in the interaction of an intense laser pulse with a solid target. Using ionization dynamics model in 2D particle-in-cell (PIC) simulations, we found that high charge state contamination ions can only be ionized in the central spot area where the intensity of sheath field surpasses their ionization threshold. These ions automatically form a microstructure target with a width of few micron scale, which is conducive to generate mono-energetic beams. In the experiment of ultraintense (< 10^21 W/cm^2) laser pulses irradiating ultrathin targets each attracted with a contamination layer of nm-thickness, high quality < 100 MeV mono-energetic ion bunches are generated. The peak energy of the self-generated micro-structured target ions with respect to different contamination layer thickness is also examined This is relatively newfound respect, which is confirmed by the consistence between experiment data and the simulation results.

  6. Extension of the BRYNTRN code to monoenergetic light ion beams

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.; Badavi, Francis F.

    1994-01-01

    A monoenergetic version of the BRYNTRN transport code is extended to beam transport of light ions (H-2, H-3, He-3, and He-4) in shielding materials (thick targets). The redistribution of energy in nuclear reactions is included in transport solutions that use nuclear fragmentation models. We also consider an equilibrium target-fragment spectrum for nuclei with mass number greater than four to include target fragmentation effects in the linear energy transfer (LET) spectrum. Illustrative results for water and aluminum shielding, including energy and LET spectra, are discussed for high-energy beams of H-2 and He-4.

  7. Two-stream instability assessment of fast ignition driven by quasi-monoenergetic ions

    NASA Astrophysics Data System (ADS)

    Khoshbinfar, Soheil

    2017-01-01

    During the past decade, the generation of energetic ion beams by high-intensity laser-plasma interactions has attracted much interest due to their many applications in high energy density physics and fast ignition. The interaction of the energetic beam with the pre-compressed DT plasma may be accompanied by micro-instabilities along normal and parallel to the beam direction. In application of ions heavier than hydrogen isotopes in fast ignition, we expect that the number of required ions reduces considerably. Here, we present a one-dimensional relativistic beam-plasma instability formulation to investigate the stabilization mode of a flow aligned two-stream instability spectrum where both cold-fluid and kinetic linear theory results are reported. In the latter, the saddle point expansion of the relativistic drift-Maxwellian distribution was applied. The stabilization mode was then extracted by using the Nyquist method. We have also restricted our stability analyses to quasi-monoenergetic ion beams of type Li3+, C6+, Al13+, and V23+ with optimal energies of 140 MeV, 450 MeV, 2.2 GeV, and 5.5 GeV, respectively, proposed by numerical simulations in fast ignition [Honrubia et al. Laser Part. Beams 32, 419 (2014)]. The stable mode is attained by two free system parameters, i.e., beam/plasma density ratio, α, and background plasma temperature, Tp. In the case of low Zb ions, by different degree levels, both parameters push the system to complete stability. However, in the case of high Zb ions, complete stabilization is achieved just through few orders of magnitude lower α. It has also been shown that in complete stabilization of the system, the α parameter scales as an inverse square of ions' atomic number, ∝Zb-2.

  8. Generating Monoenergetic Heavy-Ion Bunches with Laser-Induced Electrostatic Shocks

    SciTech Connect

    Ji Liangliang; Shen Baifei; Zhang Xiaomei; Wang Fengchao; Jin Zhangyin; Li Xuemei; Wen Meng; Cary, John R.

    2008-10-17

    A method for efficient laser acceleration of heavy ions by electrostatic shock is investigated using particle-in-cell (PIC) simulation and analytical modeling. When a small number of heavy ions are mixed with light ions, the heavy ions can be accelerated to the same velocity as the light ions so that they gain much higher energy because of their large mass. Accordingly, a sandwich target design with a thin compound ion layer between two light-ion layers and a micro-structured target design are proposed for obtaining monoenergetic heavy-ion beams.

  9. Generation of quasi-monoenergetic carbon ions accelerated parallel to the plane of a sandwich target

    SciTech Connect

    Wang, J. W.; Murakami, M.; Weng, S. M.; Xu, H.; Ju, J. J.; Luan, S. X.; Yu, W.

    2014-12-15

    A new ion acceleration scheme, namely, target parallel Coulomb acceleration, is proposed in which a carbon plate sandwiched between gold layers is irradiated with intense linearly polarized laser pulses. The high electrostatic field generated by the gold ions efficiently accelerates the embedded carbon ions parallel to the plane of the target. The ion beam is found to be collimated by the concave-shaped Coulomb potential. As a result, a quasi-monoenergetic and collimated C{sup 6+}-ion beam with an energy exceeding 10 MeV/nucleon is produced at a laser intensity of 5 × 10{sup 19} W/cm{sup 2}.

  10. Low-emittance monoenergetic electron and ion beams from ultra-intense laser-solid interactions

    SciTech Connect

    Cowan, T E; Roth, M; Allen, M M; Johnson, J; Hatchett, S P; Le Sage, G P; Wilks, S C

    2000-03-03

    Recent experiments at the LLNL Petawatt Laser have demonstrated the generation of intense, high energy beams of electrons and ions from the interaction of ultra-intense laser light with solid targets. Focused laser intensities as high as 6 x 10{sup 20} W/cm{sup 2} are achieved, at which point the quiver energies of the target electrons extend to {approx}10 MeV. In this new, fully relativistic regime of laser-plasma interactions, nuclear processes become important and nuclear techniques are required to diagnose the high-energy particle production. In recent experiments we have observed electrons accelerated to 100 MeV, up to 60 MeV brehmsstrahlung generation, photo-nuclear fission and positron-electron pair creation. We also have observed monoenergetic jets of electrons having sufficiently small emittance to be interesting as a laser-accelerated beam, if the production mechanism could be understood and controlled. The huge flux of multi-MeV ponderomotively accelerated electrons produced in the laser-solid interaction is also observed to accelerate contaminant ions from the rear surface of the solid target up to 50 MeV. We describe spectroscopic measurements which reveal intense monoenergetic beam features in the proton energy spectrum. The total spectrum contains >10{sup 13} protons, while the monoenergetic beam pulses contain {approx}1 nC of protons, and exhibits a longitudinal and transverse emittance smaller than conventional RF proton accelerator beams.

  11. Efficient GeV ion generation by ultraintense circularly polarized laser pulse

    SciTech Connect

    Zhang Xiaomei; Shen Baifei; Li Xuemei; Jin Zhangying; Wang Fengchao; Wen Meng

    2007-12-15

    The interaction of an ultraintense circularly polarized laser pulse and a solid target is studied by one-dimensional particle-in-cell simulations. Ions at the front of the target are reflected by a moving quasisteady electrostatic field and obtain a relativistic velocity. At a laser intensity of 10{sup 22} W/cm{sup 2}, almost half of the laser energy is transferred to ions and GeV ions are obtained. Effects of laser polarization state and target thickness on the laser energy conversion are investigated. It is found that a circularly polarized laser pulse can accelerate ions more efficiently than a linearly polarized laser pulse at the same laser and target parameters. A monoenergetic ion bunch is obtained for the ultrathin target, which is accelerated as a single entity.

  12. Monoenergetic ion beam acceleration from transversely confined near-critical plasmas by intense laser pulses

    NASA Astrophysics Data System (ADS)

    Zhang, W. L.; Qiao, B.; Shen, X. F.; Chang, H. X.; Zhang, H.; Zhou, C. T.; He, X. T.

    2017-09-01

    An advanced target for production of high-energy monoenergetic ion beams by intense laser pulses is proposed, in which the near-critical plasma is transversely confined between the high-Z dense wires. It is found that the ion acceleration is significantly enhanced due to the strong magnetic dipole vortex formed at the rear of the target, where large electron current density gradients from the wires to the vacuum exist. The magnetic dipole vortex helps to realize the contraction of ion momentum phase spaces and reduction of the beam divergence so that monenergetic, highly directed, and collimated ion beams can be obtained. Two-dimensional particle-in-cell simulations have shown that monoenergetic proton beams with a peak energy of 105 MeV and particle number about 2.2 × 1011 are produced by using the advanced target at a laser intensity of 2.7 × 1020 W/cm2 and a pulse duration of 0.65 ps.

  13. Approach towards quasi-monoenergetic laser ion acceleration with doped target

    SciTech Connect

    Morita, Toshimasa

    2014-05-15

    Ion acceleration using a laser pulse irradiating a disk target that includes hydrogen and carbon is examined using three-dimensional particle-in-cell simulations. It is shown that over 200 MeV protons can be generated using a 620 TW, 5 × 10{sup 21} W/cm{sup 2} laser pulse. In a polyethylene (CH{sub 2}) target, protons and carbon ions separate and form two layers by radiation pressure acceleration. A strong Coulomb explosion in this situation and Coulomb repulsion between each layer generates high energy protons. A doped target consisting of low density hydrogen within a carbon disk becomes a double layer target that is comprised of a thin low density hydrogen disk on the surface of a high-Z atom layer. This then generates a quasi-monoenergetic proton beam.

  14. Monoenergetic source of kilodalton ions from Taylor cones of ionic liquids

    NASA Astrophysics Data System (ADS)

    Larriba, C.; Castro, S.; Fernandez de la Mora, J.; Lozano, P.

    2007-04-01

    The ionic liquid ion sources (ILISs) recently introduced by Lozano and Martinez Sanchez [J. Colloid Interface Sci. 282, 415 (2005)], based on electrochemically etched tungsten tips as emitters for Taylor cones of ionic liquids (ILs), have been tested with ionic liquids [A+B-] of increasing molecular weight and viscosity. These ILs have electrical conductivities well below 1S/m and were previously thought to be unsuitable to operate in the purely ionic regime because their Taylor cones produce mostly charged drops from conventional capillary tube sources. Strikingly, all the ILs tried on ILIS form charged beams composed exclusively of small ions and cluster ions A+(AB)n or B-(AB)n, with abundances generally peaking at n =1. Particularly interesting are the positive and negative ion beams produced from the room temperature molten salts 1-methyl-3-pentylimidazolium tris(pentafluoroethyl) trifluorophosphate (C5MI-(C2F5)3PF3) and 1-ethyl-3-methylimidazolium bis(pentafluoroethyl) sulfonylimide (EMI-(C2F5SO3)2N). We extend to these heavier species the previous conclusions from Lozano and Martinez Sanchez on the narrow energy distributions of the ion beams. In combination with suitable ILs, this source yields nanoamphere currents of positive and negative monoenergetic molecular ions with masses exceeding 2000amu. Potential applications are in biological secondary ion mass spectrometry, chemically assisted high-resolution ion beam etching, and electrical propulsion. Advantages of the ILISs versus similar liquid metal ion sources include the possibility to form negative as well as positive ion beams and a much wider range of ion compositions and molecular masses.

  15. Medical Implication of Quasi-monoenergetic Proton Generated from Laser Acceleration of Ultra-thin Multi-Ion Foil

    NASA Astrophysics Data System (ADS)

    Liu, Tung-Chang; Shao, Xi; Su, Jao-Jang; Liu, Chuan-Sheng; He, Minqing; Eliasson, Bengt; Sagdeev, Roald

    2011-10-01

    Recent work by Liu et al. [2011] (presented in this conference) shows that high quality quasi-monoenergetic proton beams can be generated in laser acceleration of an ultra-thin multi-ion, i.e. carbon-proton, foil. The proton acceleration is due to the combination of radiation pressure and heavy-ion Coulomb repulsion. Using a normalized peak laser amplitude of a0 = 5 and a carbon-proton target with 10% protons, our PIC simulation shows that the resulting quasi-monoenergetic (energy spread < 10%) proton energy is ~ 70 MeV. To assess the feasibility of laser-proton cancer therapy with such a proton accelerator, simulations are carried out to model the interaction of protons with water and determine the radiation dosage deposition for particle beams produced from the PIC simulation of laser acceleration of multi-ion target. We used the SRIM code to calculate the depth and lateral dose distribution of protons energized by laser radiation pressure. The overall dosage deposition map from the proton beam is derived by superposing the radiation dosage contributed from each particle fed from the PIC simulation. Comparison between the dosage map produced from quasi-monoenergetic protons generated from laser acceleration of single ion and multi-ion targets is also presented.

  16. Radiation microscope for SEE testing using GeV ions.

    SciTech Connect

    Doyle, Barney Lee; Knapp, James Arthur; Rossi, Paolo; Hattar, Khalid M.; Vizkelethy, Gyorgy; Brice, David Kenneth; Branson, Janelle V.

    2009-09-01

    Radiation Effects Microscopy is an extremely useful technique in failure analysis of electronic parts used in radiation environment. It also provides much needed support for development of radiation hard components used in spacecraft and nuclear weapons. As the IC manufacturing technology progresses, more and more overlayers are used; therefore, the sensitive region of the part is getting farther and farther from the surface. The thickness of these overlayers is so large today that the traditional microbeams, which are used for REM are unable to reach the sensitive regions. As a result, higher ion beam energies have to be used (> GeV), which are available only at cyclotrons. Since it is extremely complicated to focus these GeV ion beams, a new method has to be developed to perform REM at cyclotrons. We developed a new technique, Ion Photon Emission Microscopy, where instead of focusing the ion beam we use secondary photons emitted from a fluorescence layer on top of the devices being tested to determine the position of the ion hit. By recording this position information in coincidence with an SEE signal we will be able to indentify radiation sensitive regions of modern electronic parts, which will increase the efficiency of radiation hard circuits.

  17. 8 GeV H- ions: Transport and injection

    SciTech Connect

    Chou, W.; Bryant, H.; Drozhdin, A.; Hill, C.; Kostin, M.; Macek, R.; Ostiguy, J.-F.; Rees, G.H.; Tang, Z.; Yoon, P.; /Fermilab /New Mexico U. /Los Alamos /Rutherford /Rochester U.

    2005-05-01

    Fermilab is working on the design of an 8 GeV superconducting RF H{sup -} linac called the Proton Driver. The energy of H{sup -} beam will be an order of magnitude higher than the existing ones. This brings up a number of technical challenges to transport and injection of H{sup -} ions. This paper will focus on the subjects of stripping losses (including stripping by blackbody radiation, field and residual gas) and carbon foil stripping efficiency, along with a brief discussion on other issues such as Stark states lifetime of hydrogen atoms, single and multiple Coulomb scattering, foil heating and stress, radiation activation, collimation and jitter correction, etc.

  18. Quasi-monoenergetic ion generation by hole-boring radiation pressure acceleration in inhomogeneous plasmas using tailored laser pulses

    SciTech Connect

    Weng, S. M. Murakami, M.; Azechi, H.; Wang, J. W.; Tasoko, N.; Chen, M.; Sheng, Z. M.; Mulser, P.; Yu, W.; Shen, B. F.

    2014-01-15

    It is proposed that laser hole-boring at a steady speed in inhomogeneous overdense plasma can be realized by the use of temporally tailored intense laser pulses, producing high-fluence quasi-monoenergetic ion beams. A general temporal profile of such laser pulses is formulated for arbitrary plasma density distribution. As an example, for a precompressed deuterium-tritium fusion target with an exponentially increasing density profile, its matched laser profile for steady hole-boring is given theoretically and verified numerically by particle-in-cell simulations. Furthermore, we propose to achieve fast ignition by the in-situ hole-boring accelerated ions using a tailored laser pulse. Simulations show that the effective energy fluence, conversion efficiency, energy spread, and collimation of the resulting ion beam can be significantly improved as compared to those found with un-tailored laser profiles. For the fusion fuel with an areal density of 1.5 g cm{sup –2}, simulation indicates that it is promising to realize fast ion ignition by using a tailored driver pulse with energy about 65 kJ.

  19. Quasi-monoenergetic ion beam acceleration by laser-driven shock and solitary waves in near-critical plasmas

    SciTech Connect

    Zhang, W. L.; Qiao, B. Huang, T. W.; Shen, X. F.; You, W. Y.; Yan, X. Q.; Wu, S. Z.; Zhou, C. T.; He, X. T.

    2016-07-15

    Ion acceleration in near-critical plasmas driven by intense laser pulses is investigated theoretically and numerically. A theoretical model has been given for clarification of the ion acceleration dynamics in relation to different laser and target parameters. Two distinct regimes have been identified, where ions are accelerated by, respectively, the laser-induced shock wave in the weakly driven regime (comparatively low laser intensity) and the nonlinear solitary wave in the strongly driven regime (comparatively high laser intensity). Two-dimensional particle-in-cell simulations show that quasi-monoenergetic proton beams with a peak energy of 94.6 MeV and an energy spread 15.8% are obtained by intense laser pulses at intensity I{sub 0} = 3 × 10{sup 20 }W/cm{sup 2} and pulse duration τ = 0.5 ps in the strongly driven regime, which is more advantageous than that got in the weakly driven regime. In addition, 233 MeV proton beams with narrow spread can be produced by extending τ to 1.0 ps in the strongly driven regime.

  20. Efficient quasi-monoenergetic ion beams from laser-driven relativistic plasmas

    DOE PAGES

    Palaniyappan, Sasi; Huang, Chengkun; Gautier, Donald C.; ...

    2015-12-11

    Here, table-top laser–plasma ion accelerators have many exciting applications, many of which require ion beams with simultaneous narrow energy spread and high conversion efficiency. However, achieving these requirements has been elusive. Here we report the experimental demonstration of laser-driven ion beams with narrow energy spread and energies up to 18 MeV per nucleon and ~5% conversion efficiency (that is 4 J out of 80-J laser). Using computer simulations we identify a self-organizing scheme that reduces the ion energy spread after the laser exits the plasma through persisting self-generated plasma electric (~1012 V m–1) and magnetic (~104 T) fields. These resultsmore » contribute to the development of next generation compact accelerators suitable for many applications such as isochoric heating for ion-fast ignition and producing warm dense matter for basic science.« less

  1. Efficient quasi-monoenergetic ion beams from laser-driven relativistic plasmas

    SciTech Connect

    Palaniyappan, Sasi; Huang, Chengkun; Gautier, Donald C.; Hamilton, Christopher E.; Santiago, Miguel A.; Kreuzer, Christian; Sefkow, Adam B.; Shah, Rahul C.; Fernández, Juan C.

    2015-12-11

    Here, table-top laser–plasma ion accelerators have many exciting applications, many of which require ion beams with simultaneous narrow energy spread and high conversion efficiency. However, achieving these requirements has been elusive. Here we report the experimental demonstration of laser-driven ion beams with narrow energy spread and energies up to 18 MeV per nucleon and ~5% conversion efficiency (that is 4 J out of 80-J laser). Using computer simulations we identify a self-organizing scheme that reduces the ion energy spread after the laser exits the plasma through persisting self-generated plasma electric (~1012 V m–1) and magnetic (~104 T) fields. These results contribute to the development of next generation compact accelerators suitable for many applications such as isochoric heating for ion-fast ignition and producing warm dense matter for basic science.

  2. Efficient quasi-monoenergetic ion beams from laser-driven relativistic plasmas

    PubMed Central

    Palaniyappan, Sasi; Huang, Chengkun; Gautier, Donald C.; Hamilton, Christopher E.; Santiago, Miguel A.; Kreuzer, Christian; Sefkow, Adam B.; Shah, Rahul C.; Fernández, Juan C.

    2015-01-01

    Table-top laser–plasma ion accelerators have many exciting applications, many of which require ion beams with simultaneous narrow energy spread and high conversion efficiency. However, achieving these requirements has been elusive. Here we report the experimental demonstration of laser-driven ion beams with narrow energy spread and energies up to 18 MeV per nucleon and ∼5% conversion efficiency (that is 4 J out of 80-J laser). Using computer simulations we identify a self-organizing scheme that reduces the ion energy spread after the laser exits the plasma through persisting self-generated plasma electric (∼1012 V m−1) and magnetic (∼104 T) fields. These results contribute to the development of next generation compact accelerators suitable for many applications such as isochoric heating for ion-fast ignition and producing warm dense matter for basic science. PMID:26657147

  3. Efficient quasi-monoenergetic ion beams from laser-driven relativistic plasmas.

    PubMed

    Palaniyappan, Sasi; Huang, Chengkun; Gautier, Donald C; Hamilton, Christopher E; Santiago, Miguel A; Kreuzer, Christian; Sefkow, Adam B; Shah, Rahul C; Fernández, Juan C

    2015-12-11

    Table-top laser-plasma ion accelerators have many exciting applications, many of which require ion beams with simultaneous narrow energy spread and high conversion efficiency. However, achieving these requirements has been elusive. Here we report the experimental demonstration of laser-driven ion beams with narrow energy spread and energies up to 18 MeV per nucleon and ∼5% conversion efficiency (that is 4 J out of 80-J laser). Using computer simulations we identify a self-organizing scheme that reduces the ion energy spread after the laser exits the plasma through persisting self-generated plasma electric (∼10(12) V m(-1)) and magnetic (∼10(4) T) fields. These results contribute to the development of next generation compact accelerators suitable for many applications such as isochoric heating for ion-fast ignition and producing warm dense matter for basic science.

  4. Generation of quasi-monoenergetic heavy ion beams via staged shock wave acceleration driven by intense laser pulses in near-critical plasmas

    NASA Astrophysics Data System (ADS)

    Zhang, W. L.; Qiao, B.; Shen, X. F.; You, W. Y.; Huang, T. W.; Yan, X. Q.; Wu, S. Z.; Zhou, C. T.; He, X. T.

    2016-09-01

    Laser-driven ion acceleration potentially offers a compact, cost-effective alternative to conventional accelerators for scientific, technological, and health-care applications. A novel scheme for heavy ion acceleration in near-critical plasmas via staged shock waves driven by intense laser pulses is proposed, where, in front of the heavy ion target, a light ion layer is used for launching a high-speed electrostatic shock wave. This shock is enhanced at the interface before it is transmitted into the heavy ion plasmas. Monoenergetic heavy ion beam with much higher energy can be generated by the transmitted shock, comparing to the shock wave acceleration in pure heavy ion target. Two-dimensional particle-in-cell simulations show that quasi-monoenergetic {{{C}}}6+ ion beams with peak energy 168 MeV and considerable particle number 2.1 × {10}11 are obtained by laser pulses at intensity of 1.66 × {10}20 {{W}} {{cm}}-2 in such staged shock wave acceleration scheme. Similarly a high-quality {{Al}}10+ ion beam with a well-defined peak with energy 250 MeV and spread δ E/{E}0=30 % can also be obtained in this scheme.

  5. Sputtering yield formula for B 4C irradiated with monoenergetic ions at normal incidence

    NASA Astrophysics Data System (ADS)

    Ono, T.; Kawamura, T.; Ishii, K.; Yamamura, Y.

    1996-09-01

    To fill a lack in sputtering yield data for a B 4C material which may be a promising plasma-facing material in fusion devices, the yields of H +, D +, T +, He +, B +, C +, Ne +, Ar + and Kr + ions were calculated for this multi-component material for normal incidence with a computer simulation code ACAT. A fitting formula of sputtering yield for a B 4C was proposed based on an empirical formula for monoatomic target materials at normal incidence. By fitting the formula to the calculated data, best-fit values of the parameters included in it were derived for the material. Good agreement was found between the formula and the data. Thus, the formula proposed for the multi-component material provides a way to estimate the erosion of a B 4C material irradiated with above ions at normal incidence. Preferential sputtering for this material was also mentioned briefly.

  6. Skin depth criterion for foil thickness in laser pressure acceleration of monoenergetic ions

    SciTech Connect

    Tripathi, Vipin K.; Liu, Chuan S.; Shao Xi; Sharma, Anamika

    2011-04-15

    An analytical formalism is developed to study the nonlinear laser penetration through radiation pressure accelerated thin foils, employed to produce high energy ions. We include the effects of relativistic mass increase and nonuniform electron density compression due to the ponderomotive force in plasma permittivity. For foils like diamond the usual optimum foil thickness l{sub opt}={lambda}{sub L}n{sub cr}a{sub 0}/{pi}n{sub 0} (where {lambda}{sub L} and a{sub 0} are the wavelength and normalized amplitude of the laser), at which the ponderomotive force on electrons balances the space charge force due to the ions left behind, is significantly below the skin depth unless the laser intensity is excessively large and significant laser transmission through the foil reduces the radiation pressure on it. The reflection coefficient decreases with laser field strength, though the ponderomotive force led electron compression tends to raise it. The reflection coefficient also decreases significantly with foil velocity, which is a sensitive function of laser field strength and foil thickness.

  7. Proton acceleration by single-cycle laser pulses offers a novel monoenergetic and stable operating regime

    NASA Astrophysics Data System (ADS)

    Zhou, M. L.; Yan, X. Q.; Mourou, G.; Wheeler, J. A.; Bin, J. H.; Schreiber, J.; Tajima, T.

    2016-04-01

    Prompted by the possibility to produce high energy, single-cycle laser pulses with tens of Petawatt (PW) power, we have investigated laser-matter interactions in the few optical cycle and ultra relativistic intensity regimes. A particularly interesting instability-free regime for ion production was revealed leading to the efficient coherent generation of short (femtosecond; 10 - 15 s ) monoenergetic ion bunches with a peak energy greater than GeV. Of paramount importance, the interaction is absent of the Rayleigh Taylor Instabilities and hole boring that plague techniques such as target normal sheath acceleration and radiation pressure acceleration.

  8. Stable GeV Ion-Beam Acceleration from Thin Foils by Circularly Polarized Laser Pulses

    SciTech Connect

    Qiao, B.; Zepf, M.; Borghesi, M.; Geissler, M.

    2009-04-10

    A stable relativistic ion acceleration regime for thin foils irradiated by circularly polarized laser pulses is suggested. In this regime, the 'light-sail' stage of radiation pressure acceleration for ions is smoothly connected with the initial relativistic 'hole-boring' stage, and a defined relationship between laser intensity I{sub 0}, foil density n{sub 0}, and thickness l{sub 0} should be satisfied. For foils with a wide range of n{sub 0}, the required I{sub 0} and l{sub 0} for the regime are theoretically estimated and verified with the particle-in-cell code ILLUMINATION. It is shown for the first time by 2D simulations that high-density monoenergetic ion beams with energy above GeV/u and divergence of 10 deg. are produced by circularly polarized lasers at intensities of 10{sup 22} W/cm{sup 2}, which are within reach of current laser systems.0.

  9. The monoenergetic approximation in stellarator neoclassical calculations

    NASA Astrophysics Data System (ADS)

    Landreman, Matt

    2011-08-01

    In 'monoenergetic' stellarator neoclassical calculations, to expedite computation, ad hoc changes are made to the kinetic equation so speed enters only as a parameter. Here we examine the validity of this approach by considering the effective particle trajectories in a model magnetic field. We find monoenergetic codes systematically under-predict the true trapped particle fraction. The error in the trapped ion fraction can be of order unity for large but experimentally realizable values of the radial electric field, suggesting some results of these codes may be unreliable in this regime. This inaccuracy is independent of any errors introduced by approximation of the collision operator.

  10. Generation of monoenergetic positrons

    SciTech Connect

    Hulett, L.D. Jr.; Dale, J.M.; Miller, P.D. Jr.; Moak, C.D.; Pendyala, S.; Triftshaeuser, W.; Howell, R.H.; Alvarez, R.A.

    1983-01-01

    Many experiments have been performed in the generation and application of monoenergetic positron beams using annealed tungsten moderators and fast sources of /sup 58/Co, /sup 22/Na, /sup 11/C, and LINAC bremstrahlung. This paper will compare the degrees of success from our various approaches. Moderators made from both single crystal and polycrystal tungsten have been tried. Efforts to grow thin films of tungsten to be used as transmission moderators and brightness enhancement devices are in progress.

  11. ION BEAM POLARIZATION DYNAMICS IN THE 8 GEV BOOSTER OF THE JLEIC PROJECT AT JLAB

    SciTech Connect

    Kondratenko, A. M.; Kondratenko, M. A.; Morozov, Vasiliy; Derbenev, Yaroslav S.; Lin, Fanglei; Zhang, Yuhong; Filatov, Yuri

    2016-05-01

    In the Jefferson Lab’s Electron-Ion Collider (JLEIC) project, an injector of polarized ions into the collider ring is a superconducting 8 GeV booster. Both figure-8 and racetrack booster versions were considered. Our analysis showed that the figure-8 ring configuration allows one to preserve the polarization of any ion species during beam acceleration using only small longitudinal field with an integral less than 0.5 Tm. In the racetrack booster, to pre-serve the polarization of ions with the exception of deu-terons, it suffices to use a solenoidal Siberian snake with a maximum field integral of 30 Tm. To preserve deuteron polarization, we propose to use arc magnets for the race-track booster structure with a field ramp rate of the order of 1 T/s. We calculate deuteron and proton beam polari-zations in both the figure-8 and racetrack boosters includ-ing alignment errors of their magnetic elements using the Zgoubi code.

  12. Acceleration of highly charged GeV Fe ions from a low-Z substrate by intense femtosecond laser

    NASA Astrophysics Data System (ADS)

    Nishiuchi, M.; Sakaki, H.; Esirkepov, T. Zh.; Nishio, K.; Pikuz, T. A.; Faenov, A. Ya.; Skobelev, I. Yu.; Orlandi, R.; Sako, H.; Pirozhkov, A. S.; Matsukawa, K.; Sagisaka, A.; Ogura, K.; Kanasaki, M.; Kiriyama, H.; Fukuda, Y.; Koura, H.; Kando, M.; Yamauchi, T.; Watanabe, Y.; Bulanov, S. V.; Kondo, K.; Imai, K.; Nagamiya, S.

    2015-03-01

    Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating a micron-thick Al foil with Fe impurity on the surface. An energetic low-emittance high-density beam of heavy ions with a large charge-to-mass ratio can be obtained, which is useful for many applications, such as a compact radio isotope source in combination with conventional technology.

  13. Direct manipulation of the uncompensated antiferromagnetic spins in exchange coupled system by GeV ion irradiation

    SciTech Connect

    Paul, Amitesh; Boeni, P.; Paul, N.; Hoepfner, Britta; Lauermann, Iver; Lux-Steiner, M.; Trautmann, C.; Mattauch, S.

    2012-06-18

    Incident ion energy to matrix electrons of a material is dissipated within a narrow cylinder surrounding the swift heavy ion path. The temperature of the lattice exceeds the melting point and upon quenching causes nanometric modifications. We present here a unique ex situ approach in manipulating the uncompensated spins in antiferromagnetic layers of ferro-/antiferromagnetic exchange coupled systems on a nanometric scale. We use the impact of relativistic heavy ion (1-2 GeV) irradiation on such systems. We find an increase in the bias field and a restoration of the reversal via domain nucleation in the trained state. These are identified as plausible results of ion-induced antiferromagnetic ordering with little or no effect on the layer structure. This study demonstrates, therefore, the possibility of nanoscale tailoring of exchange coupled systems that survive even in the trained state.

  14. Dielectric and transport properties of magnetic insulators irradiated with GeV heavy ions

    SciTech Connect

    Costantini, J.M.; Salvetat, J.P.; Brisard, F.

    1997-11-01

    The dielectric and ac/dc transport properties of single crystals of yttrium iron garnet (Y{sub 3}Fe{sub 5}O{sub 12} and Y{sub 3}Fe{sub 5}O{sub 12}:Si), and barium hexaferrite (BaFe{sub 12}O{sub 19} and BaFe{sub 12}O{sub 1 9}:Co,Ti) were investigated after irradiations with Xe and Pb ions in the GeV range. In the virgin n-type samples (Y{sub 3}Fe{sub 5}O{sub 12}:Si and BaFe{sub 12}O{sub 19}:Co,Ti), the strong dielectric relaxation below 100 kHz is found to correspond to a space-charge polarization at the blocking metal/insulator contacts yielding a nonohmic dc conductivity. The relaxation frequency decreases with increasing amorphization yield in relation to the decrease of the insulators bulk dc conductivity which becomes ohmic in the amorphous phases. The ac conductivity data of both crystalline and amorphous Y{sub 3}Fe{sub 5}O{sub 12}:Si above 100 kHz and for 100K{lt}T{lt}300K exhibit two contributions: (i) that of carrier transport in a disordered or inhomogeneous medium varying as {nu}{sup s}, with s{approx_equal}0.8, (ii) and that of a two-site polaron hopping process of charge transfer between Fe{sup 2+} and Fe{sup 3+} with an activation energy of 0.29 eV for T{gt}180K. The dc conductivity data of crystalline Y{sub 3}Fe{sub 5}O{sub 12}:Si for 80K{lt}T{lt}300K are discussed on the basis of a small polaron hopping conduction mechanism between Fe{sup 2+} and Fe{sup 3+} with an activation energy around 0.28 eV for T{gt}125K, in agreement with the activation energy around 0.28 eV of the space-charge dielectric relaxation frequency for T{gt}180K. All amorphous phases data are consistent with the picture of hopping conduction between gap states in a disordered medium with (i) an {nu}{sup s} dependence for the ac conductivity above a critical frequency proportional to the dc conductivity, (ii) and an exp({minus}T{sup {minus}1/4}) law for the dc conductivity. {copyright} {ital 1997 American Institute of Physics.}

  15. Laser Acceleration of Quasi-Monoenergetic Protons via Radiation Pressure Driven Thin Foil

    SciTech Connect

    Liu, Chuan S.; Shao Xi; Liu, T. C.; Dudnikova, Galina; Sagdeev, Roald Z.; Eliasson, Bengt

    2011-01-04

    We present a theoretical and simulation study of laser acceleration of quasi-monoenergetic protons in a thin foil irradiated by high intensity laser light. The underlying physics of radiation pressure acceleration (RPA) is discussed, including the importance of optimal thickness and circularly polarized light for efficient acceleration of ions to quasi-monoenergetic beams. Preliminary two-dimensional simulation studies show that certain parameter regimes allow for stabilization of the Rayleigh-Taylor instability and possibility of acceleration of monoenergetic ions to an excess of 200 MeV, making them suitable for important applications such as medical cancer therapy and fast ignition.

  16. Laser Acceleration of Quasi-Monoenergetic Protons via Radiation Pressure Driven Thin Foil

    NASA Astrophysics Data System (ADS)

    Liu, Chuan S.; Shao, Xi; Eliasson, Bengt; Liu, T. C.; Dudnikova, Galina; Sagdeev, Roald Z.

    2011-01-01

    We present a theoretical and simulation study of laser acceleration of quasi-monoenergetic protons in a thin foil irradiated by high intensity laser light. The underlying physics of radiation pressure acceleration (RPA) is discussed, including the importance of optimal thickness and circularly polarized light for efficient acceleration of ions to quasi-monoenergetic beams. Preliminary two-dimensional simulation studies show that certain parameter regimes allow for stabilization of the Rayleigh-Taylor instability and possibility of acceleration of monoenergetic ions to an excess of 200 MeV, making them suitable for important applications such as medical cancer therapy and fast ignition.

  17. Neutron measurements in the stray field produced by 158 GeV c(-1) per nucleon lead ion beams.

    PubMed

    Agosteo, S; Birattari, C; Foglio Para, A; Nava, E; Silari, M; Ulrici, L

    1998-12-01

    This paper discusses measurements carried out at CERN in the stray radiation field produced by 158 GeV c(-1) per nucleon 208Pb82+ ions. The purpose was to test and intercompare the response of several detectors, mainly neutron measuring devices, and to determine the neutron spectral fluence as well as the microdosimetric (absorbed dose and dose equivalent) distributions in different locations around the shielding. Both active instruments and passive dosimeters were employed, including different types of Andersson-Braun rem counters, a tissue equivalent proportional counter, a set of superheated drop detectors, a Bonner sphere system, and different types of ion chambers. Activation measurements with 12C plastic scintillators and with 32S pellets were also performed to assess the neutron yield of high energy lead ions interacting with a thin gold target. The results are compared with previous measurements and with measurements made during proton runs.

  18. Laser-driven collimated tens-GeV monoenergetic protons from mass-limited target plus preformed channel

    SciTech Connect

    Zheng, F. L.; Wu, H. C.; Wu, S. Z.; Zhou, C. T.; Cai, H. B.; He, X. T.; Yu, M. Y.; Tajima, T.; Yan, X. Q.

    2013-01-15

    Proton acceleration by ultra-intense laser pulse irradiating a target with cross-section smaller than the laser spot size and connected to a parabolic density channel is investigated. The target splits the laser into two parallel propagating parts, which snowplow the back-side plasma electrons along their paths, creating two adjacent parallel wakes and an intense return current in the gap between them. The radiation-pressure pre-accelerated target protons trapped in the wake fields now undergo acceleration as well as collimation by the quasistatic wake electrostatic and magnetic fields. Particle-in-cell simulations show that stable long-distance acceleration can be realized, and a 30 fs monoenergetic ion beam of >10 GeV peak energy and <2 Degree-Sign divergence can be produced by a circularly polarized laser pulse at an intensity of about 10{sup 22} W/cm{sup 2}.

  19. Multifractal moments in heavy ion Pb-Pb collisions at 158 A GeV

    SciTech Connect

    Dutt, Sunil

    2016-05-06

    In present work, we use the method of scaled factorial moments to search for intermittent behavior in Pb-Pb interactions at 158 A GeV. The analysis is done on photon distributions obtained using preshower photon multiplicity detector. Scaled factorial moments are used to study short range fluctuations in pseudorapidity distributions of photons. Scaled factorial moments are calculated using horizontal corrected and vertical analysis. The results are compared with simulation analysis using VENUS event generator.

  20. Efficient quasi-monoenergetic ion beams up to 18 MeV/nucleon via self-generated plasma fields in relativistic laser plasmas

    NASA Astrophysics Data System (ADS)

    Palaniyappan, Sasi; Huang, Chengkun; Gautier, Donald; Hamilton, Christopher; Santiago, Miguel; Kreuzer, Christian; Shah, Rahul; Fernandez, Juan; Los Alamos National Laboratory Team; Ludwig-Maximilian-University Team

    2015-11-01

    Table-top laser-plasma ion accelerators seldom achieve narrow energy spreads, and never without serious compromises in efficiency, particle yield, etc. Using massive computer simulations, we identify a self-organizing scheme that exploits persisting self-generated plasma electric (~ TV/m) and magnetic (~ 104 Tesla) fields to reduce the ion energy spread after the laser exits the plasma - separating the ion acceleration from the energy spread reduction. Consistent with the scheme, we experimentally demonstrate aluminum and carbon ion beams with narrow spectral peaks at energies up to 310 MeV (11.5 MeV/nucleon) and 220 MeV (18.3 MeV/nucleon), respectively, with high conversion efficiency (~ 5%, i.e., 4J out of 80J laser). This is achieved with 0.12 PW high-contrast Gaussian laser pulses irradiating planar foils with optimal thicknesses of up to 250 nm that scale with laser intensity. When increasing the focused laser intensity fourfold (by reducing the focusing optic f/number twofold), the spectral-peak energy increases twofold. These results pave the way for next generation compact accelerators suitable for applications. For example, 400 MeV (33.3 MeV/nucleon) carbon-ion beam with narrow energy spread required for ion fast ignition could be generated using PW-class lasers.

  1. Quasi-monoenergetic electron beams production in a sharp density transition

    SciTech Connect

    Fourmaux, S.; Lassonde, P.; Lebrun, G.; Kieffer, J. C.; Ta Phuoc, K.; Corde, S.; Malka, V.; Rousse, A.

    2012-09-10

    Using a laser plasma accelerator, experiments with a 80 TW and 30 fs laser pulse demonstrated quasi-monoenergetic electron spectra with maximum energy over 0.4 GeV. This is achieved using a supersonic He gas jet and a sharp density ramp generated by a high intensity laser crossing pre-pulse focused 3 ns before the main laser pulse. By adjusting this crossing pre-pulse position inside the gas jet, among the laser shots with electron injection, more than 40% can produce quasi-monoenergetic spectra. This could become a relatively straight forward technique to control laser wakefield electron beams parameters.

  2. Elliptical flow in relativistic ion collisions at \\sqrt{s}= 200 GeV

    NASA Astrophysics Data System (ADS)

    Kahana, D. E.; Kahana, S. H.

    2008-07-01

    A consistent picture of the Au + Au and D + Au, \\sqrt{s}= 200 A GeV measurements at RHIC obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors including both the rapidity and transverse momentum spectra was previously developed with the simulation LUCIFER. The approach was modelled on the early production of a fluid of pre-hadrons after the completion of an initial phase of high-energy interactions. The formation of pre-hadrons is discussed here, in a perturbative QCD approach as advocated by Kopeliovich, Nemchik and Schmidt. In the second phase of LUCIFER, a considerably lower energy hadron-like cascade ensues. Since the dominant collisions occurring in this latter phase are meson-meson in character while the initial collisions are between baryons, i.e. both involve hadron-sized interaction cross-sections, there is good reason to suspect that the observed elliptical flow will be produced naturally, and this is indeed found to be the case.

  3. Induction of Chromosomal Aberrations in Human Cells after Irradiation with Filtered and Unfiltered Beams of 1 Gev/amu Iron Ions

    NASA Astrophysics Data System (ADS)

    Wilson, P.; Williams, A.; Nagasawa, H.; Peng, Y.; Chatterjee, A.; Bedford, J.

    To determine whether shielding materials that might be utilized for radiation protection of astronauts would affect the RBE of HZE particles such as those of concern for deep space missions we irradiated non cycling G0 monolayer cultures of contact inhibited normal human fibroblasts with 1 Gev amu iron ions with and without filtration with various thicknesses of Aluminum Al or polyethylene CH 2 and then measured the frequencies of chromosome-type aberrations dicentrics and excess fragments in the first post-irradiation mitosis Irradiations were carried out at the NRSL facility at Brookhaven National Laboratory For doses ranging up to 4 to 6 Gy the dose response for the total of these aberrations per cell was not significantly affected by beam filtrations up to 5 4 cm Al or up to 11 cm polyethylene relative to the unfiltered beam Neither was the dose response significantly different for unfiltered beams of 300 or 600 Mev amu iron ions relative to the 1 Gev amu iron ions The studies with 1 Gev amu iron ions were repeated four different times over a period of four years in each case with coded samples so the individual scoring aberrations would not know the irradiation conditions employed Comparison of the same effects in parallel experiments using 137 Cs gamma-rays allowed us to estimate that the RBE for aberration induction by these HZE iron ions for these acute high dose-rate exposures was approximately

  4. Strangeness Production in 19.6 GeV Collisions at the Relativistic Heavy Ion Collider

    DTIC Science & Technology

    2010-05-12

    Heavy Ion Collider 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(SJ 5d. PROJECT NUMBER Cnglund-Krieger, Kyle Richard 5e. TASK NUMBER 5f... Richard A. Witt Physics Department ____________________________________ _____________ Acceptance for the Trident Scholar Committee...From Einstein, Bohr, Schrodinger, to Feynman , our knowledge of the world has increased many-fold over the past century, and will only continue to

  5. Calibration of CR-39 with monoenergetic protons

    NASA Astrophysics Data System (ADS)

    Xiaojiao, Duan; Xiaofei, Lan; Zhixin, Tan; Yongsheng, Huang; Shilun, Guo; Dawei, Yang; Naiyan, Wang

    2009-10-01

    Calibration of solid state nuclear track detector CR-39 was carried out with very low-energy monoenergetic protons of 20-100 keV from a Cockcroft Walton accelerator. To reduce the beam of the proton from the accelerator, a novel method was adopted by means of a high voltage pulse generator. The irradiation time of the proton beam on each CR-39 sheet was shortened to one pulse with duration of 100 ns, so that very separated proton tracks around 104 cm-2 can be irradiated and observed and measured on the surface of the CR-39 detector after etching. The variations of track diameter with etching time as well as with proton energy response curve has been carefully calibrated for the first time in this very low energy region. The calibration shows that the optical limit for the observation of etched tracks of protons in CR-39 is about or a little lower that 20 keV, above which the proton tracks can be seen clearly and the response curve can be used to distinguish protons from the other ions and determine the energy of the protons. The extension of response curve of protons from traditionally 20 to 100 keV in CR-39 is significant in retrieving information of protons produced in the studies of nuclear physics, plasma physics, ultrahigh intensity laser physics and laser acceleration.

  6. RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN

    SciTech Connect

    Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; D’Ottavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

  7. Preliminary experience with monoenergetic photon mammography

    SciTech Connect

    Johnston, R.E.; Washburn, D.; Pisano, E.; Thomlinson, W.C.; Chapman, D.; Gmur, N.F.; Zhong, Zhong; Sayers, D.

    1995-12-31

    We are using a beam port at the National Synchrotron Light Source facility at Brookhaven National Laboratory as a source of monoenergetic photons. The photon source is radiation from a bending magnet on the X-ray storage ring and provides a usable X-ray spectrum from 5 keV to over 50 keV. A tunable crystal monochromotor is used for energy selection. The beam is 79mm wide and 0.5 mm high. We imaged the ACR mammography phantom and a contrast-detail phantom using a phosphor plate as the unaging detector. Phantom images were obtained at 16, 18, 20 and 22 keV. Phantom thickness varied from 15 mm to 82 mm. These images were compared to images obtained with a conventional dedicated mammography unit. Subjective preliminary results show that image contrast of the monoenergetic images is similar to those obtained from the conventional x-ray source with somewhat sharper and cleaner images from the monoenergetic source. Quantitative analysis shows that the monoenergetic images have improved contrast compared to the polyenergetic derived images. Entrance skin dose measurements show a factor of 5 to 10 times less radiation for the monoenergetic images with equivalent or better contrast Although there remain a number of technical problems to be addressed and much more work to be done, we are encouraged to further explore the use of monoenergetic imaging.

  8. Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at √{sN N}=7.7 -62.4 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Chisman, O.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Y.; Li, W.; Li, C.; Li, X.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, Y. G.; Ma, G. L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Z.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, H.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Z.; Xu, H.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Y.; Zhang, S.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-01-01

    Elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √{sN N}= 7.7 -62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √{sN N}= 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.

  9. Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at sNN=7.7–62.4 GeV

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2016-01-19

    Here, elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √sNN = 7.7–62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √sNN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, showsmore » a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.« less

  10. First fragmentation function measurements from full jet reconstruction in heavy-ion collisions at sqrt{s_{NN}}=200 GeV by STAR

    NASA Astrophysics Data System (ADS)

    Putschke, Jörn

    2009-06-01

    Measurements of inclusive hadron suppression and di-hadron azimuthal correlations in ultra-relativistic nuclear collisions at RHIC have provided important insights into jet quenching in hot QCD matter, but are limited in their sensitivity due to well-known biases. Full jet reconstruction in heavy-ion collisions would conceptually provide a direct measurement of the energy of the scattered parton before energy loss, alleviating such biases and allowing a measurement of the energy loss probability distribution in a model-independent way from hard probes. In these proceedings we utilize recent progress in the reconstruction of jets in the heavy ion environment and present the first measurement of the fragmentation function from fully reconstructed jets in heavy ion collisions. The fragmentation function measured in central Au + Au collisions at sqrt{s_{NN}}=200 GeV will be presented and discussed with respect to p + p reference measurements.

  11. Laser Radiation Pressure Accelerator for Quasi-Monoenergetic Proton Generation and Its Medical Implications

    NASA Astrophysics Data System (ADS)

    Liu, C. S.; Shao, X.; Liu, T. C.; Su, J. J.; He, M. Q.; Eliasson, B.; Tripathi, V. K.; Dudnikova, G.; Sagdeev, R. Z.; Wilks, S.; Chen, C. D.; Sheng, Z. M.

    Laser radiation pressure acceleration (RPA) of ultrathin foils of subwavelength thickness provides an efficient means of quasi-monoenergetic proton generation. With an optimal foil thickness, the ponderomotive force of the intense short-pulse laser beam pushes the electrons to the edge of the foil, while balancing the electric field due to charge separation. The electron and proton layers form a self-organized plasma double layer and are accelerated by the radiation pressure of the laser, the so-called light sail. However, the Rayleigh-Taylor instability can limit the acceleration and broaden the energy of the proton beam. Two-dimensional particle-in-cell (PIC) simulations have shown that the formation of finger-like structures due to the nonlinear evolution of the Rayleigh-Taylor instability limits the acceleration and leads to a leakage of radiation through the target by self-induced transparency. We here review the physics of quasi-monoenergetic proton generation by RPA and recent advances in the studies of energy scaling of RPA, and discuss the RPA of multi-ion and gas targets. The scheme for generating quasi-monoenergetic protons with RPA has the potential of leading to table-top accelerators as sources for producing monoenergetic 50-250 MeV protons. We also discuss potential medical implications, such as particle therapy for cancer treatment, using quasi-monoenergetic proton beams generated from RPA. Compact monoenergetic ion sources also have applications in many other areas such as high-energy particle physics, space electronics radiation testing, and fast ignition in laser fusion.

  12. Energetics and energy scaling of quasi-monoenergetic protons in laser radiation pressure acceleration

    SciTech Connect

    Liu Tungchang; Shao Xi; Liu Chuansheng; Su Jaojang; Dudnikova, Galina; Sagdeev, Roald Z.; Eliasson, Bengt; Tripathi, Vipin

    2011-12-15

    Theoretical and computational studies of the ion energy scaling of the radiation pressure acceleration of an ultra-thin foil by short pulse intense laser irradiation are presented. To obtain a quasi-monoenergetic ion beam with an energy spread of less than 20%, two-dimensional particle-in-cell simulations show that the maximum energy of the quasi-monoenergetic ion beam is limited by self-induced transparency at the density minima caused by the Rayleigh-Taylor instability. For foils of optimal thickness, the time over which Rayleigh-Taylor instability fully develops and transparency occurs is almost independent of the laser amplitude. With a laser power of about one petawatt, quasi-monogenetic protons with 200 MeV and carbon ions with 100 MeV per nucleon can be obtained, suitable for particle therapy applications.

  13. A laser-plasma accelerator producing monoenergetic electron beams.

    PubMed

    Faure, J; Glinec, Y; Pukhov, A; Kiselev, S; Gordienko, S; Lefebvre, E; Rousseau, J-P; Burgy, F; Malka, V

    2004-09-30

    Particle accelerators are used in a wide variety of fields, ranging from medicine and biology to high-energy physics. The accelerating fields in conventional accelerators are limited to a few tens of MeV m(-1), owing to material breakdown at the walls of the structure. Thus, the production of energetic particle beams currently requires large-scale accelerators and expensive infrastructures. Laser-plasma accelerators have been proposed as a next generation of compact accelerators because of the huge electric fields they can sustain (>100 GeV m(-1)). However, it has been difficult to use them efficiently for applications because they have produced poor-quality particle beams with large energy spreads, owing to a randomization of electrons in phase space. Here we demonstrate that this randomization can be suppressed and that the quality of the electron beams can be dramatically enhanced. Within a length of 3 mm, the laser drives a plasma bubble that traps and accelerates plasma electrons. The resulting electron beam is extremely collimated and quasi-monoenergetic, with a high charge of 0.5 nC at 170 MeV.

  14. Searching for dark matter annihilation to monoenergetic neutrinos with liquid scintillation detectors

    SciTech Connect

    Kumar, J.; Sandick, P. E-mail: sandick@physics.utah.edu

    2015-06-01

    We consider searches for dark matter annihilation to monoenergetic neutrinos in the core of the Sun. We find that liquid scintillation neutrino detectors have enhanced sensitivity to this class of dark matter models, due to the energy and angular resolution possible for electron neutrinos and antineutrinos that scatter via charged-current interactions. In particular we find that KamLAND, utilizing existing data, could provide better sensitivity to such models than any current direct detection experiment for m{sub X} ∼< 15 Gev. KamLAND's sensitivity is signal-limited, and future liquid scintillation or liquid argon detectors with similar energy and angular resolution, but with larger exposure, will provide significantly better sensitivity. These detectors may be particularly powerful probes of dark matter with mass O(10) GeV.

  15. Searching for dark matter annihilation to monoenergetic neutrinos with liquid scintillation detectors

    SciTech Connect

    Kumar, J.; Sandick, P.

    2015-06-22

    We consider searches for dark matter annihilation to monoenergetic neutrinos in the core of the Sun. We find that liquid scintillation neutrino detectors have enhanced sensitivity to this class of dark matter models, due to the energy and angular resolution possible for electron neutrinos and antineutrinos that scatter via charged-current interactions. In particular we find that KamLAND, utilizing existing data, could provide better sensitivity to such models than any current direct detection experiment for m{sub X}≲15 Gev. KamLAND’s sensitivity is signal-limited, and future liquid scintillation or liquid argon detectors with similar energy and angular resolution, but with larger exposure, will provide significantly better sensitivity. These detectors may be particularly powerful probes of dark matter with mass O(10) GeV.

  16. p{sup 0} photoproduction in ultraperipheral relativistic heavy ion collisions at {radical}{ovr s}{sub NN} = 200 GeV.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration; High Energy Physics; Univ. of Illinois; Panjab Univ.; Variable Energy Cyclotron Centre; Kent State Univ.; Particle Physic Lab.

    2008-01-01

    Photoproduction reactions occur when the electromagnetic field of a relativistic heavy ion interacts with another heavy ion. The STAR Collaboration presents a measurement of {rho}{sup 0} and direct {pi}{sup +}{pi}{sup -} photoproduction in ultraperipheral relativistic heavy ion collisions at {radical}s{sub NN} = 200 GeV. We observe both exclusive photoproduction and photoproduction accompanied by mutual Coulomb excitation. We find a coherent cross section of {sigma} (AuAu {yields} Au{sup +}Au{sup +} {rho}{sup 0}) = 530 {+-} 19(stat.) {+-} 57(syst.) mb, in accord with theoretical calculations based on a Glauber approach, but considerably below the predictions of a color dipole model. The {rho}{sup p} transverse momentum spectrum (p{sub T}{sup 2}) is fit by a double exponential curve including both coherent and incoherent coupling to the target nucleus; we find {sigma}{sub inc}/{sigma}{sub coh} = 0.29 {+-} 0.03(stat.) {+-} 0.08(syst.). The ratio of direct {pi}{sup +}{pi}{sup -} to {rho}{sup 0} production is comparable to that observed in {gamma}{sub p} collisions at HERA and appears to be independent of photon energy. Finally, the measured {rho}{sup 0} spin helicity matrix elements agree within errors with the expected s-channel helicity conservation.

  17. Acceleration of highly charged GeV Fe ions from a low-Z substrate by intense femtosecond laser

    SciTech Connect

    Nishiuchi, M. Sakaki, H.; Esirkepov, T. Zh.; Pirozhkov, A. S.; Sagisaka, A.; Ogura, K.; Kiriyama, H.; Fukuda, Y.; Kando, M.; Bulanov, S. V.; Kondo, K.; Nishio, K.; Orlandi, R.; Koura, H.; Imai, K.; Pikuz, T. A.; Faenov, A. Ya.; Skobelev, I. Yu.; Sako, H.; Matsukawa, K.; and others

    2015-03-15

    Almost fully stripped Fe ions accelerated up to 0.9 GeV are demonstrated with a 200 TW femtosecond high-intensity laser irradiating a micron-thick Al foil with Fe impurity on the surface. An energetic low-emittance high-density beam of heavy ions with a large charge-to-mass ratio can be obtained, which is useful for many applications, such as a compact radio isotope source in combination with conventional technology.

  18. Quantitative and Qualitative Differences in Neurocognitive Impairment Induced by 1 GeV 56Fe Ions and X-Rays

    NASA Astrophysics Data System (ADS)

    Britten, R.; Mitchell, S.; Parris, B.; Johnson, A.; Singletary-Britten, S.; Lonart, G.; Drake, R.

    2008-10-01

    During the planned mission to Mars, Astronauts will be exposed to heavy charged particles (Hze). Our group has been determining the relative biological effectiveness (RBE) of Hze (1 GeV 56Fe, LET = 150 kev/um) with respect to neurocognitive impairment, specifically spatial memory, short-term working memory and attentional set shifting. Our current data suggest that Hze have RBE values of about 7 for hippocampal-dependent spatial memory tasks (Barnes Maze) and possibly even higher for certain attentional processes. We have also used MALDI-TOF serum profiling analysis to identify several proteins that are biomarkers of both the level and LET of the radiation exposure, and biomarkers of cognitive performance. Our data suggest that Hze particles have a distinctly different impact upon neurocognitive function in rats than do X-rays. From a mission perspective, attentional set shifting is the neurocognitive function most likely to be impacted by the predicted Hze exposure; unfortunately Set shifting underlies our ability to execute complex plans. The proteins identified could be used to monitor the Astronauts for radiation exposure and any associated loss of neurocognitive function, and some may actually give an insight into the complex processes that lead to radiation-induced cognitive impairment.

  19. Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

    NASA Technical Reports Server (NTRS)

    Stephens, D. L. Jr; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

    2002-01-01

    Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R2 respectively. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  20. Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

    NASA Technical Reports Server (NTRS)

    Stephens, D. L. Jr; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

    2002-01-01

    Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R2 respectively. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  1. Monte Carlo transport model comparison with 1A GeV accelerated iron experiment: heavy-ion shielding evaluation of NASA space flight-crew foodstuff

    NASA Astrophysics Data System (ADS)

    Stephens, D. L.; Townsend, L. W.; Miller, J.; Zeitlin, C.; Heilbronn, L.

    Deep-space manned flight as a reality depends on a viable solution to the radiation problem. Both acute and chronic radiation health threats are known to exist, with solar particle events as an example of the former and galactic cosmic rays (GCR) of the latter. In this experiment Iron ions of 1A GeV are used to simulate GCR and to determine the secondary radiation field created as the GCR-like particles interact with a thick target. A NASA prepared food pantry locker was subjected to the iron beam and the secondary fluence recorded. A modified version of the Monte Carlo heavy ion transport code developed by Zeitlin at LBNL is compared with experimental fluence. The foodstuff is modeled as mixed nuts as defined by the 71 st edition of the Chemical Rubber Company (CRC) Handbook of Physics and Chemistry. The results indicate a good agreement between the experimental data and the model. The agreement between model and experiment is determined using a linear fit to ordered pairs of data. The intercept is forced to zero. The slope fit is 0.825 and the R 2 value is 0.429 over the resolved fluence region. The removal of an outlier, Z=14, gives values of 0.888 and 0.705 for slope and R 2 respectively.

  2. Generation of quasi-monoenergetic protons from a double-species target driven by the radiation pressure of an ultraintense laser pulse

    SciTech Connect

    Pae, Ki Hong; Kim, Chul Min; Nam, Chang Hee

    2016-03-15

    In laser-driven proton acceleration, generation of quasi-monoenergetic proton beams has been considered a crucial feature of the radiation pressure acceleration (RPA) scheme, but the required difficult physical conditions have hampered its experimental realization. As a method to generate quasi-monoenergetic protons under experimentally viable conditions, we investigated using double-species targets of controlled composition ratio in order to make protons bunched in the phase space in the RPA scheme. From a modified optimum condition and three-dimensional particle-in-cell simulations, we showed by varying the ion composition ratio of proton and carbon that quasi-monoenergetic protons could be generated from ultrathin plane targets irradiated with a circularly polarized Gaussian laser pulse. The proposed scheme should facilitate the experimental realization of ultrashort quasi-monoenergetic proton beams for unique applications in high field science.

  3. Swift heavy ion irradiation of water ice from MeV to GeV energies. Approaching true cosmic ray compaction

    NASA Astrophysics Data System (ADS)

    Dartois, E.; Ding, J. J.; de Barros, A. L. F.; Boduch, P.; Brunetto, R.; Chabot, M.; Domaracka, A.; Godard, M.; Lv, X. Y.; Mejía Guamán, C. F.; Pino, T.; Rothard, H.; da Silveira, E. F.; Thomas, J. C.

    2013-09-01

    Context. Cosmic ray ion irradiation affects the chemical composition of and triggers physical changes in interstellar ice mantles in space. One of the primary structural changes induced is the loss of porosity, and the mantles evolve toward a more compact amorphous state. Previously, ice compaction was monitored at low to moderate ion energies. The existence of a compaction threshold in stopping power has been suggested. Aims: In this article we experimentally study the effect of heavy ion irradiation at energies closer to true cosmic rays. This minimises extrapolation and allows a regime where electronic interaction always dominates to be explored, providing the ice compaction cross section over a wide range of electronic stopping power. Methods: High-energy ion irradiations provided by the GANIL accelerator, from the MeV up to the GeV range, are combined with in-situ infrared spectroscopy monitoring of ice mantles. We follow the IR spectral evolution of the ice as a function of increasing fluence (induced compaction of the initial microporous amorphous ice into a more compact amorphous phase). We use the number of OH dangling bonds of the water molecule, i.e. pending OH bonds not engaged in a hydrogen bond in the initially porous ice structure as a probe of the phase transition. These high-energy experiments are combined with lower energy experiments using light ions (H, He) from other facilities in Catania, Italy, and Washington, USA. Results: We evaluated the cross section for the disappearance of OH dangling bonds as a function of electronic stopping power. A cross-section law in a large energy range that includes data from different ice deposition setups is established. The relevant phase structuring time scale for the ice network is compared to interstellar chemical time scales using an astrophysical model. Conclusions: The presence of a threshold in compaction at low stopping power suggested in some previous works seems not to be confirmed for the high

  4. Laser acceleration of monoenergetic protons via a double layer emerging from an ultra-thin foil

    NASA Astrophysics Data System (ADS)

    Eliasson, Bengt; Liu, Chuan S.; Shao, Xi; Sagdeev, Roald; Shukla, Padma K.; Dudnikova, Galina; Liu, T. C.

    2009-11-01

    Theoretical and numerical studies are presented of the acceleration of monoenergetic protons in a double layer formed by the laser irradiation of an ultra-thin film. The ponderomotive force of the laser light pushes the electrons forward, and the induced space charge electric field pulls the ions and makes the thin foil accelerate as a whole. A stable double layer is formed, in which the ions are trapped by the combined electric field and inertial force in the accelerated frame, together with the electrons that are trapped in the well of the ponderomotive and ion electric field. The trapped ions reach monoenergetic energies up to 100 MeV and beyond, making them suitable for cancer treatment. We present an analytic theory for the laser-accelerated ion energy as a function of the laser intensity, foil thickness and the plasma number density. The underlying physics of the trapped and untrapped ions and of the stabilization of the Rayleigh-Taylor instability are discussed.

  5. Neutron filters for producing monoenergetic neutron beams

    SciTech Connect

    Harvey, J.A.; Hill, N.W.; Harvey, J.R.

    1982-01-01

    Neutron transmission measurements have been made on high-purity, highly-enriched samples of /sup 58/Ni (99.9%), /sup 60/Ni (99.7%), /sup 64/Zn (97.9%) and /sup 184/W (94.5%) to measure their neutron windows and to assess their potential usefulness for producing monoenergetic beams of intermediate energies from a reactor. Transmission measurements on the Los Alamos Sc filter (44.26 cm Sc and 1.0 cm Ti) have been made to determine the characteristics of the transmitted neutron beam and to measure the total cross section of Sc at the 2.0 keV minimum. When corrected for the Ti and impurities, a value of 0.35 +- 0.03 b was obtained for this minimum.

  6. Hadronic resonance production in d+au collisions at {radical}{ovr s}{sub NN} =200 GeV measured at the BNL relativistic heavy ion collider.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration; High Energy Physics; Univ. of Illinois; Panjab Univ.; Variable Energy Cyclotron Centre; Kent State Univ.; Particle Physic Lab.

    2008-01-01

    We present the first measurements of the {rho}(770){sup 0},K*(892), {Delta}(1232){sup ++}, {sigma}(1385), and {Lambda}(1520) resonances in d+Au collisions at {radical}s{sub NN} = 200 GeV, reconstructed via their hadronic decay channels using the STAR detector (the solenoidal tracker at the BNL Relativistic Heavy Ion Collider). The masses and widths of these resonances are studied as a function of transverse momentum p{sub T}. We observe that the resonance spectra follow a generalized scaling law with the transverse mass m{sub T}. The of resonances in minimum bias collisions are compared with the of {pi},K and {bar p}. The {rho}{sup 0}/{pi}{sup -}, K{sup +}/K{sup -}, {Delta}{sup ++}/p, {Sigma}(1385)/{Lambda}, and {Lambda}(1520)/{Lambda} ratios in d+Au collisions are compared with the measurements in minimum bias p+p interactions, where we observe that both measurements are comparable. The nuclear modification factors (R{sub dAu}) of the {rho}{sup 0},K{sup +}, and {Sigma}{sup +} scale with the number of binary collisions (N{sub bin}) for p{sub T} > 1.2 GeV/c.

  7. A novel laser-collider used to produce monoenergetic 13.3 MeV 7Li (d, n) neutrons

    PubMed Central

    Zhao, J. R.; Zhang, X. P.; Yuan, D. W.; Li, Y. T.; Li, D. Z.; Rhee, Y. J.; Zhang, Z.; Li, F.; Zhu, B. J.; Li, Yan F.; Han, B.; Liu, C.; Ma, Y.; Li, Yi F.; Tao, M. Z.; Li, M. H.; Guo, X.; Huang, X. G.; Fu, S. Z.; Zhu, J. Q.; Zhao, G.; Chen, L. M.; Fu, C. B.; Zhang, J.

    2016-01-01

    Neutron energy is directly correlated with the energy of the incident ions in experiments involving laser-driven nuclear reactions. Using high-energy incident ions reduces the energy concentration of the generated neutrons. A novel “laser-collider” method was used at the Shenguang II laser facility to produce monoenergetic neutrons via 7Li (d, n) nuclear reactions. The specially designed K-shaped target significantly increased the numbers of incident d and Li ions at the keV level. Ultimately, 13.3 MeV neutrons were obtained. Considering the time resolution of the neutron detector, we demonstrated that the produced neutrons were monoenergetic. Interferometry and a Multi hydro-dynamics simulation confirmed the monoenergetic nature of these neutrons. PMID:27250660

  8. A novel laser-collider used to produce monoenergetic 13.3 MeV (7)Li (d, n) neutrons.

    PubMed

    Zhao, J R; Zhang, X P; Yuan, D W; Li, Y T; Li, D Z; Rhee, Y J; Zhang, Z; Li, F; Zhu, B J; Li, Yan F; Han, B; Liu, C; Ma, Y; Li, Yi F; Tao, M Z; Li, M H; Guo, X; Huang, X G; Fu, S Z; Zhu, J Q; Zhao, G; Chen, L M; Fu, C B; Zhang, J

    2016-06-02

    Neutron energy is directly correlated with the energy of the incident ions in experiments involving laser-driven nuclear reactions. Using high-energy incident ions reduces the energy concentration of the generated neutrons. A novel "laser-collider" method was used at the Shenguang II laser facility to produce monoenergetic neutrons via (7)Li (d, n) nuclear reactions. The specially designed K-shaped target significantly increased the numbers of incident d and Li ions at the keV level. Ultimately, 13.3 MeV neutrons were obtained. Considering the time resolution of the neutron detector, we demonstrated that the produced neutrons were monoenergetic. Interferometry and a Multi hydro-dynamics simulation confirmed the monoenergetic nature of these neutrons.

  9. A novel laser-collider used to produce monoenergetic 13.3 MeV 7Li (d, n) neutrons

    NASA Astrophysics Data System (ADS)

    Zhao, J. R.; Zhang, X. P.; Yuan, D. W.; Li, Y. T.; Li, D. Z.; Rhee, Y. J.; Zhang, Z.; Li, F.; Zhu, B. J.; Li, Yan F.; Han, B.; Liu, C.; Ma, Y.; Li, Yi F.; Tao, M. Z.; Li, M. H.; Guo, X.; Huang, X. G.; Fu, S. Z.; Zhu, J. Q.; Zhao, G.; Chen, L. M.; Fu, C. B.; Zhang, J.

    2016-06-01

    Neutron energy is directly correlated with the energy of the incident ions in experiments involving laser-driven nuclear reactions. Using high-energy incident ions reduces the energy concentration of the generated neutrons. A novel “laser-collider” method was used at the Shenguang II laser facility to produce monoenergetic neutrons via 7Li (d, n) nuclear reactions. The specially designed K-shaped target significantly increased the numbers of incident d and Li ions at the keV level. Ultimately, 13.3 MeV neutrons were obtained. Considering the time resolution of the neutron detector, we demonstrated that the produced neutrons were monoenergetic. Interferometry and a Multi hydro-dynamics simulation confirmed the monoenergetic nature of these neutrons.

  10. Baryon production and collective flow in relativistic heavy-ion collisions in the AGS, SPS, RHIC, and LHC energy regions ({radical}(s{sub NN}){<=}5 GeV to 5.5 TeV)

    SciTech Connect

    Feng Shengqin; Zhong Yang

    2011-03-15

    The features of net-baryon productions and collective flow in relativistic heavy-ion collisions at energies reached at the CERN Large Hadron Collider (LHC), BNL Relativistic Heavy Ion Collider (RHIC), CERN Super Proton Synchrotron (SPS), and BNL Alternating Gradient Synchrotron (AGS) with the model of nonuniform flow model (NUFM) are systematically studied in this paper. In particular we predict the feature of net-baryon productions and collective flow at LHC {radical}(s{sub NN})=5500 GeV based on the detailed study at RHIC {radical}(s{sub NN})=62.4 and 200 GeV. The dependencies of the features of baryon stopping and collective flow on the collision energies and centralities are investigated.

  11. Laser Guiding for GeV Laser-Plasma Accelerators

    SciTech Connect

    Leemans, Wim; Esarey, Eric; Geddes, Cameron; Schroeder, C.B.; Toth, Csaba

    2005-06-06

    Guiding of relativistically intense laser beams in preformed plasma channels is discussed for development of GeV-class laser accelerators. Experiments using a channel guided laser wakefield accelerator (LWFA) at LBNL have demonstrated that near mono-energetic 100 MeV-class electron beams can be produced with a 10 TW laser system. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator, together with loading of the accelerating structure with beam, is the key to production of mono-energetic electron beams. Increasing the energy towards a GeV and beyond will require reducing the plasma density and design criteria are discussed for an optimized accelerator module. The current progress and future directions are summarized through comparison with conventional accelerators, highlighting the unique short term prospects for intense radiation sources based on laser-driven plasma accelerators.

  12. Measurement of elliptic flow of light nuclei at √{sN N}=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV at the BNL Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, Y.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, F.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, H.; Xu, Z.; Xu, J.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, S.; Yang, C.; Yang, Y.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J.; Zhang, Y.; Zhang, X. P.; Zhang, Z.; Zhang, J. B.; Zhang, S.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-09-01

    We present measurements of second-order azimuthal anisotropy (v2) at midrapidity (|y |<1.0 ) for light nuclei d ,t ,3He (for √{sN N}=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV) and antinuclei d ¯ (√{sN N}=200 , 62.4, 39, 27, and 19.6 GeV) and ¯3He (√{sN N}=200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The v2 for these light nuclei produced in heavy-ion collisions is compared with those for p and p ¯. We observe mass ordering in nuclei v2(pT) at low transverse momenta (pT<2.0 GeV/c ). We also find a centrality dependence of v2 for d and d ¯. The magnitude of v2 for t and 3He agree within statistical errors. Light-nuclei v2 are compared with predictions from a blast-wave model. Atomic mass number (A ) scaling of light-nuclei v2(pT) seems to hold for pT/A <1.5 GeV /c . Results on light-nuclei v2 from a transport-plus-coalescence model are consistent with the experimental measurements.

  13. Observation of anomalous reaction mean free paths of nuclear-projectile fragments in research emulsion from 2 A GeV heavy-ion collisions

    SciTech Connect

    Karant, Y.J.

    1981-07-01

    From an analysis of 1460 projectile fragment collisions in nuclear research emulsion exposed to 2.1 A GeV /sup 16/O and 1.9 A GeV /sup 56/Fe at the Bevalac, evidence is presented for the existence of an anomalously short interaction mean free path of projectile fragments for the first several cm after emission. The result is significant to beyond the 3 standard deviation confidence level.

  14. XRD study of yttria stabilized zirconia irradiated with 7.3 MeV Fe, 10 MeV I, 16 MeV Au, 200 MeV Xe and 2.2 GeV Au ions

    NASA Astrophysics Data System (ADS)

    Nakano, K.; Yoshizaki, H.; Saitoh, Y.; Ishikawa, N.; Iwase, A.

    2016-03-01

    To simulate energetic neutron irradiation effects, yttria-stabilized zirconia (YSZ) which is one of the major materials for electrical corrosion potential sensors (ECP sensors) was irradiated with heavy ions at energies ranging from 7.3 MeV to 2.2 GeV. Ion irradiation effects on the lattice structure were analyzed using the X-ray diffraction (XRD). The increase in lattice constant was induced by the ion irradiation. It was dominated by the elastic collision process and not by the electronic excitation process. The lattice disordering which was observed as a broadening of XRD peaks was also induced by the irradiation especially for 200 MeV Xe ion irradiation. The present result suggests that the expansion and/or the disordering of YSZ lattice induced by energetic neutrons may affect the durability of a joint interface between a metal housing and YSZ membrane for the usage of ECP sensors in nuclear power reactors.

  15. Highly efficient generation of ultraintense high-energy ion beams using laser-induced cavity pressure acceleration

    SciTech Connect

    Badziak, J.; Jablonski, S.; Raczka, P.

    2012-08-20

    Results of particle-in-cell (PIC) simulations of fast ion generation in the recently proposed laser-induced cavity pressure acceleration (LICPA) scheme in which a picosecond circularly polarized laser pulse of intensity {approx}10{sup 21} W/cm{sup 2} irradiates a carbon target placed in a cavity are presented. It is shown that due to circulation of the laser pulse in the cavity, the laser-ions energy conversion efficiency in the LICPA scheme is more than twice as high as that for the conventional (without a cavity) radiation pressure acceleration scheme and a quasi-monoenergetic carbon ion beam of the mean ion energy {approx}0.5 GeV and the energy fluence {approx}0.5 GJ/cm{sup 2} is produced with the efficiency {approx}40%. The results of PIC simulations are found to be in fairly good agreement with the predictions of the generalized light-sail model.

  16. Observation of different azimuthal emission patterns of K+ and of K- mesons in heavy-ion collisions at 1-2 A GeV.

    PubMed

    Uhlig, F; Förster, A; Böttcher, I; Debowski, M; Dohrmann, F; Grosse, E; Koczoń, P; Kohlmeyer, B; Laue, F; Menzel, M; Naumann, L; Oeschler, H; Scheinast, W; Schwab, E; Senger, P; Shin, Y; Ströbele, H; Sturm, C; Surówka, G; Wagner, A; Waluś, W

    2005-07-01

    Azimuthal distributions of pi+, K+, and K- mesons have been measured in Au+Au reactions at 1.5A GeV and Ni+Ni reactions at 1.93 A GeV. In semicentral collisions at midrapidity, pi+ and K+ mesons are emitted preferentially perpendicular to the reaction plane in both collision systems. In contrast for K- mesons in Ni+Ni reactions, an in-plane elliptic flow was observed for the first time at these incident energies.

  17. Measurement of elliptic flow of light nuclei at sNN=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV at the BNL Relativistic Heavy Ion Collider

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2016-09-23

    Here we present measurements of second-order azimuthal anisotropy ( v2 ) at midrapidity ( |y| < 1.0 ) for light nuclei d , t , 3He (formore » $$\\sqrt{s}$$$_{NN}$$ = 200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV) and antinuclei$$\\bar{d}$$ ( $$\\sqrt{s}$$$_{NN}$$ = 200 , 62.4, 39, 27, and 19.6 GeV) and 3 ¯¯¯¯¯ He ( $$\\sqrt{s}$$$_{NN}$$ = 200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The v2 for these light nuclei produced in heavy-ion collisions is compared with those for p and $$\\bar{p}$$. We observe mass ordering in nuclei v2 ( pT) at low transverse momenta ( pT < 2.0 GeV/c). We also find a centrality dependence of v2 for d and $$\\bar{d}$$ . The magnitude of v2 for t and 3He agree within statistical errors. Light-nuclei v2 are compared with predictions from a blast-wave model. Atomic mass number ( A ) scaling of light-nuclei v2 (pT) seems to hold for pT / A < 1.5 GeV/c . Results on light-nuclei v2 from a transport-plus-coalescence model are consistent with the experimental measurements.« less

  18. Interferometry radii in heavy-ion collisions at {radical}(s)=200 GeV and 2.76 TeV

    SciTech Connect

    Bozek, Piotr

    2011-04-15

    The expansion of the fireball created in Au-Au collisions at {radical}(s)=200 GeV and Pb-Pb collisions at 2.76 TeV is modelled using relativistic viscous hydrodynamics. The experimentally observed interferometry radii are well reproduced. Additional pre-equilibrium flow slightly improves the results for the lower energies studied.

  19. Monoenergetic neutrinos from dark matter annihilation: Issues of exposure

    SciTech Connect

    Kumar, Jason

    2016-06-21

    We consider searches for dark matter annihilation in the Sun resulting in monoenergetic neutrinos, produced either directly or through the decay of stopped pions and kaons. We find that this strategy is very successful at increasing the signal-to-background ratio, but that current experiments may be signal limited. We discuss the exposures need to fully exploit this search strategy.

  20. ACCELERATING POLARIZED PROTONS TO 250 GEV

    SciTech Connect

    BAI,M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; ET AL.

    2007-06-25

    The Relativistic Heavy Ion Collider (RHIC) as the first high energy polarized proton collider was designed t o provide polarized proton collisions a t a maximum beam energy of 250 GeV. I t has been providing collisions a t a beam energy of 100 Gel' since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during the acceleration from injection to 100 GeV with careful control of the betatron tunes and the vertical orbit distortions. However, the intrinsic spin resonances beyond 100 GeV are about a factor of two stronger than those below 100 GeV? making it important t o examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were accelerated t o the record energy of 250 GeV in RHIC with a polarization of 46% measured a t top energy in 2006. The polarization measurement as a function of beam energy also shows some polarization loss around 136 GeV, the first strong intrinsic resonance above 100 GeV. This paper presents the results and discusses the sensitivity of the polarization survival t o orbit distortions.

  1. Fluctuations of charge separation perpendicular to the event plane and local parity violation in √sNN =200 GeV Au + Au collisions at the BNL Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bruna, E.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, P.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Leyva, A. Davila; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; de Souza, R. Derradi; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Dion, A.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elnimr, M.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Gliske, S.; Grebenyuk, O. G.; Grosnick, D.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jena, C.; Judd, E. G.; Kabana, S.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Kikola, D. P.; Kiryluk, J.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Mioduszewski, S.; Mitrovski, M. K.; Mohammed, Y.; Mohanty, B.; Mondal, M. M.; Munhoz, M. G.; Mustafa, M. K.; Naglis, M.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Novak, J.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Powell, C. B.; Pruneau, C.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, B.; Schmitz, N.; Schuster, T. R.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shao, M.; Sharma, B.; Sharma, M.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; de Toledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2013-12-01

    Previous experimental results based on data (˜15×106 events) collected by the STAR detector at the BNL Relativistic Heavy Ion Collider suggest event-by-event charge-separation fluctuations perpendicular to the event plane in noncentral heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high-statistics 200-GeV Au + Au collisions data set (57×106 events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge-separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same- and opposite-charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion.

  2. Elliptic Flow Study of Charmed Mesons in 200 GeV Au+Au Collisions at the Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Hamad, Ayman

    Quantum Chromodynamics (QCD), the theory of the strong interaction between quarks and gluons, predicts that at extreme conditions of high temperature and/or density, quarks and gluons are no longer confined within individual hadrons. This new deconfined state of quarks and gluons is called Quark-Gluon Plasma (QGP). The Universe was in this QGP state a few microseconds after the Big Bang. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) on Long Island, NY was built to create and study the properties of QGP. Due to their heavy masses, quarks with heavy flavor (charm and bottom) are mainly created during the early, energetic stages of the collisions. Heavy flavor is considered to be a unique probe for QGP studies, since it propagates through all phases of a collision, and is affected by the hot and dense medium throughout its evolution. Initial studies, via indirect reconstruction of heavy flavor using their decay electrons, indicated a much higher energy loss by these quarks compared to model predictions, with a magnitude comparable to that of light quarks. Mesons such as D0 could provide information about the interaction of heavy quarks with the surrounding medium through measurements such as elliptic flow. Such data help constrain the transport parameters of the QGP medium and reveal its degree of thermalization. Because heavy hadrons have a low production yield and short lifetime (e.g. ct = 120mum for D0), it is very challenging to obtain accurate measurements of open heavy flavor in heavy-ion collisions, especially since the collisions also produce large quantities of light-flavor particles. Also due to their short lifetime, it is difficult to distinguish heavy-flavor decay vertices from the primary collision vertex; one needs a very high precision vertex detector in order to separate and reconstruct the decay of the heavy flavor particles in the presence of thousands of other particles produced in each collision. The STAR

  3. Achieving Stable Radiation Pressure Acceleration of Heavy Ions via Successive Electron Replenishment from Ionization of a High-Z Material Coating

    NASA Astrophysics Data System (ADS)

    Shen, X. F.; Qiao, B.; Chang, H. X.; Kar, S.; Zhou, C. T.; Borghesi, M.; He, X. T.

    2016-10-01

    Generation of monoenergetic heavy ion beams aroused more scientific interest in recent years. Radiation pressure acceleration (RPA) is an ideal mechanism for obtaining high-quality heavy ion beams, in principle. However, to achieve the same energy per nucleon (velocity) as protons, heavy ions undergo much more serious Rayleigh-Taylor-like (RT) instability and afterwards much worse Coulomb explosion due to loss of co-moving electrons. This leads to premature acceleration termination of heavy ions and very low energy attained in experiment. The utilization of a high-Z coating in front of the target may suppress the RT instability and Coulomb explosion by continuously replenishing the accelerating heavy ion foil with co-moving electrons due to its successive ionization under laser fields with Gaussian temporal and spatial profiles. Thus stable RPA can be realized. Two-dimensional and three-dimensional particles-in-cell simulations with dynamic ionization show that a monoenergetic Al13+ beam with peak energy 4.0GeV and particle number 1010 (charge > 20nC) can be obtained at intensity 1022 W/cm2. Supported by the NSF, Nos. 11575298 and 1000-Talents Program of China.

  4. Achieving Stable Radiation Pressure Acceleration of Heavy Ions via Successive Electron Replenishment from Ionization of a High-Z Material Coating

    NASA Astrophysics Data System (ADS)

    Shen, X. F.; Qiao, B.; Zhang, H.; Kar, S.; Zhou, C. T.; Chang, H. X.; Borghesi, M.; He, X. T.

    2017-05-01

    A method to achieve stable radiation pressure acceleration (RPA) of heavy ions from laser-irradiated ultrathin foils is proposed, where a high-Z material coating in front is used. The coated high-Z material, acting as a moving electron repository, continuously replenishes the accelerating heavy ion foil with comoving electrons in the light-sail acceleration stage due to its successive ionization under laser fields with Gaussian temporal profile. As a result, the detrimental effects such as foil deformation and electron loss induced by the Rayleigh-Taylor-like and other instabilities in RPA are significantly offset and suppressed so that stable acceleration of heavy ions are maintained. Particle-in-cell simulations show that a monoenergetic Al13 + beam with peak energy 3.8 GeV and particle number 1 010 (charge >20 nC ) can be obtained at intensity 1 022 W /cm2 .

  5. Note: A monoenergetic proton backlighter for the National Ignition Facility

    DOE PAGES

    Rygg, J. R.; Zylstra, A. B.; Seguin, F. H.; ...

    2015-11-12

    Here, a monoenergetic, isotropic proton source suitable for proton radiography applications has been demonstrated at the National Ignition Facility (NIF). A deuterium and helium-3 gas-filled glass capsule was imploded with 39 kJ of laser energy from 24 of NIF’s 192 beams. Spectral, spatial, and temporal measurements of the 15-MeV proton product of the 3He(d,p)4He nuclear reaction reveal a bright (1010 protons/sphere), monoenergetic (ΔE/E = 4%) spectrum with a compact size (80 µm) and isotropic emission (~13% proton fluence variation and <0.4% mean energy variation). Simultaneous measurements of products produced by the D(d,p)T and D(d,n)3He reactions also show 2 × 1010more » isotropically distributed 3-MeV protons.« less

  6. Note: A monoenergetic proton backlighter for the National Ignition Facility.

    PubMed

    Rygg, J R; Zylstra, A B; Séguin, F H; LePape, S; Bachmann, B; Craxton, R S; Garcia, E M; Kong, Y Z; Gatu-Johnson, M; Khan, S F; Lahmann, B J; McKenty, P W; Petrasso, R D; Rinderknecht, H G; Rosenberg, M J; Sayre, D B; Sio, H W

    2015-11-01

    A monoenergetic, isotropic proton source suitable for proton radiography applications has been demonstrated at the National Ignition Facility (NIF). A deuterium and helium-3 gas-filled glass capsule was imploded with 39 kJ of laser energy from 24 of NIF's 192 beams. Spectral, spatial, and temporal measurements of the 15-MeV proton product of the (3)He(d,p)(4)He nuclear reaction reveal a bright (10(10) protons/sphere), monoenergetic (ΔE/E = 4%) spectrum with a compact size (80 μm) and isotropic emission (∼13% proton fluence variation and <0.4% mean energy variation). Simultaneous measurements of products produced by the D(d,p)T and D(d,n)(3)He reactions also show 2 × 10(10) isotropically distributed 3-MeV protons.

  7. Note: A monoenergetic proton backlighter for the National Ignition Facility

    SciTech Connect

    Rygg, J. R.; LePape, S.; Bachmann, B.; Khan, S. F.; Sayre, D. B.; Zylstra, A. B.; Séguin, F. H.; Gatu-Johnson, M.; Lahmann, B. J.; Petrasso, R. D.; Sio, H. W.; Craxton, R. S.; Garcia, E. M.; Kong, Y. Z.; McKenty, P. W.; Rinderknecht, H. G.; Rosenberg, M. J.

    2015-11-15

    A monoenergetic, isotropic proton source suitable for proton radiography applications has been demonstrated at the National Ignition Facility (NIF). A deuterium and helium-3 gas-filled glass capsule was imploded with 39 kJ of laser energy from 24 of NIF’s 192 beams. Spectral, spatial, and temporal measurements of the 15-MeV proton product of the {sup 3}He(d,p){sup 4}He nuclear reaction reveal a bright (10{sup 10} protons/sphere), monoenergetic (ΔE/E = 4%) spectrum with a compact size (80 μm) and isotropic emission (∼13% proton fluence variation and <0.4% mean energy variation). Simultaneous measurements of products produced by the D(d,p)T and D(d,n){sup 3}He reactions also show 2 × 10{sup 10} isotropically distributed 3-MeV protons.

  8. 2CG013 - A monoenergetic source of cosmic rays?

    NASA Astrophysics Data System (ADS)

    Ozel, M. E.; Ormes, J. F.

    1989-01-01

    Results from a Monte Carlo simulation of gamma-ray production under astrophysical conditions indicate that it is possible to produce gamma-ray spectra as hard as that of 2CG013+00 reported by COS-B using a monoenergetic beam of cosmic rays hitting a thin target material. It is suggested that the low mass X-ray binary GX13+1 might provide such a mechanism to produce the observed gamma-rays from the region.

  9. Monoenergetic proton emission from nuclear reaction induced by high intensity laser-generated plasmaa)

    NASA Astrophysics Data System (ADS)

    Torrisi, L.; Cavallaro, S.; Cutroneo, M.; Giuffrida, L.; Krasa, J.; Margarone, D.; Velyhan, A.; Kravarik, J.; Ullschmied, J.; Wolowski, J.; Szydlowski, A.; Rosinski, M.

    2012-02-01

    A 1016 W/cm2 Asterix laser pulse intensity, 1315 nm at the fundamental frequency, 300 ps pulse duration, was employed at PALS laboratory of Prague, to irradiate thick and thin primary CD2 targets placed inside a high vacuum chamber. The laser irradiation produces non-equilibrium plasma with deutons and carbon ions emission with energy of up to about 4 MeV per charge state, as measured by time-of-flight (TOF) techniques by using ion collectors and silicon carbide detectors. Accelerated deutons may induce high D-D cross section for fusion processes generating 3 MeV protons and 2.5 MeV neutrons, as measured by TOF analyses. In order to increase the mono-energetic proton yield, secondary CD2 targets can be employed to be irradiated by the plasma-accelerated deutons. Experiments demonstrated that high intensity laser pulses can be employed to promote nuclear reactions from which characteristic ion streams may be developed. Results open new scenario for applications of laser-generated plasma to the fields of ion sources and ion accelerators.

  10. Monoenergetic proton emission from nuclear reaction induced by high intensity laser-generated plasma.

    PubMed

    Torrisi, L; Cavallaro, S; Cutroneo, M; Giuffrida, L; Krasa, J; Margarone, D; Velyhan, A; Kravarik, J; Ullschmied, J; Wolowski, J; Szydlowski, A; Rosinski, M

    2012-02-01

    A 10(16) W∕cm(2) Asterix laser pulse intensity, 1315 nm at the fundamental frequency, 300 ps pulse duration, was employed at PALS laboratory of Prague, to irradiate thick and thin primary CD(2) targets placed inside a high vacuum chamber. The laser irradiation produces non-equilibrium plasma with deutons and carbon ions emission with energy of up to about 4 MeV per charge state, as measured by time-of-flight (TOF) techniques by using ion collectors and silicon carbide detectors. Accelerated deutons may induce high D-D cross section for fusion processes generating 3 MeV protons and 2.5 MeV neutrons, as measured by TOF analyses. In order to increase the mono-energetic proton yield, secondary CD(2) targets can be employed to be irradiated by the plasma-accelerated deutons. Experiments demonstrated that high intensity laser pulses can be employed to promote nuclear reactions from which characteristic ion streams may be developed. Results open new scenario for applications of laser-generated plasma to the fields of ion sources and ion accelerators.

  11. Diffusion of a mono-energetic implanted species with a Gaussian profile

    NASA Astrophysics Data System (ADS)

    Malherbe, Johan B.; Selyshchev, P. A.; Odutemowo, O. S.; Theron, C. C.; Njoroge, E. G.; Langa, D. F.; Hlatshwayo, T. T.

    2017-09-01

    The implanted profile in an isotropic substrate of a mono-energetic ion species is usually very near a Gaussian profile. An exact solution to the time-dependent Fick diffusion equation of an initially Gaussian profile is presented. This solution is a general one also covering the diffusion within the two limiting cases usually considered in solutions to the Fick equation, viz. a perfect sink at the surface and a perfectly reflecting surface plane at the surface. An analysis of the solutions for these two cases shows that at small diffusion times the main effect of annealing is a nearly symmetric broadening of the implanted profile. At the origin and for longer diffusion times the profile deviates significantly from Gaussian. A review is also given of past attempts to extract diffusion coefficients by fitting experimental data to approximate equations based on simplified initial profiles.

  12. Compact quasi-monoenergetic photon sources from laser-plasma accelerators for nuclear detection and characterization

    NASA Astrophysics Data System (ADS)

    Geddes, Cameron G. R.; Rykovanov, Sergey; Matlis, Nicholas H.; Steinke, Sven; Vay, Jean-Luc; Esarey, Eric H.; Ludewigt, Bernhard; Nakamura, Kei; Quiter, Brian J.; Schroeder, Carl B.; Toth, Csaba; Leemans, Wim P.

    2015-05-01

    Near-monoenergetic photon sources at MeV energies offer improved sensitivity at greatly reduced dose for active interrogation, and new capabilities in treaty verification, nondestructive assay of spent nuclear fuel and emergency response. Thomson (also referred to as Compton) scattering sources are an established method to produce appropriate photon beams. Applications are however restricted by the size of the required high-energy electron linac, scattering (photon production) system, and shielding for disposal of the high energy electron beam. Laser-plasma accelerators (LPAs) produce GeV electron beams in centimeters, using the plasma wave driven by the radiation pressure of an intense laser. Recent LPA experiments are presented which have greatly improved beam quality and efficiency, rendering them appropriate for compact high-quality photon sources based on Thomson scattering. Designs for MeV photon sources utilizing the unique properties of LPAs are presented. It is shown that control of the scattering laser, including plasma guiding, can increase photon production efficiency. This reduces scattering laser size and/or electron beam current requirements to scale compatible with the LPA. Lastly, the plasma structure can decelerate the electron beam after photon production, reducing the size of shielding required for beam disposal. Together, these techniques provide a path to a compact photon source system.

  13. Fission product yield measurements using monoenergetic photon beams

    NASA Astrophysics Data System (ADS)

    Krishichayan; Bhike, M.; Tonchev, A. P.; Tornow, W.

    2017-09-01

    Measurements of fission products yields (FPYs) are an important source of information on the fission process. During the past couple of years, a TUNL-LANL-LLNL collaboration has provided data on the FPYs from quasi monoenergetic neutron-induced fission on 235U, 238U, and 239Pu and has revealed an unexpected energy dependence of both asymmetric fission fragments at energies below 4 MeV. This peculiar FPY energy dependence was more pronounced in neutron-induced fission of 239Pu. In an effort to understand and compare the effect of the incoming probe on the FPY distribution, we have carried out monoenergetic photon-induced fission experiments on the same 235U, 238U, and 239Pu targets. Monoenergetic photon beams of Eγ = 13.0 MeV were provided by the HIγS facility, the world's most intense γ-ray source. In order to determine the total number of fission events, a dual-fission chamber was used during the irradiation. These irradiated samples were counted at the TUNL's low-background γ-ray counting facility using high efficient HPGe detectors over a period of 10 weeks. Here we report on our first ever photofission product yield measurements obtained with monoenegetic photon beams. These results are compared with neutron-induced FPY data.

  14. Characteristic X-ray radiation excited by 450 MeV/nucleon C+6 ions and 1.3 GeV protons in extracted and circulated beams of accelerator U70

    NASA Astrophysics Data System (ADS)

    Afonin, A. G.; Britvich, G. I.; Chesnokov, Yu. A.; Durum, A. A.; Kostin, M. Yu.; Maisheev, V. A.; Pikalov, V. A.; Savin, D. A.; Yanovich, A. A.; Kubankin, A. S.; Nazhmudinov, R. M.; Shul'ga, N. F.; Uglov, S. R.; Shchagin, A. V.

    2015-07-01

    The results of the experimental observation of characteristic X-ray radiation (CXR) excited in solid targets by the extracted and circulated 450 MeV/u C+6 ions beams and circulating 1.3 GeV protons beam are presented. The spectra of X-ray radiation measured from different targets are presented and discussed. It was found that the background radiation near the beams is low enough that allows the observation of the CXR spectral peaks with energies from a few to tens keV by semiconductor X-ray detectors. Applications of the CXR for monitoring of the number of accelerated particles in experimental applied and basic research, including radiobiology and radiation medicine as well as the relativistic nuclear physics and steering of beams by bent crystalline deflectors are proposed.

  15. System-size dependence of transverse momentum correlations at sNN=62.4 and 200 GeV at the BNL Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bhattarai; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bruna, E.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Cai, X. Z.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, P.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Ding, F.; Dion, A.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elnimr, M.; Engelage, J.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Gliske, S.; Grebenyuk, O. G.; Grosnick, D.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jena, C.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Kikola, D. P.; Kiryluk, J.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; LaPointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Lu, Y.; Luo, X.; Luszczak, A.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Mioduszewski, S.; Mitrovski, M. K.; Mohammed, Y.; Mohanty, B.; Mondal, M. M.; Munhoz, M. G.; Mustafa, M. K.; Naglis, M.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Novak, J.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Powell, C. B.; Pruneau, C.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, B.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shao, M.; Sharma, B.; Sharma, M.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Steadman, S. G.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yang, Y.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Zawisza, M.; Zbroszczyk, H.; Zhang, J. B.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2013-06-01

    We present a study of the average transverse momentum (pt) fluctuations and pt correlations for charged particles produced in Cu+Cu collisions at midrapidity for sNN= 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the pt correlation results have been studied as functions of the collision centralities, the ranges in pt, the pseudorapidity η, and the azimuthal angle ϕ. The square root of the measured pt correlations when scaled by mean pt is found to be independent of both colliding beam energy and system size studied. Transport-based model calculations are found to have a better quantitative agreement with the measurements compared to models which incorporate only jetlike correlations.

  16. The multiplicity dependence of inclusive p_t spectra from p-pcollis ions at sqrt s = 200 GeV

    SciTech Connect

    Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett, J.; Anderson,B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai, Y.; Balewski,J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland,L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderonde la Barca Sanchez, M.; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford, H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; Kollegger, T.; et al.

    2006-06-23

    We report measurements of transverse momentum pt spectra forten event multiplicity classes of p-p collisions at sqrt s = 200$ GeV. Byanalyzing the multiplicity dependence we find that the spectrum shape canbe decomposed into a part with amplitude proportional to multiplicity anddescribed by a Levy distribution on transverse mass mt, and a part withamplitude proportional to multiplicity squared and described by agaussian distribution on transverse rapidity yt. The functional forms ofthe two parts are nearly independent of event multiplicity. The two partscan be identified with the soft and hard components of a two-componentmodel of p-p collisions. This analysis then provides the first isolationof the hard component of the pt spectrum as a distribution of simple formon yt.

  17. Observation of pi+pi-pi+pi- photoproduction in ultraperipheral heavy-ion collisions at sqrt sNN = 200 GeV at the STAR detector

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    We present a measurement of {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} photonuclear production in ultra-peripheral Au-Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment. The {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} invariant mass spectrum of the coherent events exhibits a broad peak around 1540 {+-} 40 MeV/c{sup 2} with a width of 570 {+-} 60 MeV/c{sup 2}, in agreement with the photoproduction data for the {rho}{sup 0}(1700). We do not observe a corresponding peak in the {pi}{sup +}{pi}{sup -} final state and measure an upper limit for the ratio of the branching fractions of the {rho}{sup 0}(1700) to {pi}{sup +}{pi}{sup -} and {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} of 2.5% at 90% confidence level. The ratio of {rho}{sup 0}(1700) and {rho}{sup 0}(770) coherent production cross sections is measured to be 13.4 {+-} 0.8{sub stat.} {+-} 4.4{sub syst.}%.

  18. Observation of pi+ pi- pi+pi- photoproduction in ultraperipheral heavy-ion collisons at sqrt sNN = 200 GeV at the STAR Detector

    SciTech Connect

    Abelev, B.I.; Dunlop, J.; et al. STAR Collaboration

    2010-04-02

    We present a measurement of {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} photonuclear production in ultraperipheral Au-Au collisions at {radical}s{sub NN} = 200 GeV from the STAR experiment. The {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} final states are observed at low transverse momentum and are accompanied by mutual nuclear excitation of the beam particles. The strong enhancement of the production cross section at low transverse momentum is consistent with coherent photoproduction. The {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} invariant mass spectrum of the coherent events exhibits a broad peak around 1540 {+-} 40 MeV/c{sup 2} with a width of 570 {+-} 60 MeV/c{sup 2}, in agreement with the photoproduction data for the {rho}{sup 0}(1700). We do not observe a corresponding peak in the {pi}{sup +}{pi}{sup -} final state and measure an upper limit for the ratio of the branching fractions of the {rho}{sup 0}(1700) to {pi}{sup +}{pi}{sup -} and {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} of 2.5% at 90% confidence level. The ratio of {rho}{sup 0}(1700) and {rho}{sup 0}(770) coherent production cross sections is measured to be 13.4 {+-} 0.8{sub stat.}{+-}4.4{sub syst.}%.

  19. Initial results from a multiple monoenergetic gamma radiography system for nuclear security

    NASA Astrophysics Data System (ADS)

    O'Day, Buckley E.; Hartwig, Zachary S.; Lanza, Richard C.; Danagoulian, Areg

    2016-10-01

    The detection of assembled nuclear devices and concealed special nuclear materials (SNM) such as plutonium or uranium in commercial cargo traffic is a major challenge in mitigating the threat of nuclear terrorism. Currently available radiographic and active interrogation systems use ∼1-10 MeV bremsstrahlung photon beams. Although simple to build and operate, bremsstrahlung-based systems deliver high radiation doses to the cargo and to potential stowaways. To eliminate problematic issues of high dose, we are developing a novel technique known as multiple monoenergetic gamma radiography (MMGR). MMGR uses ion-induced nuclear reactions to produce two monoenergetic gammas for dual-energy radiography. This allows us to image the areal density and effective atomic number (Zeff) of scanned cargo. We present initial results from the proof-of-concept experiment, which was conducted at the MIT Bates Research and Engineering Center. The purpose of the experiment was to assess the capabilities of MMGR to measure areal density and Zeff of container cargo mockups. The experiment used a 3.0 MeV radiofrequency quadrupole accelerator to create sources of 4.44 MeV and 15.11 MeV gammas from the 11B(d,nγ)12C reaction in a thick natural boron target; the gammas are detected by an array of NaI(Tl) detectors after transmission through cargo mockups . The measured fluxes of transmitted 4.44 MeV and 15.11 MeV gammas were used to assess the areal density and Zeff. Initial results show that MMGR is capable of discriminating the presence of high-Z materials concealed in up to 30 cm of iron shielding from low- and mid-Z materials present in the cargo mockup.

  20. Monoenergetic acceleration of a target foil by circularly polarized laser pulse in RPA regime without thermal heating

    SciTech Connect

    Khudik, V.; Yi, S. A.; Siemon, C.; Shvets, G.

    2012-12-21

    A kinetic model of the monoenergetic acceleration of a target foil irradiated by the circularly polarized laser pulse is developed. The target moves without thermal heating with constant acceleration which is provided by chirping the frequency of the laser pulse and correspondingly increasing its intensity. In the accelerated reference frame, bulk plasma in the target is neutral and its parameters are stationary: cold ions are immobile while nonrelativistic electrons bounce back and forth inside the potential well formed by ponderomotive and electrostatic potentials. It is shown that a positive charge left behind of the moving target in the ion tail and a negative charge in front of the target in the electron sheath form a capacitor whose constant electric field accelerates the ions of the target. The charge separation is maintained by the radiation pressure pushing electrons forward. The scalings of the target thickness and electromagnetic radiation with the electron temperature are found.

  1. Brachytherapy structural shielding calculations using Monte Carlo generated, monoenergetic data

    SciTech Connect

    Zourari, K.; Peppa, V.; Papagiannis, P.; Ballester, Facundo; Siebert, Frank-André

    2014-04-15

    Purpose: To provide a method for calculating the transmission of any broad photon beam with a known energy spectrum in the range of 20–1090 keV, through concrete and lead, based on the superposition of corresponding monoenergetic data obtained from Monte Carlo simulation. Methods: MCNP5 was used to calculate broad photon beam transmission data through varying thickness of lead and concrete, for monoenergetic point sources of energy in the range pertinent to brachytherapy (20–1090 keV, in 10 keV intervals). The three parameter empirical model introduced byArcher et al. [“Diagnostic x-ray shielding design based on an empirical model of photon attenuation,” Health Phys. 44, 507–517 (1983)] was used to describe the transmission curve for each of the 216 energy-material combinations. These three parameters, and hence the transmission curve, for any polyenergetic spectrum can then be obtained by superposition along the lines of Kharrati et al. [“Monte Carlo simulation of x-ray buildup factors of lead and its applications in shielding of diagnostic x-ray facilities,” Med. Phys. 34, 1398–1404 (2007)]. A simple program, incorporating a graphical user interface, was developed to facilitate the superposition of monoenergetic data, the graphical and tabular display of broad photon beam transmission curves, and the calculation of material thickness required for a given transmission from these curves. Results: Polyenergetic broad photon beam transmission curves of this work, calculated from the superposition of monoenergetic data, are compared to corresponding results in the literature. A good agreement is observed with results in the literature obtained from Monte Carlo simulations for the photon spectra emitted from bare point sources of various radionuclides. Differences are observed with corresponding results in the literature for x-ray spectra at various tube potentials, mainly due to the different broad beam conditions or x-ray spectra assumed. Conclusions

  2. Brachytherapy structural shielding calculations using Monte Carlo generated, monoenergetic data.

    PubMed

    Zourari, K; Peppa, V; Ballester, Facundo; Siebert, Frank-André; Papagiannis, P

    2014-04-01

    To provide a method for calculating the transmission of any broad photon beam with a known energy spectrum in the range of 20-1090 keV, through concrete and lead, based on the superposition of corresponding monoenergetic data obtained from Monte Carlo simulation. MCNP5 was used to calculate broad photon beam transmission data through varying thickness of lead and concrete, for monoenergetic point sources of energy in the range pertinent to brachytherapy (20-1090 keV, in 10 keV intervals). The three parameter empirical model introduced by Archer et al. ["Diagnostic x-ray shielding design based on an empirical model of photon attenuation," Health Phys. 44, 507-517 (1983)] was used to describe the transmission curve for each of the 216 energy-material combinations. These three parameters, and hence the transmission curve, for any polyenergetic spectrum can then be obtained by superposition along the lines of Kharrati et al. ["Monte Carlo simulation of x-ray buildup factors of lead and its applications in shielding of diagnostic x-ray facilities," Med. Phys. 34, 1398-1404 (2007)]. A simple program, incorporating a graphical user interface, was developed to facilitate the superposition of monoenergetic data, the graphical and tabular display of broad photon beam transmission curves, and the calculation of material thickness required for a given transmission from these curves. Polyenergetic broad photon beam transmission curves of this work, calculated from the superposition of monoenergetic data, are compared to corresponding results in the literature. A good agreement is observed with results in the literature obtained from Monte Carlo simulations for the photon spectra emitted from bare point sources of various radionuclides. Differences are observed with corresponding results in the literature for x-ray spectra at various tube potentials, mainly due to the different broad beam conditions or x-ray spectra assumed. The data of this work allow for the accurate

  3. Exploration of Monoenergetic X-Ray Mammography with Syncrotron Radiation

    DTIC Science & Technology

    1997-07-01

    medical imaging especially mammography. We are using synchrotron radiation as our source of x-rays to provide monoenergetic beams from 16 ke V upward. We are also developing Monte Carlo techniques to calculate contrast images. To date we have demonstrated an increase in contrast in phantoms and tissue samples over that obtained with conventional x-ray machines. We are developing a Monte Carlo based 2D image model with better documentation of the scatter that can display the image from which image contrast can be calculated. We have also initiated exploration of refraction

  4. Water radiolysis with heavy ions of energies up to 28 GeV. 3. Measurement of G(MV*+) in deaerated methyl viologen solutions containing various concentrations of sodium formate and Monte Carlo simulation.

    PubMed

    Yamashita, Shinichi; Katsumura, Yosuke; Lin, Mingzhang; Muroya, Yusa; Miyazaki, Toyoaki; Murakami, Takeshi; Meesungnoen, Jintana; Jay-Gerin, Jean-Paul

    2008-10-01

    Formation yields of methyl viologen cation radicals G(MV*+) (100 eV)(-1) have been measured in deaerated aqueous solutions of 0.25 mM methyl viologen (MV(2+)) containing various concentrations of formate anion (0.01-2 M) after irradiation with six different ion beams (4He(2+), 12C(6+), 20Ne(10+), 28Si(14+), 40Ar(18+) and 56Fe(26+) with incident energies varying from 0.6 to 28 GeV) provided by the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Science (NIRS) in Japan. The sample solutions are irradiated at the incident energy of the ions using 1-cm irradiation cells. Corresponding LET values cover the range from 2.2 to 185 eV/nm. G(MV*+) increases with increasing formate concentration. In 4He(2+) radiolysis, it increases from 5.7 to 7.1 as the concentration of formate is increased from 0.01 to 2 M, while in 56Fe(26+) radiolysis, the MV*+ yield value changes from 2.2 to 4.1. The other values lie between the yields for 4He(2+) and 56Fe(26+). In addition, G(MV*+) decreases with increasing LET. In the case of 12C(6+) radiolysis, G(MV*+) increases with increasing energy of the carbon ions from 135 to 400 MeV/nucleon, i.e., with decreasing LET from 21 to 11 eV/nm. In parallel to the above measurements, Monte Carlo simulations of the radiolysis of the MV(2+)/formate solutions have been performed. Ionic strength effects on reactions between charged species are taken into account. To reproduce the experimental results, previously unreported reactions such as e(aq)(-) + MV*+, MV*(+) + *OH and *COO- + *OH have been introduced in the reaction scheme. After optimization, the rate constants of these latter two reactions are determined to be (3 +/- 0.5) x 10(10) and (5 +/- 0.5) x 10(10) M(-1) s(-1), respectively. By contrast, the reaction between e(aq)- and MV*+ is too slow to affect G(MV*+). On the basis of these calculations, characteristics of intratrack reactions induced by heavy-ion beams are discussed in reference not only to the

  5. Photoneutron spectroscopy using monoenergetic gamma rays for bulk explosives detection

    NASA Astrophysics Data System (ADS)

    McFee, J. E.; Faust, A. A.; Pastor, K. A.

    2013-03-01

    To date, the most successful nuclear methods to confirm the presence of bulk explosives have been radiative thermal neutron capture (thermal neutron activation) and prompt radiative emission following inelastic fast neutron scattering (fast neutron analysis). This paper proposes an alternative: photoneutron spectroscopy using monoenergetic gamma rays. If monoenergetic gamma rays whose energies exceed the threshold for neutron production are incident on a given isotope, the emitted neutrons have a spectrum consisting of one or more discrete energies and the spectrum can be used as a fingerprint to identify the isotope. A prototype compact gamma-ray generator is proposed as a suitable source and a commercially available 3He ionization chamber is proposed as a suitable spectrometer. Advantages of the method with respect to the previously mentioned ones may include simpler spectra and low inherent natural neutron background. Its drawbacks include a present lack of suitable commercially available photon sources, induced neutron backgrounds and low detection rates. This paper describes the method, including kinematics, sources, detectors and geometries. Simulations using a modified Geant4 Monte Carlo modelling code are described and results are presented to support feasibility. Further experiments are recommended.

  6. Centrality dependence of the direct photon yield and elliptic flow in heavy-ion collisions at √sNN =200 GeV

    NASA Astrophysics Data System (ADS)

    Linnyk, O.; Cassing, W.; Bratkovskaya, E. L.

    2014-03-01

    We calculate the centrality dependence of direct photons produced in Au+Au collisions at the invariant collision energy √sNN =200 GeV and their transverse momentum spectra within the parton-hadron-string dynamics transport approach. As sources for "direct" photons, we incorporate the interactions of quarks and gluons as well as hadronic interactions (π +π→ρ+γ, ρ +π→π+γ, meson-meson bremsstrahlung m +m→m+m+γ, and meson-baryon bremsstrahlung m +B→m+B+γ), the decays of ϕ and a1 mesons, and the photons produced in the initial hard collisions. We find that the transverse momentum pT spectra of the "thermal" photons (i.e., the direct photons after the pQCD contribution is subtracted) deviate from exponential distributions and, consequently, observe a strong dependence of the inverse slope parameter Teff on the fitting range in pT. On the other hand, all the obtained "effective temperatures" are well above the critical temperature for the deconfinement phase transition even for peripheral collisions, reflecting primarily a "blue shift" due to radial collective motion of hadrons. Our calculations suggest that the channel decomposition of the observed spectrum changes with centrality with an increasing (dominant) contribution of hadronic sources for more peripheral reactions. Furthermore, the thermal photon yield is found to scale roughly with the number of participant nucleons as Npartα with α ≈ 1.5, whereas the partonic contribution scales with an exponent αp≈1.75. Additionally, we provide predictions for the centrality dependence of the direct photon elliptic flow v2(pT). The photons from the hot deconfined matter in the early stages of the collision carry a much smaller elliptic flow than the final hadrons. Consequently, the direct photon v2 in the most central bin is of the order of a few percent. On the other hand, the elliptic flow of direct photons is considerably larger in more peripheral collisions, approaching that of hadrons.

  7. Polarized Proton Collisions at 205GeV at RHIC

    NASA Astrophysics Data System (ADS)

    Bai, M.; Roser, T.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; Beebe-Wang, J.; Blaskiewicz, M.; Bravar, A.; Brennan, J. M.; Bruno, D.; Bunce, G.; Courant, E.; Drees, A.; Fischer, W.; Gardner, C.; Gill, R.; Glenn, J.; Haeberli, W.; Huang, H.; Jinnouchi, O.; Kewisch, J.; Luccio, A.; Luo, Y.; Nakagawa, I.; Okada, H.; Pilat, F.; Mackay, W. W.; Makdisi, Y.; Montag, C.; Ptitsyn, V.; Satogata, T.; Stephenson, E.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Wise, T.; Zelenski, A.; Zeno, K.; Zhang, S. Y.

    2006-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

  8. Polarized proton collisions at 205 GeV at RHIC.

    PubMed

    Bai, M; Roser, T; Ahrens, L; Alekseev, I G; Alessi, J; Beebe-Wang, J; Blaskiewicz, M; Bravar, A; Brennan, J M; Bruno, D; Bunce, G; Courant, E; Drees, A; Fischer, W; Gardner, C; Gill, R; Glenn, J; Haeberli, W; Huang, H; Jinnouchi, O; Kewisch, J; Luccio, A; Luo, Y; Nakagawa, I; Okada, H; Pilat, F; Mackay, W W; Makdisi, Y; Montag, C; Ptitsyn, V; Satogata, T; Stephenson, E; Svirida, D; Tepikian, S; Trbojevic, D; Tsoupas, N; Wise, T; Zelenski, A; Zeno, K; Zhang, S Y

    2006-05-05

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

  9. Plasma-wall interaction in an electrostatic sheath of plasma containing a monoenergetic electron beam

    SciTech Connect

    Ou, Jing Zhao, Xiaoyun; Gan, Chunyun

    2016-04-15

    The plasma-wall interaction in the presence of a monoenergetic electron beam has been studied by taking into account the self-consistency among plasma transport in a collisionless electrostatic sheath, deposited energy flux at the wall and material thermal response for carbon and tungsten as wall materials. The variations of the potential drop across the sheath, ion velocity at the sheath edge, and surface temperature of material as a function of electron beam flux are explored in the presence of the electron emission. It is found that when electron beam does not dominate the sheath, potential drop across the sheath depends strongly on the material properties due to the impact of electron emission while the surface temperature of material shows monotonic variation. In the case of carbon wall, the electron beam may dominate the sheath at a certain electron beam concentration or energy. Under this circumstance, both the potential drop across the sheath and surface temperature of material demonstrate the sharp increasing transition. The development of local hot spot on the plasma facing material is caused by the enhanced ion energy flux instead of the electron beam energy flux. If the electron emission is not taken into account, as a smaller electron beam flux, both the potential drop across the sheath and surface temperature of material display the significant change and then it may be easier to develop for the local hot spot on the plasma facing material.

  10. Generating high-current monoenergetic proton beams by a circularly polarized laser pulse in the phase-stable acceleration regime.

    PubMed

    Yan, X Q; Lin, C; Sheng, Z M; Guo, Z Y; Liu, B C; Lu, Y R; Fang, J X; Chen, J E

    2008-04-04

    A new ion acceleration method, namely, phase-stable acceleration, using circularly-polarized laser pulses is proposed. When the initial target density n(0) and thickness D satisfy a(L) approximately (n(0)/n(c))D/lambda(L) and D>l(s) with a(L), lambda(L), l(s), and n(c) the normalized laser amplitude, the laser wavelength in vacuum, the plasma skin depth, and the critical density of the incident laser pulse, respectively, a quasiequilibrium for the electrons is established by the light pressure and the space charge electrostatic field at the interacting front of the laser pulse. The ions within the skin depth of the laser pulse are synchronously accelerated and bunched by the electrostatic field, and thereby a high-intensity monoenergetic proton beam can be generated. The proton dynamics is investigated analytically and the results are verified by one- and two-dimensional particle-in-cell simulations.

  11. Modeling of heavy-flavor pair correlations in Au-Au collisions at 200 A GeV at the BNL Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Cao, Shanshan; Qin, Guang-You; Bass, Steffen A.

    2015-11-01

    We study the nuclear modification of angular and momentum correlations between heavy quark pairs in ultrarelativistic heavy-ion collisions. The evolution of heavy quarks inside the thermalized medium is described via a modified Langevin approach that incorporates both elastic and inelastic interactions with the medium constituents. The spacetime evolution of the fireball is obtained from a (2 +1 )-dimensional viscous hydrodynamics simulation. The hadronization of heavy quarks is performed by utilizing a hybrid model of fragmentation and coalescence. Our results show that the nuclear modification of the transverse momentum imbalance of D D ¯ pairs reflects the total energy loss experienced by the heavy quarks and may help us probe specific regions of the medium. The angular correlation of heavy-flavor pairs, especially in the low- to intermediate-transverse-momentum regime, is sensitive to the detailed energy-loss mechanism of heavy quarks inside the quark-gluon plasma.

  12. Energy Differential Response of Cancer Cells for Low Dose Irradiation:Impact of Monoenergetic Brachytherapy Sources

    SciTech Connect

    Gueye, Paul; Prilepskiy, Yuriy; Keppel, Cynthia; Britten, R

    2010-06-01

    Purpose: The purpose of this work was to evaluate the energy differential response of cancer cells under identical dose exposure to asses the relevancy of mono-energetic sources for Brachytherapy treatments. Method and Materials: An electron energy spectrum impinging on lived breast cancer cell lines (MDA321) was obtained by placing a 19.65 {micro}Ci {sup 90}Sr/{sup 90}Y radioactive source in front of a non-uniform magnetic field constructed from two 5.08 x 5.0 cm x 2.54 cm neodimium ion permanent dipole magnets with a 1 cm separation gap. The cell lines were placed on the exit pole face of the magnet and were subsequently irradiated with different electron energies ranging from about 0.75 MeV to 1.85 MeV. The energy distribution was accurately measured with a scintillating fiber detector system that provided a 0.5% agreement with ICRU and a 5% energy resolution. The dosimetry was performed using a series of data acquired with a {sup 9}Sr/{sup 90}Y 4.5 mCi SIA-6 eye applicator, 6-21 MeV fixed energies from a Varian 2100 EX linac, EBT Gafchromic and Kodak ERT2 films, and an ion chamber detector. The accuracy of the dose rate obtained at different locations along and away from the magnet inside the cell containers was within 10.7%. Results: The cell lines were irradiated with a 0.5-4 Gy dose range. The data indicate a very strong differential energy response for electrons around 1 MeV (more lethal) compare to those with lesser or greater energy and a survival rate of at most 10% at very low dose (0.5-2 Gy). Conclusion: Mono-energetic Brachytherapy sources may provide a new pathway for radio-therapy treatment optimizations following a dedicated study showing very unusual high lethality in a specific energy window for MDA321 breast cancer cells.

  13. Low energy electron magnetometer using a monoenergetic electron beam

    NASA Technical Reports Server (NTRS)

    Singh, J. J.; Wood, G. M.; Rayborn, G. H.; White, F. A. (Inventor)

    1983-01-01

    A low energy electron beam magnetometer utilizes near-monoenergetic electrons thereby reducing errors due to electron energy spread and electron nonuniform angular distribution. In a first embodiment, atoms in an atomic beam of an inert gas are excited to a Rydberg state and then electrons of near zero energy are detached from the Rydberg atoms. The near zero energy electrons are then accelerated by an electric field V(acc) to form the electron beam. In a second embodiment, a filament emits electrons into an electrostatic analyzer which selects electrons at a predetermined energy level within a very narrow range. These selected electrons make up the electron beam that is subjected to the magnetic field being measured.

  14. First observation of monoenergetic muon neutrino charged current interactions

    NASA Astrophysics Data System (ADS)

    Grange, Joseph; MiniBooNE Collaboration

    2017-01-01

    The MiniBooNE neutrino experiment has ran at Fermilab since the early 2000's. A dedicated trigger for the nearby NuMI beamline has been implemented since around 2006 and the observation of events from the NuMI source in neutrino-enhanced mode has been previously published. Presented here is a new analysis of NuMI events in the antineutrino-enhanced configuration collected around 2010. The geometry of the NuMI beamline relative to the MiniBooNE detector fortuitously allows an observable source of monoenergetic neutrinos from the decay-at-rest of kaons created by protons which pass through the NuMI target and interact with the beam dump. Results and future opportunities with this tool will be discussed.

  15. Study of nuclear recoils in liquid argon with monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Regenfus, C.; Allkofer, Y.; Amsler, C.; Creus, W.; Ferella, A.; Rochet, J.; Walter, M.

    2012-07-01

    In the framework of developments for liquid argon dark matter detectors we assembled a laboratory setup to scatter neutrons on a small liquid argon target. The neutrons are produced mono-energetically (Ekin = 2.45 MeV) by nuclear fusion in a deuterium plasma and are collimated onto a 3" liquid argon cell operating in single-phase mode (zero electric field). Organic liquid scintillators are used to tag scattered neutrons and to provide a time-of-flight measurement. The setup is designed to study light pulse shapes and scintillation yields from nuclear and electronic recoils as well as from alpha particles at working points relevant for dark matter searches. Liquid argon offers the possibility to scrutinise scintillation yields in noble liquids with respect to the population strength of the two fundamental excimer states. Here we present experimental methods and first results from recent data towards such studies.

  16. Characterization of a measurement reference standard and neutron fluence determination method in IRSN monoenergetic neutron fields

    NASA Astrophysics Data System (ADS)

    Gressier, V.; Lacoste, V.; Martin, A.; Pepino, M.

    2014-10-01

    The variation in the response of instruments with neutron energy has to be determined in well-characterized monoenergetic neutron fields. The quantities associated with these fields are the neutron fluence and the mean energy of the monoenergetic neutron peak needed to determine the related dosimetric quantities. At the IRSN AMANDE facility, the reference measurement standard for neutron fluence is based on a long counter calibrated in the IRSN reference 252Cf neutron field. In this paper, the final characterization of this device is presented as well as the method used to determine the reference fluence at the calibration point in monoenergetic neutron fields.

  17. ION SOURCE WITH SPACE CHARGE NEUTRALIZATION

    DOEpatents

    Flowers, J.W.; Luce, J.S.; Stirling, W.L.

    1963-01-22

    This patent relates to a space charge neutralized ion source in which a refluxing gas-fed arc discharge is provided between a cathode and a gas-fed anode to provide ions. An electron gun directs a controlled, monoenergetic electron beam through the discharge. A space charge neutralization is effected in the ion source and accelerating gap by oscillating low energy electrons, and a space charge neutralization of the source exit beam is effected by the monoenergetic electron beam beyond the source exit end. The neutralized beam may be accelerated to any desired energy at densities well above the limitation imposed by Langmuir-Child' s law. (AEC)

  18. Monoenergetic computed tomography reconstructions reduce beam hardening artifacts from dental restorations.

    PubMed

    Stolzmann, Paul; Winklhofer, Sebastian; Schwendener, Nicole; Alkadhi, Hatem; Thali, Michael J; Ruder, Thomas D

    2013-09-01

    The aim of this study was to assess the potential of monoenergetic computed tomography (CT) images to reduce beam hardening artifacts in comparison to standard CT images of dental restoration on dental post-mortem CT (PMCT). Thirty human decedents (15 male, 58 ± 22 years) with dental restorations were examined using standard single-energy CT (SECT) and dual-energy CT (DECT). DECT data were used to generate monoenergetic CT images, reflecting the X-ray attenuation at energy levels of 64, 69, 88 keV, and at an individually adjusted optimal energy level called OPTkeV. Artifact reduction and image quality of SECT and monoenergetic CT were assessed objectively and subjectively by two blinded readers. Subjectively, beam artifacts decreased visibly in 28/30 cases after monoenergetic CT reconstruction. Inter- and intra-reader agreement was good (k = 0.72, and k = 0.73 respectively). Beam hardening artifacts decreased significantly with increasing monoenergies (repeated-measures ANOVA p < 0.001). Artifact reduction was greatest on monoenergetic CT images at OPTkeV. Mean OPTkeV was 108 ± 17 keV. OPTkeV yielded the lowest difference between CT numbers of streak artifacts and reference tissues (-163 HU). Monoenergetic CT reconstructions significantly reduce beam hardening artifacts from dental restorations and improve image quality of post-mortem dental CT.

  19. Radiobiology with laser-accelerated quasi-monoenergetic proton beams

    NASA Astrophysics Data System (ADS)

    Yogo, A.; Maeda, T.; Hori, T.; Sakaki, H.; Ogura, K.; Nishiuchi, M.; Sagisaka, A.; Bolton, P. R.; Murakami, M.; Kawanishi, S.; Kondo, K.

    2011-05-01

    Human cancer cells are irradiated by laser-driven quasi-monoenergetic protons. Laser pulse intensities at the 5×1019-W/cm2 level provide the source and acceleration field for protons that are subsequently transported by four energy-selective dipole magnets. The transport line delivers 2.25 MeV protons with an energy spread of 0.66 MeV and a bunch duration of 20 ns. The survival fraction of in-vitro cells from a human salivary gland tumor is measured with a colony formation assay following proton irradiation at dose levels up to 8 Gy, for which the single bunch does rate is 1 × 107 Gy/s and the effective dose rate is 0.2 Gy/s for 1-Hz repetition of irradiation. Relative biological effectiveness at the 10% survival fraction is measured to be 1.20 +/- 0.11 using protons with a linear energy transfer of 17.1 +/- 2.8 keV/μm.

  20. Neutrino Mass Measurement Using a Directed Mono-Energetic Beam

    NASA Astrophysics Data System (ADS)

    Tsifrinovich, Vladimir; Folan, Lorcan

    2015-04-01

    It was shown that a directed mono-energetic neutrino beam can be generated by electron capture beta-decay in a sample with a strong hyperfine field at the radioactive nuclei. We study the conditions required to measure the neutrino rest mass using the recoil force produced by a directed neutrino beam. We consider the displacement of an atomic force microscope cantilever due to such a recoil force. We find the change in the cantilever displacement associated with the non-zero neutrino mass, as a function of nuclear half-life T1 / 2, cantilever spring constant, and temperature. We consider the opportunity to increase the sensitivity of the neutrino mass measurement using averaging of the measurement signal. We show that the optimal time for the signal accumulation is, approximately, 1.8T1 / 2. We compute the optimal signal-to-noise ratio for 119Sb nuclei decaying to 119Sn with a decrease in the nuclear spin from I = 5/2 to I = 3/2, and T1 / 2 = 38.2 hours. Finally, we present the parameters values required for detection of sub-eV neutrino rest mass, and estimate the angular distribution of neutrino radiation as a function of temperature.

  1. STELLA-II: Staged Monoenergetic Laser Acceleration - Experiment Update

    NASA Astrophysics Data System (ADS)

    Kimura, W. D.; Babzien, M.; Ben-Zvi, I.; Campbell, L. C.; Cline, D. B.; Dilley, C. E.; Gallardo, J. C.; Gottschalk, S. C.; Kusche, K. P.; Pantell, R. H.; Pogorelsky, I. V.; Quimby, D. C.; Skaritka, J.; Steinhauer, L. C.; Yakimenko, V.; Zhou, F.

    2002-12-01

    The goal of STELLA-II is to demonstrate staged monoenergetic laser acceleration of microbunches using an inverse free electron laser (IFEL) buncher and IFEL accelerator. A key feature of this experiment is the usage of a single high-intensity laser beam to simultaneously drive both the buncher and accelerator. A chicane between the buncher and accelerator causes microbunches to form at the entrance to the accelerator. All hardware has been installed at the Accelerator Test Facility (ATF) located at Brookhaven National Laboratory, including a new laser beam transport system to permit delivering higher laser power. Preliminary test results indicate that modulation and acceleration of the microbunches are occurring with the new system. Energy gains >13% have been observed. Current experiments are being conducted with the ATF CO2 laser operating at a pulse length of ˜180 ps. In late autumn 2002, the ATF CO2 laser will be upgraded to produce pulse lengths of <10 ps at approximately the same output pulse energy. This higher peak power will enable higher acceleration and more complete trapping of the laser-generated microbunches in the accelerator. This higher acceleration and trapping will also result in a clean separation of the accelerated microbunch electrons from the unaccelerated ones while at the same time maintaining a narrow energy spread.

  2. 12 GeV Upgrade

    SciTech Connect

    2017-01-01

    To expand the opportunity for discovery, Jefferson Lab is upgrading its facility by doubling the maximum energy of CEBAF's electron beam from 6 billion electron volts (GeV) to 12 billion electron volts (GeV), constructing a new experimental hall and upgrading its three existing experimental halls.

  3. Inclusive particle spectra at (56 and 130)A GeV

    SciTech Connect

    Kahana, D. E.; Kahana, S. H.

    2001-03-01

    A simulation is performed of the recently reported data from PHOBOS at energies of s=56,130A GeV using the relativistic heavy ion cascade LUCIFER which had previously given a good description of the NA49 inclusive spectra at s=17.2A GeV. The results compare well with these early measurements at RHIC.

  4. OVERVIEW OF MONO-ENERGETIC GAMMA-RAY SOURCES & APPLICATIONS

    SciTech Connect

    Hartemann, F V; Albert, F; Anderson, G G; Anderson, S G; Bayramian, A J; Betts, S M; Chu, T S; Cross, R R; Ebbers, C A; Fisher, S E; Gibson, D J; Ladran, A S; Marsh, R A; Messerly, M J; O'Neill, K L; Semenov, V A; Shverdin, M Y; Siders, C W; McNabb, D P; Barty, C P; Vlieks, A E; Jongewaard, E N; Tantawi, S G; Raubenheimer, T O

    2010-05-18

    Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC NAL will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. This MEGa-ray source will be used to excite nuclear resonance fluorescence in various isotopes. Applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented, along with important applications, including nuclear resonance fluorescence. In conclusion, we have optimized the design of a high brightness Compton scattering gamma-ray source, specifically designed for NRF applications. Two different parameters sets have been considered: one where the number of photons scattered in a single shot reaches approximately 7.5 x 10{sup 8}, with a focal spot size around 8 {micro}m; in the second set, the spectral brightness is optimized by using a 20 {micro}m spot size, with 0.2% relative bandwidth.

  5. Optimization of window settings for virtual monoenergetic imaging in dual-energy CT of the liver: A multi-reader evaluation of standard monoenergetic and advanced imaged-based monoenergetic datasets.

    PubMed

    De Cecco, Carlo N; Caruso, Damiano; Schoepf, U Joseph; Wichmann, Julian L; Ter Louw, Janet R; Perry, Jonathan D; Picard, Melissa M; Schaefer, Amanda R; Parker, Leland W; Hardie, Andrew D

    2016-04-01

    To evaluate optimal window settings for display of virtual monoenergetic reconstructions in third-generation dual-source, dual-energy computed tomography (DECT) of the liver. Twenty-nine subjects were prospectively evaluated with DECT in arterial (AP) and portal venous (PVP) phases. Three reconstructed datasets were calculated: standard linearly-blended (LB120), 70-keV standard virtual monoenergetic (M70), and 50-keV advanced image-based virtual monoenergetic (M50+). Two readers assessed optimal window settings (width and level, W/L), establishing a mean for each reconstruction which was used for a blinded assessment of liver lesions. The optimal W/L for M50+ were significantly higher for both AP (W=429.3 ± 44.6 HU, L=129.4 ± 9.7 HU) and PVP (W=376.1 ± 14.2HU, L=146.6 ± 7.0 HU) than for LB120 (AP, W=215.9 ± 16.9 HU, L=82.3 ± 9.4 HU) (PVP, W=173.4 ± 8.9 HU, L=69.3 ± 6.0 HU) and M70 (AP, W=247.1 ± 22.2 HU, L=72.9 ± 6.8 HU) (PVP, W=232.0 ± 27.9 HU, L=91.6 ± 14.4 HU). Use of the optimal window setting for M50+ vs. LB120 resulted in higher sensitivity (AP, 100% vs. 86%; PVP, 96% vs. 63%). Application of dedicated window settings results in improved liver lesion detection rates in advanced image-based virtual monoenergetic DECT when customized for arterial and portal venous phases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Generation of Quasi-monoenergetic High-energy Electron Beam by Plasma Wave

    SciTech Connect

    Koyama, K.; Saito, N.; Ogata, A.; Masuda, S.; Tanimoto, M.; Miura, E.; Kato, S.; Adachi, M

    2004-12-07

    We have demonstrated an acceleration of a quasi-monoenergetic electron beam by trapping electrons in a plasma wave. Experiments were performed by focusing 2-TW (50 fs) laser pulses on supersonic gas jet targets. An intensity was 5 x 1018W/cm2(a0 = 1.5). An electron density was estimated to be 1.3 x 1020cm-3. The quasi-monoenergetic electron beam at 7 MeV was observed with a peak to foot ratio of 10. An appearance of a Stokes Raman satellite in the forward scattering well correlated with the quasi-monoenergetic electron beam. A frequency shift of the satellite coincided with a plasma frequency at the measured plasma density. Appearance of the Raman satellite coincided with appearances of a fishbone structure in a side-scattering image. Supposing the fishbone structure originated from the plasma wave, an acceleration length was estimated to be 200 to 500 microns.

  7. The Liège Intranuclear Cascade model - Towards a unified description of nuclear reactions induced by nucleons and light ions from a few MeV to a few GeV

    NASA Astrophysics Data System (ADS)

    Cugnon, Joseph; Boudard, Alain; David, Jean-Christophe; Leray, Sylvie; Mancusi, Davide

    2014-03-01

    The predictive power of the last version INCL4.6 of the Liège Intranuclear Cascade model for spallation is reviewed. The good results obtained both at low and high energy extend the domain of validity of the model and allow the description of spallation reactions, except the coherent processes, by a unique model from a few MeV to a few GeV incident energy.

  8. Atlas of photoneutron cross sections obtained with monoenergetic photons. Final edition, 1986

    SciTech Connect

    Dietrich, S.S.; Berman, B.L.

    1986-06-01

    In view of the need for a comprehensive compilation of photoneutron cross-section data, these monoenergetic-photon data are gathered together here and presented in a uniform format. This compilation updates and supersedes the earlier editions of this Atlas. A more complete compilation is being assembled by the photonuclear group at the National Bureau of Standards. 15 refs., 174 figs.

  9. The exact solution of the monoenergetic transport equation for critical cylinders

    NASA Technical Reports Server (NTRS)

    Westfall, R. M.; Metcalf, D. R.

    1972-01-01

    An analytic solution for the critical, monoenergetic, bare, infinite cylinder is presented. The solution is obtained by modifying a previous development based on a neutron density transform and Case's singular eigenfunction method. Numerical results for critical radii and the neutron density as a function of position are included and compared with the results of other methods.

  10. Analysis of the response of innovative neutron detectors with monoenergetic neutron beams

    SciTech Connect

    Romei, C.; Ciolini, R.; Mirzajani, N.; Selici, S.; Di Fulvio, A.; D'Errico, F.; Souza, S. O.; Piotto, M.; Esposito, J.; Colautti, P.

    2013-07-18

    Various neutron detectors are currently under development at the University of Pisa. The response of these devices is investigated using monoenergetic neutron beams produced at the CN accelerator of INFN Legnaro National Laboratories with thin lithium target bombarded by protons at different energies, exploiting the {sup 7}Li(p,n){sup 7}Be reaction.

  11. The response of monoenergetic gamma rays in finite media are investigated

    NASA Technical Reports Server (NTRS)

    Snow, W. J.

    1969-01-01

    In a study of the transport of radiation in matter, the response parameters of monoenergetic gamma rays incident on various materials with finite geometries were calculated on a CDC 3600 computer. The report includes results for gamma rays normal to cyclindrical germanium and silicon detectors.

  12. Theory of laser acceleration of light-ion beams from interaction of ultrahigh-intensity lasers with layered targets.

    PubMed

    Albright, B J; Yin, L; Hegelich, B M; Bowers, Kevin J; Kwan, T J T; Fernández, J C

    2006-09-15

    Experiments at the LANL Trident facility demonstrated the production of monoenergetic ion beams from the interaction of an ultraintense laser with a target comprising a heavy ion substrate and thin layer of light ions. An analytic model is obtained that predicts how the mean energy and quality of monoenergetic ion beams and the energy of substrate ions vary with substrate material and light-ion layer composition and thickness. Dimensionless parameters controlling the dynamics are derived and the model is validated with particle-in-cell simulations and experimental data.

  13. First polarized proton collision at a beam energy of 250 GeV in RHIC

    SciTech Connect

    Bai,M.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; et al.

    2009-05-04

    After providing collisions of polarized protons at a beam energy of 100 GeV since 2001, the Relativistic Heavy Ion Collider (RHIC) at BNL had its first opportunity to collide polarized protons at its maximum beam energy of 250 GeV in the 2009 polarized proton operations. Equipped with two full Siberian snakes [1] in each ring, RHIC preserves polarization during acceleration from injection to 100 GeV with precise control of the betatron tunes and vertical orbit distortions. However, the strong intrinsic spin resonances beyond 100 GeV are more than two times stronger than those below 100 GeV, requiring much tighter tolerances on vertical orbit distortions and betatron tunes. With the currently achieved orbit correction and tune control, average polarizations of {approx_equal} 42% at top energy and average polarizations of {approx_equal} 55% at injection energy were achieved. Polarization measurements as a function of beam energy also indicated aU polarization losses occurred around three strong intrinsic resonances at 136 GeV, 199.3 GeV and 220.8 GeV Peak luminosity of 122 x 10{sup 30} cm{sup -2} s{sup -1} was also demonstrated. This paper presents the performance of the first RHIC 250 GeV operation and discusses the depolarization issues encountered during the run.

  14. Quantifying potential reduction in contrast dose with monoenergetic images synthesized from duallayer detector spectral CT.

    PubMed

    Tsang, Derek S; Merchant, Thomas E; Merchant, Sophie E; Smith, Hanna; Yagil, Yoad; Hua, Chia-Ho

    2017-07-27

    To estimate the potential dose reduction in iodinated contrast when interpreting monoenergetic images from spectral CT. 51 pediatric patients received contrast-enhanced CT simulation for radiation therapy using a single-source, dual-layer detector spectral CT. The contrast-to-noise ratios (CNR) of blood vessels were measured relative to surrounding soft tissue. CNRs on monoenergetic 40-70 keV images were compared with polychromatic 120 kVp images. To compare with in vivo results, a phantom with iodine inserts (2-20 mg/mL concentration) was scanned and CNRs were calculated relative to water background. Monoenergetic keV and body site had significant effects on CNR ratio (P < 0.0001). Across all body sites, the mean CNR ratio (monoenergetic/polychromatic CNR) was 3.3 (20(th) percentile [%20] 2.6), 2.4 (%20 2.1), 1.7 (%20 1.5), 1.2 (%20 1.0) for 40, 50, 60 and 70 keV images, respectively. Image noise was highest at 40 keV and lowest at 70 keV. Phantom measurements indicated that the same CNR as 120 kVp images can be achieved with a 4.0-fold lower iodine concentration on 40 keV images and 2.5-fold lower on 50 keV images. 50 keV monoenergetic images provided the best balance of improved CNR on all studies (mean 2.4-fold increase in vivo) for enhancing vessels versus image noise. A 50% reduction in contrast dose on a 50 keV image should maintain comparable or better CNR as compared with polychromatic CT in over 80% of CT studies. Advances in Knowledge: Use of a novel, single-source, dual-layer detector spectral CT scanner to improve visualization of contrast-enhanced blood vessels will reduce the amount of iodinated contrast required for radiation oncology treatment planning.

  15. Measurement of elliptic flow of light nuclei at sNN=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV at the BNL Relativistic Heavy Ion Collider

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, Y.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, F.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, H.; Xu, Z.; Xu, J.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, S.; Yang, C.; Yang, Y.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J.; Zhang, Y.; Zhang, X. P.; Zhang, Z.; Zhang, J. B.; Zhang, S.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2016-09-23

    Here we present measurements of second-order azimuthal anisotropy ( v2 ) at midrapidity ( |y| < 1.0 ) for light nuclei d , t , 3He (for $\\sqrt{s}$$_{NN}$ = 200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV) and antinuclei$\\bar{d}$ ( $\\sqrt{s}$$_{NN}$ = 200 , 62.4, 39, 27, and 19.6 GeV) and 3 ¯¯¯¯¯ He ( $\\sqrt{s}$$_{NN}$ = 200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The v2 for these light nuclei produced in heavy-ion collisions is compared with those for p and $\\bar{p}$. We observe mass ordering in nuclei v2 ( pT) at low transverse momenta ( pT < 2.0 GeV/c). We also find a centrality dependence of v2 for d and $\\bar{d}$ . The magnitude of v2 for t and 3He agree within statistical errors. Light-nuclei v2 are compared with predictions from a blast-wave model. Atomic mass number ( A ) scaling of light-nuclei v2 (pT) seems to hold for pT / A < 1.5 GeV/c . Results on light-nuclei v2 from a transport-plus-coalescence model are consistent with the experimental measurements.

  16. Measurement of elliptic flow of light nuclei at sNN=200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV at the BNL Relativistic Heavy Ion Collider

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, M. K.; Sharma, B.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, Y.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, F.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, H.; Xu, Z.; Xu, J.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, S.; Yang, C.; Yang, Y.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J.; Zhang, Y.; Zhang, X. P.; Zhang, Z.; Zhang, J. B.; Zhang, S.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2016-09-23

    Here we present measurements of second-order azimuthal anisotropy ( v2 ) at midrapidity ( |y| < 1.0 ) for light nuclei d , t , 3He (for $\\sqrt{s}$$_{NN}$ = 200 , 62.4, 39, 27, 19.6, 11.5, and 7.7 GeV) and antinuclei$\\bar{d}$ ( $\\sqrt{s}$$_{NN}$ = 200 , 62.4, 39, 27, and 19.6 GeV) and 3 ¯¯¯¯¯ He ( $\\sqrt{s}$$_{NN}$ = 200 GeV) in the STAR (Solenoidal Tracker at RHIC) experiment. The v2 for these light nuclei produced in heavy-ion collisions is compared with those for p and $\\bar{p}$. We observe mass ordering in nuclei v2 ( pT) at low transverse momenta ( pT < 2.0 GeV/c). We also find a centrality dependence of v2 for d and $\\bar{d}$ . The magnitude of v2 for t and 3He agree within statistical errors. Light-nuclei v2 are compared with predictions from a blast-wave model. Atomic mass number ( A ) scaling of light-nuclei v2 (pT) seems to hold for pT / A < 1.5 GeV/c . Results on light-nuclei v2 from a transport-plus-coalescence model are consistent with the experimental measurements.

  17. Centrality dependence of identified particle elliptic flow in relativistic heavy ion collisions at sNN=7.762.4 GeV

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Chisman, O.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, Y.; Li, W.; Li, C.; Li, X.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, Y. G.; Ma, G. L.; Ma, R.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, X.; Sun, Z.; Sun, Y.; Sun, X. M.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, G.; Wang, Y.; Wang, J. S.; Wang, H.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Z.; Xu, H.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Y.; Zhang, S.; Zhang, J.; Zhang, J.; Zhang, Z.; Zhang, X. P.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2016-01-19

    Here, elliptic flow (v2) values for identified particles at midrapidity in Au + Au collisions measured by the STAR experiment in the Beam Energy Scan at the Relativistic Heavy Ion Collider at √sNN = 7.7–62.4 GeV are presented for three centrality classes. The centrality dependence and the data at √sNN = 14.5 GeV are new. Except at the lowest beam energies, we observe a similar relative v2 baryon-meson splitting for all centrality classes which is in agreement within 15% with the number-of-constituent quark scaling. The larger v2 for most particles relative to antiparticles, already observed for minimum bias collisions, shows a clear centrality dependence, with the largest difference for the most central collisions. Also, the results are compared with a multiphase transport (AMPT) model and fit with a blast wave model.

  18. Research Perspectives at Jefferson Lab: 12 GeV and Beyond

    SciTech Connect

    Kees de Jager

    2002-09-01

    The plans for upgrading the CEBAF accelerator at Jefferson Lab to 12 GeV are presented. The research program supporting that upgrade are illustrated with a few selected examples. The instrumentation under design to carry out that research program is discussed. Finally, a conceptual design of a future upgrade which combines a 25 GeV fixed-target facility and an electron-ion collider facility at a luminosity of up to 10{sup 35}cm{sup -2}s{sup -1} and a CM energy of over 40 GeV.

  19. Comparison of virtual monoenergetic and polyenergetic images reconstructed from dual-layer detector CT angiography of the head and neck.

    PubMed

    Neuhaus, Victor; Große Hokamp, Nils; Abdullayev, Nuran; Maus, Volker; Kabbasch, Christoph; Mpotsaris, Anastasios; Maintz, David; Borggrefe, Jan

    2017-10-10

    To compare the image quality of virtual monoenergetic images and polyenergetic images reconstructed from dual-layer detector CT angiography (DLCTA). Thirty patients who underwent DLCTA of the head and neck were retrospectively identified and polyenergetic as well as virtual monoenergetic images (40 to 120 keV) were reconstructed. Signals (± SD) of the cervical and cerebral vessels as well as lateral pterygoid muscle and the air surrounding the head were measured to calculate the CNR and SNR. In addition, subjective image quality was assessed using a 5-point Likert scale. Student's t-test and Wilcoxon test were used to determine statistical significance. Compared to polyenergetic images, although noise increased with lower keV, CNR (p < 0.02) and SNR (p > 0.05) of the cervical, petrous and intracranial vessels were improved in virtual monoenergetic images at 40 keV and virtual monoenergetic images at 45 keV were also rated superior regarding vascular contrast, assessment of arteries close to the skull base and small arterial branches (p < 0.0001 each). Compared to polyenergetic images, virtual monoenergetic images reconstructed from DLCTA at low keV ranging from 40 to 45 keV improve the objective and subjective image quality of extra- and intracranial vessels and facilitate assessment of vessels close to the skull base and of small arterial branches. • Virtual monoenergetic images greatly improve attenuation, while noise only slightly increases. • Virtual monoenergetic images show superior contrast-to-noise ratios compared to polyenergetic images. • Virtual monoenergetic images significantly improve image quality at low keV.

  20. Value of monoenergetic low-kV dual energy CT datasets for improved image quality of CT pulmonary angiography.

    PubMed

    Apfaltrer, Paul; Sudarski, Sonja; Schneider, David; Nance, John W; Haubenreisser, Holger; Fink, Christian; Schoenberg, Stefan O; Henzler, Thomas

    2014-02-01

    High vessel attenuation and high contrast-to-noise ratio (CNR) are prerequisites for high diagnostic confidence in CT pulmonary angiography (CTPA). This study evaluated the impact of calculated monoenergetic dual-energy (DE) CTPA datasets on vessel attenuation and CNR. 50 Patients (24 men, mean age 68 ± 14 years) who underwent DE-CTPA were retrospectively included in this study. The 80 and 140-kV DE polyenergetic image data were used to calculate virtual monoenergetic image datasets in 10 kiloelectron volt (keV) increments from 40 to 120 keV. Vessel and soft tissue attenuation and image noise were measured in various regions of interest and the CNR was subsequently calculated. Differences in vessel attenuation and CNR were compared between the different monoenergetic datasets. The best monoenergetic dataset was then compared to the standard 120-kV polyenergetic dataset. Vessel attenuation and CNR of 70-keV CTPA datasets were superior to all other monoenergetic image datasets (all p<0.05). 70-keV monoenergetic datasets provided a statistically significant 12% increase in mean vessel attenuation compared to standard 120-kV polyenergetic datasets (384 ± 117 HU vs. 342 ± 106 HU, respectively; p<0.0001) and a statistically significant 18% increase in mean CNR (29 ± 13 vs. 24 ± 11 respectively; p<0.0001). Virtual 70-keV monoenergetic CTPA image datasets significantly increase vessel attenuation and CNR of DE-CTPA studies, suggesting that clinical application of low-keV monoenergetic reconstructions may allow a decrease in the amount of iodinated contrast required for adequate image quality in DE-CTPA examinations. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. The p + 9Be(thin target) reaction as a source of quasi-monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Novák, J.; Bém, P.; Majerle, M.; Mrázek, J.; Šimečková, E.; Štefánik, M.; Yasin, Z.

    2017-09-01

    The cyclotron driven fast quasi-monoenergetic neutron source based on the p+ 9Be (thin target) reaction was studied at the proton energy around 30 MeV Due to higher melting point of Be, the p+ 9Be(thin), reaction could be considered as an alternative to the most used p+Li(thin) neutron source, providing a similar quasi-monoenergetic neutron spectrum at significantly higher neutron output owing to advance in higher incident proton beam current. The neutron spectrum measured by the time-of-flight method agrees with other experimental data and indicates dominant contribution of ground and first excited states leading to only two peaks, separated by some 2-3 MeV, in the p+thin 9Be neutron spectrum.

  2. Multiple quasi-monoenergetic electron beams from laser-wakefield acceleration with spatially structured laser pulse

    SciTech Connect

    Ma, Y.; Li, M. H.; Li, Y. F.; Wang, J. G.; Tao, M. Z.; Han, Y. J.; Zhao, J. R.; Huang, K.; Yan, W. C.; Ma, J. L.; Li, Y. T.; Chen, L. M.; Li, D. Z.; Chen, Z. Y.; Sheng, Z. M.; Zhang, J.

    2015-08-15

    By adjusting the focus geometry of a spatially structured laser pulse, single, double, and treble quasi-monoenergetic electron beams were generated, respectively, in laser-wakefield acceleration. Single electron beam was produced as focusing the laser pulse to a single spot. While focusing the laser pulse to two spots that are approximately equal in energy and size and intense enough to form their own filaments, two electron beams were produced. Moreover, with a proper distance between those two focal spots, three electron beams emerged with a certain probability owing to the superposition of the diffractions of those two spots. The energy spectra of the multiple electron beams are quasi-monoenergetic, which are different from that of the large energy spread beams produced due to the longitudinal multiple-injection in the single bubble.

  3. Observation of monoenergetic protons from a near-critical gas target tailored by a hydrodynamic shock

    NASA Astrophysics Data System (ADS)

    Chen, Y.-H.; Helle, M. H.; Ting, A.; Gordon, D. F.; Polyanskiy, M. N.; Pogorelsky, I.; Babzien, M.; Najmudin, Z.

    2015-05-01

    We present our recent experimental results of monoenergetic protons accelerated from the interaction of an intense terawatt CO2 laser pulse with a near-critical hydrogen gas target, with its density profile tailored by a hydrodynamic shock. A 5-ns Nd:YAG laser pulse is focused onto a piece of stainless steel foil mounted at the front edge of the gas jet nozzle orifice. The ablation launches a spherical shock into the near-critical gas column, which creates a sharp density gradient at the front edge of the target, with ~ 6X local density enhancement up to several times of critical density within ~<100 microns. With such density profile, we have obtained monoenergetic proton beams with good shot-to-shot reproducibility and energies up to 1.2 MeV.

  4. Tumor induction by monoenergetic neutrons in B6C3F1 mice.

    PubMed

    Watanabe, Hiromitsu; Kashimoto, Naoki; Kajimura, Junko; Ishikawa, Masayori; Kamiya, Kenji

    2007-05-01

    This study was undertaken to investigate induction of tumors by monoenergetic neutrons in B6C3F1 mice. Individual groups of 6 week-old animals of both sexes (about 30 mice/group) were exposed to 0.5 Gy of various monoenergetic neutrons (dose rate 0.5 cGy/min) and then observed for 13 months. The incidences of tumors (mainly liver neoplasms) in non-irradiated male and female controls were 11% and 0%, respectively. In the irradiated animals, the incidences were 53%, 50%, 60% and 43% in males, and 75%, 81%, 71%, and 85% in females, after 0.18, 0.32, 0.6 and 1.0 MeV neutron exposure, respectively. There were no significant differences in the tumor induction rate among the different energy groups.

  5. Characterization of Bonner sphere systems at monoenergetic and thermal neutron fields.

    PubMed

    Lacoste, V; Gressier, V; Pochat, J-L; Fernández, F; Bakali, M; Bouassoule, T

    2004-01-01

    The Institute for Radiological Protection and Nuclear Safety (IRSN) and the GFR, Universitat Autónoma de Barcelona (UAB) use Bonner spheres (BS) for neutron spectrometry at workplaces. The two systems, equipped with similar cylindrical 3He proportional counters, were simulated with the MCNP Monte-Carlo code to determine the response to neutrons of different energies for each polyethylene sphere. The BS systems were characterized at monoenergetic and thermal neutron fields. Measurements were performed at the Physikalisch-Technische Bundesanstalt (PTB) and at the National Physical Laboratory (NPL) standard laboratories, and with the newly characterized IRSN 'SIGMA' thermal neutron facility. The energy distribution of the reference neutron fluence was folded with the response functions for comparison purposes with the experimental data. In almost all cases related to monoenergetic neutrons, a good agreement between the experimental and the calculated count rates was found, and some discrepancies of a few per cent were observed in the thermal region.

  6. Solutions of Boltzmann`s Equation for Mono-energetic Neutrons in an Infinite Homogeneous Medium

    DOE R&D Accomplishments Database

    Wigner, E. P.

    1943-11-30

    Boltzman's equation is solved for the case of monoenergetic neutrons created by a plane or point source in an infinite medium which has spherically symmetric scattering. The customary solution of the diffusion equation appears to be multiplied by a constant factor which is smaller than 1. In addition to this term the total neutron density contains another term which is important in the neighborhood of the source. It varies as 1/r{sup 2} in the neighborhood of a point source. (auth)

  7. Response functions of Fuji imaging plates to monoenergetic protons in the energy range 0.6-3.2 MeV

    SciTech Connect

    Bonnet, T.; Denis-Petit, D.; Gobet, F.; Hannachi, F.; Tarisien, M.; Versteegen, M.; Aleonard, M. M.

    2013-01-15

    We have measured the responses of Fuji MS, SR, and TR imaging plates (IPs) to protons with energies ranging from 0.6 to 3.2 MeV. Monoenergetic protons were produced with the 3.5 MV AIFIRA (Applications Interdisciplinaires de Faisceaux d'Ions en Region Aquitaine) accelerator at the Centre d'Etudes Nucleaires de Bordeaux Gradignan (CENBG). The IPs were irradiated with protons backscattered off a tantalum target. We present the photo-stimulated luminescence response of the IPs together with the fading measurements for these IPs. A method is applied to allow correction of fading effects for variable proton irradiation duration. Using the IP fading corrections, a model of the IP response function to protons was developed. The model enables extrapolation of the IP response to protons up to proton energies of 10 MeV. Our work is finally compared to previous works conducted on Fuji TR IP response to protons.

  8. Calibration of Cherenkov detectors for monoenergetic photon imaging in active interrogation applications

    NASA Astrophysics Data System (ADS)

    Rose, P. B.; Erickson, A. S.

    2015-11-01

    Active interrogation of cargo containers using monoenergetic photons offers a rapid and low-dose approach to search for shielded special nuclear materials. Cherenkov detectors can be used for imaging of the cargo provided that gamma ray energies used in interrogation are well resolved, as the case in 11B(d,n-γ)12C reaction resulting in 4.4 MeV and 15.1 MeV photons. While an array of Cherenkov threshold detectors reduces low energy background from scatter while providing the ability of high contrast transmission imaging, thus confirming the presence of high-Z materials, these detectors require a special approach to energy calibration due to the lack of resolution. In this paper, we discuss the utility of Cherenkov detectors for active interrogation with monoenergetic photons as well as the results of computational and experimental studies of their energy calibration. The results of the studies with sources emitting monoenergetic photons as well as complex gamma ray spectrum sources, for example 232Th, show that calibration is possible as long as the energies of photons of interest are distinct.

  9. [A Generator of Mono-energetic Electrons for Response Test of Charged Particle Detectors.].

    PubMed

    Matsubayashi, Fumiyasu; Yoshida, Katsuhide; Maruyama, Koichi

    2005-01-01

    We designed and fabricated a generator of mono-energetic electrons for the response test of charged particle detectors, which is used to measure fragmented particles of the carbon beam for cancer therapy. Mono-energetic electrons are extracted from (90)Sr by analyzing the energy of beta rays in the generator with a magnetic field. We evaluated performance parameters of the generator such as the absolute energy, the energy resolution and the counting rates of extracted electrons. The generator supplies mono-energetic electrons from 0.5MeV to 1.7MeV with the energy resolution of 20% in FWHM at higher energies than 1.0MeV. The counting rate of electrons is 400cpm at the maximum when the activity of (90)Sr is 298kBq. The generator was used to measure responses of fragmented-particle detectors and to determine the threshold energy of the detectors. We evaluated the dependence of pulse height variation on the detector position and the threshold energy by using the generator. We concluded this generator is useful for the response test of general charged particle detectors.

  10. Progress in collisions of multiply charged ions

    SciTech Connect

    Phaneuf, R.A.

    1991-01-01

    The increasing power and availability of supercomputers during the last decade led to significant progress in the theory of multicharged ion interactions. However, important tests of many theoretical predictions were lacking, and have become possible only quite recently as new capabilities have been realized in the laboratory. This paper broadly surveys some of these experimental developments, and their impact on our understanding of collisional interactions of multicharged ions. The scope is limited to measurements made with monoenergetic beams. 35 refs., 6 figs.

  11. The 12 GeV Energy Upgrade at Jefferson Laboratory

    SciTech Connect

    Pilat, Fulvia C.

    2012-09-01

    Two new cryomodules and an extensive upgrade of the bending magnets at Jefferson Lab has been recently completed in preparation for the full energy upgrade in about one year. Jefferson Laboratory has undertaken a major upgrade of its flagship facility, the CW re-circulating CEBAF linac, with the goal of doubling the linac energy to 12 GeV. I will discuss here the main scope and timeline of the upgrade and report on recent accomplishments and the present status. I will then discuss in more detail the core of the upgrade, the new additional C100 cryomodules, their production, tests and recent successful performance. I will then conclude by looking at the future plans of Jefferson Laboratory, from the commissioning and operations of the 12 GeV CEBAF to the design of the MEIC electron ion collider.

  12. Optimization of kiloelectron volt settings in cerebral and cervical dual-energy CT angiography determined with virtual monoenergetic imaging.

    PubMed

    Schneider, David; Apfaltrer, Paul; Sudarski, Sonja; Nance, John W; Haubenreisser, Holger; Fink, Christian; Schoenberg, Stefan O; Henzler, Thomas

    2014-04-01

    Dual-energy computed tomography (DECT) offers various fields of application, especially in angiography using virtual monoenergetic imaging. The aim of this study was to evaluate objective image quality indices of calculated low-kiloelectron volt monoenergetic DECT angiographic cervical and cerebral data sets compared to virtual 120-kV polyenergetic images. Forty-one patients (21 men, mean age 58 ± 14) who underwent DECT angiography of the cervical (n = 7) or cerebral vessels (n = 34) were retrospectively included in this study. Data acquired with the 80 and 140 kVp tube using dual-source CT technology were subsequently used to calculate low-kiloelectron volt monoenergetic image data sets ranging from 120 to 40 keV (at 10-keV intervals per patient). Vessel and soft tissue attenuation and image noise were measured in various regions of interest, and contrast-to-noise ratio (CNR) was subsequently calculated. Differences in image attenuation and CNR were compared between the different monoenergetic data sets and virtual 120-kV polyenergetic images. For cervical angiography, 60-keV monoenergetic data sets resulted in the greatest improvements in vessel attenuation and CNR compared to virtual 120-kV polyenergetic data sets (+40%, +16%; all P < .01). Also for cerebral vessel assessment, 60-keV monoenergetic data sets provided the greatest improvement in vessel attenuation and CNR (+40%, +9%; all P < .01) compared to virtual 120-kV polyenergetic data sets. 60-keV monoenergetic image data significantly improve vessel attenuation and CNR of cervical and cerebral DECT angiographic studies. Future studies have to evaluate whether the technique can lead to an increased diagnostic accuracy or should be used for dose reduction of iodinated contrast material. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  13. Spin alignment measurements of the K{sup *0}(892) and {sup}{o}(1020) vector mesons in heavy ion collisions at {radical}{ovr s}{sub NN}=200 GeV.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration; High Energy Physics; Univ. of Illinois; Panjab Univ.; Variable Energy Cyclotron Centre; Kent State Univ.; Particle Physic Lab.

    2008-01-01

    We present the first spin alignment measurements for the K*{sup 0}(892) and (1020) vector mesons produced at midrapidity with transverse momenta up to 5 GeV/c at {radical}s{sub NN} = 200 GeV at RHIC. The diagonal spin-density matrix elements with respect to the reaction plane in Au+Au collisions are {rho}{sub 00} = 0.32 {+-} 0.04 (stat) {+-} 0.09 (syst) for the K*{sup 0} (0.8 < p{sub T} < 5.0 GeV/c) and {rho}{sub 00} = 0.34 {+-} 0.02 (stat) {+-} 0.03 (syst) for the {phi} (0.4 < p{sub T} < 5.0 GeV/c) and are constant with transverse momentum and collision centrality. The data are consistent with the unpolarized expectation of 1/3 and thus no evidence is found for the transfer of the orbital angular momentum of the colliding system to the vector-meson spins. Spin alignments for K*{sup 0} and {phi} in Au+Au collisions were also measured with respect to the particle's production plane. The {phi} result, {rho}{sub 00} = 0.41 {+-} 0.02 (stat) {+-} 0.04 (syst), is consistent with that in p+p collisions, {rho}{sub 00} = 0.39 {+-} 0.03 (stat) {+-} 0.06 (syst), also measured in this work. The measurements thus constrain the possible size of polarization phenomena in the production dynamics of vector mesons.

  14. Isotope-specific detection of low density materials with mono-energetic (gamma)-rays

    SciTech Connect

    Albert, F; Anderson, S G; Gibson, D J; Hagmann, C A; Johnson, M S; Messerly, M J; Semenov, V A; Shverdin, M Y; Tremaine, A M; Hartemann, F V; Siders, C W; McNabb, D P; Barty, C J

    2009-03-16

    The first demonstration of isotope-specific detection of a low-Z, low density object, shielded by a high-Z and high density material using mono-energetic gamma-rays is reported. Isotope-specific detection of LiH shielded by Pb and Al is accomplished using the nuclear resonance fluorescence line of {sup 7}Li at 0.478 MeV. Resonant photons are produced via laser-based Compton scattering. The detection techniques are general and the confidence level obtained is shown to be superior to that yielded by conventional x-ray/{gamma}-ray techniques in these situations.

  15. Monoenergetic collimated nano-Coulomb electron beams driven by crossed laser beams

    SciTech Connect

    Wang Jingwei; Murakami, M.; Weng, S. M.; Ruhl, H.; Luan Shixia; Yu Wei

    2013-07-08

    Monoenergetic collimated electron acceleration by two crossed laser beams is investigated through an analytical model and particle-in-cell simulations. Electron bunches with a total charge of order nano-Coulombs are accelerated by the axial electric field formed by the crossed laser beams to nearly 760 MeV with an energy spread of 2.7%. The transverse components of both electric and magnetic fields vanish along the axis, making the electron beam highly collimated. This acceleration scheme appears promising in producing high quality electron beams.

  16. Filtered epithermal quasi-monoenergetic neutron beams at research reactor facilities.

    PubMed

    Mansy, M S; Bashter, I I; El-Mesiry, M S; Habib, N; Adib, M

    2015-03-01

    Filtered neutron techniques were applied to produce quasi-monoenergetic neutron beams in the energy range of 1.5-133keV at research reactors. A simulation study was performed to characterize the filter components and transmitted beam lines. The filtered beams were characterized in terms of the optimal thickness of the main and additive components. The filtered neutron beams had high purity and intensity, with low contamination from the accompanying thermal emission, fast neutrons and γ-rays. A computer code named "QMNB" was developed in the "MATLAB" programming language to perform the required calculations.

  17. Oncogenic transformation following sequential irradiations with monoenergetic neutrons and X rays.

    PubMed

    Miller, R C; Geard, C R; Marino, S A; Richards, M; Randers-Pehrson, G

    1991-03-01

    Mouse C3H 10T1/2 cells were exposed sequentially to low doses (0.1 and 0.3 Gy) of monoenergetic neutrons (0.35, 0.45, 5.9, and 13.7 MeV) and 250-kVp X rays (1 and 3 Gy). The incidences of oncogenic transformation in the cells exposed to neutrons followed by X rays indicated that the effects of the individual radiations were simply additive. This supports the contention that risks associated with the two different radiation modalities may be considered to be additive.

  18. Computational modeling of monoenergetic neutral particle inverse transport problems in slab geometry

    NASA Astrophysics Data System (ADS)

    Gomes, Rodrigo R.; Barros, Ricardo C.

    2012-09-01

    Presented here is an analytical numerical method applied to three different types of monoenergetic neutral particle inverse transport problems in the discrete ordinates (SN) formulation: (a) boundary condition estimation; (b) interior source estimation; and (c) effective slab length estimation. These three types of inverse problems governed by the linear integrodifferential transport equation in SN formulation are related respectively to medical physics (a); nuclear waste storage (b); and non-destructive testing in industry (c). Numerical results and a brief discussion are given to conclude this paper.

  19. Potential formation in front of an electron emitting electrode immersed in a plasma that contains a monoenergetic electron beam

    SciTech Connect

    Gyergyek, T.; Kovacic, J.; Cercek, M.

    2010-08-15

    A one-dimensional fluid model of the sheath formation in front of a large, planar electron emitting electrode (collector) immersed in a plasma that contains a monoenergetic electron beam is presented. Expressions for the Bohm criterion, the total electric current to the collector, and for the zero electric field at the collector are derived. When there is no electron emission, the model predicts, in some cases, up to three different solutions. The low and the high solutions correspond to the fact that the presheath potential drop can be determined either by thermal or by the beam electrons. The middle solution between them has no physical meaning. When the electron emission is space charge limited, the model may have up to five solutions because the low solution can sometimes split into three parts. The current-voltage characteristic of the collector that exhibits triple floating potential is calculated and it shows qualitative similarity with experimental ones [C.-H. Nam et al., J. Appl. Phys. 63, 5674 (1988)]. When the emission is below the space charge limit, the model again exhibits up to five solutions, which are the low, middle, high, and two additional 'singularity solutions'. These two appear because of the singularity in the Bohm criterion. Regions of validity of the low and high solutions are determined from numerical solutions of the Poisson equation [T. Gyergyek et al., Plasma Sources Sci. Technol. 18, 035001 (2009)] and with the maximum positive ion flux test [J. I. Fernandez Palop et al., J. Appl. Phys. 91, 2587 (2002)]. In the case of no or small emission, both methods give the same results. If the emission is space charge limited, the numerical solution method is much more reliable.

  20. Quasi-monoenergetic proton beam from a proton-layer embedded metal foil irradiated by an intense laser pulse

    SciTech Connect

    Kim, Kyung Nam; Lee, Kitae Kumar, Manoj; Kim, Ha-Na; Park, Seong Hee; Jeong, Young Uk; Vinokurov, Nikolay; Kim, Yong Gi

    2016-03-15

    A target structure, ion-layer embedded foil (ILEF) is proposed for producing a quasi-monoenergetic proton beam by utilizing a bulk electrostatic field, which is generated by irradiating the target with an ultra-intense laser pulse, inside the plasma. Compared with the case of a single metal foil in which the proton layer is initially present on the surface, in the ILEF target, the proton layer is initially located inside a metal foil. A two-dimensional particle-in-cell (PIC) simulation shows that the target generates a proton beam with a narrow energy spread. With a laser intensity of 2 × 10{sup 19 }W/cm{sup 2}, a 22-MeV proton beam with an energy spread of 8% at the full-width-half-maximum (FWHM) is obtained when the proton layer is located at 0.4 μm inside the rear surface of a 2.4 μm-thick copper foil. When the proton layer moves toward the front side, a proton beam with a flat-top energy distribution ranging from 15 MeV to 35 MeV is obtained. Further, with a higher laser intensity of 10{sup 21 }W/cm{sup 2}, a proton beam with the maximum energy of 345 MeV and FWHM energy spread of 7.2% is obtained. The analysis of the PIC simulation with an aid of a fluid analysis shows that the spectrum is affected by the initial position of the proton layer, its initial spread during the formation of the sheath field, and the space charge effect.

  1. Effects of a monoenergetic electron beam on the sheath formation in a plasma with a q-nonextensive electron velocity distribution

    NASA Astrophysics Data System (ADS)

    Arghand-Hesar, A.; Esfandyari-Kalejahi, A.; Akbari-Moghanjoughi, M.

    2017-06-01

    The characteristics of a plasma sheath consisting of nonextensive electrons and thermal ions in the presence of a monoenergetic electron beam is studied in the framework of a one dimensional hydrodynamic model. Because of the electron beam, bulk electron distribution of plasma is assumed to be non-Maxwellian in general. Using the Sagdeev pseudopotential method, a modified Bohm criterion is obtained. It is shown that the criterion is significantly affected by the nonextensivity degree (q) and the beam parameters. The criterion is reduced to the standard form of the Bohm criterion when (i) the electrons have Maxwellian distribution ( q → 1 ), and (ii) the beam density is taken to be zero. A small amplitude analytical solution is also given for the potential in the sheath region. Moreover, assuming the total current on the electrode surface to be negligible, the floating potential is derived. The set of nonlinear hydrodynamic equations is solved numerically and the effects of many parameters such as nonextensivity, beam density, and velocity on the electric potential of the sheath region, ion density, and sheath thickness are studied. It is shown that the electron beam can control the potential and ion density of the sheath region.

  2. Benchmarking of the mono-energetic transport coefficients—results from the International Collaboration on Neoclassical Transport in Stellarators (ICNTS)

    NASA Astrophysics Data System (ADS)

    Beidler, C. D.; Allmaier, K.; Isaev, M. Yu.; Kasilov, S. V.; Kernbichler, W.; Leitold, G. O.; Maaßberg, H.; Mikkelsen, D. R.; Murakami, S.; Schmidt, M.; Spong, D. A.; Tribaldos, V.; Wakasa, A.

    2011-07-01

    Numerical results for the three mono-energetic transport coefficients required for a complete neoclassical description of stellarator plasmas have been benchmarked within an international collaboration. These transport coefficients are flux-surface-averaged moments of solutions to the linearized drift kinetic equation which have been determined using field-line-integration techniques, Monte Carlo simulations, a variational method employing Fourier-Legendre test functions and a finite-difference scheme. The benchmarking has been successfully carried out for past, present and future devices which represent different optimization strategies within the extensive configuration space available to stellarators. A qualitative comparison of the results with theoretical expectations for simple model fields is provided. The behaviour of the results for the mono-energetic radial and parallel transport coefficients can be largely understood from such theoretical considerations but the mono-energetic bootstrap current coefficient exhibits characteristics which have not been predicted.

  3. Evaluation of a personal and environmental dosemeter based on CR-39 track detectors in quasi-monoenergetic neutron fields.

    PubMed

    Caresana, M; Ferrarini, M; Parravicini, A; Sashala Naik, A

    2014-10-01

    In this paper, the evaluation of the dosimetric capability of a detector based on a CR-39 solid-state nuclear track detector coupled to a 1 cm thickness of PMMA radiator was made with the aim of understanding the applicability of this technique to personal and environmental neutron dosimetry. The dosemeter has been exposed to monoenergetic and quasi-monoenergetic neutron beams at PTB in Braunschweig, Germany and at Ithemba Laboratories, in Faure, South Africa, with peak energies ranging from 0.565 to 100 MeV. The results showed a response that is almost independent of the neutron energy in the whole energy range.

  4. Dual-Energy Computed Tomography Virtual Monoenergetic Imaging of Lung Cancer: Assessment of Optimal Energy Levels.

    PubMed

    Kaup, Moritz; Scholtz, Jan-Erik; Engler, Alexander; Albrecht, Moritz H; Bauer, Ralf W; Kerl, J Matthias; Beeres, Martin; Lehnert, Thomas; Vogl, Thomas J; Wichmann, Julian L

    2016-01-01

    The aim of the study was to evaluate objective and subjective image qualities of virtual monoenergetic imaging (VMI) in dual-source dual-energy computed tomography (DECT) and optimal kiloelectron-volt (keV) levels for lung cancer. Fifty-nine lung cancer patients underwent chest DECT. Images were reconstructed as VMI series at energy levels of 40, 60, 80, and 100 keV and standard linear blending (M_0.3) for comparison. Objective and subjective image qualities were assessed. Lesion contrast peaked in 40-keV VMI reconstructions (2.5 ± 2.9) and 60 keV (1.9 ± 3.0), which was superior to M_0.3 (0.5 ± 2.7) for both comparisons (P < 0.001). Compared with M_0.3, subjective ratings were highest for 60-keV VMI series regarding general image quality (4.48 vs 4.52; P = 0.74) and increased for lesion demarcation (4.07 vs 4.84; P < 0.001), superior to all other VMI series (P < 0.001). Image sharpness was similar between both series. Image noise was rated superior in the 80-keV and M_0.3 series, followed by 60 keV. Virtual monoenergetic imaging reconstructions at 60-keV provided the best combination of subjective and objective image qualities in DECT of lung cancer.

  5. LASER TECHNOLOGY FOR PRECISION MONOENERGETIC GAMMA-RAY SOURCE R&D AT LLNL

    SciTech Connect

    Shverdin, M Y; Bayramian, A; Albert, F; Anderson, S G; Betts, S M; Chu, T S; Cross, R R; Gibson, D J; Marsh, R; Messerly, M; Phan, H; Prantil, M; Wu, S; Ebbers, C; Scarpetti, R D; Hartemann, F V; Siders, C W; McNabb, D P; Bonanno, R E; Barty, C P

    2010-04-20

    Generation of mono-energetic, high brightness gamma-rays requires state of the art lasers to both produce a low emittance electron beam in the linac and high intensity, narrow linewidth laser photons for scattering with the relativistic electrons. Here, we overview the laser systems for the 3rd generation Monoenergetic Gamma-ray Source (MEGa-ray) currently under construction at Lawrence Livermore National Lab (LLNL). We also describe a method for increasing the efficiency of laser Compton scattering through laser pulse recirculation. The fiber-based photoinjector laser will produce 50 {micro}J temporally and spatially shaped UV pulses at 120 Hz to generate a low emittance electron beam in the X-band RF photoinjector. The interaction laser generates high intensity photons that focus into the interaction region and scatter off the accelerated electrons. This system utilizes chirped pulse amplification and commercial diode pumped solid state Nd:YAG amplifiers to produce 0.5 J, 10 ps, 120 Hz pulses at 1064 nm and up to 0.2 J after frequency doubling. A single passively mode-locked Ytterbium fiber oscillator seeds both laser systems and provides a timing synch with the linac.

  6. Green`s function method for the monoenergetic transport equation in heterogeneous plane geometry

    SciTech Connect

    Ganapol, B.D.

    1995-12-31

    For the past several years, a series of papers by the transport group at the University of Arizona dealing with benchmark solutions of the monoenergetic transport equation has appeared. The approach has been to take advantage of highly successful numerical Laplace Fourier transform inversions to provide benchmark quality solutions in infinite media, half-space in one and two dimensions and in homogeneous slabs. This paper extends the set of solutions to include heterogeneous slab geometry by using the recently established Green`s Function Method (GFM). Analytical benchmark solutions are an essential part of the quality control of computational algorithms developed for particle transport. In addition, benchmarking methods have applications in the classroom by providing examples of how computational mathematics is used to solve physical problems to obtain meaningful answers. In a structural context, monoenergetic solutions are directly applicable to the investigation of the microlight environment within a leaf. The leaf is considered to be a composition of alternating layers of highly absorbing pigments and water superimposed on a refractively scattering background.

  7. The interaction of quasi-monoenergetic protons with pre-compressed inertial fusion fuels

    NASA Astrophysics Data System (ADS)

    Mahdavi, M.; Koohrokhi, T.; Azadifar, R.

    2012-08-01

    The interaction of a quasi-monoenergetic proton beam with a pre-compressed plasma is studied in the context of inertial fusion fast ignition (FI). Based on fundamental principles, a kinetic model is developed by considering hard collisions, nuclear scattering, and the contribution due to collective processes. The penetration depth, longitudinal straggling, and the transverse blooming are evaluated by solving the Boltzmann transport equation using the multiple scattering theory. The stopping power, transport scattering cross sections, and convenient expressions for the angular moments of the proton distribution function have been used in modeling the collisional proton transport in a three-dimensional (3D) Monte Carlo code. The transport of a proton beam with a quasi-monoenergetic energy ⟨E⟩=10 MeV is studied for pre-compressed deuterium-tritium plasma with an average density of ρ =400 g cm-3 and temperatures T =1 keV, 5 keV, and 10 keV. The net effects of multiple scattering are to reduce the penetration from 1.028 to 0.828 g cm-2 with range straggling ρΣR=0.044 g cm-2 and beam blooming ρΣB=0.272 g cm-2, for 10 MeV protons in a ρ =400 gcm-3 plasma at T = 5 keV. This model can be used for quantitatively assessing ignition requirements for proton fast ignition.

  8. Monoenergetic Particle backlighter for Radiography and measuring E and B fields and Plasma Areal density

    NASA Astrophysics Data System (ADS)

    Petrasso, R. D.; Li, C. K.; Séguin, F. H.; Frenje, J. A.; Rygg, J. R.; Manuel, M.; Smalyuk, V.; Betti, R.; Craxton, S.; Knauer, J. P.; Marshall, F. J.; Meyerhofer, D. D.; Myatt, J.; Radha, P. B.; Sangster, T. C.; Theobald, W.; Town, R. P. J.; Amendt, P.; Celliers, P.; Hatchett, S.; Hicks, D.; Landen, O.; MacKinnon, A.; Patel, P.; Tabak, M.

    2006-10-01

    J.COBBLE, N.M. HOFFMAN, G.A. KYRALA, D.C. WILSON, LANL; R. STEPHENS, J. KILKENNY, GA--A novel monoenergetic particle backlighter source (14.7 and 3.0 MeV P, 3.5 and 0.8 MeV α, and 1.0 MeV T), has been utilized at OMEGA to quantitatively measure the evolution of electric (E) and magnetic (B) fields generated by laser-plasma interactions, and will be utilized in the near future to radiograph plasmas and fields generated from fast ignitor implosions, magnetic compression experiments, magnetized foil experiments, hohlraums and, more generally, from 2- and 3-D laser-plasmas. The backlighter consists of an exploding-pusher glass micro-balloon, filled with D^3He, in which a fraction of the OMEGA 60-beams are used to drive the implosion. The width of the spectral line, ˜ 3%, is determined by the burn temperature (˜ 10 keV); the monoenergetic character, as well as multiple particles, enables unique discrimination between E and B fields; it further allows for the probing of cold (warm) plasmas with areal densities of order 1 (10) to 200 (1000) mg/cm**2. New results and planned experiments will be presented.

  9. Dual-fission chamber and neutron beam characterization for fission product yield measurements using monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Bhatia, C.; Fallin, B.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.; Arnold, C. W.; Bond, E. M.; Bredeweg, T. A.; Fowler, M. M.; Moody, W. A.; Rundberg, R. S.; Rusev, G.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Macri, R.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.

    2014-09-01

    A program has been initiated to measure the energy dependence of selected high-yield fission products used in the analysis of nuclear test data. We present out initial work of neutron activation using a dual-fission chamber with quasi-monoenergetic neutrons and gamma-counting method. Quasi-monoenergetic neutrons of energies from 0.5 to 15 MeV using the TUNL 10 MV FM tandem to provide high-precision and self-consistent measurements of fission product yields (FPY). The final FPY results will be coupled with theoretical analysis to provide a more fundamental understanding of the fission process. To accomplish this goal, we have developed and tested a set of dual-fission ionization chambers to provide an accurate determination of the number of fissions occurring in a thick target located in the middle plane of the chamber assembly. Details of the fission chamber and its performance are presented along with neutron beam production and characterization. Also presented are studies on the background issues associated with room-return and off-energy neutron production. We show that the off-energy neutron contribution can be significant, but correctable, while room-return neutron background levels contribute less than <1% to the fission signal.

  10. The interaction of quasi-monoenergetic protons with pre-compressed inertial fusion fuels

    SciTech Connect

    Mahdavi, M.; Koohrokhi, T.; Azadifar, R.

    2012-08-15

    The interaction of a quasi-monoenergetic proton beam with a pre-compressed plasma is studied in the context of inertial fusion fast ignition (FI). Based on fundamental principles, a kinetic model is developed by considering hard collisions, nuclear scattering, and the contribution due to collective processes. The penetration depth, longitudinal straggling, and the transverse blooming are evaluated by solving the Boltzmann transport equation using the multiple scattering theory. The stopping power, transport scattering cross sections, and convenient expressions for the angular moments of the proton distribution function have been used in modeling the collisional proton transport in a three-dimensional (3D) Monte Carlo code. The transport of a proton beam with a quasi-monoenergetic energy =10 MeV is studied for pre-compressed deuterium-tritium plasma with an average density of {rho}=400 g cm{sup -3} and temperatures T=1 keV, 5 keV, and 10 keV. The net effects of multiple scattering are to reduce the penetration from 1.028 to 0.828 g cm{sup -2} with range straggling {rho}{Sigma}{sub R}=0.044 g cm{sup -2} and beam blooming {rho}{Sigma}{sub B}=0.272 g cm{sup -2}, for 10 MeV protons in a {rho}=400 g cm{sup -3} plasma at T = 5 keV. This model can be used for quantitatively assessing ignition requirements for proton fast ignition.

  11. Monoenergetic beams of relativistic electrons from intense laser-plasma interactions.

    PubMed

    Mangles, S P D; Murphy, C D; Najmudin, Z; Thomas, A G R; Collier, J L; Dangor, A E; Divall, E J; Foster, P S; Gallacher, J G; Hooker, C J; Jaroszynski, D A; Langley, A J; Mori, W B; Norreys, P A; Tsung, F S; Viskup, R; Walton, B R; Krushelnick, K

    2004-09-30

    High-power lasers that fit into a university-scale laboratory can now reach focused intensities of more than 10(19) W cm(-2) at high repetition rates. Such lasers are capable of producing beams of energetic electrons, protons and gamma-rays. Relativistic electrons are generated through the breaking of large-amplitude relativistic plasma waves created in the wake of the laser pulse as it propagates through a plasma, or through a direct interaction between the laser field and the electrons in the plasma. However, the electron beams produced from previous laser-plasma experiments have a large energy spread, limiting their use for potential applications. Here we report high-resolution energy measurements of the electron beams produced from intense laser-plasma interactions, showing that--under particular plasma conditions--it is possible to generate beams of relativistic electrons with low divergence and a small energy spread (less than three per cent). The monoenergetic features were observed in the electron energy spectrum for plasma densities just above a threshold required for breaking of the plasma wave. These features were observed consistently in the electron spectrum, although the energy of the beam was observed to vary from shot to shot. If the issue of energy reproducibility can be addressed, it should be possible to generate ultrashort monoenergetic electron bunches of tunable energy, holding great promise for the future development of 'table-top' particle accelerators.

  12. Baryon number fluctuations from a crossover equation of state compared to heavy-ion collision measurements in the beam energy range √{sNN}=7.7 to 200 GeV

    NASA Astrophysics Data System (ADS)

    Albright, M.; Kapusta, J.; Young, C.

    2015-10-01

    Fluctuations of the proton number distribution in central Au-Au collisions have been measured by the STAR Collaboration in a beam energy scan at the Relativistic Heavy Ion Collider (RHIC). The motivation is a search for evidence of a critical point in the equation of state. It was found that the skewness and kurtosis display an interesting energy dependence. We compare these measurements to an equation of state which smoothly interpolates between an excluded volume hadron resonance gas at low energy density to a perturbative plasma of quarks and gluons at high energy density. This crossover equation of state agrees very well with the lattice QCD equation of state. The crossover equation of state can reproduce the data if the fluctuations are frozen at a temperature significantly lower than the average chemical freeze-out.

  13. Fragmentation of nitrogen-14 nuclei at 2.1 Gev per nucleon.

    NASA Technical Reports Server (NTRS)

    Heckman, H. H.; Greiner, D. E.; Lindstrom, P. J.; Bieser, F. S.

    1971-01-01

    An experiment has been carried out at the bevatron on the nuclear fragmentation of nitrogen-14 ions at an energy of 2.1 billion electron volts (Gev) per nucleon. Because of the near equality of the velocities of the nitrogen-14 beam and the fragmentation products at an angle of 0 deg, we find it possible to identify the nuclear fragments isotopically.

  14. Fragmentation of N-14 nuclei at 29 GeV - Inclusive isotope spectra at 0 deg.

    NASA Technical Reports Server (NTRS)

    Heckman, H. H.; Greiner, D. E.; Lindstrom, P. J.; Bieser, F. S.

    1972-01-01

    We report the first results of a Bevatron heavy-ion experiment on the inclusive spectra of isotopically identified nuclei 3(Z-range between 3 and 7), produced by the fragmentation of 29-GeV N-14 ions in carbon and hydrogen. The preliminary values of the partial differential cross sections at 0 deg give evidence that the modes of fragmentation of N-14 projectiles are independent of the target nucleus.

  15. Chromosome aberrations in human fibroblasts induced by monoenergetic neutrons. I. Relative biological effectiveness.

    PubMed

    Pandita, T K; Geard, C R

    1996-06-01

    The relative biological effectiveness (RBE) of neutrons for many biological end points varies with neutron energy. To test the hypothesis that the RBE of neutrons varies with respect to their energy for chromosome aberrations in a cell system that does not face interphase death, we studied the yield of chromosome aberrations induced by monoenergetic neutrons in normal human fibroblasts at the first mitosis postirradiation. Monoenergetic neutrons at 0.22, 0.34, 0.43, 1, 5.9 and 13.6 MeV were generated at the Accelerator Facility of the Center for Radiological Research, Columbia University, and were used to irradiate plateau-phase fibroblasts at low absorbed doses from 0.3 to 1.2 Gy at a low dose rate. The reference low-LET, low-dose-rate radiation was 137Cs-gamma rays (0.66 MeV). A linear dose response (Y = alphaD) for chromosome aberrations was obtained for all monoenergetic neutrons and for the gamma rays. The yield of chromosome aberrations per unit dose was high at low neutron energies (0.22, 0.34 and 0.43 MeV) with a gradual decline with the increase in neutron energy. Maximum RBE (RBEm) values varied for the different types of chromosome aberrations. The highest RBE (24.3) for 0.22 and 0.43 MeV neutrons was observed for intrachromosomal deletions, a category of chromosomal change common in solid tumors. Even for the 13.6 MeV neutrons the RBEm (11.1) exceeded 10. These results show that the RBE of neutrons varies with neutron energy and that RBEs are dissimilar between different types of asymmetric chromosome aberrations and suggest that the radiation weighting factors applicable to low-energy neutrons need firmer delineation. This latter may best be attained with neutrons of well-defined energies. This would enable integrations of appropriate quality factors with measured radiation fields, such as those in high-altitude Earth atmosphere. The introduction of commercial flights at high altitude could result in many more individuals being exposed to neutrons than

  16. Measurement of reaction rate distributions in a plastic phantom irradiated by 40- and 65-MEV quasi-monoenergetic neutrons.

    PubMed

    Nakane, Y; Nakashima, H; Sakamoto, Y; Tanaka, S

    1997-01-01

    Reaction rate distributions in a plastic phantom were measured with solid state nuclear track detectors and a fission counter for 40- and 65-MeV quasi-monoenergetic neutrons generated by the 7Li(p,n) reactions with 43- and 68-MeV protons at AVF cyclotron of Japan Atomic Energy Research Institute. Measured distributions were compared with calculated ones.

  17. RBE of quasi-monoenergetic 60 MeV neutron radiation for induction of dicentric chromosomes in human lymphocytes.

    PubMed

    Nolte, R; Mühlbradt, K-H; Meulders, J P; Stephan, G; Haney, M; Schmid, E

    2005-12-01

    The production of dicentric chromosomes in human lymphocytes by high-energy neutron radiation was studied using a quasi-monoenergetic 60 MeV neutron beam. The average yield coefficient [see text] of the linear dose-response relationship for dicentric chromosomes was measured to be (0.146+/-0.016) Gy-1. This confirms our earlier observations that above 400 keV, the yield of dicentric chromosomes decreases with increasing neutron energy. Using the linear-quadratic dose-response relationship for dicentric chromosomes established in blood of the same donor for 60Co gamma-rays as a reference radiation, an average maximum low-dose RBE (RBEM) of 14+/-4 for 60 MeV quasi-monoenergetic neutrons with a dose-weighted average energy [see text] of 41.0 MeV is obtained. A correction procedure was applied, to account for the low-energy continuum of the quasi-monoenergetic spectral neutron distribution, and the yield coefficient alpha for 60 MeV neutrons was determined from the measured average yield coefficient [see text]. For alpha, a value of (0.115+/-0.026) Gy-1 was obtained corresponding to an RBEM of 11+/-4. The present experiments extend earlier investigations with monoenergetic neutrons to higher energies.

  18. Highly collimated monoenergetic target-surface electron acceleration in near-critical-density plasmas

    SciTech Connect

    Mao, J. Y.; Chen, L. M.; Huang, K.; Ma, Y.; Zhao, J. R.; Yan, W. C.; Ma, J. L.; Wei, Z. Y.; Li, D. Z.; Aeschlimann, M.; Zhang, J.

    2015-03-30

    Optimized-quality monoenergetic target surface electron beams at MeV level with low normalized emittance (0.03π mm mrad) and high charge (30 pC) per shot have been obtained from 3 TW laser-solid interactions at a grazing incidence. The 2-Dimension particle-in-cell simulations suggest that electrons are wake-field accelerated in a large-scale, near-critical-density preplasma. It reveals that a bubble-like structure as an accelerating cavity appears in the near-critical-density plasma region and travels along the target surface. A bunch of electrons are pinched transversely and accelerated longitudinally by the wake field in the bubble. The outstanding normalized emittance and monochromaticity of such highly collimated surface electron beams could make it an ideal beam for fast ignition or may serve as an injector in traditional accelerators.

  19. Comparison of monoenergetic photon organ dose rate coefficients for stylized and voxel phantoms submerged in air

    SciTech Connect

    Bellamy, Michael B.; Hiller, Mauritius M.; Dewji, Shaheen A.; Veinot, Kenneth G.; Leggett, Richard Wayne; Eckerman, Keith F.; Easterly, Clay E.; Hertel, Nolan E.

    2016-02-01

    As part of a broader effort to calculate effective dose rate coefficients for external exposure to photons and electrons emitted by radionuclides distributed in air, soil or water, age-specific stylized phantoms have been employed to determine dose coefficients relating dose rate to organs and tissues in the body. In this article, dose rate coefficients computed using the International Commission on Radiological Protection reference adult male voxel phantom are compared with values computed using the Oak Ridge National Laboratory adult male stylized phantom in an air submersion exposure geometry. Monte Carlo calculations for both phantoms were performed for monoenergetic source photons in the range of 30 keV to 5 MeV. Furthermore, these calculations largely result in differences under 10 % for photon energies above 50 keV, and it can be expected that both models show comparable results for the environmental sources of radionuclides.

  20. A Monte Carlo simulation of monoenergetic neutrons traversing rectangular and spherical polyethylene moderators.

    PubMed

    Monk, S D; Selwood, M

    2011-03-01

    A Monte Carlo-based simulation of the transport of a series of monoenergetic neutron sources through first a rectangular block of 0.93 g cm(-3) density polyethylene and secondly through a sphere made of the same substance is presented here. In both instances, the neutron fields are monitored at closely spread intervals through the moderator mass, producing a lot of data in the process. To reduce the amount of data presented, a figure of merit is created by estimating the cross section for each discrete neutron energy and by applying this to the number of neutrons present of each energy giving an arbitrary response figure. This work was undertaken in order to aid the design and development of a novel neutron spectrometer.

  1. Annealing properties of open volumes in strained SiN films studied by monoenergetic positron beams

    SciTech Connect

    Uedono, A.; Ito, K.; Narumi, T.; Sometani, M.; Yamabe, K.; Miyagawa, Y.; Murata, T.; Honda, K.; Hattori, N.; Matsuura, M.; Asai, K.; Ohdaira, T.; Suzuki, R.

    2007-09-15

    The effect of annealing on open volumes in strained SiN films deposited on Si by plasma enhanced chemical vapor deposition was studied using monoenergetic positron beams. For compressive SiN, the stress was reduced by postdeposition annealing; this effect was attributed to the relaxation of matrix structures accompanied by an expansion of small open spaces intrinsically existing in the matrix and the introduction of large open volumes. For tensile SiN, although annealing tends to decrease the concentration of large open volumes, the size of the small open spaces and the film stress were almost constant up to 1000 deg. C annealing. This was attributed to the network structure related to the open spaces remaining stable even at 1000 deg. C annealing, and this mainly determines the stress in the tensile film.

  2. Comparison of monoenergetic photon organ dose rate coefficients for stylized and voxel phantoms submerged in air

    DOE PAGES

    Bellamy, Michael B.; Hiller, Mauritius M.; Dewji, Shaheen A.; ...

    2016-02-01

    As part of a broader effort to calculate effective dose rate coefficients for external exposure to photons and electrons emitted by radionuclides distributed in air, soil or water, age-specific stylized phantoms have been employed to determine dose coefficients relating dose rate to organs and tissues in the body. In this article, dose rate coefficients computed using the International Commission on Radiological Protection reference adult male voxel phantom are compared with values computed using the Oak Ridge National Laboratory adult male stylized phantom in an air submersion exposure geometry. Monte Carlo calculations for both phantoms were performed for monoenergetic source photonsmore » in the range of 30 keV to 5 MeV. Furthermore, these calculations largely result in differences under 10 % for photon energies above 50 keV, and it can be expected that both models show comparable results for the environmental sources of radionuclides.« less

  3. Quasi-monoenergetic positron beam generation from ultra-intense laser-matter interactions

    NASA Astrophysics Data System (ADS)

    Nakamura, Tatsufumi; Hayakawa, Takehito

    2016-10-01

    In ultra-intense laser-matter interactions in which the radiation reaction effect plays an important role, γ-rays are effectively generated that are intense, collimated, and of short duration. These γ-rays propagate through the target, which results in the electron-positron pair creation caused by the interaction of the γ-rays with the nuclear electric fields. The positron beam thus generated has several unique features; it is quasi-monoenergetic in nature with a peak energy of hundreds of MeV, well collimated, and of ultra-short duration. Based on the numerical simulations, the dependences of the number and monochromaticity of the positrons on the laser and target parameters are explored, which leads to the proposal of a new type of the laser-driven positron source.

  4. Effects of 1.9 MeV monoenergetic neutrons on Vicia faba chromosomes: microdosimetric considerations.

    PubMed

    Geard, C R

    1980-01-01

    Aerated Vicia faba root meristems were irradiated with 1.9 MeV monoenergetic neutrons. This source of neutrons optimally provides one class of particles (recoil protons) with ranges able to traverse cell nuclei at moderate to high-LET. The volumes of the Vicia faba nuclei were log-normally distributed with a mean of 1100 micrometer3. The yield of chromatid-type aberrations was linear against absorbed dose and near-constant over 5 collection periods (2-12 h), after irradiation. Energy deposition events (recoil protons) determined by microdosimetry were related to cytological changes with the finding that 19% of incident recoil protons initiate visible changes in Vicia faba chromosomes. It is probable that a substantial fraction of recoil proton track length and deposited energy is in insensitive (non-DNA containing) portions of the nuclear volume.

  5. Laser-wakefield acceleration of monoenergetic electron beams in the first plasma-wave period.

    PubMed

    Mangles, S P D; Thomas, A G R; Kaluza, M C; Lundh, O; Lindau, F; Persson, A; Tsung, F S; Najmudin, Z; Mori, W B; Wahlström, C-G; Krushelnick, K

    2006-06-02

    Beam profile measurements of laser-wakefield accelerated electron bunches reveal that in the monoenergetic regime the electrons are injected and accelerated at the back of the first period of the plasma wave. With pulse durations ctau >or= lambda(p), we observe an elliptical beam profile with the axis of the ellipse parallel to the axis of the laser polarization. This increase in divergence in the laser polarization direction indicates that the electrons are accelerated within the laser pulse. Reducing the plasma density (decreasing ctau/lambda(p)) leads to a beam profile with less ellipticity, implying that the self-injection occurs at the rear of the first period of the plasma wave. This also demonstrates that the electron bunches are less than a plasma wavelength long, i.e., have a duration <25 fs. This interpretation is supported by 3D particle-in-cell simulations.

  6. Building protection- and building shielding-factors for environmental exposure to radionuclides and monoenergetic photon emissions.

    PubMed

    Dickson, E D; Hamby, D M

    2016-09-01

    We describe a simplified method for calculating both building protection- and shielding-factors for generic one- and two-story housing-unit models that are source-term dependent. Typically, radionuclide-independent factors are applied generically to external dose coefficients to account for the radiation shielding effects of indoor residences. In reality, the shielding effectiveness of each housing-unit would change over time as the radionuclide mixture and gamma-ray energy spectrum change due to physical effects such as deposition, radioactive decay, weathering effects, and decontamination efforts. Thus, it is necessary to develop factors designed for multiple photon energy spectrums to generate a more realistic estimate of the shielding effectiveness of a particular building. It is impractical to develop factors specific to a spectrum of photons emitted by each radionuclide of interest. Therefore, Monte Carlo simulations have been performed for sixteen monoenergetic photon energies from 0.10 to 3.0 MeV to characterize the 3D radiation fluence through each housing-unit produced by two idealized, yet realistic, environmental exposure scenarios. Results of these simulations were then used to develop fitted logarithmic functions (extrapolated to 0.0 MeV) to correlate an estimated factor to any monoenergetic photon energy up to 3.0 MeV. To verify these functions, another series of Monte Carlo simulations were performed for a select set of radionuclides to develop radionuclide-specific building protection- and shielding-factors. Good agreement is achieved between factors estimated using the presented functions and those calculated directly using Monte Carlo methods. Factors predicted by these functions are found to be in general agreement with other study results reported on similar structures which applied various computational methods and source-terms. This study only focuses on generic one- and two-story homes to provide a practical application that can contribute

  7. Mono-energetic mono-directional resonance neutron activation of natural indium metal target

    SciTech Connect

    Ertek, C.; Oigawa, Hiroyuki

    1994-12-31

    The mono-energetic neutrons of 1.456eV energy are obtained from 2 MWth TR-I swimming pool type research reactor using double collimated beams and BRAGG reflection of pure Beryllium mono-crystal with extremely fine energy resolution. Foil thickness for 3 foils were 26., 28, and 44.10-4 cm and they were perpendicular to the beam of mono-energetic neutrons and were irradiated in sandwich form. After irradiation, the saturation activities were obtained using Phillips two-pie special beta-ray detector in a well controlled and shielded geometry. Counting reproducibility was excellent (better than 0.1%). Special Attention was paid to the irradiated (side A) and non-irradiated (side B) sides of the foils. Usual irradiation and decay corrections were applied to obtain the saturation activities. In this work, the preliminary calculations of reaction rates using Nakazawa M. et al., JENDL Dosimetry file, JAERI 1325, (1992) were performed. Considerable differences are found between the calculations and experiment and possible reasons are still under investigation. The preliminary calculations of reaction rates using ENDFB/VI are in agreement with JENDL-3 estimates. Absolute reaction rate estimates are not yet ready. Considerable numbers of research centers are interested in the experiment and very constructive inputs are expressed and obtained from Hiroyuki Oigawa, Shigeaki Okajima and T. Mukaiyama, JAERI, Japan; N.P. Baumann and K.O. Ott, USA; E. Zsolnay and E. Szondy, Hungary; M.C. Lopes and J. Molina, Portugal; F. Bensch, H. Boeck Austria; and M. Turgut and A. Isyar, Turkey. Investigations using collision theory, multiple scattering and monte-carlo techniques have been undertaken.

  8. Microdosimetry calculations for monoenergetic electrons using Geant4-DNA combined with a weighted track sampling algorithm

    NASA Astrophysics Data System (ADS)

    Famulari, Gabriel; Pater, Piotr; Enger, Shirin A.

    2017-07-01

    The aim of this study was to calculate microdosimetric distributions for low energy electrons simulated using the Monte Carlo track structure code Geant4-DNA. Tracks for monoenergetic electrons with kinetic energies ranging from 100 eV to 1 MeV were simulated in an infinite spherical water phantom using the Geant4-DNA extension included in Geant4 toolkit version 10.2 (patch 02). The microdosimetric distributions were obtained through random sampling of transfer points and overlaying scoring volumes within the associated volume of the tracks. Relative frequency distributions of energy deposition f(>E)/f(>0) and dose mean lineal energy (\\bar{y}D ) values were calculated in nanometer-sized spherical and cylindrical targets. The effects of scoring volume and scoring techniques were examined. The results were compared with published data generated using MOCA8B and KURBUC. Geant4-DNA produces a lower frequency of higher energy deposits than MOCA8B. The \\bar{y}D values calculated with Geant4-DNA are smaller than those calculated using MOCA8B and KURBUC. The differences are mainly due to the lower ionization and excitation cross sections of Geant4-DNA for low energy electrons. To a lesser extent, discrepancies can also be attributed to the implementation in this study of a new and fast scoring technique that differs from that used in previous studies. For the same mean chord length (\\bar{l} ), the \\bar{y}D calculated in cylindrical volumes are larger than those calculated in spherical volumes. The discrepancies due to cross sections and scoring geometries increase with decreasing scoring site dimensions. A new set of \\bar{y}D values has been presented for monoenergetic electrons using a fast track sampling algorithm and the most recent physics models implemented in Geant4-DNA. This dataset can be combined with primary electron spectra to predict the radiation quality of photon and electron beams.

  9. Noise-optimized advanced image-based virtual monoenergetic imaging for improved visualization of lung cancer: Comparison with traditional virtual monoenergetic imaging.

    PubMed

    Frellesen, Claudia; Kaup, Moritz; Wichmann, Julian L; Hüsers, Kristina; Scholtz, Jan-Erik; Albrecht, Moritz H; Metzger, Sarah C; Bauer, Ralf W; Kerl, J Matthias; Lehnert, Thomas; Vogl, Thomas J; Bodelle, Boris

    2016-03-01

    To assess the effect of a noise-optimized image-based virtual monoenergetic imaging (VMI+) algorithm in direct comparison with the traditional VMI technique and standard linearly-blended images emulating 120-kVp acquisition (M_0.3) on image quality at dual-energy CT in patients with lung cancer. Dual-source dual-energy CT examinations of 48 patients with biopsy-proven primary (n=31) or recurrent (n=20) lung cancer were evaluated. Images were reconstructed as M_0.3, and VMI+ and traditional VMI series at 40, 55, and 70keV. Attenuation of tumor, descending aorta, pulmonary trunk, latissimus muscle, and noise were measured. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Five-point scales were used by three observers to subjectively evaluate general image impression, tumor delineation, image sharpness, and image noise. Background noise was consistently lower with VMI+ compared to VMI at all keV levels (all p<0.0001) and M_0.3 (all p≤0.0004). Tumor SNR and CNR peaked in the 40keV VMI+ series, significantly higher compared to all VMI and M_0.3 series (all p<0.0008). Observers preferred the 55keV VMI+ series regarding general image impression and tumor delineation compared to all other series (all p<0.0001). Image sharpness and image noise ratings were highest in the 55keV VMI+ and 70keV VMI and VMI+ reconstructions. Tumor CNR peaked at 40keV VMI+ while observers preferred 55keV VMI+ series overall other series for dual-energy CT of lung cancer. The noise-optimized VMI+ technique showed significantly lower background noise and higher SNR and CNR compared to the traditional VMI technique at matching keV levels. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Response functions of Fuji imaging plates to monoenergetic protons in the energy range 0.6-3.2 MeV.

    PubMed

    Bonnet, T; Comet, M; Denis-Petit, D; Gobet, F; Hannachi, F; Tarisien, M; Versteegen, M; Aleonard, M M

    2013-01-01

    We have measured the responses of Fuji MS, SR, and TR imaging plates (IPs) to protons with energies ranging from 0.6 to 3.2 MeV. Monoenergetic protons were produced with the 3.5 MV AIFIRA (Applications Interdisciplinaires de Faisceaux d'Ions en Région Aquitaine) accelerator at the Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG). The IPs were irradiated with protons backscattered off a tantalum target. We present the photo-stimulated luminescence response of the IPs together with the fading measurements for these IPs. A method is applied to allow correction of fading effects for variable proton irradiation duration. Using the IP fading corrections, a model of the IP response function to protons was developed. The model enables extrapolation of the IP response to protons up to proton energies of 10 MeV. Our work is finally compared to previous works conducted on Fuji TR IP response to protons.

  11. Jefferson Lab 12 GEV Cebaf Upgrade

    NASA Astrophysics Data System (ADS)

    Rode, C. H.

    2010-04-01

    The existing continuous electron beam accelerator facility (CEBAF) at Thomas Jefferson National Accelerator Facility (TJNAF) is a 5-pass, recirculating cw electron Linac operating at ˜6 GeV and is devoted to basic research in nuclear physics. The 12 GeV CEBAF Upgrade is a 310 M project, sponsored by the Department of Energy (DOE) Office of Nuclear Physics, that will expand its research capabilities substantially by doubling the maximum energy and adding major new experimental apparatus. The project received construction approval in September 2008 and has started the major procurement process. The cryogenic aspects of the 12 GeV CEBAF Upgrade includes: doubling the accelerating voltages of the Linacs by adding ten new high-performance, superconducting radiofrequency (SRF) cryomodules (CMs) to the existing 42 1/4 cryomodules; doubling of the 2 K cryogenics plant; and the addition of eight superconducting magnets.

  12. Nuclear reaction effects in conventional risk assessment for energetic ion exposure

    NASA Technical Reports Server (NTRS)

    Wilson, John W.; Shinn, Judy L.; Townsend, Lawrence W.

    1990-01-01

    A volume of tissue through which a monoenergetic ion fluence has passed is considered, and the energy absorbed by the media in the passage is evaluated. Various contributions to biological risk are quantified using quality factors presently in force. The effects of newly proposed quality factors are evaluated.

  13. Quasi-Monoenergetic Dense and Uniform Electron Bunch Generation from Laser Driven Double-Layer Thin Films

    NASA Astrophysics Data System (ADS)

    Wang, C.; Roycroft, R.; McCary, E.; Meadows, A.; Blakeney, J.; Serratto, K.; Kuk, D.; Chester, C.; Gao, L.; Fu, H.; Yan, X. Q.; Schreiber, J.; Pomerantz, I.; Bernstein, A.; Quevedo, H.; Dyer, G.; Gaul, E.; Ditmire, T.; Gautier, D. C.; Fernandez, J.; Hegelich, B. M.

    2014-10-01

    We demonstrate that dense, uniform quasi-monoenergetic relativistic electron bunches can be generated from the interaction of a high-intensity laser pulse with a double-layer thin film target. The first layer of the target is a freestanding, nanometer-scale, diamond-like carbon production layer. The second layer is a thin plastic reflection layer which reflects the drive-laser pulse, but allows electrons to pass through. Although no electron bunch is generated from the second layer alone, by adding it behind the first layer we obtained a quasi-monoenergetic bunch along the laser axis, 35 times denser than a bunch from the single layer target. Comparing the angular distribution of the electron spectra from a double-layer target with that of a single-layer target, we observed an increase of the electron cutoff energy at larger angles, which improves the uniformity of created electron bunches.

  14. Development of a low-energy monoenergetic neutron source for applications in low-dose radiobiological and radiochemical research.

    PubMed

    Aslam; Prestwich, W V; McNeill, F E; Waker, A J

    2003-06-01

    The McMaster University 3 MV KN Van de Graff accelerator facility primarily dedicated to in vivo neutron activation measurements has been used to produce moderate dose rates of monoenergetic fast neutrons of energy ranging from 150 to 600 keV with a small energy spread of about 25 keV (1sigma width of Gaussian) by bombarding thin lithium targets with 2.00-2.40 MeV protons. The calculated dose rate of the monoenergetic neutrons produced using thin lithium targets as functions of beam energy, target thickness, lab angle relative to beam direction, and the solid angle subtended by the sample with the target has also been reported.

  15. Photon dose mixed in monoenergetic neutron calibration fields using 7Li(p,n)7Be reaction.

    PubMed

    Tanimura, Y; Tsutsumi, M; Yoshizawa, M

    2014-10-01

    The ambient dose equivalents H*(10) of photons mixed in the 144, 250 and 565 keV monoenergetic neutron fields were evaluated using measurements from an NaI(Tl) detector and calculations done using the MCNP-ANT code. It was found that H*(10) of the photons produced in the target assembly dominates the dose, particularly near the target. The H*(10) of the photons produced in other materials in the field increases with the increase in distance from the target and could not be neglected at a large distance from the target. The ratios of the H*(10) of the mixed photons to that of the monoenergetic neutrons for 144, 250 and 565 keV neutron fields, were evaluated to be below 5.5, 6.9 and 1.5 %, respectively. The ratios were calculated at calibration points between 100 and 500 cm from the target.

  16. Low Momentum Direct Photons in Au + Au collisions at √{ s} = 39 GeV and 62 . 4 GeV measured by the PHENIX Experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Khachatryan, Vladimir; Phenix Collaboration

    2015-10-01

    Direct photons, which are produced during all stages of a heavy-ion collision, directly probe the conditions of their production environment. The large yield and large anisotropy of low momentum direct photons observed in 200 GeV Au + Au collisions pose a significant challenge to theoretical models. Measurements at lower collision energy may provide new insight on the origin of the low momentum direct photons. Direct photons are difficult to measure with electromagnetic calorimeters, in particular at low momentum, because of neutral hadron and minimal-ionizing particle contamination, large decay photon backgrounds, and worsening calorimeter resolution. Therefore PHENIX has measured the direct photons at √{ s} = 200 GeV via their external conversion to di-electron pairs. This method virtually eliminates the hadron contamination due to a very clean photon identification based on di-electron pair. The same method is also used in our current analysis of the direct photons at two lower energies. We will present the current status on the measurements of the low momentum direct photons at √{ s} = 39 GeV and 62 . 4 GeV.

  17. Evaluation of monoenergetic late iodine enhancement dual-energy computed tomography for imaging of chronic myocardial infarction.

    PubMed

    Wichmann, Julian L; Arbaciauskaite, Ruta; Kerl, J Matthias; Frellesen, Claudia; Bodelle, Boris; Lehnert, Thomas; Monsefi, Nadejda; Vogl, Thomas J; Bauer, Ralf W

    2014-06-01

    To evaluate image quality and diagnostic accuracy of selective monoenergetic reconstructions of late iodine enhancement (LIE) dual-energy computed tomography (DECT) for imaging of chronic myocardial infarction (CMI). Twenty patients with a history of coronary bypass surgery underwent cardiac LIE-DECT and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI). LIE-DECT images were reconstructed as selective monoenergetic spectral images with photon energies of 40, 60, 80, and 100 keV and the standard linear blending setting (M_0.6). Images were assessed for late enhancement, transmural extent, signal characteristics and subjective image quality. Seventy-nine myocardial segments (23 %) showed LGE. LIE-DECT detected 76 lesions. Images obtained at 80 keV and M_0.6 showed a high signal-to-noise ratio (15.9; 15.1), contrast-to-noise ratio (4.2; 4.0) and sensitivity (94.9 %; 92.4 %) while specificity was identical (99.6 %). Differences between these series were not statistically significant. Transmural extent of LIE was overestimated in both series (80 keV: 40 %; M_0.6: 35 %) in comparison to MRI. However, observers preferred 80 keV in 13/20 cases (65 %, κ = 0.634) over M_0.6 (4/20 cases) regarding subjective image quality. Post-processing of LIE-DECT data with selective monoenergetic reconstructions at 80 keV significantly improves subjective image quality while objective image quality shows no significant difference compared to standard linear blending. Late enhancement dual-energy CT allows for detection of chronic myocardial infarction. Monoenergetic reconstructions at 80 keV significantly improve subjective image quality. 80 keV and standard linear blending reconstructions show no significant differences. Extent of CMI detected with LIE-DECT is overestimated compared with MRI.

  18. Beta-Decay Study of ^{150}Er, ^{152}Yb, and ^{156}Yb: Candidates for a Monoenergetic Neutrino Beam Facility

    SciTech Connect

    Estevez Aguado, M. E.; Algora, A.; Rubio, B.; Bernabeu, J.; Nacher, E.; Tain, J. L.; Gadea, A.; Agramunt, J.; Burkard, K.; Hueller, W.; Doring, J.; Kirchner, R.; Mukha, I.; Plettner, C.; Roeckl, E.; Grawe, H.; Collatz, R.; Hellstrom, M.; Cano-Ott, D.; Karny, M.; Janas, Z.; Gierlik, M.; Plochocki, A.; Rykaczewski, Krzysztof Piotr; Batist, L.; Moroz, F.; Wittman, V.; Blazhev, A.; Valiente, J. J.; Espinoza, C.

    2011-01-01

    The beta decays of ^{150}Er, ^{152}Yb, and ^{156}Yb nuclei are investigated using the total absorption spectroscopy technique. These nuclei can be considered possible candidates for forming the beam of a monoenergetic neutrino beam facility based on the electron capture (EC) decay of radioactive nuclei. Our measurements confirm that for the cases studied, the EC decay proceeds mainly to a single state in the daughter nucleus.

  19. Concurrence of monoenergetic electron beams and bright X-rays from an evolving laser-plasma bubble.

    PubMed

    Yan, Wenchao; Chen, Liming; Li, Dazhang; Zhang, Lu; Hafz, Nasr A M; Dunn, James; Ma, Yong; Huang, Kai; Su, Luning; Chen, Min; Sheng, Zhengming; Zhang, Jie

    2014-04-22

    Desktop laser plasma acceleration has proven to be able to generate gigaelectronvolt-level quasi-monoenergetic electron beams. Moreover, such electron beams can oscillate transversely (wiggling motion) in the laser-produced plasma bubble/channel and emit collimated ultrashort X-ray flashes known as betatron radiation with photon energy ranging from kiloelectronvolts to megaelectronvolts. This implies that usually one cannot obtain bright betatron X-rays and high-quality electron beams with low emittance and small energy spread simultaneously in the same accelerating wave bucket. Here, we report the first (to our knowledge) experimental observation of two distinct electron bunches in a single laser shot, one featured with quasi-monoenergetic spectrum and another with continuous spectrum along with large emittance. The latter is able to generate high-flux betatron X-rays. Such is observed only when the laser self-guiding is extended over 4 mm at a fixed plasma density (4 × 10(18) cm(-3)). Numerical simulation reveals that two bunches of electrons are injected at different stages due to the bubble evolution. The first bunch is injected at the beginning to form a stable quasi-monoenergetic electron beam, whereas the second one is injected later due to the oscillation of the bubble size as a result of the change of the laser spot size during the propagation. Due to the inherent temporal synchronization, this unique electron-photon source can be ideal for pump-probe applications with femtosecond time resolution.

  20. Concurrence of monoenergetic electron beams and bright X-rays from an evolving laser-plasma bubble

    PubMed Central

    Yan, Wenchao; Chen, Liming; Li, Dazhang; Zhang, Lu; Hafz, Nasr A. M.; Dunn, James; Ma, Yong; Huang, Kai; Su, Luning; Chen, Min; Sheng, Zhengming; Zhang, Jie

    2014-01-01

    Desktop laser plasma acceleration has proven to be able to generate gigaelectronvolt-level quasi-monoenergetic electron beams. Moreover, such electron beams can oscillate transversely (wiggling motion) in the laser-produced plasma bubble/channel and emit collimated ultrashort X-ray flashes known as betatron radiation with photon energy ranging from kiloelectronvolts to megaelectronvolts. This implies that usually one cannot obtain bright betatron X-rays and high-quality electron beams with low emittance and small energy spread simultaneously in the same accelerating wave bucket. Here, we report the first (to our knowledge) experimental observation of two distinct electron bunches in a single laser shot, one featured with quasi-monoenergetic spectrum and another with continuous spectrum along with large emittance. The latter is able to generate high-flux betatron X-rays. Such is observed only when the laser self-guiding is extended over 4 mm at a fixed plasma density (4 × 1018 cm−3). Numerical simulation reveals that two bunches of electrons are injected at different stages due to the bubble evolution. The first bunch is injected at the beginning to form a stable quasi-monoenergetic electron beam, whereas the second one is injected later due to the oscillation of the bubble size as a result of the change of the laser spot size during the propagation. Due to the inherent temporal synchronization, this unique electron–photon source can be ideal for pump–probe applications with femtosecond time resolution. PMID:24711405

  1. Influence of spectral detector CT based monoenergetic images on the computer-aided detection of pulmonary artery embolism.

    PubMed

    Kröger, Jan Robert; Hickethier, Tilman; Pahn, Gregor; Gerhardt, Felix; Maintz, David; Bunck, Alexander C

    2017-10-01

    To evaluate the influence of monoenergetic reconstructions using a spectral detector CT (SDCT) on the computer aided detection (CAD) of pulmonary artery embolism (PAE) on CT pulmonary angiography (CTPA) and CT in venous contrast phase (CTV). A retrospective data base search identified 15 patients with CTPA and 18 patients with CTV and diagnosis of PAE. For these patients, monoenergetic (monoE) images at different energy levels or with a fixed attenuation in the pulmonary artery were generated and independently analyzed using a commercially available computer aided detection (CAD) tool. Attenuation in the pulmonary artery and in the embolus was measured. For CTPA and CTV, in monoenergetic images the difference in attenuation between vessel and embolus was significantly higher than in conventional images. In CTPA the detection rate was highest in the >500 HU monoE images with 67,9% detected emboli and 93,3% of patients correctly identified as having PAE. At the same time the false positive rate could be significantly reduced by using monoE images compared to conventional images. Detection rates for CTV were lower than in CTPA but were raised significantly by monoE reconstructions. The combination of SDCT and CAD improves the diagnostic accuracy of CAD and enables CAD interpretation of CTV. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Paternal monoenergetic neutron exposure results in abnormal sperm, and embryonal lethality and transgenerational tumorigenesis in mouse F1 offspring.

    PubMed

    Watanabe, Hiromitsu; Toyoshima, Megumi; Ishikawa, Masayori; Kamiya, Kenji

    2010-05-01

    Experiments were conducted to assay whether monoenergetic neutron-induced genetic damage in parental germline cells can give rise to development of cancer in the offspring. Seven-week-old C3H male mice were irradiated with monoenergetic neutrons with energy levels of 0.2 or 0.6 MeV at doses of 0, 50, 100 or 200 cGy. Two weeks after irradiation, when the male mice showed an increased incidence of sperm abnormalities, they were mated with virgin 9-week-old C57BL females. Litter size was decreased and embryo lethalities were increased in a dose-dependent manner. Furthermore, tumor incidence in male offspring born to male mice irradiated with 25 or 50 cGy at 0.6 MeV showed a tendency for increase as compared to the non-irradiated group value. Liver tumors in the 50 cGy group were significantly increased (P=0.03). It is concluded that the increased hepatic tumor risk in the F1 generation may have been caused by genetic transmission of some hepatoma-associated trait(s) induced by monoenergetic neutron irradiation.

  3. Ratio of Jet Cross Sections at s = 630 GeV and 1800 GeV

    NASA Astrophysics Data System (ADS)

    Abbott, B.; Abolins, M.; Abramov, V.; Acharya, B. S.; Adams, D. L.; Adams, M.; Alves, G. A.; Amos, N.; Anderson, E. W.; Baarmand, M. M.; Babintsev, V. V.; Babukhadia, L.; Baden, A.; Baldin, B.; Balm, P. W.; Banerjee, S.; Bantly, J.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bean, A.; Begel, M.; Belyaev, A.; Beri, S. B.; Bernardi, G.; Bertram, I.; Besson, A.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Blazey, G.; Blessing, S.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Brandt, A.; Breedon, R.; Briskin, G.; Brock, R.; Brooijmans, G.; Bross, A.; Buchholz, D.; Buehler, M.; Buescher, V.; Burtovoi, V. S.; Butler, J. M.; Canelli, F.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chan, K. M.; Chekulaev, S. V.; Cho, D. K.; Choi, S.; Chopra, S.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cochran, J.; Coney, L.; Connolly, B.; Cooper, W. E.; Coppage, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, G. A.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Demina, R.; Demine, P.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Doulas, S.; Draper, P.; Ducros, Y.; Dudko, L. V.; Duensing, S.; Dugad, S. R.; Dyshkant, A.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Estrada, J.; Evans, H.; Evdokimov, V. N.; Fahland, T.; Feher, S.; Fein, D.; Ferbel, T.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Fleuret, F.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Gavrilov, V.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gibbard, B.; Gilmartin, R.; Ginther, G.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Graham, G.; Grannis, P. D.; Green, J. A.; Greenlee, H.; Grinstein, S.; Groer, L.; Grudberg, P.; Grünendahl, S.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hanlet, P.; Hansen, S.; Hauptman, J. M.; Hays, C.; Hebert, C.; Hedin, D.; Heinson, A. P.; Heintz, U.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hou, S.; Huang, Y.; Ito, A. S.; Jerger, S. A.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Juste, A.; Kahn, S.; Kajfasz, E.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Kim, S. K.; Klima, B.; Klopfenstein, C.; Knuteson, B.; Ko, W.; Kohli, J. M.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kubantsev, M.; Kuleshov, S.; Kulik, Y.; Kunori, S.; Kuznetsov, V. E.; Landsberg, G.; Leflat, A.; Lehner, F.; Li, J.; Li, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Lucotte, A.; Lueking, L.; Lundstedt, C.; Maciel, A. K.; Madaras, R. J.; Manankov, V.; Mao, H. S.; Marshall, T.; Martin, M. I.; Martin, R. D.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McMahon, T.; Melanson, H. L.; Meng, X. C.; Merkin, M.; Merritt, K. W.; Miao, C.; Miettinen, H.; Mihalcea, D.; Mincer, A.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Moore, R. W.; Mostafa, M.; da Motta, H.; Nagy, E.; Nang, F.; Narain, M.; Narasimham, V. S.; Neal, H. A.; Negret, J. P.; Negroni, S.; Norman, D.; Oesch, L.; Oguri, V.; Olivier, B.; Oshima, N.; Padley, P.; Pan, L. J.; Para, A.; Parashar, N.; Partridge, R.; Parua, N.; Paterno, M.; Patwa, A.; Pawlik, B.; Perkins, J.; Peters, M.; Peters, O.; Piegaia, R.; Piekarz, H.; Pope, B. G.; Popkov, E.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramberg, E.; Rapidis, P. A.; Reay, N. W.; Reucroft, S.; Rha, J.; Rijssenbeek, M.; Rockwell, T.; Roco, M.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Schwartzman, A.; Sculli, J.; Sen, N.; Shabalina, E.; Shankar, H. C.; Shivpuri, R. K.; Shpakov, D.; Shupe, M.; Sidwell, R. A.; Simak, V.; Singh, H.; Singh, J. B.; Sirotenko, V.; Slattery, P.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sorín, V.; Sosebee, M.; Sotnikova, N.; Soustruznik, K.; Souza, M.; Stanton, N. R.; Steinbrück, G.; Stephens, R. W.; Stevenson, M. L.; Stichelbaut, F.; Stoker, D.; Stolin, V.; Stoyanova, D. A.; Strauss, M.; Streets, K.; Strovink, M.; Stutte, L.; Sznajder, A.; Taylor, W.; Tentindo-Repond, S.; Thompson, J.; Toback, D.; Tripathi, S. M.; Trippe, T. G.; Turcot, A. S.; Tuts, P. M.; van Gemmeren, P.; Vaniev, V.; van Kooten, R.; Varelas, N.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, H.; Wang, Z.-M.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Whiteson, D.; Wightman, J. A.; Wijngaarden, D. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Wood, D. R.; Yamada, R.; Yamin, P.; Yasuda, T.; Yip, K.; Youssef, S.; Yu, J.; Yu, Z.; Zanabria, M.; Zheng, H.; Zhou, Z.; Zhu, Z. H.; Zielinski, M.; Zieminska, D.; Zieminski, A.; Zutshi, V.; Zverev, E. G.; Zylberstejn, A.

    2001-03-01

    The D0 Collaboration has measured the inclusive jet cross section in p¯p collisions at s = 630 GeV. The results for pseudorapidities η<0.5 are combined with our previous results at s = 1800 GeV to form a ratio of cross sections with smaller uncertainties than either individual measurement. Next-to-leading-order QCD predictions show excellent agreement with the measurement at 630 GeV; agreement is also satisfactory for the ratio. Specifically, despite a 10% to 15% difference in the absolute magnitude, the dependence of the ratio on jet transverse momentum is very similar for data and theory.

  4. Characterization of a Tunable Quasi-Monoenergetic Neutron Beamfrom Deuteron Breakup

    SciTech Connect

    Bleuel, D.L.; McMahan, M.A.; Ahle, L.; Barquest, B.R.; Cerny, J.; Heilbronn, L.H.; Jewett, C.C.

    2006-12-14

    A neutron irradiation facility is being developed at the88-Inch Cyclotron at Lawrence Berkeley National Laboratory for thepurposes of measuring neutron reaction cross sections on radioactivetargets and for radiation effects testing. Applications are of benefit tostockpile stewardship, nuclear astrophysics, next generation advancedfuel reactors, and cosmic radiation biology and electronics in space. Thefacility will supply a tunable, quasi-monoenergetic neutron beam in therange of 10-30 MeV or a white neutron source, produced by deuteronbreakup reactions on thin and thick targets, respectively. Because thedeuteron breakup reaction has not been well studied at intermediateincident deuteron energies, above the target Coulomb barrier and below 56MeV, a detailed characterization was necessary of the neutron spectraproduced by thin targets.Neutron time of flight (TOF) methods have beenused to measure the neutron spectra produced on thin targets of low-Z(titanium) and high-Z (tantalum) materials at incident deuteron energiesof 20 MeV and 29 MeV at 0 deg. Breakup neutrons at both energies fromlow-Z targets appear to peak at roughly half of the available kineticenergy, while neutrons from high-Z interactions peak somewhat lower inenergy, owing to the increased proton energy due to breakup within theCoulomb field. Furthermore, neutron spectra appear narrower for high-Ztargets. These centroids are consistent with recent preliminary protonenergy measurements using silicon telescope detectors conducted at LBNL,though there is a notable discrepancy with spectral widths.

  5. A 0. 5 to 3. 0 MeV monoenergetic positron beam

    SciTech Connect

    Huomo, H.; AsokaKumar, P.; Henderson, S.D.; Phlips, B.F.; Mayer, R.; McDonough, J.; Hacker, H.; McCorkle, S.; Schnitzenbaumer, P.; Greenberg, J.S.

    1988-01-01

    An adjustable, 0.5--3 MeV monoenergetic positron beam has been constructed at Brookhaven. Currently a /sup 22/Na source with a W(100) foil transmission moderator produces a 1.1 mm FWHN beam with an intensity of 3/times/10/sup 5/ e/sup +//sec at a target located downstream from the accelerator. The divergence of the beam is less than 0.1/degree/ at 2.2 MeV energy. A SOA gun with 2 lens transport system brings the beam to a focus at the entrance of an electrostatic 3 MeV Dynamitron accelerator. The post acceleration beam transport system comprises 3 focusing solenolds, 4 sets of steering magnets and a 90/degree/ double focusing bending magnet. The beam energy spread at the target is <1 keV FWHN deduced from the beam size. Below we describe the positron extraction optics and acceleration, the construction of the beamline and the beam diagnostic devices. The salient beam parameters are listed at the end of this paper. 2 refs., 3 figs., 1 tab.

  6. Dark matter searches for monoenergetic neutrinos arising from stopped meson decay in the Sun

    SciTech Connect

    Rott, Carsten; In, Seongjin; Kumar, Jason; Yaylali, David

    2015-11-24

    Dark matter can be gravitationally captured by the Sun after scattering off solar nuclei. Annihilations of the dark matter trapped and accumulated in the centre of the Sun could result in one of the most detectable and recognizable signals for dark matter. Searches for high-energy neutrinos produced in the decay of annihilation products have yielded extremely competitive constraints on the spin-dependent scattering cross sections of dark matter with nuclei. Recently, the low energy neutrino signal arising from dark-matter annihilation to quarks which then hadronize and shower has been suggested as a competitive and complementary search strategy. These high-multiplicity hadronic showers give rise to a large amount of pions which will come to rest in the Sun and decay, leading to a unique sub-GeV neutrino signal. We here improve on previous works by considering the monoenergetic neutrino signal arising from both pion and kaon decay. We consider searches at liquid scintillation, liquid argon, and water Cherenkov detectors and find very competitive sensitivities for few-GeV dark matter masses.

  7. Capture-gated Spectroscopic Measurements of Monoenergetic Neutrons with a Composite Scintillation Detector

    SciTech Connect

    Nattress, Jason; Mayer, M.; Foster, A.; Barhoumi Meddeb, A.; Trivelpiece, C.; Ounaies, Z.; Jovanovic, I.

    2016-04-01

    Abstract—We report on the measurements of Monoenergetic neutrons from DD and DT fusion reactions by use of the capture gating method in a heterogeneous plastic-glass composite scintillation detector. The cylindrical detector is 5.08 cm in diameter and 5.05 cm in height and was fabricated using 1-mm diameter Li-doped glass rods(GS20) and scintillating polyvinyl toluene (EJ-290). Different scintillation decay constants are used to identify energy depositions in two materials constituting the composite scintillator. Geant4 simulations of the neutron thermalization and capture process were conducted, finding a mean capture time of approximately 2.6 ms for both DD and DT neutrons. A capture gating time acceptance window based on simulation results was used to identify the neutron thermalization pulses. The total scintillation light yield produced in neutron thermalization was measured and found to show consistency on event-by-event basis despite the variety of neutron thermalization histories prior to capture. The ratio of light yields from thermalization of 14.1 MeV and 2.45 MeV neutrons in the EJ-290 scintillator was determined to be 14.6, and the light output from 2.45 MeV neutrons was also correlated to its electron equivalent, obtaining a value of 0.58*0.05 MeVee.

  8. Vacancy-type defects induced by grinding of Si wafers studied by monoenergetic positron beams

    SciTech Connect

    Uedono, Akira; Yoshihara, Nakaaki; Mizushima, Yoriko; Kim, Youngsuk; Nakamura, Tomoji; Ohba, Takayuki; Oshima, Nagayasu; Suzuki, Ryoichi

    2014-10-07

    Vacancy-type defects introduced by the grinding of Czochralski-grown Si wafers were studied using monoenergetic positron beams. Measurements of Doppler broadening spectra of the annihilation radiation and the lifetime spectra of positrons showed that vacancy-type defects were introduced in the surface region (<98 nm), and the major defect species were identified as (i) relatively small vacancies incorporated in dislocations and (ii) large vacancy clusters. Annealing experiments showed that the defect concentration decreased with increasing annealing temperature in the range between 100 and 500°C. After 600–700°C annealing, the defect-rich region expanded up to about 170 nm, which was attributed to rearrangements of dislocation networks, and a resultant emission of point defects toward the inside of the sample. Above 800°C, the stability limit of those vacancies was reached and they started to disappear. After the vacancies were annealed out (900°C), oxygen-related defects were the major point defects and they were located at <25 nm.

  9. Gaseous 83mKr generator of monoenergetic electrons based on 83Rb deposited in zeolite

    NASA Astrophysics Data System (ADS)

    Sentkerestiová, J.; Vénos, D.; Slezák, M.

    2017-09-01

    The gaseous 83mKr electron source is currently used in neutrino mass experiments KATRIN and Project 8, dark matter experiments XENON, LUX and DarkSide, and ALICE (CERN) experiment. The main attractive features of this radioactive noble gas are its monoenergetic conversion electrons with well known energies and a half-life of 1.8 h, which is short enough to avoid any long-lasting contamination of the system. The long half-life of the mother 83Rb isotope (T1/2 = 86.2 d) enables more time demanding measurement. Particularly, in the neutrino mass experiments with gaseous tritium in which the 83mKr is applied in the same manner as the tritium, the K-32 conversion electrons with energy conveniently close to the beta spectrum endpoint represent an important test and calibration tool. Here, the design and characteristics of the gaseous 83mKr generator, including the 83mKr source itself, for KATRIN (KArlsruhe TRItium Neutrino) experiment are presented.

  10. Z-dependence of thick-target bremsstrahlung produced by monoenergetic low-energy electrons

    NASA Astrophysics Data System (ADS)

    Czarnecki, S.; Short, A.; Williams, S.

    2016-07-01

    The dependence of thick-target bremsstrahlung emitted by low-energy beams of monoenergetic electrons on the atomic number of the target material has been investigated experimentally for incident electron energies of 4.25 keV and 5.00 keV using thick aluminum, copper, silver, tungsten, and gold targets. Experimental data suggest that the intensity of the thick-target bremsstrahlung emitted is more strongly dependent on the atomic number of the target material for photons with energies that are approximately equal to the energy of the incident electrons than at lower energies, and also that the dependence of thick-target bremsstrahlung on the atomic number of the target material is stronger for incident electrons of higher energies than for incident electrons of lower energies. The results of the experiments are compared to the results of simulations performed using the PENELOPE program (which is commonly used in medical physics) and to thin-target bremsstrahlung theory, as well. Comparisons suggest that the experimental dependence of thick-target bremsstrahlung on the atomic number of the target material may be slightly stronger than the results of the PENELOPE code suggest.

  11. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

    SciTech Connect

    Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.; Casey, D. T.; Rosenberg, M. J.; Sinenian, N.; Li, C. K.; Frenje, J. A.; Seguin, F. H.; Petrasso, R. D.

    2012-06-15

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)] laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be {approx}16% and {approx}26% of the mean for DD and D{sup 3}He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of Greater-Than-Or-Equivalent-To 50 rad{sup -1} contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)] framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within Less-Than-Or-Equivalent-To 10% of the analytic plasma model in the example scenario.

  12. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

    NASA Astrophysics Data System (ADS)

    Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.; Casey, D. T.; Rosenberg, M. J.; Sinenian, N.; Li, C. K.; Frenje, J. A.; Séguin, F. H.; Petrasso, R. D.

    2012-06-01

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)], 10.1016/S0030-4018(96)00325-2 laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be ˜16% and ˜26% of the mean for DD and D3He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of ≳50 rad-1 contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)], 10.1016/S0168-9002(03)01368-8 framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within ≲10% of the analytic plasma model in the example scenario.

  13. Dark matter searches for monoenergetic neutrinos arising from stopped meson decay in the Sun

    SciTech Connect

    Rott, Carsten; In, Seongjin; Kumar, Jason; Yaylali, David E-mail: seongjin.in@gmail.com E-mail: yaylali@email.arizona.edu

    2015-11-01

    Dark matter can be gravitationally captured by the Sun after scattering off solar nuclei. Annihilations of the dark matter trapped and accumulated in the centre of the Sun could result in one of the most detectable and recognizable signals for dark matter. Searches for high-energy neutrinos produced in the decay of annihilation products have yielded extremely competitive constraints on the spin-dependent scattering cross sections of dark matter with nuclei. Recently, the low energy neutrino signal arising from dark-matter annihilation to quarks which then hadronize and shower has been suggested as a competitive and complementary search strategy. These high-multiplicity hadronic showers give rise to a large amount of pions which will come to rest in the Sun and decay, leading to a unique sub-GeV neutrino signal. We here improve on previous works by considering the monoenergetic neutrino signal arising from both pion and kaon decay. We consider searches at liquid scintillation, liquid argon, and water Cherenkov detectors and find very competitive sensitivities for few-GeV dark matter masses.

  14. Ionization-assisted Relativistic Electron Generation with Monoenergetic Features from Laser Thin Foil Interaction

    NASA Astrophysics Data System (ADS)

    Karpeev, Artem; Glazyrin, Igor; Kotova, Olga; Bychenkov, Valery; Fedosejevs, Robert; Rozmus, Wojciech

    2013-10-01

    The concept of ionization-induced injection into the laser pulse to produce quasi-monoenergetic bunches of electrons from ultra-thin solid dense targets is analyzed. When the laser pulse propagates through semi-transparent foil the electrons from inner atom shells remain bound during the rise time of the laser pulse and are ionized by the laser intensity near its maximum amplitude, which satisfies the best injection condition for subsequent acceleration. The 2D3V PIC code PICNIC was used for simulation of a linearly polarized laser pulse with a wavelength λ = 1 . 053 μ m normally incident onto nano-sized DLC target. We performed simulations for 3 cases: (1) 5 nm carbon foil ionized due to field ionization (FI); (2) the same, but already ionized foil, i.e. the foil in the form of a plasma slab with average charge < Z > = 3.4; (3) 42 nm carbon foil with FI. Comparison of the results obtained with different target models shows that a correct description of the interaction of a high contrast laser pulse with an ultra-thin solid dense target should include the FI effect. It was found that for the case (1) a bunch of quasimonoenergetic electrons from inner atom shells moves co-directionally with laser pulse and acquire energy ~mec2a2 / 2 .

  15. Quasi-monoenergetic laser-plasma acceleration of electrons to 2 GeV

    PubMed Central

    Wang, Xiaoming; Zgadzaj, Rafal; Fazel, Neil; Li, Zhengyan; Yi, S. A.; Zhang, Xi; Henderson, Watson; Chang, Y.-Y.; Korzekwa, R.; Tsai, H.-E.; Pai, C.-H.; Quevedo, H.; Dyer, G.; Gaul, E.; Martinez, M.; Bernstein, A. C.; Borger, T.; Spinks, M.; Donovan, M.; Khudik, V.; Shvets, G.; Ditmire, T.; Downer, M. C.

    2013-01-01

    Laser-plasma accelerators of only a centimetre’s length have produced nearly monoenergetic electron bunches with energy as high as 1 GeV. Scaling these compact accelerators to multi-gigaelectronvolt energy would open the prospect of building X-ray free-electron lasers and linear colliders hundreds of times smaller than conventional facilities, but the 1 GeV barrier has so far proven insurmountable. Here, by applying new petawatt laser technology, we produce electron bunches with a spectrum prominently peaked at 2 GeV with only a few per cent energy spread and unprecedented sub-milliradian divergence. Petawatt pulses inject ambient plasma electrons into the laser-driven accelerator at much lower density than was previously possible, thereby overcoming the principal physical barriers to multi-gigaelectronvolt acceleration: dephasing between laser-driven wake and accelerating electrons and laser pulse erosion. Simulations indicate that with improvements in the laser-pulse focus quality, acceleration to nearly 10 GeV should be possible with the available pulse energy. PMID:23756359

  16. Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA.

    PubMed

    Manuel, M J-E; Zylstra, A B; Rinderknecht, H G; Casey, D T; Rosenberg, M J; Sinenian, N; Li, C K; Frenje, J A; Séguin, F H; Petrasso, R D

    2012-06-01

    A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)] laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be ∼16% and ∼26% of the mean for DD and D(3)He fusion protons, respectively. From individual fluence images, it was found that the angular frequencies of ≳50 rad(-1) contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)] framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within ≲10% of the analytic plasma model in the example scenario.

  17. Experimental determination of the response functions of a Bonner sphere spectrometer to monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Hu, Z.; Chen, Z.; Peng, X.; Du, T.; Cui, Z.; Ge, L.; Zhu, W.; Wang, Z.; Zhu, X.; Chen, J.; Zhang, G.; Li, X.; Chen, J.; Zhang, H.; Zhong, G.; Hu, L.; Wan, B.; Gorini, G.; Fan, T.

    2017-06-01

    A Bonner sphere spectrometer (BSS) plays an important role in characterizing neutron spectra and determining their neutron dose in a neutron-gamma mixed field. A BSS consisting of a set of nine polyethylene spheres with a 3He proportional counter was developed at Peking University to perform neutron spectrum and dosimetry measurements. Response functions (RFs) of the BSS were calculated with the general Monte Carlo code MCNP5 for the neutron energy range from thermal up to 20 MeV, and were experimentally calibrated with monoenergetic neutron beams from 144 keV to 14 MeV on a 4.5 MV Van de Graaff accelerator. The calculated RFs were corrected with the experimental values, and the whole response matrix was completely established. The spectrum of a 241Am-Be source was obtained after unfolding the measurement data of the BSS to the source and in fair agreement with the expected one. The integral ambient dose equivalent corresponding to the spectrum was 0.95 of the expected value. Results of the unfolded spectrum and the integral dose equivalent measured by the BSS verified that the RFs of the BSS were well established.

  18. Decisive disappearance search at high Δ m2 with monoenergetic muon neutrinos

    NASA Astrophysics Data System (ADS)

    Axani, S.; Collin, G.; Conrad, J. M.; Shaevitz, M. H.; Spitz, J.; Wongjirad, T.

    2015-11-01

    "KPipe" is a proposed experiment which will study muon neutrino disappearance for a sensitive test of the Δ m2˜1 eV2 anomalies, possibly indicative of one or more sterile neutrinos. The experiment is to be located at the J-PARC Materials and Life Science Experimental Facility's spallation neutron source, which represents the world's most intense source of charged kaon decay-at-rest monoenergetic (236 MeV) muon neutrinos. The detector vessel, designed to measure the charged-current interactions of these neutrinos, will be 3 m in diameter and 120 m long, extending radially at a distance of 32 to 152 m from the source. This design allows a sensitive search for νμ disappearance associated with currently favored light sterile neutrino models and features the ability to reconstruct the neutrino oscillation wave within a single, extended detector. The required detector design, technology, and costs are modest. The KPipe measurements will be robust since they depend on a known energy neutrino source with low expected backgrounds. Further, since the measurements rely only on the measured rate of detected events as a function of distance, with no required knowledge of the initial flux and neutrino interaction cross section, the results will be largely free of systematic errors. The experimental sensitivity to oscillations, based on a shape-only analysis of the L /E distribution, will extend an order of magnitude beyond present experimental limits in the relevant high-Δ m2 parameter space.

  19. High-energy quasi-monoenergetic neutron fields: existing facilities and future needs.

    PubMed

    Pomp, S; Bartlett, D T; Mayer, S; Reitz, G; Röttger, S; Silari, M; Smit, F D; Vincke, H; Yasuda, H

    2014-10-01

    The argument that well-characterised quasi-monoenergetic neutron (QMN) sources reaching into the energy domain >20 MeV are needed is presented. A brief overview of the existing facilities is given, and a list of key factors that an ideal QMN source for dosimetry and spectrometry should offer is presented. The authors conclude that all of the six QMN facilities currently in existence worldwide operate in sub-optimal conditions for dosimetry. The only currently available QMN facility in Europe capable of operating at energies >40 MeV, TSL in Uppsala, Sweden, is threatened with shutdown in the immediate future. One facility, NFS at GANIL, France, is currently under construction. NFS could deliver QMN beams up to about 30 MeV. It is, however, so far not clear if and when NFS will be able to offer QMN beams or operate with only so-called white neutron beams. It is likely that by 2016, QMN beams with energies >40 MeV will be available only in South Africa and Japan, with none in Europe.

  20. Response of a lithium gadolinium borate scintillator in monoenergetic neutron fields.

    PubMed

    Williams, A M; Beeley, P A; Spyrou, N M

    2004-01-01

    Accurate estimation of neutron dose requires knowledge of the neutron energy distribution in the working environment. Existing neutron spectrometry systems, Bonner spheres for example, are large and bulky, and require long data acquisition times. A portable system that could indicate the approximate neutron energy spectrum in a short time would be extremely useful in radiation protection. A composite scintillator, consisting of lithium gadolinium borate crystals in a plastic scintillator matrix, produced by Photogenics is being tested for this purpose. A prototype device based on this scintillator and digital pulse processing electronics has been calibrated using quasi-monoenergetic neutron fields at the low-scatter facility of the UK National Physical Laboratory (NPL). Energies selected were 144, 250, 565, 1400, 2500 and 5000 keV, with correction for scattered neutrons being made using the shadow cone technique. Measurements were also made in the NPL thermal neutron field. Pulse distributions collected with the digitiser in capture-gated mode are presented, and detection efficiency and energy resolution derived. For comparison, neutron spectra were also collected using the commercially available Microspec N-Probe from Bubble Technology Industries, which consists of an NE213 scintillator and a 3He proportional counter.

  1. Overview of Mono-Energetic Gamma-Ray Sources and Applications

    SciTech Connect

    Hartemann, Fred; Albert, Felicie; Anderson, Scott; Barty, Christopher; Bayramian, Andy; Chu, Tak Sum; Cross, R.; Ebbers, Chris; Gibson, David; Marsh, Roark; McNabb, Dennis; Messerly, Michael; Shverdin, Miroslav; Siders, Craig; Jongewaard, Erik; Raubenheimer, Tor; Tantawi, Sami; Vlieks, Arnold; Semenov, Vladimir; /UC, Berkeley

    2012-06-25

    Recent progress in accelerator physics and laser technology have enabled the development of a new class of tunable gamma-ray light sources based on Compton scattering between a high-brightness, relativistic electron beam and a high intensity laser pulse produced via chirped-pulse amplification (CPA). A precision, tunable Mono-Energetic Gamma-ray (MEGa-ray) source driven by a compact, high-gradient X-band linac is currently under development and construction at LLNL. High-brightness, relativistic electron bunches produced by an X-band linac designed in collaboration with SLAC NAL will interact with a Joule-class, 10 ps, diode-pumped CPA laser pulse to generate tunable {gamma}-rays in the 0.5-2.5 MeV photon energy range via Compton scattering. This MEGaray source will be used to excite nuclear resonance fluorescence in various isotopes. Applications include homeland security, stockpile science and surveillance, nuclear fuel assay, and waste imaging and assay. The source design, key parameters, and current status are presented, along with important applications, including nuclear resonance fluorescence.

  2. Estimating Shock Spectra: Extensions beyond GEVS

    NASA Technical Reports Server (NTRS)

    Igusa, Takeru; Maahs, Gordon L.

    2008-01-01

    Shock response spectra (SRS) are the standard description of some vibration environments on spacecraft for equipment qualification. For shock events produced by pyrotechnic devices, SRS can have significant frequency content as high as 10 kHz. It is difficult to construct and analyze finite element models that can resolve dynamic behavior at such high frequencies. GEVS provides simple, empirically based methods for approximating the SRS for a wide variety of shock events. It begins with a base SRS according to the type of pyrotechnic device, and then provides attenuation relations to adjust this SRS according to distance from the shock source, the type of structural frame and the properties of any structural joints between the source and equipment. In our paper we extend GEVS to include more detailed information about the spacecraft structure. To retain the general framework of GEVS, we begin with a base SRS and adjust this SRS using attenuation relations. We use modal and traveling wave concepts to derive the attenuation relations for simple canonical structures. Then we show how these concepts can be used to analyze more complex structures using finite element mode shapes to explicitly calculate the attenuation factors. Since the low- to mid-frequency finite element modal information is extrapolated to obtain the low- to high-frequency attenuation relations, the resulting attenuated SRS is formulated as an upper bound rather than as mean predicted values. We illustrate the extended GEVS approach by analyzing the impact response of composite tubes and the shock response of the STEREO spacecraft.

  3. Nonintrusive Emittance Measurement of 1GeV H- Beam with a Laser

    SciTech Connect

    Liu, Yun; Aleksandrov, Alexander V; Long, Cary D; Menshov, Alexander A; Pogge, James R; Webster, Anthony W; Zhukov, Alexander P

    2012-01-01

    A laser wire based transverse phase space measurement system has been developed at the Spallation Neutron Source (SNS). The system allows a nonintrusive measurement of 1GeV hydrogen ion (H-) beam at the high energy beam transport (HEBT). This paper describes the design, installation, and measurement performance of the system. Major technical challenges in the implementation and commissioning of the nonintrusive phase space diagnostics at high brightness particle accelerator facilities are discussed.

  4. Net charge fluctuations in Au + Au interactions at sqrt[s(NN)]=130 GeV.

    PubMed

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; El Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H-A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kotchetkov, D; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S

    2002-08-19

    Data from Au + Au interactions at sqrt[s(NN)]=130 GeV, obtained with the PHENIX detector at the Relativistic Heavy-Ion Collider, are used to investigate local net charge fluctuations among particles produced near midrapidity. According to recent suggestions, such fluctuations may carry information from the quark-gluon plasma. This analysis shows that the fluctuations are dominated by a stochastic distribution of particles, but are also sensitive to other effects, like global charge conservation and resonance decays.

  5. Research in atomic and applied physics using a 6-GeV synchrotron source

    SciTech Connect

    Jones, K.W.

    1985-12-01

    The Division of Atomic and Applied Physics in the Department of Applied Science at Brookhaven National Laboratory conducts a broad program of research using ion beams and synchrotron radiation for experiments in atomic physics and nuclear analytical techniques and applications. Many of the experiments would benefit greatly from the use of high energy, high intensity photon beams from a 6-GeV synchrotron source. A survey of some of the specific scientific possibilities is presented.

  6. Effect of a Noise-Optimized Second-Generation Monoenergetic Algorithm on Image Noise and Conspicuity of Hypervascular Liver Tumors: An In Vitro and In Vivo Study.

    PubMed

    Marin, Daniele; Ramirez-Giraldo, Juan Carlos; Gupta, Sonia; Fu, Wanyi; Stinnett, Sandra S; Mileto, Achille; Bellini, Davide; Patel, Bhavik; Samei, Ehsan; Nelson, Rendon C

    2016-06-01

    The purpose of this study is to investigate whether the reduction in noise using a second-generation monoenergetic algorithm can improve the conspicuity of hypervascular liver tumors on dual-energy CT (DECT) images of the liver. An anthropomorphic liver phantom in three body sizes and iodine-containing inserts simulating hypervascular lesions was imaged with DECT and single-energy CT at various energy levels (80-140 kV). In addition, a retrospective clinical study was performed in 31 patients with 66 hypervascular liver tumors who underwent DECT during the late hepatic arterial phase. Datasets at energy levels ranging from 40 to 80 keV were reconstructed using first- and second-generation monoenergetic algorithms. Noise, tumor-to-liver contrast-to-noise ratio (CNR), and CNR with a noise constraint (CNRNC) set with a maximum noise increase of 50% were calculated and compared among the different reconstructed datasets. The maximum CNR for the second-generation monoenergetic algorithm, which was attained at 40 keV in both phantom and clinical datasets, was statistically significantly higher than the maximum CNR for the first-generation monoenergetic algorithm (p < 0.001) or single-energy CT acquisitions across a wide range of kilovoltage values. With the second-generation monoenergetic algorithm, the optimal CNRNC occurred at 55 keV, corresponding to lower energy levels compared with first-generation algorithm (predominantly at 70 keV). Patient body size did not substantially affect the selection of the optimal energy level to attain maximal CNR and CNRNC using the second-generation monoenergetic algorithm. A noise-optimized second-generation monoenergetic algorithm significantly improves the conspicuity of hypervascular liver tumors.

  7. Use of a Noise Optimized Monoenergetic Algorithm for Patient-Size Independent Selection of an Optimal Energy Level During Dual-Energy CT of the Pancreas.

    PubMed

    Bellini, Davide; Gupta, Sonia; Ramirez-Giraldo, Juan Carlos; Fu, Wanyi; Stinnett, Sandra S; Patel, Bhavik; Mileto, Achille; Marin, Daniele

    2017-01-01

    To investigate the impact of a second-generation noise-optimized monoenergetic algorithm on selection of the optimal energy level, image quality, and effect of patient body habitus for dual-energy multidetector computed tomography of the pancreas. Fifty-nine patients (38 men, 21 women) underwent dual-energy multidetector computed tomography (80/Sn140 kV) in the pancreatic parenchymal phase. Image data sets, at energy levels ranging from 40 to 80 keV (in 5-keV increments), were reconstructed using first-generation and second-generation noise-optimized monoenergetic algorithm. Noise, pancreatic contrast-to-noise ratio (CNRpancreas), and CNR with a noise constraint (CNRNC) were calculated and compared among the different reconstructed data sets. Qualitative assessment of image quality was performed by 3 readers. For all energy levels below 70 keV, noise was significantly lower (P ≤ 0.05) and CNRpancreas significantly higher (P < 0.001), with the second-generation monoenergetic algorithm. Furthermore, the second-generation algorithm was less susceptible to variability related to patient body habitus in the selection of the optimal energy level. The maximal CNRpancreas occurred at 40 keV in 98% (58 of 59) of patients with the second-generation monoenergetic algorithm. However, the CNRNC and readers' image quality scores showed that, even with a second-generation monoenergetic algorithm, higher reconstructed energy levels (60-65 keV) represented the optimal energy level. Second-generation noise-optimized monoenergetic algorithm can improve the image quality of lower-energy monoenergetic images of the pancreas, while decreasing the variability related to patient body habitus in selection of the optimal energy level.

  8. Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams.

    PubMed

    Rahman, Wan Nordiana; Corde, Stéphanie; Yagi, Naoto; Abdul Aziz, Siti Aishah; Annabell, Nathan; Geso, Moshi

    2014-01-01

    Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. In this research, synchrotron-generated monoenergetic X-rays in the 30-100 keV range were used to investigate the energy dependence of radiosensitization by gold nanoparticles and also to determine the photon energy that produces optimum effects. This investigation was conducted using cells in culture to measure dose enhancement. Bovine aortic endothelial cells with and without gold nanoparticles were irradiated with X-rays at energies of 30, 40, 50, 60, 70, 81, and 100 keV. Trypan blue exclusion assays were performed after irradiation to determine cell viability. Cell radiosensitivity enhancement was indicated by the dose enhancement factor which was found to be maximum at 40 keV with a value of 3.47. The dose enhancement factor obtained at other energy levels followed the same direction as the theoretical calculations based on the ratio of the mass energy absorption coefficients of gold and water. This experimental evidence shows that the radiosensitization effect of gold nanoparticles varies with photon energy as predicted from theoretical calculations. However, prediction based on theoretical assumptions is sometimes difficult due to the complexity of biological systems, so further study at the cellular level is required to fully characterize the effects

  9. Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams

    PubMed Central

    Rahman, Wan Nordiana; Corde, Stéphanie; Yagi, Naoto; Abdul Aziz, Siti Aishah; Annabell, Nathan; Geso, Moshi

    2014-01-01

    Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. In this research, synchrotron-generated monoenergetic X-rays in the 30–100 keV range were used to investigate the energy dependence of radiosensitization by gold nanoparticles and also to determine the photon energy that produces optimum effects. This investigation was conducted using cells in culture to measure dose enhancement. Bovine aortic endothelial cells with and without gold nanoparticles were irradiated with X-rays at energies of 30, 40, 50, 60, 70, 81, and 100 keV. Trypan blue exclusion assays were performed after irradiation to determine cell viability. Cell radiosensitivity enhancement was indicated by the dose enhancement factor which was found to be maximum at 40 keV with a value of 3.47. The dose enhancement factor obtained at other energy levels followed the same direction as the theoretical calculations based on the ratio of the mass energy absorption coefficients of gold and water. This experimental evidence shows that the radiosensitization effect of gold nanoparticles varies with photon energy as predicted from theoretical calculations. However, prediction based on theoretical assumptions is sometimes difficult due to the complexity of biological systems, so further study at the cellular level is required to fully characterize the

  10. Monoenergetic positron beam at the reactor based positron source at FRM-II

    NASA Astrophysics Data System (ADS)

    Hugenschmidt, C.; Kögel, G.; Repper, R.; Schreckenbach, K.; Sperr, P.; Straßer, B.; Triftshäuser, W.

    2002-05-01

    The principle of the in-pile positron source at the Munich research reactor FRM-II is based on absorption of high energy prompt γ-rays from thermal neutron capture in 113Cd. For this purpose, a cadmium cap is placed inside the tip of the inclined beam tube SR-11 in the moderator tank of the reactor, where an undisturbed thermal neutron flux up to 2×10 14n cm-2 s-1 is expected. Inside the cadmium cap a structure of platinum foils is placed for converting high energy γ-radiation into positron-electron pairs. Due to the negative positron work function, moderation in annealed platinum leads to emission of monoenergetic positrons. Therefore, platinum will also be used as moderator, since its moderation property seems to yield long-term stability under reactor conditions and it is much easier to handle than tungsten. Model calculations were performed with SIMION-7.0w to optimise geometry and potential of Pt-foils and electrical lenses. It could be shown that the potentials between the Pt-foils must be chosen in the range of 1-10 V to extract moderated positrons. After successive acceleration to 5 keV by four electrical lenses the beam is magnetically guided in a solenoid field of 7.5 mT resulting in a beam diameter of about 25 mm. An intensity of about 10 10 slow positrons per second is expected in the primary positron beam. Outside of the reactor shield a W(1 0 0) single crystal remoderation stage will lead to an improvement of the positron beam brilliance before the positrons are guided to the experimental facilities.

  11. Dose point kernel simulation for monoenergetic electrons and radionuclides using Monte Carlo techniques.

    PubMed

    Wu, J; Liu, Y L; Chang, S J; Chao, M M; Tsai, S Y; Huang, D E

    2012-11-01

    Monte Carlo (MC) simulation has been commonly used in the dose evaluation of radiation accidents and for medical purposes. The accuracy of simulated results is affected by the particle-tracking algorithm, cross-sectional database, random number generator and statistical error. The differences among MC simulation software packages must be validated. This study simulated the dose point kernel (DPK) and the cellular S-values of monoenergetic electrons ranging from 0.01 to 2 MeV and the radionuclides of (90)Y, (177)Lu and (103 m)Rh, using Fluktuierende Kaskade (FLUKA) and MC N-Particle Transport Code Version 5 (MCNP5). A 6-μm-radius cell model consisting of the cell surface, cytoplasm and cell nucleus was constructed for cellular S-value calculation. The mean absolute percentage errors (MAPEs) of the scaled DPKs, simulated using FLUKA and MCNP5, were 7.92, 9.64, 4.62, 3.71 and 3.84 % for 0.01, 0.1, 0.5, 1 and 2 MeV, respectively. For the three radionuclides, the MAPEs of the scaled DPKs were within 5 %. The maximum deviations of S(N←N), S(N←Cy) and S(N←CS) for the electron energy larger than 10 keV were 6.63, 6.77 and 5.24 %, respectively. The deviations for the self-absorbed S-values and cross-dose S-values of the three radionuclides were within 4 %. On the basis of the results of this study, it was concluded that the simulation results are consistent between FLUKA and MCNP5. However, there is a minor inconsistency for low energy range. The DPK and the cellular S-value should be used as the quality assurance tools before the MC simulation results are adopted as the gold standard.

  12. Development of a High- Brightness, Quasi- Monoenergetic Neutron Source at LLNL for Nuclear Physics Applications

    NASA Astrophysics Data System (ADS)

    Johnson, M. S.; Anderson, S. G.; Bleuel, D.; Fitsos, P. J.; Gibson, D.; Hall, J. M.; Marsh, R.; Rusnak, B.

    2016-09-01

    Lawrence Livermore National Laboratory is developing a high-brightness, quasi-monoenergetic neutron source. The intensity of the neutron source is expected to be 1011 n/s/sr with energies between 7 MeV and 10 MeV at 5% bandwidth at 0-degrees. This energy region is important for the study of neutron-induced reactions, nuclear astrophysics, and nuclear structure. For example, for neutrons between 1 and 10 MeV, the capturing states are below the GDR in many nuclei and the dominant reactions are compound and direct capture. The intensity and energy selection of the source makes it appealing for measurements of sparse targets at specific energies. We will present an array of nuclear physics measurements that will benefit from this source. The source is also of interest to generating activated targets for decay-out studies or for target production for other reaction-based measurements, e.g. fusion-evaporation reactions. Other usage examples include practical applications for imaging of very dense objects such as machine parts. For this presentation, we will discuss our method to use (d,n) production reaction on deuterium in a windowless gas target system. This approach is required because of the large power of the 7 MeV, 300 μA deuteron beams. We will discuss our facility and its capabilities. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  13. Meson Spectroscopy At Jlab At 12 Gev

    SciTech Connect

    Fegan, Stuart

    2014-12-01

    The 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab will enable a new generation of experiments in hadronic nuclear physics, seeking to address fundamental questions in our understanding of QCD. The existence of exotic states, suggested by both quark models and lattice calculations, would allow gluonic degrees of freedom to be explored, and may help explain the role played by gluons in the QCD interaction. This article will review the meson spectroscopy program being planned at the lab following the 12 GeV upgrade, utilising real and quasi-real photon beams in two of the lab's four experimental halls, whose distinct capabilities will enable an extensive set of spectroscopy experiments to be performed at the same facility.

  14. Centrality and pseudorapidity dependence of elliptic flow for charged hadrons in Au+Au collisions at {radical}(s{sub NN})=200 GeV

    SciTech Connect

    Back, B.B.; Wuosmaa, A.H.; Baker, M.D.; Barton, D.S.; Carroll, A.; Gushue, S.; Heintzelman, G.A.; Holzman, B.; Nguyen, M.; Pak, R.; Remsberg, L.P.; Steinberg, P.; Sukhanov, A.; Ballintijn, M.; Busza, W.; Decowski, M.P.; Gulbrandsen, K.; Henderson, C.; Kane, J.L.; Kulinich, P.

    2005-11-01

    This Rapid Communication describes the measurement of elliptic flow for charged particles in Au+Au collisions at {radical}(s{sub NN})=200 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider. The measured azimuthal anisotropy is presented over a wide range of pseudorapidity for three broad collision centrality classes for the first time at this energy. Two distinct methods of extracting the flow signal were used to reduce systematic uncertainties. The elliptic flow falls sharply with increasing |{eta}| at 200 GeV for all the centralities studied, as observed for minimum-bias collisions at {radical}(s{sub NN})=130 GeV.

  15. Booster 6-GeV study

    SciTech Connect

    Yang, Xi; Ankenbrandt, Charles M.; Pellico, William A.; Lackey, James; Padilla, Rene; Norem, James; /Argonne

    2005-05-01

    A wider aperture, which has been obtained along the Booster beam line recently, brings the opportunity to run beams with the intensity higher than ever before. Sooner or later, the available RF accelerating voltage will become a new limit for the beam intensity. Extra accelerating voltages can be achieved either by increasing the RFSUM or by reducing the accelerating rate via a slower acceleration, and this motivates the 6-GeV study.

  16. Booster 6-GeV study

    SciTech Connect

    Yang, Xi; Ankenbrandt, Charles M.; Pellico, William A.; Lackey, James; Padilla, Rene; Norem, J.; /Argonne

    2004-12-01

    Since a wider aperture has been obtained along the Booster beam line, this opens the opportunity for Booster running a higher intensity beam than ever before. Sooner or later, the available RF accelerating voltage will become a new limit for the beam intensity. Either by increasing the RFSUM or by reducing the accelerating rate can achieve the similar goal. The motivation for the 6-GeV study is to gain the relative accelerating voltage via a slower acceleration.

  17. Λ Λ Correlation Function in Au +Au Collisions at √{sN N }=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-01-01

    We present Λ Λ correlation measurements in heavy-ion collisions for Au +Au collisions at √{sN N }=200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the Λ Λ correlation function and interaction parameters for dihyperon searches are discussed.

  18. Measurements of low energy auroral ions

    NASA Astrophysics Data System (ADS)

    Urban, A.

    1981-12-01

    Ion measurements in the energy range 0.1-30 keV observed during the 'Substorm Phenomena' and 'Porcupine' campaigns are summarized. Acceleration of the ions by an electrostatic field aligned parallel to the magnetic field is identified and found to be accompanied by intense electron precipitation. On the other hand, deceleration of the ions is observed in other field-aligned current sheets which are indicated by the electron and magnetic field measurements. Temporal successive monoenergetic ion variations suggest energy dispersion and a location of the source region at 9 earth radii. What is more, ion fluxes higher than those of the electrons are measured at pitch angles parallel to the magnetic field. It is noted that each of the examples was observed during different flights.

  19. Mixed methods for fitting the GEV distribution

    NASA Astrophysics Data System (ADS)

    Ailliot, Pierre; Thompson, Craig; Thomson, Peter

    2011-05-01

    The generalized extreme-value (GEV) distribution is widely used for modeling and characterizing extremes. It is a flexible three-parameter distribution that combines three extreme-value distributions within a single framework: the Gumbel, Frechet, and Weibull. Common methods used for estimating the GEV parameters are the method of maximum likelihood and the method of L-moments. This paper generalizes the mixed maximum likelihood and L-moments GEV estimation procedures proposed by Morrison and Smith (2002) and derives the asymptotic properties of the resulting estimators. Analytic expressions are given for the asymptotic covariance matrices in a number of important cases, including the estimators proposed by Morrison and Smith (2002). These expressions are verified by simulation and the efficiencies of the various estimators established. The asymptotic results are compared to those obtained for small to medium-size samples by simulation with the estimated parameters and quantiles assessed for accuracy and bias. Using simplified constraints for the support of the log likelihood, computational strategies and graphical tools are developed which lead to computationally efficient, numerically robust, estimation procedures suitable for automatic batch processing of many data sets. The methods are illustrated by application to annual maximum rainfall data at a large number of New Zealand locations. For Wellington, 24 h annual maximum rainfall over the period 1940-1999 is also considered within each phase of the Interdecadal Pacific Oscillation.

  20. The application of metal artifact reduction (MAR) in CT scans for radiation oncology by monoenergetic extrapolation with a DECT scanner.

    PubMed

    Schwahofer, Andrea; Bär, Esther; Kuchenbecker, Stefan; Grossmann, J Günter; Kachelrieß, Marc; Sterzing, Florian

    2015-12-01

    Metal artifacts in computed tomography CT images are one of the main problems in radiation oncology as they introduce uncertainties to target and organ at risk delineation as well as dose calculation. This study is devoted to metal artifact reduction (MAR) based on the monoenergetic extrapolation of a dual energy CT (DECT) dataset. In a phantom study the CT artifacts caused by metals with different densities: aluminum (ρ Al=2.7 g/cm(3)), titanium (ρ Ti=4.5 g/cm(3)), steel (ρ steel=7.9 g/cm(3)) and tungsten (ρ W=19.3g/cm(3)) have been investigated. Data were collected using a clinical dual source dual energy CT (DECT) scanner (Siemens Sector Healthcare, Forchheim, Germany) with tube voltages of 100 kV and 140 kV(Sn). For each tube voltage the data set in a given volume was reconstructed. Based on these two data sets a voxel by voxel linear combination was performed to obtain the monoenergetic data sets. The results were evaluated regarding the optical properties of the images as well as the CT values (HU) and the dosimetric consequences in computed treatment plans. A data set without metal substitute served as the reference. Also, a head and neck patient with dental fillings (amalgam ρ=10 g/cm(3)) was scanned with a single energy CT (SECT) protocol and a DECT protocol. The monoenergetic extrapolation was performed as described above and evaluated in the same way. Visual assessment of all data shows minor reductions of artifacts in the images with aluminum and titanium at a monoenergy of 105 keV. As expected, the higher the densities the more distinctive are the artifacts. For metals with higher densities such as steel or tungsten, no artifact reduction has been achieved. Likewise in the CT values, no improvement by use of the monoenergetic extrapolation can be detected. The dose was evaluated at a point 7 cm behind the isocenter of a static field. Small improvements (around 1%) can be seen with 105 keV. However, the dose uncertainty remains of the order of 10

  1. Directional searches at DUNE for sub-GeV monoenergetic neutrinos arising from dark matter annihilation in the Sun

    NASA Astrophysics Data System (ADS)

    Rott, Carsten; In, Seongjin; Kumar, Jason; Yaylali, David

    2017-01-01

    We consider the use of directionality in the search for monoenergetic sub-GeV neutrinos arising from the decay of stopped kaons, which can be produced by dark matter annihilation in the core of the Sun. When these neutrinos undergo charged-current interactions with a nucleus at a neutrino detector, they often eject a proton which is highly peaked in the forward direction. The direction of this track can be measured at DUNE, allowing one to distinguish signal from background by comparing on-source and off-source event rates. We find that directional information can enhance the signal to background ratio by up to a factor of 5.

  2. Performance of the UAB and the INFN-LNF Bonner sphere spectrometers in quasi monoenergetic neutron fields.

    PubMed

    Bedogni, R; Esposito, A; Domingo, C; Fernández, F; Garcia, M J; Angelone, M

    2007-01-01

    In the framework of collaboration between the Universidad Autónoma de Barcelona and the INFN Frascati National Laboratories, an experimental Bonner Sphere neutron spectrometry exercise has been performed in the 2.5 MeV and 14.2 MeV quasi monoenergetic neutron beams of the ENEA Fast Neutron Generator. The neutron spectra at given distances from the accelerator target have been determined, taking advantage of the new unfolding FRUIT code, recently developed by the LNF group. The results show a good coherence between the two spectrometers, and between the measured and simulated data.

  3. Virtual monoenergetic dual-energy computed tomography: optimization of kiloelectron volt settings in head and neck cancer.

    PubMed

    Wichmann, Julian L; Nöske, Eva-Maria; Kraft, Johannes; Burck, Iris; Wagenblast, Jens; Eckardt, Anne; Frellesen, Claudia; Kerl, J Matthias; Bauer, Ralf W; Bodelle, Boris; Lehnert, Thomas; Vogl, Thomas J; Schulz, Boris

    2014-11-01

    The aim of this study was to evaluate the effects on objective and subjective image quality of virtual monoenergetic reconstructions at various energy levels of dual-energy computed tomography (DECT) in patients with head and neck cancer. We included 71 (53 men, 18 women; age, 59.3 ± 12.0 years; range, 33-90 years) patients with biopsy-proven untreated primary (n = 55) or recurrent (n = 16) squamous cell carcinoma who underwent head and neck DECT. Images were reconstructed with a linear blending setting emulating 120 kV acquisition (M_0.3; 30% of 80 kV, 70% of 140 kV spectrum) and as virtual monoenergetic images with photon energies of 40, 60, 80, and 100 keV. Attenuation of lesion, various anatomic landmarks, and image noise were objectively measured, and lesion contrast-to-noise ratio (CNR) was calculated. Two independent blinded radiologists subjectively rated each image series using a 5-point grading scale regarding overall image quality, lesion delineation, image sharpness, and image noise. Tumor attenuation peaked at 40 keV (140.2 ± 42.6 HU) followed by the 60 keV (121.7 ± 25.5 HU) and M_0.3 series (102.7 ± 22.3; all P < 0.001). However, the calculated lesion CNR was highest in the 60 keV reconstructions (12.45 ± 7.17), 80 keV reconstructions (8.66 ± 6.58), and M_0.3 series (5.21 ± 3.15; all P < 0.001) and superior to the other monoenergetic series (all P < 0.001). Subjective image analysis was highest for the 60 keV series regarding overall image quality (4.22; κ = 0.411) and lesion delineation (4.35; κ = 0.459) followed by the M_0.3 series (3.81; κ = 0.394; 3.77; κ = 0.451; all P < 0.001). Image sharpness showed no significant difference between both series (3.81 vs 3.79; P = 0.78). Image noise was rated superior in the 80 and 100 keV series (4.31 vs 4.34; P = 0.522). Compared with linearly blended images, virtual monoenergetic reconstructions of DECT data at 60 keV significantly improve lesion enhancement and CNR, subjective overall image

  4. Technical Note: Improved CT number stability across patient size using dual-energy CT virtual monoenergetic imaging

    SciTech Connect

    Michalak, Gregory; Grimes, Joshua; Fletcher, Joel; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia; Halaweish, Ahmed

    2016-01-15

    Purpose: The purpose of this study was to evaluate, over a wide range of phantom sizes, CT number stability achieved using two techniques for generating dual-energy computed tomography (DECT) virtual monoenergetic images. Methods: Water phantoms ranging in lateral diameter from 15 to 50 cm and containing a CT number test object were scanned on a DSCT scanner using both single-energy (SE) and dual-energy (DE) techniques. The SE tube potentials were 70, 80, 90, 100, 110, 120, 130, 140, and 150 kV; the DE tube potential pairs were 80/140, 70/150Sn, 80/150Sn, 90/150Sn, and 100/150Sn kV (Sn denotes that the 150 kV beam was filtered with a 0.6 mm tin filter). Virtual monoenergetic images at energies ranging from 40 to 140 keV were produced from the DECT data using two algorithms, monoenergetic (mono) and monoenergetic plus (mono+). Particularly in large phantoms, water CT number errors and/or artifacts were observed; thus, datasets with water CT numbers outside ±10 HU or with noticeable artifacts were excluded from the study. CT numbers were measured to determine CT number stability across all phantom sizes. Results: Data exclusions were generally limited to cases when a SE or DE technique with a tube potential of less than 90 kV was used to scan a phantom larger than 30 cm. The 90/150Sn DE technique provided the most accurate water background over the large range of phantom sizes evaluated. Mono and mono+ provided equally improved CT number stability as a function of phantom size compared to SE; the average deviation in CT number was only 1.4% using 40 keV and 1.8% using 70 keV, while SE had an average deviation of 11.8%. Conclusions: The authors’ report demonstrates, across all phantom sizes, the improvement in CT number stability achieved with mono and mono+ relative to SE.

  5. TU-F-18A-09: CT Number Stability Across Patient Sizes Using Virtual-Monoenergetic Dual-Energy CT

    SciTech Connect

    Michalak, G; Grimes, J; Fletcher, J; McCollough, C; Halaweish, A

    2014-06-15

    Purpose: Virtual-monoenergetic imaging uses dual-energy CT data to synthesize images corresponding to a single photon energy, thereby reducing beam-hardening artifacts. This work evaluated the ability of a commercial virtual-monoenergetic algorithm to achieve stable CT numbers across patient sizes. Methods: Test objects containing a range of iodine and calcium hydroxyapatite concentrations were placed inside 8 torso-shaped water phantoms, ranging in lateral width from 15 to 50 cm, and scanned on a dual-source CT system (Siemens Somatom Force). Single-energy scans were acquired from 70-150 kV in 10 kV increments; dual-energy scans were acquired using 4 energy pairs (low energy: 70, 80, 90, and 100 kV; high energy: 150 kV + 0.6 mm Sn). CTDIvol was matched for all single- and dual-energy scans for a given phantom size. All scans used 128×0.6 mm collimation and were reconstructed with 1-mm thickness at 0.8-mm increment and a medium smooth body kernel. Monoenergetic images were generated using commercial software (syngo Via Dual Energy, VA30). Iodine contrast was calculated as the difference in mean iodine and water CT numbers from respective regions-of-interest in 10 consecutive images. Results: CT numbers remained stable as phantom width varied from 15 to 50 cm for all dual-energy data sets (except for at 50 cm using 70/150Sn due to photon starvation effects). Relative to the 15 cm phantom, iodine contrast was within 5.2% of the 70 keV value for phantom sizes up to 45 cm. At 90/150Sn, photon starvation did not occur at 50 cm, and iodine contrast in the 50-cm phantom was within 1.4% of the 15-cm phantom. Conclusion: Monoenergetic imaging, as implemented in the evaluated commercial system, eliminated the variation in CT numbers due to patient size, and may provide more accurate data for quantitative tasks, including radiation therapy treatment planning. Siemens Healthcare.

  6. Particle size analysis of radioactive aerosols formed by irradiation of argon using 65 MeV quasi-monoenergetic neutrons.

    PubMed

    Endo, A; Noguchi, H; Tanaka, Su; Kanda, Y; Oki, Y; Iida, T; Sato, K; Tsuda, S

    2002-04-01

    The size distributions of 38Cl and 39Cl aerosols formed from the irradiation of argon gas containing di-octyl phthalate (DOP) aerosols by 65 MeV quasi-monoenergetic neutrons were measured to study the formation mechanism of radioactive aerosols in high-energy radiation fields. Both the number size distribution and the activity-weighted size distribution were measured using an electrical low-pressure impactor. It was found that the 35Cl and 39Cl aerosols are formed by attachment of the radioactive atoms generated by the neutron-induced reaction to the DOP aerosol particles.

  7. Evaluation of Neutron Response of Criticality Accident Alarm System Detector to Quasi-Monoenergetic 24 keV Neutrons

    NASA Astrophysics Data System (ADS)

    Tsujimura, Norio; Yoshida, Tadayoshi; Yashima, Hiroshi

    The criticality accident alarm system (CAAS), which was recently developed and installed at the Japan Atomic Energy Agency's Tokai Reprocessing Plant, consists of a plastic scintillator combined with a cadmium-lined polyethylene moderator and thereby responds to both neutrons and gamma rays. To evaluate the neutron absorbed dose rate response of the CAAS detector, a 24 keV quasi-monoenergetic neutron irradiation experiment was performed at the B-1 facility of the Kyoto University Research Reactor. The detector's evaluated neutron response was confirmed to agree reasonably well with prior computer-predicted responses.

  8. Assessment of Impact of Monoenergetic Photon Sources on Prioritized Nonproliferation Applications: Simulation Study Report

    SciTech Connect

    Geddes, Cameron; Ludewigt, Bernhard; Valentine, John; Quiter, Brian; Descalle, Marie-Anne; Warren, Glen; Kinlaw, Matt; Thompson, Scott; Chichester, David; Miller, Cameron; Pozzi, Sara

    2016-12-30

    Near-monoenergetic photon sources (MPSs) have the potential to improve sensitivity at greatly reduced dose in existing applications and enable new capabilities in other applications. MPS advantages include the ability to select energy, energy spread, flux, and pulse structures to deliver only the photons needed for the application, while suppressing extraneous dose and background. Some MPSs also offer narrow divergence photon beams which can target dose and/or mitigate scattering contributions to image contrast degradation. Current broad-band, bremsstrahlung photon sources (e.g., linacs and betatrons) deliver unnecessary dose that in some cases also interferes with the signature to be detected and/or restricts operations, and must be collimated (reducing flux) to generate narrow divergence beams. While MPSs can in principle resolve these issues, they are technically challenging to produce. Candidate MPS technologies for nonproliferation applications are now being developed, each of which have different properties (e.g. broad divergence vs. narrow). Within each technology, source parameters trade off against one another (e.g. flux vs. energy spread), representing a large operation space. To guide development, requirements for each application of interest must be defined and simulations conducted to define MPS parameters that deliver benefit relative to current systems. The present project conducted a broad assessment of potential nonproliferation applications where MPSs may provide new capabilities or significant performance enhancement (reported separately), which led to prioritization of several applications for detailed analysis. The applications prioritized were: cargo screening and interdiction of Special Nuclear Materials (SNM), detection of hidden SNM, treaty/dismantlement verification, and spent fuel dry storage cask content verification. High resolution imaging for stockpile stewardship was considered as a sub-area of the treaty topic, as it is also of

  9. Walking from 750 GeV to 950 GeV in the technipion zoo

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Shinya; Yamawaki, Koichi

    2016-06-01

    If the 750-GeV diphoton excess is identified with the color-singlet isosinglet technipion P0 (750) in the one-family walking technicolor model, as in our previous paper, then there should exist another color-singlet technipion-isotriplet one, P±,3, predicted at around 950 GeV independently of the dynamical details. The P±,3(950 ) are produced at the LHC via vector-boson and photon-fusion processes, predominantly decaying to W γ and γ γ , respectively. Those walking technicolor signals can be explored at run 2 or 3, which would further open the door for a plethora of other (colored) technipions.

  10. Medium energy heavy ion operations at RHIC

    SciTech Connect

    Drees, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.M.C.; Blaskiewicz, M.; Brown, K.A.; Brennan, M.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Fischer, W.; Fu, W.; Gassner, D.; Harvey, M.; Hayes, T.; Huang, H.; Hulsart, R.; Ingrassia, P.; Kling, N.; Lafky, M.; Laster, J.; Lee, R.C.; Litvinenko, V.; Luo, Y.; MacKay, W.W.; Marr, G.; Mapes. M.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.S.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; van Kuik, B.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    As part of the search for a phase transition or critical point on the QCD phase diagram, an energy scan including 5 different energy settings was performed during the 2010 RHIC heavy ion run. While the top beam energy for heavy ions is at 100 GeV/n and the lowest achieved energy setpoint was significantly below RHICs injection energy of approximately 10 GeV/n, we also provided beams for data taking in a medium energy range above injection energy and below top beam energy. This paper reviews RHIC experience and challenges for RHIC medium energy operations that produced full experimental data sets at beam energies of 31.2 GeV/n and 19.5 GeV/n. The medium energy AuAu run covered two beam energies, both above the RHIC injection energy of 9.8 GeV but well below the standard store energy of 100 GeV (see table 1). The low energy and full energy runs with heavy ions in FY10 are summarized in [1] and [2]. Stochastic Cooling ([3]) was only used for 100 GeV beams and not used in the medium energy run. The efficiency of the transition from 100 GeV operation to 31.2 GeV and then to 19.5 GeV was remarkable. Setup took 32 h and 19 h respectively for the two energy settings. The time in store, defined to be the percentage of time RHIC provides beams in physics conditions versus calendar time, was approximately 52% for the entire FY10 heavy ion run. In both medium energy runs it was well above this average, 68% for 31.5 GeV and 82% for 19.5 GeV. For both energies RHIC was filled with 111 bunches with 1.2 10{sup 9} and 1.3 10{sup 9} ions per bunch respectively.

  11. A Monte Carlo study of monoenergetic and polyenergetic normalized glandular dose (DgN) coefficients in mammography

    NASA Astrophysics Data System (ADS)

    Sarno, Antonio; Mettivier, Giovanni; Di Lillo, Francesca; Russo, Paolo

    2017-01-01

    We investigated the influence of model assumptions in GEANT4 Monte Carlo (MC) simulations for the calculation of monoenergetic and polyenergetic normalized glandular dose coefficients (DgN) in mammography, focussing on the effect of the skin thickness and composition, of the role of compression paddles and of the bremsstrahlung processes. We showed that selecting a skin thickness of 4 mm instead of 1.45 mm produced DgN values with deviations from 9% to 32% for x-ray spectra routinely adopted in mammography. Consideration of the bremsstrahlung radiation had a weak influence on monoenergetic DgN. Simulations (in the range 8-40 kVp) which included consideration of bremsstrahlung radiation, a skin thickness of 1.45 mm and a 2 mm thick compression paddles produced polyenergetic DgN coefficients up to 19% higher than corresponding literature data. Adding a 2 mm thick adipose layer between the skin layer and the radiosensitive portion of the breast produces polyenergetic DgN values up to 15% higher than those routinely adopted. These findings provide a quantitative estimate of the influence of model parameters on the calculation of the mean glandular dose in mammography.

  12. Correction and verification of AECL Bonner Sphere response matrix based on mono-energetic neutron calibration performed at NPL.

    PubMed

    Atanackovic, J; Thomas, D J; Roberts, N J; Witharana, S; Dubeau, J; Yonkeu, A

    2014-10-01

    The AECL Bonner Sphere Spectrometer (BSS) was taken to National Physical Laboratory (NPL) for calibration in mono-energetic neutron fields and bare (252)Cf neutron fields. The mono-energetic radiations were performed using ISO-8529 prescribed neutron energies: 0.071, 0.144, 0.565, 1.2, 5 and 17 MeV. A central SP9 proportional counter was also evaluated at the NPL thermal neutron calibration facility in order to assess an effective pressure of (3)He inside the counter, i.e. number density of (3)He atoms. Based on these measurements and methods outlined by Thomas and Soochak, a new BSS response matrix was generated. The response matrix is then verified by unfolding spectra corresponding to various neutron fields. Those are NPL bare (252)Cf source, National Institute of Standards and Technology bare and heavy water moderated (252)Cf source and (241)AmBe calibration source located at National Research Council. A good agreement was observed with expected neutron fluence rates, as well as derived dosimetric quantities, such as International Commission on Radiological Protection-74 ambient dose equivalent.

  13. Monoenergetic proton backlighter for measuring E and B fields and for radiographing implosions and high-energy density plasmas (invited)

    SciTech Connect

    Li, C. K.; Seguin, F. H.; Frenje, J. A.; Rygg, J. R.; Petrasso, R. D.; Town, R. P. J.; Amendt, P. A.; Hatchett, S. P.; Landen, O. L.; Mackinnon, A. J.; Patel, P. K.; Smalyuk, V. A.; Knauer, J. P.; Sangster, T. C.; Stoeckl, C.

    2006-10-15

    A novel monoenergetic proton backlighter source and matched imaging detector have been utilized on the OMEGA laser system to study electric (E) and magnetic (B) fields generated by laser-plasma interactions and will be utilized in the future to radiograph implosions and high-energy density (HED) plasmas. The backlighter consists of an imploding glass microballoon with D {sup 3}He fuel, producing 14.7 MeV D {sup 3}He protons and 3 MeV DD protons that are then passed through a mesh that divides the protons into beamlets. For quantitative study of E+B field structure, monoenergetic protons have several unique advantages compared to the broad energy spectrum used in previous experiments. Recent experiments have been performed with a single laser beam (intensity of {approx}10{sup 14} W/cm{sup 2}) interacting with a CH foil, and B fields of {approx}0.5 MG and E fields of {approx}1.5x10{sup 8} V/m have been measured using proton deflectometry. LASNEX simulations are being used to interpret these experiments. Additional information will also be presented on the application of this technique to measuring E and B fields associated with Hohlraums and directly driven implosions, to radiographically mapping the areal density ({rho}R) distribution in imploded capsules, and to radiographing HED plasmas.

  14. Effect of monoenergetic neutron irradiation on the postnatal development of the cochlea in C3H/HeN mice.

    PubMed

    Nitta, Yumiko; Araki, Nobukazu; Nitta, Kohsaku; Harada, Toshihide; Ishizaki, Fumiko; Cheng, Weiping; Ando, Juko

    2005-06-01

    To investigate the toxic effect of neutrons at energies of approximately 1MeV on the ear, we exposed 7-day-old mice to 1.0 Gy of monoenergetic neutrons (1.026 MeV) or (137)Cs gamma rays, and assessed subsequent morphological changes in the inner ear by light and scanning electron microscopy. Monoenergetic neutrons, but not gamma rays, caused acute changes in the ear. The epithelium of the greater epithelial ridge in the organ of Corti had disappeared by 72 hr post-irradiation, as a result of epithelial apoptosis observed 6 hr post-irradiation. Radiation could induce apoptotic cell death of the epithelium of the greater epithelial ridge at 3 or 4 days of age. Protruding structures were detected on the surface of the hair cells by 72 hr post-irradiation. The neutron-irradiation also caused the apoptotic cell death of epithelial cells at the nasal conchae, and subsequent acute otitis media continued until 10 weeks of age.

  15. Proton-antiproton suppression in 200A GeV Au-Au collisions

    NASA Astrophysics Data System (ADS)

    Renk, Thorsten; Eskola, Kari J.

    2007-08-01

    We discuss the measured nuclear suppression of p+p¯ production in 200A GeV Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) within radiative energy loss. For the Albino-Kniehl-Kramer (AKK) set of fragmentation functions, proton production is dominated by gluons, giving rise to the expectation that the nuclear suppression for p+p¯ should be stronger than for pions due to the stronger coupling of gluons to the quenching medium. Using a hydrodynamical description for the soft matter evolution, we show that this is indeed seen in the calculation. However, the expected suppression factors for pions and protons are sufficiently similar that a discrimination with present data is not possible. In the high pT region above 6 GeV where the contributions of hydrodynamics and recombination to hadron production are negligible, the model calculation is in good agreement with the data on p+p¯ suppression.

  16. Proton-antiproton suppression in 200A GeV Au-Au collisions

    SciTech Connect

    Renk, Thorsten; Eskola, Kari J.

    2007-08-15

    We discuss the measured nuclear suppression of p+p production in 200A GeV Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) within radiative energy loss. For the Albino-Kniehl-Kramer (AKK) set of fragmentation functions, proton production is dominated by gluons, giving rise to the expectation that the nuclear suppression for p+p should be stronger than for pions due to the stronger coupling of gluons to the quenching medium. Using a hydrodynamical description for the soft matter evolution, we show that this is indeed seen in the calculation. However, the expected suppression factors for pions and protons are sufficiently similar that a discrimination with present data is not possible. In the high p{sub T} region above 6 GeV where the contributions of hydrodynamics and recombination to hadron production are negligible, the model calculation is in good agreement with the data on p+p suppression.

  17. A CONCEPTUAL 3-GEV LANSCE LINAC UPGRADE FOR ENHANCED PROTON RADIOGRAPHY

    SciTech Connect

    Garnett, Robert W; Rybarcyk, Lawrence J.; Merrill, Frank E.; O'Hara, James F.; Rees, Daniel E.; Walstrom, Peter L.

    2012-05-14

    A conceptual design of a 3-GeV linac upgrade that would enable enhanced proton radiography at the Los Alamos Neutron Science Center (LANSCE) is presented. The upgrade is based on the use of superconducting accelerating cavities to increase the present LANSCE linac output energy from 800 MeV to 3 GeV. The LANSCE linac currently provides negative hydrogen ion (H{sup -}) and proton (H{sup +}) beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. Required changes to the front-end, the accelerating structures, and to the RF systems to meet the new performance goals, and changes to the existing beam switchyard to maintain operations for a robust user program are also described.

  18. Ion beam requirements for fast ignition of inertial fusion targets

    SciTech Connect

    Honrubia, J. J.; Murakami, M.

    2015-01-15

    Ion beam requirements for fast ignition are investigated by numerical simulation taking into account new effects, such as ion beam divergence, not included before. We assume that ions are generated by the TNSA scheme in a curved foil placed inside a re-entrant cone and focused on the cone apex or beyond. From the focusing point to the compressed core, ions propagate with a given divergence angle. Ignition energies are obtained for two compressed fuel configurations heated by proton and carbon ion beams. The dependence of the ignition energies on the beam divergence angle and on the position of the ion beam focusing point has been analyzed. Comparison between TNSA and quasi-monoenergetic ions is also shown.

  19. Commissioning and Operation of 12 GeV CEBAF

    SciTech Connect

    Freyberger, Arne P.

    2015-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) located at the Thomas Jefferson National Accelerator Laboratory (JLab) has been recently upgraded to deliver continuous electron beams to the experimental users at a maximum energy of 12 GeV, three times the original design energy of 4 GeV. This paper will present an overview of the upgrade, referred to as the 12GeV upgrade, and highlights from recent beam commissioning results.

  20. High-current ion-ring accelerator

    SciTech Connect

    Sudan, R.N. )

    1993-03-15

    An accelerator concept is outlined which enables 10[sup 15] to 10[sup 18] ions in the form of a charge neutralized ion ring to be accelerated to GeV energies. A repetition rate of 10 Hz will deliver an average current in the range of 0.1 A.

  1. Optimizing window settings for improved presentation of virtual monoenergetic images in dual-energy computed tomography.

    PubMed

    Fu, Wanyi; Marin, Daniele; Ramirez-Giraldo, Juan Carlos; Choudhury, Kingshuk Roy; Solomon, Justin; Schabel, Christoph; Patel, Bhavik N; Samei, Ehsan

    2017-08-04

    Dual-energy computed tomography virtual monoenergetic imaging (VMI) at 40 keV exhibits superior contrast-to-noise ratio (CNR), although practicing radiologists do not consistently prefer it over VMI at 70 keV due to high perceivable noise. We hypothesize that the presentation of 40 keV VMI may be compromised using window settings (i.e., window-and-level values [W-L values]) designed for conventional single-energy CT. This study aimed to devise optimum window settings that reduce the apparent noise and utilize the high CNR of 40 keV VMI, in order to improve the conspicuity of hypervascular liver lesions. Three W-L value adjustment methods were investigated to alter the presentation of 40 keV VMI. To harness the high CNR of 40 keV VMI, the methods were designed to achieve (a) liver histogram distribution, (b) lesion-to-liver contrast, or (c) liver background noise comparable to those perceived in 70 keV VMI. This IRB-approved study included 18 patient abdominal datasets reconstructed at 40 and 70 keV. For each patient, the W-L values were determined using the three methods. For each of the images with default or adjusted W-L values, the noise, contrast, and CNR were calculated in terms of both display space and native CT number (referred to as HU) space. An observer study was performed to compare the 40 keV images with the three adjusted W-L values, and 40 and 70 keV images with default W-L values in terms of noise, contrast, and diagnostic preference. A comparison was also made in terms of the applicability of using patient-specific or patient-averaged W-L values. Using the default W-L values, 40 keV VMI exhibited higher HU CNR than 70 keV VMI by 24.6 ± 14.9% (P < 0.001) but lower display CNR by 38.0 ± 16.4% (P < 0.001). Using adjusted W-L values, 40 keV images showed increased display CNR as compared to 70 keV images, by 21.2 ± 13.1%, 17.4 ± 13.6%, and 24.2 ± 15.9% (P < 0.001) for histogram-, noise-, and contrast equalization methods, respectively. The 40 ke

  2. Ion acceleration by petawatt class laser pulses and pellet compression in a fast ignition scenario

    NASA Astrophysics Data System (ADS)

    Benedetti, C.; Londrillo, P.; Liseykina, T. V.; Macchi, A.; Sgattoni, A.; Turchetti, G.

    2009-07-01

    target, produce 2×1011 monoenergetic ions of 0.5 GeV with 30% efficiency. Fully 3D simulations show a non-dramatic degradation of the beam properties. In order to reach regimes interesting for the inertial fusion, 1-2 kJ lasers with pulse duration in the 100-500 fs range should be considered with an illuminated surface of few hundreds squared microns, which would insure ˜1012 ions per shot to be produced. The efficiencies would range from 30% to 70% so that the energy of ions would vary from 0.3 to 1.5 kJ. With a few hundreds of such lasers a total energy of ˜0.2-0.6 MJ, required in the fast ignition scenario, would be reached. By tailoring the space distribution of the beams and their time sequence an adiabatic compression may be reached avoiding the issues related to the charge neutralization in the final focus.

  3. A direct-drive exploding-pusher implosion as the first step in development of a monoenergetic charged-particle backlighting platforn at the National Ignition Facility

    SciTech Connect

    Rosenberg, M. J.; Zylstra, A. B.; Seguin, F. H.; Rinderknecht, H. G.; Frenje, J. A.; Johnson, M. Gatu; Sio, H.; Waugh, C. J.; Li, C. K.; Petrasso, R. D.; LaPape, S.; Ma, T.; Mackinnon, A. J.; Rygg, J. R.; Amendt, P. A.; Bellei, C.; Benedetti, L. R.; Hopkins, L. Berzak; Bionta, R. M.; Casey, D. T.; Divol, L.; Edwards, M. J.; Glenn, S.; Glenzer, S. H.; Hicks, D. G.; Kimbrough, J. R.; Landen, O. L.; Lindl, J. D.; MacPhee, A.; McNaney, J. M.; Meezan, N. B.; Moody, J. D.; Moran, M. J.; Park, H. -S.; Pino, J.; Remington, B. A.; Robey, H.; Rosen, M. D.; Wilks, S. C.; Zacharias, R. A.; McKenty, P. W.; Hohenberger, M.; Radha, P. B.; Edgell, D.; Marshall, F. J.; Delettrez, J. A.; Glebov, V. Yu.; Betti, R.; Goncharov, V. N.; Knauer, J. P.; Sangster, T. C.; Herrmann, H. W.; Hoffman, N. M.; Kyrala, G. A.; Leeper, R. J.; Olson, R. E.; Kilkenny, J. D.; Nikroo, A.; Sinenian, N.

    2016-01-18

    A thin-glass-shell, D3He-filled exploding-pusher inertial confinement fusion implosion at the National Ignition Facility (NIF) has been demonstrated as a proton source that serves as a promising first step toward development of a monoenergetic proton, alpha, and triton backlighting platform at the NIF. Among the key measurements, the D3He-proton emission on this experiment (shot N121128) has been well-characterized spectrally, temporally, and in terms of emission isotropy, revealing a highly monoenergetic (ΔE/E~4%) and isotropic source (~3% proton fluence variation and ~0.5% proton energy variation). On a similar shot (N130129, with D2 fill), the DD-proton spectrum has been obtained as well, illustrating that monoenergetic protons of multiple energies may be utilized in a single experiment. In conclusion, these results, and experiments on OMEGA, point toward future steps in the development of a precision, monoenergetic proton, alpha, and triton source that can readily be implemented at the NIF for backlighting a broad range of high energy density physics (HEDP) experiments in which fields and flows are manifest, and also utilized for studies of stopping power in warm dense matter and in classical plasmas.

  4. A direct-drive exploding-pusher implosion as the first step in development of a monoenergetic charged-particle backlighting platform at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Rosenberg, M. J.; Zylstra, A. B.; Séguin, F. H.; Rinderknecht, H. G.; Frenje, J. A.; Gatu Johnson, M.; Sio, H.; Waugh, C. J.; Sinenian, N.; Li, C. K.; Petrasso, R. D.; LePape, S.; Ma, T.; Mackinnon, A. J.; Rygg, J. R.; Amendt, P. A.; Bellei, C.; Benedetti, L. R.; Berzak Hopkins, L.; Bionta, R. M.; Casey, D. T.; Divol, L.; Edwards, M. J.; Glenn, S.; Glenzer, S. H.; Hicks, D. G.; Kimbrough, J. R.; Landen, O. L.; Lindl, J. D.; MacPhee, A.; McNaney, J. M.; Meezan, N. B.; Moody, J. D.; Moran, M. J.; Park, H.-S.; Pino, J.; Remington, B. A.; Robey, H.; Rosen, M. D.; Wilks, S. C.; Zacharias, R. A.; McKenty, P. W.; Hohenberger, M.; Radha, P. B.; Edgell, D.; Marshall, F. J.; Delettrez, J. A.; Glebov, V. Yu.; Betti, R.; Goncharov, V. N.; Knauer, J. P.; Sangster, T. C.; Herrmann, H. W.; Hoffman, N. M.; Kyrala, G. A.; Leeper, R. J.; Olson, R. E.; Kilkenny, J. D.; Nikroo, A.

    2016-03-01

    A thin-glass-shell, D3He-filled exploding-pusher inertial confinement fusion implosion at the National Ignition Facility (NIF) has been demonstrated as a proton source that serves as a promising first step toward development of a monoenergetic proton, alpha, and triton backlighting platform at the NIF. Among the key measurements, the D3He-proton emission on this experiment (shot N121128) has been well-characterized spectrally, temporally, and in terms of emission isotropy, revealing a highly monoenergetic (ΔE / E ∼ 4 %) and isotropic source (~3% proton fluence variation and ~0.5% proton energy variation). On a similar shot (N130129, with D2 fill), the DD-proton spectrum has been obtained as well, illustrating that monoenergetic protons of multiple energies may be utilized in a single experiment. These results, and experiments on OMEGA, point toward future steps in the development of a precision, monoenergetic proton, alpha, and triton source that can readily be implemented at the NIF for backlighting a broad range of high energy density physics (HEDP) experiments in which fields and flows are manifest, and also utilized for studies of stopping power in warm dense matter and in classical plasmas.

  5. [Dependence of the yield of chromosome aberrations on the dosage in irradiating human peripheral blood lymphocytes with monoenergetic neutrons with 2, 4 and 6 MeV energies].

    PubMed

    Sevan'kaev, A V; Obaturov, G M; Nasonova, V A; Izmaĭlova, N N

    1984-01-01

    A study was made of the dose-dependence of the yield of chromosome aberrations in human lymphocyte culture irradiated at the G0 stage with monoenergetic neutrons of 2, 4 and 6 MeV. The dose dependence was found to be linear for all types of aberrations. The RBE of neutrons under study increased with the decrease in their energy.

  6. A direct-drive exploding-pusher implosion as the first step in development of a monoenergetic charged-particle backlighting platforn at the National Ignition Facility

    DOE PAGES

    Rosenberg, M. J.; Zylstra, A. B.; Seguin, F. H.; ...

    2016-01-18

    A thin-glass-shell, D3He-filled exploding-pusher inertial confinement fusion implosion at the National Ignition Facility (NIF) has been demonstrated as a proton source that serves as a promising first step toward development of a monoenergetic proton, alpha, and triton backlighting platform at the NIF. Among the key measurements, the D3He-proton emission on this experiment (shot N121128) has been well-characterized spectrally, temporally, and in terms of emission isotropy, revealing a highly monoenergetic (ΔE/E~4%) and isotropic source (~3% proton fluence variation and ~0.5% proton energy variation). On a similar shot (N130129, with D2 fill), the DD-proton spectrum has been obtained as well, illustrating thatmore » monoenergetic protons of multiple energies may be utilized in a single experiment. In conclusion, these results, and experiments on OMEGA, point toward future steps in the development of a precision, monoenergetic proton, alpha, and triton source that can readily be implemented at the NIF for backlighting a broad range of high energy density physics (HEDP) experiments in which fields and flows are manifest, and also utilized for studies of stopping power in warm dense matter and in classical plasmas.« less

  7. Fluence-to-Absorbed Dose Conversion Coefficients for Use in Radiological Protection of Embryo and Foetus Against External Exposure to Muons from 20MeV to 50GeV

    SciTech Connect

    Chen Jing

    2008-08-07

    This study used the Monte-Carlo code MCNPX to determine mean absorbed doses to the embryo and foetus when the mother is exposed to external muon fields. Monoenergetic muons ranging from 20 MeV to 50 GeV were considered. The irradiation geometries include anteroposterior (AP), postero-anterior (PA), lateral (LAT), rotational (ROT), isotropic (ISO), and top-down (TOP). At each of these irradiation geometries, absorbed doses to the foetal body were calculated for the embryo of 8 weeks and the foetus of 3, 6 or 9 months, respectively. Muon fluence-to-absorbed-dose conversion coefficients were derived for the four prenatal ages. Since such conversion coefficients are yet unknown, the results presented here fill a data gap.

  8. 3 GeV Injector Design Handbook

    SciTech Connect

    Wiedemann, H.; /SLAC, SSRL

    2009-12-16

    This Design Handbook is intended to be the main reference book for the specifications of the 3 GeV SPEAR booster synchrotron project. It is intended to be a consistent description of the project including design criteria, key technical specifications as well as current design approaches. Since a project is not complete till it's complete changes and modifications of early conceptual designs must be expected during the duration of the construction. Therefore, this Design Handbook is issued as a loose leaf binder so that individual sections can be replaced as needed. Each page will be dated to ease identification with respect to latest revisions. At the end of the project this Design Handbook will have become the 'as built' reference book of the injector for operations and maintenance personnel.

  9. Dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources

    DOEpatents

    Barty, Christopher P.J.

    2013-02-05

    A dual isotope notch observer for isotope identification, assay and imaging with mono-energetic gamma-ray sources includes a detector arrangement consists of three detectors downstream from the object under observation. The latter detector, which operates as a beam monitor, is an integrating detector that monitors the total beam power arriving at its surface. The first detector and the middle detector each include an integrating detector surrounding a foil. The foils of these two detectors are made of the same atomic material, but each foil is a different isotope, e.g., the first foil may comprise U235 and second foil may comprise U238. The integrating detectors surrounding these pieces of foil measure the total power scattered from the foil and can be similar in composition to the final beam monitor. Non-resonant photons will, after calibration, scatter equally from both foils.

  10. Quasi-monoenergetic electron beams from a few-terawatt laser driven plasma acceleration using a nitrogen gas jet

    NASA Astrophysics Data System (ADS)

    Rao, B. S.; Moorti, A.; Chakera, J. A.; Naik, P. A.; Gupta, P. D.

    2017-06-01

    An experimental investigation on the laser plasma acceleration of electrons has been carried out using 3 TW, 45 fs duration titanium sapphire laser pulse interaction with a nitrogen gas jet at an intensity of 2 × 1018 W cm-2. We have observed the stable generation of a well collimated electron beam with divergence and pointing variation ˜10 mrad from nitrogen gas jet plasma at an optimum plasma density around 3 × 1019 cm-3. The energy spectrum of the electron beam was quasi-monoenergetic with an average peak energy and a charge around 25 MeV and 30 pC respectively. The results will be useful for better understanding and control of ionization injection and the laser wakefield acceleration (LWFA) of electrons in high-Z gases and also towards the development of practical LWFA for various applications including injectors for high energy accelerators.

  11. Differential absorbed dose distributions in lineal energy for neutrons and gamma rays at the mono-energetic neutron calibration facility.

    PubMed

    Takada, M; Baba, M; Yamaguchi, H; Fujitaka, K

    2005-01-01

    Absorbed dose distributions in lineal energy for neutrons and gamma rays of mono-energetic neutron sources from 140 keV to 15 MeV were measured in the Fast Neutron Laboratory at Tohoku University. By using both a tissue-equivalent plastic walled counter and a graphite-walled low-pressure proportional counter, absorbed dose distributions in lineal energy for neutrons were obtained separately from those for gamma rays. This method needs no knowledge of energy spectra and dose distributions for gamma rays. The gamma-ray contribution in this neutron calibration field >1 MeV neutron was <3%, while for <550 keV it was >40%. The measured neutron absolute absorbed doses per unit neutron fluence agreed with the LA150 evaluated kerma factors. By using this method, absorbed dose distributions in lineal energy for neutrons and gamma rays in an unknown neutron field can be obtained separately.

  12. AMANDE: a new facility for monoenergetic neutron fields production between 2 keV and 20 MeV.

    PubMed

    Gressier, V; Guerre-Chaley, J F; Lacoste, V; Lebreton, L; Pelcot, G; Pochat, J L; Bolognese-Milstajn, T; Champion, D

    2004-01-01

    The variation of the response of the instruments with the neutron energy has to be determined in well-characterized monoenergetic neutron fields. The AMANDE facility will deliver such neutron fields between 2 keV and 20 MeV in an experimental hall designed with metallic walls for neutron scattering minimisation. The neutrons will be produced by nuclear interaction of accelerated protons or deuterons on thin targets of selected materials. The measuring devices to be characterised will be accurately placed with a fully automated detector transport system. The energy of the neutron field will be validated by time-of-flight experiments and a large set of standard detectors and fluence monitors will be used to determine the neutron fluence references. The scattered neutron fluence and dose equivalent were calculated by the MCNP Monte Carlo code at several measuring points in order to determine their contribution to the neutron field.

  13. Comparison of Monoenergetic Photon Organ Dose Rate Coefficients for the Female Stylized and Voxel Phantoms Submerged in Air

    DOE PAGES

    Hiller, Mauritius; Dewji, Shaheen Azim

    2017-02-16

    Dose rate coefficients computed using the International Commission on Radiological Protection (ICRP) reference adult female voxel phantom were compared with values computed using the Oak Ridge National Laboratory (ORNL) adult female stylized phantom in an air submersion exposure geometry. This is a continuation of previous work comparing monoenergetic organ dose rate coefficients for the male adult phantoms. With both the male and female data computed, effective dose rate as defined by ICRP Publication 103 was compared for both phantoms. Organ dose rate coefficients for the female phantom and ratios of organ dose rates for the voxel and stylized phantoms aremore » provided in the energy range from 30 to 5 MeV. Analysis of the contribution of the organs to effective dose is also provided. Lastly, comparison of effective dose rates between the voxel and stylized phantoms was within 8% at 100 keV and is <5% between 200 and 5000 keV.« less

  14. On the accuracy of homotopy perturbation and variational iteration methods for lateral broadening of a monoenergetic proton beam

    NASA Astrophysics Data System (ADS)

    Noshad, Houshyar; Bahador, Seyyedeh Samira; Mohammadi, Saeed

    2013-10-01

    In this article, dispersion of a 60 MeV proton pencil beam at various depths in a muscle tissue was numerically investigated via solving a three dimensional Fokker-Planck equation using homotopy perturbation method (HPM) and variational iteration method (VIM). The accuracy of these methods was benchmarked by comparison the radial flux distribution of protons traversing different depths in the tissue with the data of the High Charge and Energy Transport (HZETRN) model and Monte Carlo simulations. Furthermore, the computed depth dose distributions obtained from the HPM and VIM for monoenergetic protons passing through a medium were compared with the results of GEANT4.5.2 code as well as the experimental data reported in the literature. The satisfactory agreement obtained from our computations shows the reliability and applicability of the HPM and VIM in our analysis.

  15. Construction of monoenergetic neutron calibration fields using 45Sc(p, n)45Ti reaction at JAEA.

    PubMed

    Tanimura, Y; Saegusa, J; Shikaze, Y; Tsutsumi, M; Shimizu, S; Yoshizawa, M

    2007-01-01

    The 8 and 27 keV monoenergetic neutron calibration fields have been developed by using (45)Sc(p, n)(45)Ti reaction. Protons from a 4-MV Pelletron accelerator are used to bombard a thin scandium target evaporated onto a platinum disc. The proton energies are finely adjusted to the resonance to generate the 8 and 27 keV neutrons by applying a high voltage to the target assemblies. The neutron energies were measured using the time-of-flight method with a lithium glass scintillation detector. The neutron fluences at a calibration point located at 50 cm from the target were evaluated using Bonner spheres. A long counter was placed at 2.2 m from the target and at 60 degrees to the direction of the proton beam in order to monitor the fluence at the calibration point. Fluence and dose equivalent rates at the calibration point are sufficient to calibrate many types of the neutron survey metres.

  16. Photon and neutron dose contributions and mean quality factors phantoms of different size irradiated by monoenergetic neutrons.

    PubMed

    Dietze, G; Siebert, B R

    1994-10-01

    The International Commission on Radiological Protection (ICRP) in its Publication 60 introduced important changes in the concept of risk-related quantities. For external neutron radiation in particular the introduction of the equivalent dose with the radiation weighting factor wR instead of the dose equivalent concept with the quality factor Q(L) has many consequences. The value of wR is defined by the external neutron radiation field, while the radiation quality in the phantom depends on the radiation field at the position of interest and hence on the size of and the position in the phantom. It has been investigated to what extent the size of the phantom influences the mean radiation quality in the phantoms. For incident monoenergetic neutrons, mean photon dose contributions and mean quality factors have been calculated. Results are presented for various phantoms which characterize the conditions for a mouse, a rat, the ICRU sphere and a human body.

  17. CEBAF at 12 and 25 GeV

    SciTech Connect

    Harwood, Leigh; Reece, Charles

    2001-09-01

    The US nuclear physics community has identified an upgrade of CEBAF to 12 GeV as one of its top priorities. The principal motivation is to enable meson spectroscopy with 9 GeV polarized, quasi-monochromatic photons. A plan for implementing the 12 GeV upgrade has been prepared. Subsystem designs are being tested. Additional opportunities to reduce total project costs have been identified and will be pursued. The plan now calls for the addition to CEBAF of 10 new high-performance cryomodules and a new recirculation arc, yielding 12 GeV after 5.5 passes through the accelerator. Formal construction start could be in 2006. The same cryomodule design would subsequently be the building block for an eventual upgrade to 25 GeV.

  18. Endoleaks after endovascular aortic aneurysm repair: Improved detection with noise-optimized virtual monoenergetic dual-energy CT.

    PubMed

    Martin, Simon S; Wichmann, Julian L; Weyer, Hendrik; Scholtz, Jan-Erik; Leithner, Doris; Spandorfer, Adam; Bodelle, Boris; Jacobi, Volkmar; Vogl, Thomas J; Albrecht, Moritz H

    2017-09-01

    To assess image quality and diagnostic performance of a noise-optimized algorithm to reconstruct virtual monoenergetic images (VMI+) for the detection of endoleaks after endovascular abdominal aortic aneurysm repair (EVAR) using dual-energy CT angiography (DE-CTA). Seventy-five patients (42 men; 66.2±11.7years) underwent DE-CTA following EVAR. Arterial phase images were acquired in dual-energy mode for the reconstruction of standard linearly-blended M_0.5, VMI+ and traditional monoenergetic images (VMI) at 40-100keV in 10-keV intervals. Contrast-to-noise ratios (CNR) were calculated for the area of leakage in patients with endoleaks. Diagnostic accuracy for endoleak detection was evaluated by three blinded radiologists using the objectively best series for each reconstruction technique. Thirty-four out of 75 patients showed endoleaks. Quantitative image parameters were highest at 40-keV VMI+ (CNR, 21.3±11.1), compared to M_0.5 (CNR, 10.9±5.5) and all VMI series that showed highest values at 70keV (CNR, 13.5±6.6; all P<0.001). ROC analysis for endoleak detection revealed an area under the curve (AUC) of 0.992 for 40-keV VMI+ series, which was significantly higher (P≤0.039) compared to 70-keV VMI (0.914) and M_0.5 series (0.916). Noise-optimized VMI+ series at 40keV improve diagnostic accuracy for the detection and rule-out of endoleaks after EVAR. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. GeV gamma-ray flux upper limits from clusters of galaxies

    DOE PAGES

    Ackermann, M.; Ajello, M.; Allafort, A.; ...

    2010-06-16

    The detection of diffuse radio emission associated with clusters of galaxies indicates populations of relativistic leptons infusing the intracluster medium (ICM). Those electrons and positrons are either injected into and accelerated directly in the ICM, or produced as secondary pairs by cosmic-ray ions scattering on ambient protons. Radiation mechanisms involving the energetic leptons together with the decay of neutral pions produced by hadronic interactions have the potential to produce abundant GeV photons. Here in this paper, we report on the search for GeV emission from clusters of galaxies using data collected by the Large Area Telescope on the Fermi Gamma-raymore » Space Telescope from 2008 August to 2010 February. Thirty-three galaxy clusters have been selected according to their proximity and high mass, X-ray flux and temperature, and indications of non-thermal activity for this study. We report upper limits on the photon flux in the range 0.2-100 GeV toward a sample of observed clusters (typical values (1-5) ×10–9 photon cm–2 s–1) considering both point-like and spatially resolved models for the high-energy emission and discuss how these results constrain the characteristics of energetic leptons and hadrons, and magnetic fields in the ICM. The volume-averaged relativistic-hadron-to-thermal energy density ratio is found to be <5%-10% in several clusters.« less

  20. GeV gamma-ray flux upper limits from clusters of galaxies

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.; Blasi, P.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Colafrancesco, S.; Cominsky, L. R.; Conrad, J.; Dermer, C. D.; de Palma, F.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Dumora, D.; Edmonds, Y.; Farnier, C.; Favuzzi, C.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M. -H.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Jeltema, T. E.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kerr, M.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S. -H.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Mazziotta, M. N.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Pepe, M.; Pesce-Rollins, M.; Petrosian, V.; Pfrommer, C.; Piron, F.; Porter, T. A.; Profumo, S.; Rainò, S.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Ripken, J.; Ritz, S.; Rodriguez, A. Y.; Romani, R. W.; Roth, M.; Sadrozinski, H. F. -W.; Sander, A.; Parkinson, P. M. Saz; Scargle, J. D.; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Starck, J. -L.; Stawarz, Ł.; Strickman, M. S.; Strong, A. W.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.

    2010-06-16

    The detection of diffuse radio emission associated with clusters of galaxies indicates populations of relativistic leptons infusing the intracluster medium (ICM). Those electrons and positrons are either injected into and accelerated directly in the ICM, or produced as secondary pairs by cosmic-ray ions scattering on ambient protons. Radiation mechanisms involving the energetic leptons together with the decay of neutral pions produced by hadronic interactions have the potential to produce abundant GeV photons. Here in this paper, we report on the search for GeV emission from clusters of galaxies using data collected by the Large Area Telescope on the Fermi Gamma-ray Space Telescope from 2008 August to 2010 February. Thirty-three galaxy clusters have been selected according to their proximity and high mass, X-ray flux and temperature, and indications of non-thermal activity for this study. We report upper limits on the photon flux in the range 0.2-100 GeV toward a sample of observed clusters (typical values (1-5) ×10–9 photon cm–2 s–1) considering both point-like and spatially resolved models for the high-energy emission and discuss how these results constrain the characteristics of energetic leptons and hadrons, and magnetic fields in the ICM. The volume-averaged relativistic-hadron-to-thermal energy density ratio is found to be <5%-10% in several clusters.

  1. Deep subthreshold Xi;{-} production in Ar + KCl reactions at 1.76A GeV.

    PubMed

    Agakishiev, G; Balanda, A; Bassini, R; Belver, D; Belyaev, A V; Blanco, A; Böhmer, M; Boyard, J L; Braun-Munzinger, P; Cabanelas, P; Castro, E; Chernenko, S; Christ, T; Destefanis, M; Díaz, J; Dohrmann, F; Dybczak, A; Eberl, T; Fabbietti, L; Fateev, O V; Finocchiaro, P; Fonte, P; Friese, J; Fröhlich, I; Galatyuk, T; Garzón, J A; Gernhäuser, R; Gil, A; Gilardi, C; Golubeva, M; González-Díaz, D; Guber, F; Hennino, T; Holzmann, R; Iori, I; Ivashkin, A; Jurkovic, M; Kämpfer, B; Kanaki, K; Karavicheva, T; Kirschner, D; Koenig, I; Koenig, W; Kolb, B W; Kotte, R; Krizek, F; Krücken, R; Kühn, W; Kugler, A; Kurepin, A; Lang, S; Lange, J S; Lapidus, K; Liu, T; Lopes, L; Lorenz, M; Maier, L; Mangiarotti, A; Markert, J; Metag, V; Michalska, B; Michel, J; Mishra, D; Morinière, E; Mousa, J; Müntz, C; Naumann, L; Otwinowski, J; Pachmayer, Y C; Palka, M; Parpottas, Y; Pechenov, V; Pechenova, O; Pietraszko, J; Przygoda, W; Ramstein, B; Reshetin, A; Roy-Stephan, M; Rustamov, A; Sadovsky, A; Sailer, B; Salabura, P; Schmah, A; Sobolev, Yu G; Spataro, S; Spruck, B; Ströbele, H; Stroth, J; Sturm, C; Sudol, M; Tarantola, A; Teilab, K; Tlusty, P; Traxler, M; Trebacz, R; Tsertos, H; Wagner, V; Weber, M; Wisniowski, M; Wojcik, T; Wüstenfeld, J; Yurevich, S; Zanevsky, Y V; Zhou, P; Zumbruch, P

    2009-09-25

    We report first results on a deep subthreshold production of the doubly strange hyperon Xi;{-} in a heavy-ion reaction. At a beam energy of 1.76A GeV the reaction Ar + KCl was studied with the High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Lambda sample was collected, allowing for the investigation of the decay channel Xi;{-} --> Lambdapi;{-}. The deduced Xi;{-}/(Lambda + Sigma;{0}) production ratio of (5.6 +/- 1.2_{-1.7};{+1.8}) x 10;{-3} is significantly larger than available model predictions.

  2. Two-pion Bose-Einstein correlations in pp collisions at s=900GeV

    NASA Astrophysics Data System (ADS)

    Aamodt, K.; Abel, N.; Abeysekara, U.; Abrahantes Quintana, A.; Abramyan, A.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agocs, A. G.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad, A.; Ahmad, N.; Ahn, S. U.; Akimoto, R.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Almaráz Aviña, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Andrei, C.; Andronic, A.; Anelli, G.; Angelov, V.; Anson, C.; Antičić, T.; Antinori, F.; Antinori, S.; Antipin, K.; Antończyk, D.; Antonioli, P.; Anzo, A.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Arceo, R.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bablok, S.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Baldit, A.; Bán, J.; Barbera, R.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Barile, F.; Basile, M.; Basmanov, V.; Bastid, N.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I. G.; Becker, B.; Belikov, I.; Bellwied, R.; Belmont-Moreno, E.; Belogianni, A.; Benhabib, L.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdermann, E.; Berdnikov, Y.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bimbot, L.; Biolcati, E.; Blanc, A.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Bohm, J.; Boldizsár, L.; Bombara, M.; Bombonati, C.; Bondila, M.; Borel, H.; Borisov, A.; Bortolin, C.; Bose, S.; Bosisio, L.; Bossú, F.; Botje, M.; Böttger, S.; Bourdaud, G.; Boyer, B.; Braun, M.; Braun-Munzinger, P.; Bravina, L.; Bregant, M.; Breitner, T.; Bruckner, G.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Calvo, E.; Camacho, E.; Camerini, P.; Campbell, M.; Canoa Roman, V.; Capitani, G. P.; Cara Romeo, G.; Carena, F.; Carena, W.; Carminati, F.; Casanova Díaz, A.; Caselle, M.; Castillo Castellanos, J.; Castillo Hernandez, J. F.; Catanescu, V.; Cattaruzza, E.; Cavicchioli, C.; Cerello, P.; Chambert, V.; Chang, B.; Chapeland, S.; Charpy, A.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chiavassa, E.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chuman, F.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Cobanoglu, O.; Coffin, J.-P.; Coli, S.; Colla, A.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Conner, E. S.; Constantin, P.; Contin, G.; Contreras, J. G.; Corrales Morales, Y.; Cormier, T. M.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cuautle, E.; Cunqueiro, L.; Cussonneau, J.; Dainese, A.; Dalsgaard, H. H.; Danu, A.; Das, I.; Dash, A.; Dash, S.; de Barros, G. O. V.; de Caro, A.; de Cataldo, G.; de Cuveland, J.; de Falco, A.; de Gaspari, M.; de Groot, J.; de Gruttola, D.; de Marco, N.; de Pasquale, S.; de Remigis, R.; de Rooij, R.; de Vaux, G.; Delagrange, H.; Delgado, Y.; Dellacasa, G.; Deloff, A.; Demanov, V.; Dénes, E.; Deppman, A.; D'Erasmo, G.; Derkach, D.; Devaux, A.; di Bari, D.; di Giglio, C.; di Liberto, S.; di Mauro, A.; di Nezza, P.; Dialinas, M.; Díaz, L.; Díaz, R.; Dietel, T.; Divià, R.; Djuvsland, Ø.; Dobretsov, V.; Dobrin, A.; Dobrowolski, T.; Dönigus, B.; Domínguez, I.; Don, D. M. M.; Dordic, O.; Dubey, A. K.; Dubuisson, J.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, A. K.; Dutta Majumdar, M. R.; Elia, D.; Emschermann, D.; Enokizono, A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evrard, S.; Eyyubova, G.; Fabjan, C. W.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fateev, O.; Fearick, R.; Fedunov, A.; Fehlker, D.; Fekete, V.; Felea, D.; Fenton-Olsen, B.; Feofilov, G.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Ferretti, R.; Figueredo, M. A. S.; Filchagin, S.; Fini, R.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Fodor, Z.; Foertsch, S.; Foka, P.; Fokin, S.; Formenti, F.; Fragiacomo, E.; Fragkiadakis, M.; Frankenfeld, U.; Frolov, A.; Fuchs, U.; Furano, F.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gadrat, S.; Gagliardi, M.; Gago, A.; Gallio, M.; Ganoti, P.; Ganti, M. S.; Garabatos, C.; García Trapaga, C.; Gebelein, J.; Gemme, R.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Giraudo, G.; Giubellino, P.; Gladysz-Dziadus, E.; Glasow, R.; Glässel, P.; Glenn, A.; Gómez Jiménez, R.; González Santos, H.; González-Trueba, L. H.; González-Zamora, P.; Gorbunov, S.; Gorbunov, Y.; Gotovac, S.; Gottschlag, H.; Grabski, V.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerra, C.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Gustafsson, H.-A.; Gutbrod, H.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hamblen, J.; Han, B. H.; Harris, J. W.; Hartig, M.; Harutyunyan, A.; Hasch, D.; Hasegan, D.; Hatzifotiadou, D.; Hayrapetyan, A.; Heide, M.; Heinz, M.; Helstrup, H.; Herghelegiu, A.; Hernández, C.; Herrera Corral, G.; Herrmann, N.; Hetland, K. F.; Hicks, B.; Hiei, A.; Hille, P. T.; Hippolyte, B.; Horaguchi, T.; Hori, Y.; Hristov, P.; Hřivnáčová, I.; Hu, S.; Huang, M.; Huber, S.; Humanic, T. J.; Hutter, D.; Hwang, D. S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Innocenti, P. G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, A.; Ivanov, M.; Ivanov, V.; Iwasaki, T.; Jachołkowski, A.; Jacobs, P.; Jančurová, L.; Jangal, S.; Janik, R.; Jena, C.; Jena, S.; Jirden, L.; Jones, G. T.; Jones, P. G.; Jovanović, P.; Jung, H.; Jung, W.; Jusko, A.; Kaidalov, A. B.; Kalcher, S.; Kaliňák, P.; Kalisky, M.; Kalliokoski, T.; Kalweit, A.; Kamal, A.; Kamermans, R.; Kanaki, K.; Kang, E.; Kang, J. H.; Kapitan, J.; Kaplin, V.; Kapusta, S.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Khan, M. M.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kikola, D.; Kileng, B.; Kim, D. J.; Kim, D. S.; Kim, D. W.; Kim, H. N.; Kim, J.; Kim, J. H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S. H.; Kim, S.; Kim, Y.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kliemant, M.; Klovning, A.; Kluge, A.; Knichel, M. L.; Kniege, S.; Koch, K.; Kolevatov, R.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskih, A.; Kornaś, E.; Kour, R.; Kowalski, M.; Kox, S.; Kozlov, K.; Kral, J.; Králik, I.; Kramer, F.; Kraus, I.; Kravčáková, A.; Krawutschke, T.; Krivda, M.; Krumbhorn, D.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucheriaev, Y.; Kuhn, C.; Kuijer, P. G.; Kumar, L.; Kumar, N.; Kupczak, R.; Kurashvili, P.; Kurepin, A.; Kurepin, A. N.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kutouski, M.; Kvaerno, H.; Kweon, M. J.; Kwon, Y.; La Rocca, P.; Lackner, F.; Ladrón de Guevara, P.; Lafage, V.; Lal, C.; Lara, C.; Larsen, D. T.; Laurenti, G.; Lazzeroni, C.; Le Bornec, Y.; Le Bris, N.; Lee, H.; Lee, K. S.; Lee, S. C.; Lefèvre, F.; Lenhardt, M.; Leistam, L.; Lehnert, J.; Lenti, V.; León, H.; León Monzón, I.; León Vargas, H.; Lévai, P.; Li, X.; Li, Y.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Liu, L.; Loginov, V.; Lohn, S.; Lopez, X.; López Noriega, M.; López-Ramírez, R.; López Torres, E.; Løvhøiden, G.; Lozea Feijo Soares, A.; Lu, S.; Lunardon, M.; Luparello, G.; Luquin, L.; Lutz, J.-R.; Ma, K.; Ma, R.; Madagodahettige-Don, D. M.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Makhlyueva, I.; Mal'Kevich, D.; Malaev, M.; Malagalage, K. J.; Maldonado Cervantes, I.; Malek, M.; Malinina, L.; Malkiewicz, T.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Martashvili, I.; Martinengo, P.; Martínez Hernández, M. I.; Martínez Davalos, A.; Martínez García, G.; Maruyama, Y.; Marzari Chiesa, A.; Masciocchi, S.; Masera, M.; Masetti, M.; Masoni, A.; Massacrier, L.; Mastromarco, M.; Mastroserio, A.; Matthews, Z. L.; Matyja, A.; Mayani, D.; Mazza, G.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Mendez Lorenzo, P.; Meoni, M.; Mercado Pérez, J.; Mereu, P.; Miake, Y.; Michalon, A.; Miftakhov, N.; Milano, L.; Milosevic, J.; Minafra, F.; Mischke, A.; Miśkowiec, D.; Mitu, C.; Mizoguchi, K.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Mondal, M. M.; Montaño Zetina, L.; Monteno, M.; Montes, E.; Morando, M.; Moretto, S.; Morsch, A.; Moukhanova, T.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Müller, H.; Munhoz, M. G.; Munoz, J.; Musa, L.; Musso, A.; Nandi, B. K.; Nania, R.; Nappi, E.; Navach, F.; Navin, S.; Nayak, T. K.; Nazarenko, S.; Nazarov, G.; Nedosekin, A.; Nendaz, F.; Newby, J.; Nianine, A.; Nicassio, M.; Nielsen, B. S.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Nilsson, M. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Novitzky, N.; Nyatha, A.; Nygaard, C.; Nyiri, A.; Nystrand, J.; Ochirov, A.; Odyniec, G.; Oeschler, H.; Oinonen, M.; Okada, K.; Okada, Y.; Oldenburg, M.; Oleniacz, J.; Oppedisano, C.; Orsini, F.; Ortiz Velasquez, A.; Ortona, G.; Oskarsson, A.; Osmic, F.; Österman, L.; Ostrowski, P.; Otterlund, I.; Otwinowski, J.; Øvrebekk, G.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S.; Pal, S. K.; Palaha, A.; Palmeri, A.; Panse, R.; Papikyan, V.; Pappalardo, G. S.; Park, W. J.; Pastirčák, B.; Pastore, C.; Paticchio, V.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pepato, A.; Pereira, H.; Peressounko, D.; Pérez, C.; Perini, D.; Perrino, D.; Peryt, W.; Peschek, J.; Pesci, A.; Peskov, V.; Pestov, Y.; Peters, A. J.; Petráček, V.; Petridis, A.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Peyré, J.; Piano, S.; Piccotti, A.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piuz, F.; Platt, R.; Płoskoń, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta Lerma, P. L. M.; Poggio, F.; Poghosyan, M. G.; Polák, K.; Polichtchouk, B.; Polozov, P.; Polyakov, V.; Pommeresch, B.; Pop, A.; Posa, F.; Pospíšil, V.; Potukuchi, B.; Pouthas, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Pulvirenti, A.; Punin, A.; Punin, V.; Putiš, M.; Putschke, J.; Quercigh, E.; Rachevski, A.; Rademakers, A.; Radomski, S.; Räihä, T. S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Ramírez Reyes, A.; Rammler, M.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rashevskaya, I.; Rath, S.; Read, K. F.; Real, J. S.; Redlich, K.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Ricaud, H.; Riccati, L.; Ricci, R. A.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rodriguez Cahuantzi, M.; Røed, K.; Röhrich, D.; Román López, S.; Romita, R.; Ronchetti, F.; Rosinský, P.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roukoutakis, F.; Rousseau, S.; Roy, C.; Roy, P.; Rubio-Montero, A. J.; Rui, R.; Rusanov, I.; Russo, G.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Saini, J.; Saiz, P.; Sakata, D.; Salgado, C. A.; Salgueiro Domingues da Silva, R.; Salur, S.; Samanta, T.; Sambyal, S.; Samsonov, V.; Šándor, L.; Sandoval, A.; Sano, M.; Sano, S.; Santo, R.; Santoro, R.; Sarkamo, J.; Saturnini, P.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schindler, H.; Schmidt, C.; Schmidt, H. R.; Schossmaier, K.; Schreiner, S.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P. A.; Segato, G.; Semenov, D.; Senyukov, S.; Seo, J.; Serci, S.; Serkin, L.; Serradilla, E.; Sevcenco, A.; Sgura, I.; Shabratova, G.; Shahoyan, R.; Sharkov, G.; Sharma, N.; Sharma, S.; Shigaki, K.; Shimomura, M.; Shtejer, K.; Sibiriak, Y.; Siciliano, M.; Sicking, E.; Siddi, E.; Siemiarczuk, T.; Silenzi, A.; Silvermyr, D.; Simili, E.; Simonetti, G.; Singaraju, R.; Singh, R.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R.; Snow, H.; Søgaard, C.; Soloviev, A.; Soltveit, H. K.; Soltz, R.; Sommer, W.; Son, C. W.; Son, H.; Song, M.; Soos, C.; Soramel, F.; Soyk, D.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Staley, F.; Stan, E.; Stefanek, G.; Stefanini, G.; Steinbeck, T.; Stenlund, E.; Steyn, G.; Stocco, D.; Stock, R.; Stolpovsky, P.; Strmen, P.; Suaide, A. A. P.; Subieta Vásquez, M. A.; Sugitate, T.; Suire, C.; Šumbera, M.; Susa, T.; Swoboda, D.; Symons, J.; Szanto de Toledo, A.; Szarka, I.; Szostak, A.; Szuba, M.; Tadel, M.; Tagridis, C.; Takahara, A.; Takahashi, J.; Tanabe, R.; Tapia Takaki, J. D.; Taureg, H.; Tauro, A.; Tavlet, M.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Thäder, J.; Tieulent, R.; Tlusty, D.; Toia, A.; Tolyhy, T.; Torcato de Matos, C.; Torii, H.; Torralba, G.; Toscano, L.; Tosello, F.; Tournaire, A.; Traczyk, T.; Tribedy, P.; Tröger, G.; Truesdale, D.; Trzaska, W. H.; Tsiledakis, G.; Tsilis, E.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Turvey, A.; Tveter, T. S.; Tydesjö, H.; Tywoniuk, K.; Ulery, J.; Ullaland, K.; Uras, A.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Vacchi, A.; Vala, M.; Valencia Palomo, L.; Vallero, S.; van der Kolk, N.; Vande Vyvre, P.; van Leeuwen, M.; Vannucci, L.; Vargas, A.; Varma, R.; Vasiliev, A.; Vassiliev, I.; Vasileiou, M.; Vechernin, V.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vetlitskiy, I.; Vickovic, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopianov, A.; Voloshin, K.; Voloshin, S.; Volpe, G.; von Haller, B.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Wagner, B.; Wagner, V.; Wallet, L.; Wan, R.; Wang, D.; Wang, Y.; Wang, Y.; Watanabe, K.; Wen, Q.; Wessels, J.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilk, A.; Wilk, G.; Williams, M. C. S.; Willis, N.; Windelband, B.; Xu, C.; Yang, C.; Yang, H.; Yasnopolskiy, S.; Yermia, F.; Yi, J.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yuan, X.; Yurevich, V.; Yushmanov, I.; Zabrodin, E.; Zagreev, B.; Zalite, A.; Zampolli, C.; Zanevsky, Yu.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zbroszczyk, H.; Zelnicek, P.; Zenin, A.; Zepeda, A.; Zgura, I.; Zhalov, M.; Zhang, X.; Zhou, D.; Zhou, S.; Zhu, J.; Zichichi, A.; Zinchenko, A.; Zinovjev, G.; Zoccarato, Y.; Zycháček, V.; Zynovyev, M.

    2010-09-01

    We report on the measurement of two-pion correlation functions from pp collisions at s=900GeV performed by the ALICE experiment at the Large Hadron Collider. Our analysis shows an increase of the Hanbury Brown-Twiss radius with increasing event multiplicity, in line with other measurements done in particle- and nuclear collisions. Conversely, the strong decrease of the radius with increasing transverse momentum, as observed at the Relativistic Heavy Ion Collider and at Tevatron, is not manifest in our data.

  3. Elliptic Flow in Au+Au Collisions at √sNN = 130 GeV

    NASA Astrophysics Data System (ADS)

    Ackermann, K. H.; Adams, N.; Adler, C.; Ahammed, Z.; Ahmad, S.; Allgower, C.; Amsbaugh, J.; Anderson, M.; Anderssen, E.; Arnesen, H.; Arnold, L.; Averichev, G. S.; Baldwin, A.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Beddo, M.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Bennett, S.; Bercovitz, J.; Berger, J.; Betts, W.; Bichsel, H.; Bieser, F.; Bland, L. C.; Bloomer, M.; Blyth, C. O.; Boehm, J.; Bonner, B. E.; Bonnet, D.; Bossingham, R.; Botlo, M.; Boucham, A.; Bouillo, N.; Bouvier, S.; Bradley, K.; Brady, F. P.; Braithwaite, E. S.; Braithwaite, W.; Brandin, A.; Brown, R. L.; Brugalette, G.; Byrd, C.; Caines, H.; Calderón de La Barca Sánchez, M.; Cardenas, A.; Carr, L.; Carroll, J.; Castillo, J.; Caylor, B.; Cebra, D.; Chatopadhyay, S.; Chen, M. L.; Chen, W.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Chrin, J.; Christie, W.; Coffin, J. P.; Conin, L.; Consiglio, C.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Danilov, V. I.; Dayton, D.; Demello, M.; Deng, W. S.; Derevschikov, A. A.; Dialinas, M.; Diaz, H.; Deyoung, P. A.; Didenko, L.; Dimassimo, D.; Dioguardi, J.; Dominik, W.; Drancourt, C.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Eggert, T.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Etkin, A.; Fachini, P.; Feliciano, C.; Ferenc, D.; Ferguson, M. I.; Fessler, H.; Finch, E.; Fine, V.; Fisyak, Y.; Flierl, D.; Flores, I.; Foley, K. J.; Fritz, D.; Gagunashvili, N.; Gans, J.; Gazdzicki, M.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Gojak, C.; Grabski, J.; Grachov, O.; Grau, M.; Greiner, D.; Greiner, L.; Grigoriev, V.; Grosnick, D.; Gross, J.; Guilloux, G.; Gushin, E.; Hall, J.; Hallman, T. J.; Hardtke, D.; Harper, G.; Harris, J. W.; He, P.; Heffner, M.; Heppelmann, S.; Herston, T.; Hill, D.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Howe, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Hunt, W.; Hunter, J.; Igo, G. J.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Jacobson, S.; Jared, R.; Jensen, P.; Johnson, I.; Jones, P. G.; Judd, E.; Kaneta, M.; Kaplan, M.; Keane, D.; Kenney, V. P.; Khodinov, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Koehler, G.; Konstantinov, A. S.; Kormilitsyne, V.; Kotchenda, L.; Kotov, I.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Krupien, T.; Kuczewski, P.; Kuhn, C.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamas-Valverde, J.; Lamont, M. A.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lecompte, T.; Leonhardt, W. J.; Leontiev, V. M.; Leszczynski, P.; Levine, M. J.; Li, Q.; Li, Q.; Li, Z.; Liaw, C.-J.; Lin, J.; Lindenbaum, S. J.; Lindenstruth, V.; Lindstrom, P. J.; Lisa, M. A.; Liu, H.; Ljubicic, T.; Llope, W. J.; Locurto, G.; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Lopiano, D.; Love, W. A.; Lutz, J. R.; Lynn, D.; Madansky, L.; Maier, R.; Majka, R.; Maliszewski, A.; Margetis, S.; Marks, K.; Marstaller, R.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; Matyushevski, E. A.; McParland, C.; McShane, T. S.; Meier, J.; Melnick, Yu.; Meschanin, A.; Middlekamp, P.; Mikhalin, N.; Miller, B.; Milosevich, Z.; Minaev, N. G.; Minor, B.; Mitchell, J.; Mogavero, E.; Moiseenko, V. A.; Moltz, D.; Moore, C. F.; Morozov, V.; Morse, R.; de Moura, M. M.; Munhoz, M. G.; Mutchler, G. S.; Nelson, J. M.; Nevski, P.; Ngo, T.; Nguyen, M.; Nguyen, T.; Nikitin, V. A.; Nogach, L. V.; Noggle, T.; Norman, B.; Nurushev, S. B.; Nussbaum, T.; Nystrand, J.; Odyniec, G.; Ogawa, A.; Ogilvie, C. A.; Olchanski, K.; Oldenburg, M.; Olson, D.; Ososkov, G. A.; Ott, G.; Padrazo, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Pentia, M.; Perevotchikov, V.; Peryt, W.; Petrov, V. A.; Pinganaud, W.; Pirogov, S.; Platner, E.; Pluta, J.; Polk, I.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Puskar-Pasewicz, J.; Rai, G.; Rasson, J.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J.; Renfordt, R. E.; Retiere, F.; Ridiger, A.; Riso, J.; Ritter, H. G.; Roberts, J. B.; Roehrich, D.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Russ, D.; Rykov, V.; Sakrejda, I.; Sanchez, R.; Sandler, Z.; Sandweiss, J.; Sappenfield, P.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Scheblien, J.; Scheetz, R.; Schlueter, R.; Schmitz, N.; Schroeder, L. S.; Schulz, M.; Schüttauf, A.; Sedlmeir, J.; Seger, J.; Seliverstov, D.; Seyboth, J.; Seyboth, P.; Seymour, R.; Shakaliev, E. I.; Shestermanov, K. E.; Shi, Y.; Shimanskii, S. S.; Shuman, D.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Smykov, L. P.; Snellings, R.; Solberg, K.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Stone, N.; Stone, R.; Strikhanov, M.; Stringfellow, B.; Stroebele, H.; Struck, C.; Suaide, A. A.; Sugarbaker, E.; Suire, C.; Symons, T. J.; Takahashi, J.; Tang, A. H.; Tarchini, A.; Tarzian, J.; Thomas, J. H.; Tikhomirov, V.; Szanto de Toledo, A.; Tonse, S.; Trainor, T.; Trentalange, S.; Tokarev, M.; Tonjes, M. B.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; Vakula, I.; van Buren, G.; Vandermolen, A. M.; Vanyashin, A.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Visser, G.; Voloshin, S. A.; Vu, C.; Wang, F.; Ward, H.; Weerasundara, D.; Weidenbach, R.; Wells, R.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitfield, J. P.; Whitten, C.; Wieman, H.; Willson, R.; Wilson, K.; Wirth, J.; Wisdom, J.; Wissink, S. W.; Witt, R.; Wolf, J.; Wood, L.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yokosawa, A.; Yurevich, V. I.; Zanevski, Y. V.; Zhang, J.; Zhang, W. M.; Zhu, J.; Zimmerman, D.; Zoulkarneev, R.; Zubarev, A. N.

    2001-01-01

    Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at sNN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

  4. Radiation in 1.5 GeV and 12 GeV Laser Wakefield Acceleration Stages from PIC Simulations

    SciTech Connect

    Martins, J. L.; Martins, S. F.; Silva, L. O.

    2010-11-04

    A massivelly parallel post-processing radiation diagnostic for PIC codes is presented, which is then used to study the main features of the radiation from single LWFA stages (1.5 GeV and 12 GeV). This diagnostic also allows to examine radiation signatures associated with the physics of self-injection.

  5. Laser-driven wavebreaking, electron trapping, and mono-energetic beam production

    NASA Astrophysics Data System (ADS)

    Esarey, Eric

    2006-10-01

    Recent breakthrough results reported in Nature demonstrate that laser-plasma accelerators can produce high quality (e.g., narrow energy spread) electron bunches at the 100 MeV level that may be useful for numerous applications. More recently, high quality electron beams at 1 GeV were produced in experiments at LBNL using 40 TW laser pulse interacting with a 3.3 cm plasma channel. In these experiments, the accelerated electrons were self-trapped from the background plasma, often attributed to the process of wavebreaking. Using a warm fluid model, a general analytic theory of wavebreaking has been developed that is valid for all regimes of interest, i.e., arbitrary temperature and phase velocity. This theory indicates that the maximum electric field obtainable by a relativistic plasma wave is lower that previously calculated. The relation between wavebreaking and particle trapping is discussed, and various quantities, such as the fraction of electrons trapped (i.e., the dark current), are calculated. A variety of methods for particle trapping relevant to present experiments, including 2D wavebreaking, density ramps, and laser injection, will be described. Limitations from dephasing and pump depletion will be summarized. Also presented will be 2D and 3D simulations modeling the production high quality electron beams from laser-plasma accelerators. C.G.R. Geddes et al., Nature 431, 538 (2004); S.P.D. Mangles et al., ibid., p. 535; J. Faure et al., ibid., p. 541. W.P. Leemans et al., submitted. C.B. Schroeder et al., Phys. Rev. E bf 72, 055401 (2005). C.B. Schroeder et al., Phys. Plasmas 13, 033103 (2006). G. Fubiani et al., Phys. Rev. E 73, 026402 (2006).

  6. Visualization of expanding warm dense gold and diamond heated uniformly by laser-generated ion beams

    NASA Astrophysics Data System (ADS)

    Bang, W.; Albright, B. J.; Bradley, P. A.; Gautier, D. C.; Palaniyappan, S.; Vold, E. L.; Santiago Cordoba, M. A.; Hamilton, C. E.; Fernández, J. C.

    2015-11-01

    With a laser-generated beam of quasi-monoenergetic ions, a solid density target can be heated uniformly and isochorically. On the LANL Trident laser facility, we have used a beam of quasi-monoenergetic aluminum ions to heat gold and diamond foils. We visualized directly the expanding warm dense gold and diamond with an optical streak camera. Furthermore, we present a new technique to determine the initial temperatures of these heated samples from the measured expansion speeds of gold and diamond into vacuum. These temperatures are in good agreement with the expected temperatures calculated using the total deposited energy into the cold targets and SESAME equation-of-state tables at solid densities. We anticipate the uniformly heated solid density target will allow for direct quantitative measurements of equation-of-state, conductivity, opacity, and stopping power of warm dense matter, benefiting plasma physics, astrophysics, and nuclear physics. *This work is sponsored by the LANL LDRD Program.

  7. Improvement of Image Quality in Unenhanced Dual-Layer CT of the Head Using Virtual Monoenergetic Images Compared With Polyenergetic Single-Energy CT.

    PubMed

    Neuhaus, Victor; Abdullayev, Nuran; Große Hokamp, Nils; Pahn, Gregor; Kabbasch, Christoph; Mpotsaris, Anastasios; Maintz, David; Borggrefe, Jan

    2017-08-01

    The aims of this study were to compare virtual monoenergetic images and polyenergetic images reconstructed from unenhanced dual-layer detector computed tomography (DLCT) of the head and to determine kiloelectron volt levels that optimize image quality, particularly the gray-white matter contrast, and reduce beam hardening artifacts caused by the skull. Institutional review board approval was obtained. Forty patients that received DLCT were included in this retrospective study; of these patients, 22 were women and 18 were men. The average age was 61.5 ± 14.3 years. Virtual monoenergetic images were reconstructed from spectral base images at 40 keV to 120 keV. To calculate signal-to-noise ratio and contrast-to-noise ratio, attenuation and standard deviation of supratentorial gray and white matter were measured in virtual monoenergetic and polyenergetic images. Beam hardening artifacts were detected close to the calvarium and in the posterior fossa. Two radiologists rated the assessment of gray-white matter differentiation and of the subcalvarial space, as well as the artifacts caused by the skull and image noise. Student t test and Wilcoxon test were used to determine significance. Compared with polyenergetic images, superior signal-to-noise ratio and superior contrast-to-noise ratio of gray and white matter were observed in virtual monoenergetic images at low kiloelectron volt levels (P < 0.0001). Subcalvarial artifacts were significantly lower at 120 keV (P < 0.02). Artifacts measured in the posterior fossa were generally lower at high kiloelectron volt levels; however, no statistical significance was detected. Virtual monoenergetic images were rated superior to polyenergetic images in regard to all 4 criteria (P < 0.0001). The observers reported an optimal radiological assessment of gray-white matter differentiation at 65 keV and optimal assessment of subcalvarial space at 120 keV. In comparison to polyenergetic images, virtual monoenergetic images reconstructed

  8. ΛΛ correlation function in Au + Au collisions at √sNN = 200 GeV

    SciTech Connect

    Adamczyk, L.

    2015-01-12

    In this study, we present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at √sNN = 200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for di-hyperon searches are discussed.

  9. ΛΛ correlation function in Au + Au collisions at √sNN = 200 GeV

    DOE PAGES

    Adamczyk, L.

    2015-01-12

    In this study, we present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at √sNN = 200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for di-hyperon searches are discussed.

  10. X-Ray Counterparts of Puzzling Gev-Tev Sources

    NASA Astrophysics Data System (ADS)

    Kargaltsev, Oleg

    2014-09-01

    We propose to look for X-ray counterparts of the extended TeV source HESS J1616-508 that may also have been detected with Fermi at GeV energies. The nature of the source and the connection between the TeV source and the nearby GeV sources are unknown. It has been suggested that it may be a relic plerion powered by the offset PSR J1617-5055, but a deep Chandra observation of this pulsar and its wind nebula has not confirmed this hypothesis. To understand the nature of this long-standing "dark accelerator", we propose to observe the GeV sources (which could be young pulsars) and another nearby young pulsar (J1614-5048) to check whether or not they could supply relativistic particles and power the TeV source. We will also explore the nature of the GeV sources.

  11. Design of 3 GeV booster ring lattice

    SciTech Connect

    Etisken, O. Ciftci, A. K.

    2016-03-25

    The aim of this study is to design of a 3 GeV booster ring for the 3 GeV storage ring. Electrons are needed to be accelerated to 3.0 GeV from 0.15 GeV energy. In this frame, we studied on two options for booster ring; a compact booster and the booster that shares the same tunnel with the storage ring. The lattice type has been chosen FODO for both options, lattice parameters are calculated, sextupole magnets are used to decrease dynamic aperture problem and dynamic aperture calculations are also made with considering of the necessary conditions. After designing and calculating of the parameters, these designs have been compared with each other. In addition to this comparison, these booster design parameters have been compared with some world centers design parameters and the reliability of the booster design is seen. Beam optics, OPA and Elegant simulation programs have been used in the study calculations.

  12. Can dual-energy computed tomography improve visualization of hypoenhancing liver lesions in portal venous phase? Assessment of advanced image-based virtual monoenergetic images.

    PubMed

    Caruso, Damiano; De Cecco, Carlo N; Schoepf, U Joseph; Schaefer, Amanda R; Leland, Parker W; Johnson, Dustin; Laghi, Andrea; Hardie, Andrew D

    The purpose was to assess image quality of portal-venous phase dual-energy computed tomography (DECT) for liver lesions. We performed 120-kVp-equivalent linear-blended (LB) and monoenergetic reconstructions from 40 to 190 keV by standard (VMI) and advanced virtual monoenergetic (VMI+) methods. Diagnostic performance, and quantitative and qualitative image analyses were assessed and compared. Liver contrast to noise ratio peaked at 40 keV_VMI+, while image quality and reader preference peaked at 50 keV_VMI+. 50 keV_VMI+ scored overall higher diagnostic performance: lesion sensitivity 95.4% vs. 83.3% for both 75 keV_VMI and LB. DECT improves assessment of hypoenhancing liver lesions on portal venous phase. 50 keV_VMI+ demonstrated the highest image quality and diagnostic performance over VMI and LB. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Study of the 15N(p,n)15O reaction as a monoenergetic neutron source for the measurement of differential scattering cross sections

    NASA Astrophysics Data System (ADS)

    Poenitz, E.; Nolte, R.; Schmidt, D.; Chen, G.

    2017-03-01

    The 15N(p,n) reaction is a promising candidate for the production of monoenergetic neutrons with energies of up to 5.7 MeV at the facilities where the T(p,n)3He reaction cannot be used. The characteristic properties of this reaction were studied focusing on its suitability as a source of monoenergetic neutrons for the measurement of differential scattering cross sections in the neutron energy range of 2 MeV to 5 MeV . For this purpose differential and integral cross sections were measured and the choice of optimum target conditions was investigated. The reaction has already been used successfully to measure of elastic and inelastic neutron scattering cross sections for natPb in the energy range from 2 MeV to 4 MeV and for 209Bi and 181Ta at 4 MeV .

  14. Preliminary Results of Mono-energetic Electron Beams from a Laser-plasma Accelerator Driven by 200 TW Femto Second Pulses

    SciTech Connect

    Taki, R.; Kameshima, T.; An, W. M.; Hua, J. F.; Huang, W. H.; Tang, C. X.; Gu, Y. Q.; Guo, Y.; Hong, W.; Jiao, C. Y.; Lin, Y. Z.; Liu, H. J.; Peng, H. S.; Sun, L.; Tang, C. M.; Wang, X. D.; Wen, T. S.; Wen, X. L.; Wu, Y. C.; Zhang, B. H.

    2006-11-27

    Relativistic mono-energetic electron beams have been demonstrated by worldwide laser-plasma accelerator experiments in the range of a few tens TW. Laser-plasma accelerator experiment has been carried out with 200TW, 30fs Ti:Sapphire laser pulses focused on helium gas-jets with F/8.7 optics. Intense mono-energetic electron beams have been produced in the energy range of 30 to 150 MeV by controlling plasma length and density precisely. Images of Thomson scattering and fluorescence side scattering from plasma indicate highly relativistic effects such as a long self-channeling and filamentation as well as energetic electron deflection and intense backward Raman scattering. Preliminary results of the first laser-plasma accelerator experiment in the range of 200TW femto second pulses are presented.

  15. Giant electromagnetic vortex and MeV monoenergetic electrons generated by short laser pulses in underdense plasma near quarter critical density region.

    PubMed

    Zhidkov, Alexei; Nemoto, Koshichi; Nayuki, Takuya; Oishi, Yuji; Fuji, Takashi

    2007-07-01

    Very efficient generation of monoenergetic, about 1MeV , electrons from underdense plasma with its electron density close to the critical, when irradiated by an intense femtosecond laser pulse, is found via two dimensional particle-in-cell simulation. The stimulated Raman scattering of a laser pulse with frequency omega< or =2omega(pl max) gives rise to a giant electromagnetic vortex. In contrast to electron acceleration by the well-known laser pulse wake, injected plasma electrons are accelerated up to vortex ponderomotive potential forming a quite monoenergetic distribution. A relatively high charge of such an electron source makes very efficient generation of soft gamma rays with homega>300 keV .

  16. Calculated shielding characteristics of eight materials for neutrons and secondary photons produced by monoenergetic source neutrons with energies less than 400 MeV

    SciTech Connect

    Nakanishi, Noriyoshi; Shikata, Takashi; Fujita, Shin; Kosako, Toshiso

    1995-10-01

    Shielding characteristics of iron, lead, ordinary concrete, heavy concrete, graphite, marble, water, and paraffin were calculated for monoenergetic source neutrons with energies < 400 MeV. The depth dependence of neutron and secondary photon transmitted dose equivalents at the exit surfaces of shields of varying thickness is exhibited for some monoenergetic source neutrons and for each material. Their shielding characteristics are compared and discussed in terms of the degradation process of neutron energy and the change of neutron spectrum in typical shielding materials. Calculations were carried out by using the one-dimensional discrete ordinates code ANISN-JR and the cross-section library DLC-87/HILO. Systematic knowledge concerning the shielding of neutrons with energies < 400 MeV was successfully obtained.

  17. The JLab TMD Program at 6 GeV and 11 GeV

    SciTech Connect

    Puckett, Andrew J.

    2016-05-01

    The precise mapping of the nucleon’s transverse momentum dependent parton distributions (TMDs) in the valence quark region has emerged as one of the flagship physics programs of the recently upgraded Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab). The TMDs describe the three-dimensional, spin-correlated densities of quarks and gluons in the nucleon in momentum space, and are accessible experimentally through detailed studies of the Semi-Inclusive Deep Inelastic Scattering (SIDIS) process, N ( e ; e 0 h ) X . The already unrivaled intensity, polarization and duty factor performance of CEBAF will combine with the dramatic expansion of its kinematic reach embodied by the recent near-doubling of the maximum beam energy to enable the first fully differential precision measurements of SIDIS structure functions in the valence region. In this paper, I will review the existing and forthcoming SIDIS results from the 6 GeV era of CEBAF operations and present an overview of the planned JLab SIDIS program at 11 GeV beam energy

  18. Ion-Ion Neutralization.

    DTIC Science & Technology

    1982-05-31

    Accession No. 3. Recipient’s Catalog Number FGL -TR-82 -0202 b- /- 4. Title (and Subtitle) 5. Type of Report & Period Covered ION-ION NEUTRALIZATION Final...few years under the terms of the grant has been the detailed study of binary ion-ion neutralization reactions involving ions of atmospheric...2TT, England. 1. INTRODUCTION Binary positive-ion negative-ion mutual neutralization viz: A+ + B->C + D (1) can be an important loss process for

  19. Analysis and comparison of monoenergetic fast neutron fluence determination using 238U samples at different positions with respect to the neutron source.

    PubMed

    Zhang, Guohui; Liu, Xiang; Gao, Zhiqi; Wu, Hao; Liu, Jiaming

    2012-05-01

    Using two (238)U samples placed in a gridded ionization chamber and a parallel-plate fission chamber, fluence of monoenergetic fast neutrons was determined. Four runs of measurements were performed. Analysis showed that although the neutron fluences for the two (238)U samples differ by 20-33 times in the present work, the fluences at the position of the sample in the gridded ionization chamber determined by the two ways are in agreement within experimental uncertainties.

  20. High-energy monoenergetic proton bunch from laser interaction with a complex target

    SciTech Connect

    Wang Fengchao; Shen Baifei; Zhang Xiaomei; Jin Zhangying; Wen Meng; Ji Liangliang; Wang Wenpeng; Xu Jiancai; Yu, M. Y.; Cary, J.

    2009-09-15

    Generation of high-energy proton bunch in the interaction of a high-power laser pulse with a complex target consisting of a front horizontal slice adjoining a conventional heavy ion and proton double-layer slab is investigated using two-dimensional particle-in-cell simulation. The laser pulse propagates along both sides of the slice. A large number of hot electrons are generated and accelerated by the surface ponderomotive force, and transported through the double layer, forming a backside sheath field which is considerably stronger and more localized than that produced by the electrons from a simple double layer. As a result, the protons in the proton layer can be accelerated to energies more than three times, and the energy spread halved, that from the simple double layer.

  1. Observation of snake resonances at Relativistic Heavy Ion Collider

    SciTech Connect

    Bai, M.; Ahrens, L.; Alekseev, I.G.; Alessi, J.; et al

    2010-09-27

    The Siberian snakes are powerful tools in preserving polarization in high energy accelerators has been demonstrated at the Brookhaven Relativistic Heavy Ion Collider (RHIC). Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the Siberian snakes also introduce a new set of depolarization resonances, i.e. snake resonances as first discovered by Lee and Tepikian. The intrinsic spin resonances above 100 GeV are about a factor of two stronger than those below 100 GeV which raises the challenge to preserve the polarization up to 250 GeV. In 2009, polarized protons collided for the first time at the RHIC design store energy of 250 GeV. This paper presents the experimental measurements of snake resonances at RHIC. The plan for avoiding these resonances is also presented.

  2. Observation of snake resonances at Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Bai, M.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; Courant, E.; Drees, A.; Fischer, W.; Gardner, C.; Gill, R.; Glenn, J.; Huang, H.; Litvinenko, V.; Luccio, A.; Luo, Y.; Pilat, F.; MacKay, W. W.; Makdisi, Y.; Marusic, A.; Minty, M.; Montag, C.; Ptitsyn, V.; Roser, T.; Svirida, D.; Satogata, T.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Zelenski, A.; Zeno, K.; Zhang, S. Y.

    2011-05-01

    The Siberian snakes are powerful tools in preserving polarization in high energy accelerators has been demonstrated at the Brookhaven Relativistic Heavy Ion Collider (RHIC). Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the Siberian snakes also introduce a new set of depolarization resonances, i.e. snake resonances as first discoverd by Lee and Tepikian [1]. The intrinsic spin resonances above 100 GeV are about a factor of two stronger than those below 100 GeV which raises the challenge to preserve the polarization up to 250 GeV. In 2009, polarized protons collided for the first time at the RHIC design store energy of 250 GeV. This paper presents the experimental measurements of snake resonances at RHIC. The plan for avoiding these resonanances is also presented.

  3. Selection of optimal tube potential settings for dual-energy CT virtual mono-energetic imaging of iodine in the abdomen.

    PubMed

    Michalak, Gregory; Grimes, Joshua; Fletcher, Joel; Halaweish, Ahmed; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia

    2017-04-01

    To determine the appropriate tube potential settings for dual-source, dual-energy data acquisition across a range of phantom sizes, and to determine the optimal photon energies for virtual mono-energetic imaging. Water phantoms (15-50-cm wide) containing an iodine test object were scanned on a third-generation dual-source CT scanner using all available tube potential pairs. Virtual mono-energetic images at 40, 50, 60, and 70 keV were produced using Mono-energetic Plus. To determine the practical operating parameters for the evaluated CT system, data exclusions were made based on water CT number accuracy, artifacts, and using a noise constraint. Image quality metrics were measured and compared. Excluded tube potential pairs were identified; these were generally at low tube potentials for the low-energy beam and low photon energies. For non-excluded conditions, the highest CNR was obtained using the 70/150Sn setting in phantoms ≤35 cm at 40 keV. 70/150Sn provided optimal iodine CNR below 40 cm lateral phantom width at 40 keV, while 90/150Sn allowed acceptable image quality in phantoms >40-cm wide at or above 60 keV.

  4. Reduction of dark-band-like metal artifacts caused by dental implant bodies using hypothetical monoenergetic imaging after dual-energy computed tomography.

    PubMed

    Tanaka, Ray; Hayashi, Takafumi; Ike, Makiko; Noto, Yoshiyuki; Goto, Tazuko K

    2013-06-01

    The aim of this study was to evaluate the usefulness of hypothetical monoenergetic images after dual-energy computed tomography (DECT) for assessment of the bone encircling dental implant bodies. Seventy-two axial images of implantation sites clipped out from image data scanned using DECT in dual-energy mode were used. Subjective assessment on reduction of dark-band-like artifacts (R-DBAs) and diagnosability of adjacent bone condition (D-ABC) in 3 sets of DECT images-a fused image set (DE120) and 2 sets of hypothetical monoenergetic images (ME100, ME190)-was performed and the results were statistically analyzed. With regards to R-DBAs and D-ABC, significant differences among DE120, ME100, and ME190 were observed. The ME100 and ME190 images revealed more artifact reduction and diagnosability than those of DE120. DECT imaging followed by hypothetical monoenergetic image construction can cause R-DBAs and increase D-ABC and may be potentially used for the evaluation of postoperative changes in the bone encircling implant bodies. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Modeling filters for formation of mono-energetic neutron beams in the research reactor IRT MEPhI and optimization of radiation shielding for liquid-xenon detector

    SciTech Connect

    Ivakhin, S. V.; Tikhomirov, G. V.; Bolozdynya, A. I.; Efremenko, Y. V.; Akimov, D. Y.; Stekhanov, V. N.

    2012-07-01

    The paper considers formation of mono-energetic neutron beams at the entrance of experimental channels in research reactors for various applications. The problem includes the following steps: 1. Full-scale mathematical model of the research IRT MEPhI was developed for numerical evaluations of neutron spectra and neutron spatial distribution in the area of experimental channels. 2. Modeling of filters in the channel to shift neutron spectrum towards the required mono-energetic line was performed. 3. Some characteristics of neutron beams at the entrance of detector were evaluated. The filter materials were selected. The calculations were carried out with application of the computer code based on the high-precision Monte-Carlo code MCNP. As a result, mathematical model was created for the filter which is able to form mono-energetic (24 keV) neutron beam. The study was carried out within the frames of the research project on development of Russian emission detector with liquid noble gas to observe rare processes of neutrino scattering and particles of hypothetical dark matter in atomic nuclei. (authors)

  6. Transverse-mass dependence of two-pion correlations in Au+Au collisions at square root[s(NN)] = 130 GeV.

    PubMed

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H-A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kotchetkov, D; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; Van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S

    2002-05-13

    Two-pion correlations in square root[s(NN)] = 130 GeV Au+Au collisions at RHIC have been measured over a broad range of pair transverse momentum k(T) by the PHENIX experiment at RHIC. The k(T) dependent transverse radii are similar to results from heavy-ion collisions at square root[s(NN)] = 4.1, 4.9, and 17.3 GeV, whereas the longitudinal radius increases monotonically with beam energy. The ratio of the outwards to sidewards transverse radii (R(out)/R(side)) is consistent with unity and independent of k(T).

  7. Exploratory study of fission product yield determination from photofission of Pu239 at 11 MeV with monoenergetic photons

    DOE PAGES

    Bhike, Megha; Tornow, W.; Krishichayan, -; ...

    2017-02-14

    Here, measurements of fission product yields play an important role for the understanding of fundamental aspects of the fission process. Recently, neutron-induced fission product-yield data of 239Pu at energies below 4 MeV revealed an unexpected energy dependence of certain fission fragments. In order to investigate whether this observation is prerogative to neutron-induced fission, a program has been initiated to measure fission product yields in photoinduced fission. Here we report on the first ever photofission product yield measurement with monoenergetic photons produced by Compton back-scattering of FEL photons. The experiment was performed at the High-Intensity Gamma-ray Source at Triangle Universities Nuclear Laboratory on 239Pu at Eγmore » = 11 MeV. In this exploratory study the yield of eight fission products ranging from 91Sr to 143Ce has been obtained.« less

  8. Detection of Special Nuclear Material from Delayed Neutron Emission Induced by a Dual-Particle Monoenergetic Source

    SciTech Connect

    Mayer, Michael F.; Nattress, J.; Jovanovic, I

    2016-06-30

    Detection of unique signatures of special nuclear materials is critical for their interdiction in a variety of nuclear security and nonproliferation scenarios. We report on the observation of delayed neutrons from fission of uranium induced in dual-particle active interrogation based on the 11B(d,n gamma)12C nuclear reaction. Majority of the fissions are attributed to fast fission induced by the incident quasi-monoenergetic neutrons. A Li-doped glass–polymer composite scintillation neutron detector, which displays excellent neutron/γ discrimination at low energies, was used in the measurements, along with a recoil-based liquid scintillation detector. Time- dependent buildup and decay of delayed neutron emission from 238U were measured between the interrogating beam pulses and after the interrogating beam was turned off, respectively. Characteristic buildup and decay time profiles were compared to the common parametrization into six delayed neutron groups, finding a good agreement between the measurement and nuclear data. This method is promising for detecting fissile and fissionable materials in cargo scanning applications and can be readily integrated with transmission radiography using low-energy nuclear reaction sources.

  9. Detection of special nuclear material from delayed neutron emission induced by a dual-particle monoenergetic source

    SciTech Connect

    Mayer, M.; Nattress, J.; Jovanovic, I.

    2016-06-27

    Detection of unique signatures of special nuclear materials is critical for their interdiction in a variety of nuclear security and nonproliferation scenarios. We report on the observation of delayed neutrons from fission of uranium induced in dual-particle active interrogation based on the {sup 11}B(d,n γ){sup 12}C nuclear reaction. Majority of the fissions are attributed to fast fission induced by the incident quasi-monoenergetic neutrons. A Li-doped glass–polymer composite scintillation neutron detector, which displays excellent neutron/γ discrimination at low energies, was used in the measurements, along with a recoil-based liquid scintillation detector. Time-dependent buildup and decay of delayed neutron emission from {sup 238}U were measured between the interrogating beam pulses and after the interrogating beam was turned off, respectively. Characteristic buildup and decay time profiles were compared to the common parametrization into six delayed neutron groups, finding a good agreement between the measurement and nuclear data. This method is promising for detecting fissile and fissionable materials in cargo scanning applications and can be readily integrated with transmission radiography using low-energy nuclear reaction sources.

  10. Neutron production during the interaction of monoenergetic electrons with a Tungsten foil in the radiotherapeutic energy range

    NASA Astrophysics Data System (ADS)

    Soto-Bernal, Tzinnia Gabriela; Baltazar-Raigosa, Antonio; Medina-Castro, Diego; Vega-Carrillo, Hector Rene

    2017-10-01

    The electron, photon, and neutron spectra produced during the interaction between monoenergetic electron beams (8, 10, 12, 15, and 18 MeV) and a 0.05 cm-thick tungsten scattering foil were estimated using Monte Carlo method. Incoming electrons is a pencil beam that after collide with the foil acquires a broader distribution peaked in the same direction of the incoming electrons. Electron spectra show the influence of the binding energy of electrons in the tungsten shells and the increase of the electron fluence. In the interaction between the electrons in the beam and the tungsten atoms in the foil, bremsstrahlung and characteristic photons are produced. These photons are also peaked in the same direction of the incoming beam, and the electron fluence increases as the energy of the electron beam raises. The electron and photon spectra have particles whose energy is larger than the binding energy of neutron in the nucleus. Thus neutron production was noticed for 10, 12, 15, and 18 MeV electron beam. The neutron fluence becomes larger as the energy of the electron beam increases, the neutron spectra are mainly evaporation neutrons for 10 and 12 MeV, and for 15 and 18 MeV knock-on neutrons are also produced. Neutrons are produced in the foil volume having a quasi-isotropic distribution.

  11. Construction of 144, 565 keV and 5.0 MeV monoenergetic neutron calibration fields at JAERI.

    PubMed

    Tanimura, Y; Yoshizawa, M; Saegusa, J; Fujii, K; Shimizu, S; Yoshida, M; Shibata, Y; Uritani, A; Kudo, K

    2004-01-01

    Monoenergetic neutron calibration fields of 144, 565 keV and 5.0 MeV have been developed at the Facility of Radiation Standards of JAERI using a 4 MV Pelletron accelerator. The 7Li(p,n)7Be and 2H(d,n)3He reactions are employed for neutron production. The neutron energy was measured by the time-of-flight method with a liquid scintillation detector and calculated with the MCNP-ANT code. A long counter is employed as a neutron monitor because of the flat response. The monitor is set up where the influence of inscattered neutrons from devices and their supporting materials at a calibration point is as small as possible. The calibration coefficients from the monitor counts to the neutron fluence at a calibration point were obtained from the reference fluence measured with the transfer instrument of the primary standard laboratory (AIST), a 24.13 cm phi Bonner sphere counter. The traceability of the fields to AIST was established through the calibration.

  12. Neoplastic transformation of C3H 10T1/2 cells: a study with fractionated doses of monoenergetic neutrons.

    PubMed

    Saran, A; Pazzaglia, S; Pariset, L; Rebessi, S; Broerse, J J; Zoetelief, J; Di Majo, V; Coppola, M; Covelli, V

    1994-05-01

    As most occupational and environmental exposures to ionizing radiation are at low dose rates or in small dose fractions, risk estimation requires that the effects of the temporal distribution of dose are taken into account. Previous in vitro studies of oncogenic transformation, as well as in vivo studies of carcinogenesis induced by high-LET radiation, yielded controversial results concerning the presence of an inverse dose-rate effect. The present study tested the influence of one scheme of dose fractionation of monoenergetic neutrons on neoplastic transformation of C3H 10T1/2 cells. Neutrons of 0.5, 1.0 and 6.0 MeV were used. Cells were exposed to doses of 0.25 and 0.5 Gy, given acutely or in five fractions at 2-h intervals. The acute and fractionated irradiations with each energy were done on the same day. No significant difference between the two irradiation modes was found for both cell inactivation and neoplastic transformation at all energies. These results are in agreement with our data for fractionated fission-spectrum neutrons from the RSV-TAPIRO reactor.

  13. Detection of special nuclear material from delayed neutron emission induced by a dual-particle monoenergetic source

    NASA Astrophysics Data System (ADS)

    Mayer, M.; Nattress, J.; Jovanovic, I.

    2016-06-01

    Detection of unique signatures of special nuclear materials is critical for their interdiction in a variety of nuclear security and nonproliferation scenarios. We report on the observation of delayed neutrons from fission of uranium induced in dual-particle active interrogation based on the 11B(d,n γ)12C nuclear reaction. Majority of the fissions are attributed to fast fission induced by the incident quasi-monoenergetic neutrons. A Li-doped glass-polymer composite scintillation neutron detector, which displays excellent neutron/γ discrimination at low energies, was used in the measurements, along with a recoil-based liquid scintillation detector. Time-dependent buildup and decay of delayed neutron emission from 238U were measured between the interrogating beam pulses and after the interrogating beam was turned off, respectively. Characteristic buildup and decay time profiles were compared to the common parametrization into six delayed neutron groups, finding a good agreement between the measurement and nuclear data. This method is promising for detecting fissile and fissionable materials in cargo scanning applications and can be readily integrated with transmission radiography using low-energy nuclear reaction sources.

  14. The response of a 300 micron silicon detector to monoenergetic neutrons determined by the use of the Monte Carlo technique

    NASA Technical Reports Server (NTRS)

    Tahezadeh, M.; Anno, G.

    1972-01-01

    The response of a 300 micron thick silicon detector to an incident monoenergetic neutron beam is evaluated by the Monte Carlo method for the cases of both a shielded and a bare detector. The result of Monte Carlo calculation, using elastic, inelastic, and absorption reactions indicates that the response of the silicon detector to neutrons is basically due to the elastic scattering. In addition, the gamma rays generated in the shield of the detector will result in a response which is 3 or 4 orders of magnitude smaller than response to incident photons. The response of a bare silicon detector is calculated for neutron energies up to 6 MeV and bias energies from 50 to 250 KeV. It is found that the maximum response for a 300 micron thick silicon detector is less than .004 c/n within this selected neutron and bias energy range. When the pulse height defect is introduced in the calculation the results at low energy neutrons were reduced.

  15. Analysis of the reliability of the local effect model for the use in carbon ion treatment planning systems.

    PubMed

    Russo, G; Attili, A; Bourhaleb, F; Marchetto, F; Peroni, C; Schmitt, E; Bertrand, D

    2011-02-01

    In radiotherapy with carbon ions, biological effects of treatments have to be predicted. For this purpose, one of the most used models is the local effect model (LEM) developed at the Gesellschaft für Schwerionenforschung (GSI), Germany. At the Istituto Nazionale di Fisica Nucleare, Italy, the reliability of the last published version of LEM (LEM III) in reproducing radiobiological data has been checked under both monoenergetic and spread-out Bragg peak (SOBP) carbon-ion irradiation. The reproduction of the monoenergetic measurements with the LEM was rather successful for some cell lines, while it failed for the less-radioresistant ones. The SOBP experimental trend was predicted by the LEM, but a large shift between model curves and measured points was observed.

  16. Metallic artefact reduction with monoenergetic dual-energy CT: systematic ex vivo evaluation of posterior spinal fusion implants from various vendors and different spine levels.

    PubMed

    Guggenberger, R; Winklhofer, S; Osterhoff, G; Wanner, G A; Fortunati, M; Andreisek, G; Alkadhi, H; Stolzmann, P

    2012-11-01

    To evaluate optimal monoenergetic dual-energy computed tomography (DECT) settings for artefact reduction of posterior spinal fusion implants of various vendors and spine levels. Posterior spinal fusion implants of five vendors for cervical, thoracic and lumbar spine were examined ex vivo with single-energy (SE) CT (120 kVp) and DECT (140/100 kVp). Extrapolated monoenergetic DECT images at 64, 69, 88, 105 keV and individually adjusted monoenergy for optimised image quality (OPTkeV) were generated. Two independent radiologists assessed quantitative and qualitative image parameters for each device and spine level. Inter-reader agreements of quantitative and qualitative parameters were high (ICC = 0.81-1.00, κ = 0.54-0.77). HU values of spinal fusion implants were significantly different among vendors (P < 0.001), spine levels (P < 0.01) and among SECT, monoenergetic DECT of 64, 69, 88, 105 keV and OPTkeV (P < 0.01). Image quality was significantly (P < 0.001) different between datasets and improved with higher monoenergies of DECT compared with SECT (V = 0.58, P < 0.001). Artefacts decreased significantly (V = 0.51, P < 0.001) at higher monoenergies. OPTkeV values ranged from 123-141 keV. OPTkeV according to vendor and spine level are presented herein. Monoenergetic DECT provides significantly better image quality and less metallic artefacts from implants than SECT. Use of individual keV values for vendor and spine level is recommended. • Artefacts pose problems for CT following posterior spinal fusion implants. • CT images are interpreted better with monoenergetic extrapolation using dual-energy (DE) CT. • DECT extrapolation improves image quality and reduces metallic artefacts over SECT. • There were considerable differences in monoenergy values among vendors and spine levels. • Use of individualised monoenergy values is indicated for different metallic hardware devices.

  17. Collimated GeV proton beam generated by the interaction of ultra-intense laser with a uniform near-critical underdense plasma

    NASA Astrophysics Data System (ADS)

    Gu, Y. J.; Zhu, Z.; Li, Y. Y.; Li, X. F.; Chen, C. Y.; Kong, Q.; Kawata, S.

    2011-08-01

    An ultra-intense short-pulsed laser interacting with a uniform underdense plasma with near-critical density is investigated by 2.5-dimensional particle-in-cell simulations. It is found that a collimated proton beam with maximum energy up to the GeV was generated. The corresponding proton acceleration mechanism is analyzed. The laser wakefield acceleration (LWFA) electrons play an important role as a driving beam. Due to the features of LWFA electrons, quasi-monoenergetic distribution and good collimation, the protons can be accelerated for a long distance by the charge-separated electric field. The proton beam in this regime is also well collimated and the amount can reach several nC. Moreover, it is found that the LWFA electrons can overtake the laser and stand quasi-synchronized in the center of pulse. Therefore the electrons can absorb energy from the laser and transfer it to the protons like in the break-out afterburner (BOA) scheme in laser irradiated on ultra-thin film target.

  18. Cellular track model for study of heavy ion beams

    NASA Technical Reports Server (NTRS)

    Shinn, Judy L.; Katz, Robert; Cucinotta, Francis A.; Wilson, John W.; Ngo, Duc M.

    1993-01-01

    Track theory is combined with a realistic model of a heavy ion beam to study the effects of nuclear fragmentation on cell survival and biological effectiveness. The effects of secondary reaction products are studied as a function of depth in a water column. Good agreement is found with experimental results for the survival of human T-l cells exposed to monoenergetic carbon, neon, and argon beams under aerobic and hypoxia conditions. The present calculation, which includes the effect of target fragmentation, is a significant improvement over an earlier calculation because of the use of a vastly improved beam model with no change in the track theory or cellular response parameters.

  19. Microdosimetry of proton and carbon ions

    SciTech Connect

    Liamsuwan, Thiansin; Hultqvist, Martha; Lindborg, Lennart; Nikjoo, Hooshang; Uehara, Shuzo

    2014-08-15

    Purpose: To investigate microdosimetry properties of 160 MeV/u protons and 290 MeV/u{sup 12}C ion beams in small volumes of diameters 10–100 nm. Methods: Energy distributions of primary particles and nuclear fragments in the beams were calculated from simulations with the general purpose code SHIELD-HIT, while energy depositions by monoenergetic ions in nanometer volumes were obtained from the event-by-event Monte Carlo track structure ion code PITS99 coupled with the electron track structure code KURBUC. Results: The results are presented for frequencies of energy depositions in cylindrical targets of diameters 10–100 nm, dose distributionsyd(y) in lineal energy y, and dose-mean lineal energies y{sup ¯}{sub D}. For monoenergetic ions, the y{sup ¯}{sub D} was found to increase with an increasing target size for high-linear energy transfer (LET) ions, but decrease with an increasing target size for low-LET ions. Compared to the depth dose profile of the ion beams, the maximum of the y{sup ¯}{sub D} depth profile for the 160 MeV proton beam was located at ∼0.5 cm behind the Bragg peak maximum, while the y{sup ¯}{sub D} peak of the 290 MeV/u {sup 12}C beam coincided well with the peak of the absorbed dose profile. Differences between the y{sup ¯}{sub D} and dose-averaged linear energy transfer (LET{sub D}) were large in the proton beam for both target volumes studied, and in the {sup 12}C beam for the 10 nm diameter cylindrical volumes. The y{sup ¯}{sub D} determined for 100 nm diameter cylindrical volumes in the {sup 12}C beam was approximately equal to the LET{sub D}. The contributions from secondary particles to the y{sup ¯}{sub D} of the beams are presented, including the contributions from secondary protons in the proton beam and from fragments with atomic number Z = 1–6 in the {sup 12}C beam. Conclusions: The present investigation provides an insight into differences in energy depositions in subcellular-size volumes when irradiated by proton and

  20. Microdosimetry of proton and carbon ions.

    PubMed

    Liamsuwan, Thiansin; Hultqvist, Martha; Lindborg, Lennart; Uehara, Shuzo; Nikjoo, Hooshang

    2014-08-01

    To investigate microdosimetry properties of 160 MeV/u protons and 290 MeV/u(12)C ion beams in small volumes of diameters 10-100 nm. Energy distributions of primary particles and nuclear fragments in the beams were calculated from simulations with the general purpose code SHIELD-HIT, while energy depositions by monoenergetic ions in nanometer volumes were obtained from the event-by-event Monte Carlo track structure ion code PITS99 coupled with the electron track structure code KURBUC. The results are presented for frequencies of energy depositions in cylindrical targets of diameters 10-100 nm, dose distributions yd(y) in lineal energy y, and dose-mean lineal energies yD. For monoenergetic ions, the yD was found to increase with an increasing target size for high-linear energy transfer (LET) ions, but decrease with an increasing target size for low-LET ions. Compared to the depth dose profile of the ion beams, the maximum of the yD depth profile for the 160 MeV proton beam was located at ∼ 0.5 cm behind the Bragg peak maximum, while the yD peak of the 290 MeV/u (12)C beam coincided well with the peak of the absorbed dose profile. Differences between the yD and dose-averaged linear energy transfer (LETD) were large in the proton beam for both target volumes studied, and in the (12)C beam for the 10 nm diameter cylindrical volumes. The yD determined for 100 nm diameter cylindrical volumes in the (12)C beam was approximately equal to the LETD. The contributions from secondary particles to the yD of the beams are presented, including the contributions from secondary protons in the proton beam and from fragments with atomic number Z = 1-6 in the (12)C beam. The present investigation provides an insight into differences in energy depositions in subcellular-size volumes when irradiated by proton and carbon ion beams. The results are useful for characterizing ion beams of practical importance for biophysical modeling of radiation-induced DNA damage response and repair in

  1. Spot size dependence of laser accelerated protons in thin multi-ion foils

    SciTech Connect

    Liu, Tung-Chang Shao, Xi; Liu, Chuan-Sheng; Eliasson, Bengt; Wang, Jyhpyng; Chen, Shih-Hung

    2014-06-15

    We present a numerical study of the effect of the laser spot size of a circularly polarized laser beam on the energy of quasi-monoenergetic protons in laser proton acceleration using a thin carbon-hydrogen foil. The used proton acceleration scheme is a combination of laser radiation pressure and shielded Coulomb repulsion due to the carbon ions. We observe that the spot size plays a crucial role in determining the net charge of the electron-shielded carbon ion foil and consequently the efficiency of proton acceleration. Using a laser pulse with fixed input energy and pulse length impinging on a carbon-hydrogen foil, a laser beam with smaller spot sizes can generate higher energy but fewer quasi-monoenergetic protons. We studied the scaling of the proton energy with respect to the laser spot size and obtained an optimal spot size for maximum proton energy flux. Using the optimal spot size, we can generate an 80 MeV quasi-monoenergetic proton beam containing more than 10{sup 8} protons using a laser beam with power 250 TW and energy 10 J and a target of thickness 0.15 wavelength and 49 critical density made of 90% carbon and 10% hydrogen.

  2. Proposed double-layer target for the generation of high-quality laser-accelerated ion beams.

    PubMed

    Esirkepov, T Zh; Bulanov, S V; Nishihara, K; Tajima, T; Pegoraro, F; Khoroshkov, V S; Mima, K; Daido, H; Kato, Y; Kitagawa, Y; Nagai, K; Sakabe, S

    2002-10-21

    In order to achieve a high-quality, i.e., monoenergetic, intense ion beam, we propose the use of a double-layer target. The first layer, at the target front, consists of high-Z atoms, while the second (rear) layer is a thin coating of low-Z atoms. The generation of high-quality proton beams from the double-layer target, irradiated by an ultraintense laser pulse, is demonstrated with three-dimensional particle-in-cell simulations.

  3. COMMISSIONING OF RHIC AT 100 GEV / NUCLEON.

    SciTech Connect

    TRBOJEVIC,D.; AHRENS,L.; BLASKIEWICZ,M.; BRENNAN,J.M.; BAI,M.; CAMERON,P.; CARDONA,J.; CONNOLLY,R.; DREES,A.; FLILLER,R.P.; ET AL

    2002-06-02

    This report describes commissioning of the Relativistic Heavy Ion Collider (RHIC) for 100 GeV/nucleon collisions at designed luminosity. To achieve these goals new systems had to be commissioned: Gamma-t transition crossing jump quadrupoles, rebucketing with the new RF storage cavities, phase lock loop feedback, betatron and crystal collimation, beta squeeze along the ramp, Siberian snake magnets for the proton polarization run, AC dipole system chromaticity measurements along the acceleration ramp, orbit correction, new ramp management system, upgraded sequencer, new data instrumentation and logger acquisition system etc.

  4. Dielectron azimuthal anisotropy at mid-rapidity in Au + Au collisions at √{sN N}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-12-01

    We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e- pairs) at mid-rapidity from √{sN N}=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Me e<1.1 GeV /c2 the dielectron v2 measurements are found to be consistent with expectations from π0,η ,ω , and ϕ decay contributions. In the mass region 1.1 GeV /c2 , the measured dielectron v2 is consistent, within experimental uncertainties, with that from the c c ¯ contributions.

  5. Search for Chiral Magnetic Effect with Identified Particles in Au+Au Collisions at √{sNN} = 39 GeV from RHIC/STAR

    NASA Astrophysics Data System (ADS)

    Huang, Yiwen; STAR Collaboration

    2016-09-01

    Chirality imbalance could occur in local domains inside the hot nuclear matter formed in high-energy heavy-ion collisions. In the presence of a strong magnetic field, this chirality imbalance will induce an electric charge separation along the magnetic field direction, owing to the chiral magnetic effect (CME). Previous azimuthal-angle correlation measurements with unidentified charged particles have manifested charge separation signals consistent with the predictions of the CME. But the magnitudes of the background contributions have not been understood. In this poster, we present the correlation results with identified particles (protons and pions) using STAR data of 39 GeV Au+Au collisions. The results will be compared with those from Au+Au at √{sNN} = 200GeV , as well as the published results of unidentified particles at √{sNN} = 39GeV . For the STAR Collaboration.

  6. Microstructured snow targets for high energy quasi-monoenergetic proton acceleration

    NASA Astrophysics Data System (ADS)

    Schleifer, E.; Nahum, E.; Eisenmann, S.; Botton, M.; Baspaly, A.; Pomerantz, I.; Abricht, F.; Branzel, J.; Priebe, G.; Steinke, S.; Andreev, A.; Schnuerer, M.; Sandner, W.; Gordon, D.; Sprangle, P.; Ledingham, K. W. D.; Zigler, A.

    2013-05-01

    Compact size sources of high energy protons (50-200MeV) are expected to be key technology in a wide range of scientific applications 1-8. One promising approach is the Target Normal Sheath Acceleration (TNSA) scheme 9,10, holding record level of 67MeV protons generated by a peta-Watt laser 11. In general, laser intensity exceeding 1018 W/cm2 is required to produce MeV level protons. Another approach is the Break-Out Afterburner (BOA) scheme which is a more efficient acceleration scheme but requires an extremely clean pulse with contrast ratio of above 10-10. Increasing the energy of the accelerated protons using modest energy laser sources is a very attractive task nowadays. Recently, nano-scale targets were used to accelerate ions 12,13 but no significant enhancement of the accelerated proton energy was measured. Here we report on the generation of up to 20MeV by a modest (5TW) laser system interacting with a microstructured snow target deposited on a Sapphire substrate. This scheme relax also the requirement of high contrast ratio between the pulse and the pre-pulse, where the latter produces the highly structured plasma essential for the interaction process. The plasma near the tip of the snow target is subject to locally enhanced laser intensity with high spatial gradients, and enhanced charge separation is obtained. Electrostatic fields of extremely high intensities are produced, and protons are accelerated to MeV-level energies. PIC simulations of this targets reproduce the experimentally measured energy scaling and predict the generation of 150 MeV protons from laser power of 100TW laser system18.

  7. Ion-acoustic Shocks with Reflected Ions: Implications for laser-based proton accelerators

    NASA Astrophysics Data System (ADS)

    Sagdeev, Roald; Malkov, Mikhail; Dudnikova, Galina; Liseykina, Tatyana; Diamond, Patrick; Liu, C.-S.; Su, J.-J.

    2014-10-01

    Analytic solution for an ion-acoustic collisionless shock with reflected ions is obtained. Its relation to classical non-reflecting solitons propagating at Mach numbers strictly limited by M ions and turns into a shock. The shock has a double-structure consisting of two receding transitions. The first transition is the ion-acoustic shock itself formed in place of the soliton. The shock reflected ions progressively fill up an extended foot region ending with the second transition that propagates faster than the rear shock but slower than the most of reflected ions. A small fraction of these ions still remains trapped in the transition to maintain charge neutrality. Most of them pass through this front transition, and accelerate whereas their distribution becomes noteworthily monoenergetic. The obtained solution may thus have interesting implications for the laser-based ion accelerators. Applications to particle acceleration in geophysical and astrophysical shocks are discussed. Partially supported by NASA, ATP NNX14AH36G, and the US DoE.

  8. Hadron Production and Freeze-Out Dynamics at square root of sNN = 3.0 GeV Au+Al and square root of sNN = 19.6 GeV Au+Au Collisions as Measured at STAR

    NASA Astrophysics Data System (ADS)

    Brovko, Samantha Gail

    The Beam Energy Scan program at RHIC was commissioned to search for the critical point and the turn-off of QGP signatures. The program has completed collisions of Au+Au at energies from 7.7 to 62.4 GeV per nucleon pair in 2010 and 2011. The addition of a full-coverage Time-of-Flight detector at STAR extended the momentum range for clean particle identification. Mid-rapidity (|y| < 0.5) hadron spectra will be used to determine the freeze-out dynamics of the system. Particle spectra for pi, K, p and p¯ as a function of mT -- m0 will be presented and these will be used to discuss in particular the source's Coulombic effect on soft pions, as well as three of the four signs of the onset of deconfinement: the "Kink," the "Horn," and the "Step." Comparisons will be made to √s NN) = 7.7 GeV, 11.5 GeV, 19.6 GeV (from 2001), 27 GeV, 39 GeV Au+Au data from STAR, and (sqrt of sNN = 17.3 GeV Pb+Pb data from the SPS heavy ion program. Collisions between gold ions in the RHIC beam with aluminum nuclei in the beam pipe allow us to analyze fixed-target interactions with the STAR detector at RHIC. These lower-energy fixed-target collisions may allow us to extend the low-energy reach of the RHIC beam energy scan and possibly improve the chance of finding the critical point of the hadronic to quark matter phase boundary. In this thesis, we will present preliminary results of spectra analyses for a fixed target collision system at √sNN)= 3.0 GeV and colliding beam system at √sNN = 19.6 GeV . Also, the viability of doing fixed-target experiments with a collider detector will be discussed. Comparisons to simulation, using UrQMD, will also be made. The analysis provides a good reference to study excitation functions of strangeness production, net baryon number, and collective flow in heavy-ion collisions.

  9. Carotid dual-energy CT angiography: Evaluation of low keV calculated monoenergetic datasets by means of a frequency-split approach for noise reduction at low keV levels.

    PubMed

    Riffel, Philipp; Haubenreisser, Holger; Meyer, Mathias; Sudarski, Sonja; Morelli, John N; Schmidt, Bernhard; Schoenberg, Stefan O; Henzler, Thomas

    2016-04-01

    Calculated monoenergetic ultra-low keV datasets did not lead to improved contrast-to-noise ratio (CNR) due to the dramatic increase in image noise. The aim of the present study was to evaluate the objective image quality of ultra-low keV monoenergetic images (MEIs) calculated from carotid DECT angiography data with a new monoenergetic imaging algorithm using a frequency-split technique. 20 patients (12 male; mean age 53±17 years) were retrospectively analyzed. MEIs from 40 to 120 keV were reconstructed using the monoenergetic split frequency approach (MFSA). Additionally MEIs were reconstructed for 40 and 50 keV using a conventional monoenergetic (CM) software application. Signal intensity, noise, signal-to-noise ratio (SNR) and CNR were assessed in the basilar, common, internal carotid arteries. Ultra-low keV MEIs at 40 keV and 50 keV demonstrated highest vessel attenuation, significantly greater than those of the polyenergetic images (PEI) (all p-values <0.05). The highest SNR level and CNR level was found at 40 keV and 50 keV (all p-values <0.05). MEIs with MFSA showed significantly lower noise levels than those processed with CM (all p-values <0.05) and no significant differences in vessel attenuation (p>0.05). Thus MEIs with MFSA showed significantly higher SNR and CNR compared to MEIs with CM. Combining the lower spatial frequency stack for contrast at low keV levels with the high spatial frequency stack for noise at high keV levels (frequency-split technique) leads to improved image quality of ultra-low keV monoenergetic DECT datasets when compared to previous monoenergetic reconstruction techniques without the frequency-split technique. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Characterising the 750 GeV diphoton excess

    NASA Astrophysics Data System (ADS)

    Bernon, Jérémy; Goudelis, Andreas; Kraml, Sabine; Mawatari, Kentarou; Sengupta, Dipan

    2016-05-01

    We study kinematic distributions that may help characterise the recently observed excess in diphoton events at 750 GeV at the LHC Run 2. Several scenarios are considered, including spin-0 and spin-2 750 GeV resonances that decay directly into photon pairs as well as heavier parent resonances that undergo three-body or cascade decays. We find that combinations of the distributions of the diphoton system and the leading photon can distinguish the topology and mass spectra of the different scenarios, while patterns of QCD radiation can help differentiate the production mechanisms. Moreover, missing energy is a powerful discriminator for the heavy parent scenarios if they involve (effectively) invisible particles. While our study concentrates on the current excess at 750 GeV, the analysis is general and can also be useful for characterising other potential diphoton signals in the future.

  11. The 6 GeV TMD Program at Jefferson Lab

    SciTech Connect

    Puckett, Andrew J.

    2015-01-01

    The study of the transverse momentum dependent parton distributions (TMDs) of the nucleon in semi-inclusive deep-inelastic scattering (SIDIS) has emerged as one of the major physics motivations driving the experimental program using the upgraded 11 GeV electron beam at Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF). The accelerator construction phase of the CEBAF upgrade is essentially complete and commissioning of the accelerator has begun as of April, 2014. As the new era of CEBAF operations begins, it is appropriate to review the body of published and forthcoming results on TMDs from the 6 GeV era of CEBAF operations, discuss what has been learned, and discuss the key challenges and opportunities for the 11 GeV SIDIS program of CEBAF.

  12. The Jefferson Lab 12 GeV Upgrade

    SciTech Connect

    R.D. McKeown

    2010-09-01

    Construction of the 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility is presently underway. This upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and the construction of upgraded detector hardware. An overview of this upgrade project is presented, along with highlights of the anticipated experimental program. The 12 GeV upgrade project at Jefferson Lab will enable a powerful new experimental program that will advance our understanding of the quark/gluon structure of hadronic matter, the nature of Quantum Chromodynamics, and the properties of a new extended standard model of particle interactions. Commissioning of the upgraded beam will be begin in 2013, and the full complement of upgraded experimental equipment will be completed in 2015. This unique facility will provide many opportunities for exploration and discovery for a large international community of nuclear scientists.

  13. S5 0716+714: GeV variability study

    SciTech Connect

    Rani, B.; Krichbaum, T. P.; Lott, B.; Zensus, J. A.

    2013-02-19

    The GeV observations by Fermi-LAT give us the opportunity to characterize the high-energy emission (100 MeV–300 GeV) variability properties of the BL Lac object S5 0716+714. In this study, we performed flux and spectral analysis of more than 3 year long (August 2008 to April 2012) Fermi-LAT data of the source. During this period, the source exhibits two different modes of flux variability with characteristic timescales of ~75 and ~140 days, respectively. In addition, we also notice that the flux variations are characterized by a weak spectral hardening. The GeV spectrum of the source shows a clear deviation from a simple power law, and is better explained by a broken power law. Similar to other bright Fermi blazars, the break energy does not vary with the source flux during the different activity states. Finally, we discuss several possible scenarios to explain the observed spectral break.

  14. Asymmetric dark matter from a GeV hidden sector

    SciTech Connect

    Cohen, Timothy; Zurek, Kathryn M.; Phalen, Daniel J.; Pierce, Aaron

    2010-09-01

    Asymmetric dark matter (ADM) models relate the dark matter (DM) density to the baryon asymmetry, so that a natural mass scale for ADM is around a few GeV. In existing models of ADM, this mass scale is unexplained; here we generate this GeV scale for DM) from the weak scale via gauge kinetic mixing with a new Abelian dark force. In addition, this dark sector provides an efficient mechanism for suppressing the symmetric abundance of DM through annihilations to the dark photon. We augment this sector with a higher dimensional operator responsible for communicating the baryon asymmetry to the dark sector. Our framework also provides a DM candidate for gauge mediation models. It results in a direct detection cross section of interest for current experiments: {sigma}{sub p} < or approx. 10{sup -41} cm{sup 2} for DM masses in the range 1-15 GeV.

  15. The 12 GeV Upgrade at Jefferson Lab

    SciTech Connect

    Rolf Ent

    2002-02-01

    There has been a remarkable fruitful evolution of our picture of the behavior of strongly interacting matter during the almost two decades that have passed since the parameters of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab were defined. These advances have revealed important new experimental questions best addressed by a CEBAF-class machine at higher energy. Fortunately, favorable technical developments coupled with foresight in the design of the facility make it feasible to triple (double) CEBAF's design (achieved) beam energy from 4 (6) GeV to 12 GeV, in a cost-effective manner: the Upgrade can be realized for about 15% of the cost of the initial facility. This Upgrade would enable the worldwide community to greatly expand its physics horizons. In addition to in general improving the figure of merit and momentum transfer range of the present Jefferson Lab physics program, raising the energy of the accelerator to 12 GeV opens up two main new areas of physics: (1) It allows direct exploration of the quark-gluon structure of hadrons and nuclei in the ''valence quark region''. It is known that inclusive electron scattering at the high momentum and energy transfers available at 12 GeV is governed by elementary interactions with quarks and, indirectly, gluons. The original CEBAF energy is not adequate to study this critical region, while with continuous 12 GeV beams one can cleanly access the entire ''valence quark region'' and exploit the newly discovered Generalized Parton Distributions. In addition, a 12-GeV Jefferson Lab can essentially complete the studies of the transition from hadronic to quark-gluon degrees of freedom. (2) It allows crossing the threshold above which the origins of quark confinement can be investigated. Specifically, 12 GeV will enable the production of certain ''exotic'' mesons. Whereas in the QCD region of asymptotic freedom ample evidence for the role of gluons exist through the observation of gluon jets

  16. CEBAF SRF Performance during Initial 12 GeV Commissioning

    SciTech Connect

    Bachimanchi, Ramakrishna; Allison, Trent; Daly, Edward; Drury, Michael; Hovater, J; Lahti, George; Mounts, Clyde; Nelson, Richard; Plawski, Tomasz

    2015-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of eleven new 100 MV cryomodules (88 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. Not all the cavities were operated at the minimum gradient of 19.3 MV/m with the beam. Though the initial 12 GeV milestones were achieved during the initial commissioning of CEBAF, there are still some issues to be addressed for long term reliable operation of these modules. This paper reports the operational experiences during the initial commissioning and the path forward to improve the performance of C100 (100 MV) modules.

  17. Spin Structure with JLab 6 and 12 GeV

    SciTech Connect

    Jian-Ping Chen

    2012-02-01

    Highlights of JLab 6 GeV results on spin structure study and plan for 12 GeV program. Spin structure study is full of surprises and puzzles. A decade of experiments from JLab yield these exciting results: (1) valence spin structure; (2) precision measurements of g{sub 2}/d{sub 2} - high-twist; (3) spin sum rules and polarizabilities; and (4) first neutron transversity. There is a bright future as the 12 GeV Upgrade will greatly enhance our capability: (1) Precision determination of the valence quark spin structure flavor separation; (2) Precision measurements of g{sub 2}/d{sub 2}; and (3) Precision extraction of transversity/tensor charge.

  18. GeV flares observations with GLAST LAT

    SciTech Connect

    Galli, A.; Omodei, N.; Piro, L.

    2007-07-12

    Early X-ray afterglow observations show that X-ray flares are very common features in GRB light curves. X-ray flares may reflect long duration central engine activity. The delayed flare photons are expected to interact with relativistic electrons by Inverse Compton giving delayed high energy counterparts that potentially will be detected by GLAST LAT, which could observe GRB from 20 MeV to more than 300 GeV. The nature oh high energy spectral components from GRB detected by EGRET is still debated. Observations with GLAST LAT will give useful information to constrain the origin of X-ray flares. In this work we simulate a set of possible GeV emitting flares in the context of External Shock model to study the capability of GLAST LAT to detect GeV flares at different intensities and durations.

  19. RHIC 100 GeV Polarized Proton Luminosity

    SciTech Connect

    Zhang, S. Y.

    2014-01-17

    A big problem in RHIC 100 GeV proton run 2009 was the significantly lower luminosity lifetime than all previous runs. It is shown in this note that the beam intensity decay in run 2009 is caused by the RF voltage ramping in store. It is also shown that the beam decay is not clearly related to the beam momentum spread, therefore, not directly due to the 0.7m. β* Furthermore, the most important factor regarding the low luminosity lifetime is the faster transverse emittance growth in store, which is also much worse than the previous runs, and is also related to the RF ramping. In 100 GeV proton run 2012a, the RF ramping was abandoned, but the β* was increased to 0.85m, with more than 20% loss of luminosity, which is not necessary. It is strongly suggested to use smaller β* in 100 GeV polarized proton run 2015/2016

  20. Calculation of the Coulomb Fission Cross Sections for Pb-Pb and Bi-Pb Interactions at 158 A GeV

    NASA Technical Reports Server (NTRS)

    Poyser, William J.; Ahern, Sean C.; Norbury, John W.; Tripathi, R. K.

    2002-01-01

    The Weizsacker-Williams (WW) method of virtual quanta is used to make approximate cross section calculations for peripheral relativistic heavy-ion collisions. We calculated the Coulomb fission cross sections for projectile ions of Pb-208 and Bi-209 with energies of 158 A GeV interacting with a Pb-208 target. We also calculated the electromagnetic absorption cross section for Pb-208 ion interacting as described. For comparison we use both the full WW method and a standard approximate WW method. The approximate WW method in larger cross sections compared to the more accurate full WW method.

  1. Intra-individual comparison between abdominal virtual mono-energetic spectral and conventional images using a novel spectral detector CT

    PubMed Central

    Wybranski, Christian; Byrtus, Jonathan; Houbois, Christian; Hauger, Myriam; Heneweer, Carola; Siedek, Florian; Hickethier, Tilman; Große Hokamp, Nils; Maintz, David; Haneder, Stefan

    2017-01-01

    Objectives To quantitatively and qualitatively assess abdominal arterial and venous phase contrast-enhanced spectral detector computed tomography (SDCT) virtual mono-energetic (MonoE) datasets in comparison to conventional CT reconstructions provided by the same system. Materials and methods Conventional and MonoE images at 40–120 kilo-electron volt (keV) levels with a 10 keV increment as well as 160 and 200 keV were reconstructed in abdominal SDCT datasets of 55 patients. Attenuation, image noise, and contrast- / signal-to-noise ratios (CNR, SNR) of vessels and solid organs were compared between MonoE and conventional reconstructions. Two readers assessed contrast conditions, detail visualization, overall image quality and subjective image noise with both, fixed and adjustable window settings. Results Attenuation, CNR and SNR of vessels and solid organs showed a stepwise increase from high to low keV reconstructions in both contrast phases while image noise stayed stable at low keV MonoE reconstruction levels. Highest levels were found at 40 keV MonoE reconstruction (p<0.001), respectively. Solid abdominal organs showed a stepwise decrease from low to high energy levels in regard to attenuation, CNR and SNR with significantly higher values at 40 and 50 keV, compared to conventional images. The 70 keV MonoE was comparable to conventional poly-energetic reconstruction (p≥0.99). Subjective analysis displayed best image quality for the 70 keV MonoE reconstruction level in both phases at fixed standard window presets and at 40 keV if window settings could be adjusted. Conclusion SDCT derived low keV MonoE showed markedly increased CNR and SNR values due to constantly low image noise values over the whole energy spectrum from 40 to 200 keV. PMID:28837641

  2. Single-source dual-energy computed tomography: use of monoenergetic extrapolation for a reduction of metal artifacts.

    PubMed

    Mangold, Stefanie; Gatidis, Sergios; Luz, Oliver; König, Benjamin; Schabel, Christoph; Bongers, Malte N; Flohr, Thomas G; Claussen, Claus D; Thomas, Christoph

    2014-12-01

    The objective of this study was to retrospectively determine the potential of virtual monoenergetic (ME) reconstructions for a reduction of metal artifacts using a new-generation single-source computed tomographic (CT) scanner. The ethics committee of our institution approved this retrospective study with a waiver of the need for informed consent. A total of 50 consecutive patients (29 men and 21 women; mean [SD] age, 51.3 [16.7] years) with metal implants after osteosynthetic fracture treatment who had been examined using a single-source CT scanner (SOMATOM Definition Edge; Siemens Healthcare, Forchheim, Germany; consecutive dual-energy mode with 140 kV/80 kV) were selected. Using commercially available postprocessing software (syngo Dual Energy; Siemens AG), virtual ME data sets with extrapolated energy of 130 keV were generated (medium smooth convolution kernel D30) and compared with standard polyenergetic images reconstructed with a B30 (medium smooth) and a B70 (sharp) kernel. For quantification of the beam hardening artifacts, CT values were measured on circular lines surrounding bone and the osteosynthetic device, and frequency analyses of these values were performed using discrete Fourier transform. A high proportion of low frequencies to the spectrum indicates a high level of metal artifacts. The measurements in all data sets were compared using the Wilcoxon signed rank test. The virtual ME images with extrapolated energy of 130 keV showed significantly lower contribution of low frequencies after the Fourier transform compared with any polyenergetic data set reconstructed with D30, B70, and B30 kernels (P < 0.001). Sequential single-source dual-energy CT allows an efficient reduction of metal artifacts using high-energy ME extrapolation after osteosynthetic fracture treatment.

  3. The effectiveness of monoenergetic neutrons at 565 keV in producing dicentric chromosomes in human lymphocytes at low doses.

    PubMed

    Schmid, E; Regulla, D; Guldbakke, S; Schlegel, D; Bauchinger, M

    2000-09-01

    The induction of dicentric chromosomes in human lymphocytes from one individual irradiated in vitro with monoenergetic neutrons at 565 keV was examined to provide additional data for an improved evaluation of neutrons with respect to radiation risk in radioprotection. The resulting linear dose-response relationship obtained (0.813 +/- 0.052 dicentrics per cell per gray) over the dose range of 0.0213-0.167 Gy is consistent with published results obtained for irradiation with neutrons from different sources and with different spectra at energies lower than 1000 keV. Comparing this value to previously published "average" dose-response curves obtained by different laboratories for (60)Co gamma rays and orthovoltage X rays resulted in maximum RBEs (RBE(m)) of about 37 +/- 8 and 16 +/- 4, respectively. However, when our neutron data were matched to low-LET dose responses that were constructed several years earlier for lymphocytes from the same individual, higher values of RBE(m) resulted: 76.0 +/- 29.5 for (60)Co gamma rays and 54.2 +/- 18.4 for (137)Cs gamma rays; differentially filtered 220 kV X rays produced values of RBE(m) between 20.3 +/- 2.0 or 37.0 +/- 7. 1. The results highlight the dependence of RBE(m) on the choice of low-LET reference radiation and raise the possibility that differential individual response to low-LET radiations may need to be examined more fully in this context.

  4. Reconstruction of GeV Neutrino Events in LENA

    SciTech Connect

    Moellenberg, R.; Feilitzsch, F. von; Goeger-Neff, M.; Hellgartner, D.; Lewke, T.; Meindl, Q.; Oberauer, L.; Potzel, W.; Tippmann, M.; Winter, J.; Wurm, M.; Peltoniemi, J.

    2011-10-06

    LENA (Low Energy Neutrino Astronomy) is a proposed next generation liquid-scintillator detector with about 50 kt target mass. Besides the detection of solar neutrinos, geoneutrinos, supernova neutrinos and the search for the proton decay, LENA could also be used as the far detector of a next generation neutrino beam. The present contribution outlines the status of the Monte Carlo studies towards the reconstruction of GeV neutrinos in LENA. Both the tracking capabilities at a few hundred MeV, most interesting for a beta beam, and above 1 GeV for a superbeam experiment are presented.

  5. Polarimetry in the few GeV region

    SciTech Connect

    Perdrisat, C.F.

    1994-10-26

    The properties of polarimeters used in a number of Laboratories, to measure the polarization of secondaries produced in a nuclear target, in the range of energy 100 MeV to 12 GeV, are reviewed. The nature of polarization experiments will be discussed and several examples of new experiments used to illustrate the power of this technique. New development both for protons and for deuterons win be discussed in some details. Calibrations data and fits both for protons, to 2.4 GeV, and deuterons, to 700 MeV, will be presented.

  6. Ion acceleration with a narrow energy spectrum by nanosecond laser-irradiation of solid target

    SciTech Connect

    Altana, C.; Lanzalone, G.; Mascali, D.; Cirrone, G. A. P.; Schillaci, F.; Tudisco, S.; Muoio, A.

    2016-02-15

    In laser-driven plasma, ion acceleration of aluminum with the production of a quasi-monoenergetic beam has occurred. A useful device to analyze the ions is the Thomson parabolas spectrometer, a well-known diagnostic that is able to obtain information on charge-to-mass ratio and energy distribution of the charged particles. At the LENS (Laser Energy for Nuclear Science) laboratory of INFN-LNS in Catania, experimental measures were carried out; the features of LENS are: Q-switched Nd:YAG laser with 2 J laser energy, 1064 nm fundamental wavelengths, and 6 ns pulse duration.

  7. Balloon measurements of the energy spectrum of cosmic electrons between 1 GeV and 25 GeV

    NASA Technical Reports Server (NTRS)

    Earl, J. A.; Neely, D. E.; Rygg, T. A.

    1971-01-01

    During three balloon flights made in 1966 and 1967, cosmic electrons were investigated with the aid of a hodoscope detector which provided extensive and detailed information on each cosmic ray event triggering the apparatus. Similar information obtained during calibration exposures to protons and pions as well as to electrons was used to provide identification of cosmic electrons and to determine their energies. Differential primary electron intensities measured in the range from 1 GeV to 25 GeV were substantially larger than some earlier measurements. Taken in conjunction with existing measurements at energies above 100 GeV, this indicates that the energy spectrum of cosmic electrons is steeper than that of cosmic-ray nuclei and, consequently, suggests that Compton/synchrotron energy loss plays a significant role in shaping the electron spectrum.

  8. Calculations of absorbed fractions in small water spheres for low-energy monoenergetic electrons and the Auger-emitting radionuclides (123)Ι and (125)Ι.

    PubMed

    Bousis, Christos; Emfietzoglou, Dimitris; Nikjoo, Hooshang

    2012-12-01

    To calculate the absorbed fraction (AF) of low energy electrons in small tissue-equivalent spherical volumes by Monte Carlo (MC) track structure simulation and assess the influence of phase (liquid water versus density-scaled water vapor) and of the continuous-slowing-down approximation (CSDA) used in semi-analytic calculations. An event-by-event MC code simulating the transport of electrons in both the vapor and liquid phase of water using appropriate electron-water interaction cross sections was used to quantify the energy deposition of low-energy electrons in spherical volumes. Semi-analytic calculations within the CSDA using a convolution integral of the Howell range-energy expressions are also presented for comparison. The AF for spherical volumes of radii from 10-1000 nm are presented for monoenergetic electrons over the energy range 100-10,000 eV and the two Auger-emitting radionuclides (125)I and (123)I. The MC calculated AF for the liquid phase are found to be smaller than those of the (density scaled) gas phase by up to 10-20% for the monoenergetic electrons and 10% for the two Auger-emitters. Differences between the liquid-phase MC results and the semi-analytic CSDA calculations are up to ∼ 55% for the monoenergetic electrons and up to ∼ 35% for the two Auger-emitters. Condensed-phase effects in the inelastic interaction of low-energy electrons with water have a noticeable but relatively small impact on the AF for the energy range and target sizes examined. Depending on the electron energies, the semi-analytic approach may lead to sizeable errors for target sizes with linear dimensions below 1 micron.

  9. Shielding Design Aspects of SR Beamlines for 3-GeV And 8-GeV Class Synchrotron Radiation Facilities

    SciTech Connect

    Asano, Yoshihiro; Liu, James C.; Rokni, Sayed; /SLAC

    2007-09-24

    Differences in synchrotron radiation beamline shielding design between the facilities of 3 GeV class and 8 GeV class are discussed with regard to SLAC SSRL and SPring-8 beamlines. Requirements of beamline shielding as well as the accelerator shielding depend on the stored electron energy, and here some factors in beamline shielding depending on the stored energy in particular, are clarified, namely the effect of build up, the effect of double scattering of photons at branch beamlines, and the spread of gas bremsstrahlung.

  10. Subthreshold Ξ- Production in Collisions of p (3.5 GeV )+Nb

    NASA Astrophysics Data System (ADS)

    Agakishiev, G.; Arnold, O.; Balanda, A.; Belver, D.; Belyaev, A. V.; Berger-Chen, J. C.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Chernenko, S.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O. V.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Göbel, K.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kornakov, G.; Kotte, R.; Krása, A.; Krizek, F.; Krücken, R.; Kuc, H.; Kühn, W.; Kugler, A.; Kurepin, A.; Ladygin, V.; Lalik, R.; Lang, S.; Lapidus, K.; Lebedev, A.; Liu, T.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michalska, B.; Michel, J.; Müntz, C.; Müntzer, R.; Naumann, L.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Yu. G.; Spataro, S.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Trebacz, R.; Tsertos, H.; Vasiliev, T.; Wagner, V.; Weber, M.; Wendisch, C.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y. V.; Hades Collaboration

    2015-05-01

    Results on the production of the double strange cascade hyperon Ξ- are reported for collisions of p (3.5 GeV )+Nb , studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18 at GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt. For the first time, subthreshold Ξ- production is observed in proton-nucleus interactions. Assuming a Ξ- phase-space distribution similar to that of Λ hyperons, the production probability amounts to PΞ-=[2.0 ±0.4 (stat)±0.3 (norm)±0.6 (syst)]×1 0-4 resulting in a Ξ-/(Λ +Σ0) ratio of PΞ-/PΛ +Σ0=[1.2 ±0.3 (stat)±0.4 (syst)]×1 0-2 . Available model predictions are significantly lower than the measured Ξ- yield.

  11. Medium effects in proton-induced K0 production at 3.5 GeV

    NASA Astrophysics Data System (ADS)

    Agakishiev, G.; Arnold, O.; Belver, D.; Belyaev, A.; Berger-Chen, J. C.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Chernenko, S.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Finocchiaro, P.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Göbel, K.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Korcyl, G.; Kornakov, G.; Kotte, R.; Krása, A.; Krizek, F.; Krücken, R.; Kuc, H.; Kühn, W.; Kugler, A.; Kunz, T.; Kurepin, A.; Ladygin, V.; Lalik, R.; Lapidus, K.; Lebedev, A.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michel, J.; Müntz, C.; Münzer, R.; Naumann, L.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Yu. G.; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Tsertos, H.; Vasiliev, T.; Wagner, V.; Weber, M.; Wendisch, C.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.; Gaitanos, T.; Weil, J.; Hades Collaboration

    2014-11-01

    We present the analysis of the inclusive K0 production in p +p and p +Nb collisions measured with the HADES detector (GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt) at a beam kinetic energy of 3.5 GeV. Data are compared to the Giessen Boltzmann-Uehling-Uhlenbeck (GiBUU) transport model. The data suggest the presence of a repulsive momentum-dependent kaon potential as predicted by the chiral perturbation theory (ChPT). For the kaon at rest and at normal nuclear density, the ChPT potential amounts to ≈35 MeV. A detailed tuning of the kaon production cross sections implemented in the model has been carried out to reproduce the experimental data measured in p +p collisions. The uncertainties in the parameters of the model were examined with respect to the sensitivity of the experimental results from p +Nb collisions to the in-medium kaon potential.

  12. 200 A GeV Au + Au collisions serve a nearly perfect quark-gluon liquid.

    PubMed

    Song, Huichao; Bass, Steffen A; Heinz, Ulrich; Hirano, Tetsufumi; Shen, Chun

    2011-05-13

    A new robust method to extract the specific shear viscosity (η/s)(QGP) of a quark-gluon plasma (QGP) at temperatures T(c) < T ≲ 2T(c) from the centrality dependence of the eccentricity-scaled elliptic flow v2/ε measured in ultrarelativistic heavy-ion collisions is presented. Coupling viscous fluid dynamics for the QGP with a microscopic transport model for hadronic freeze-out we find for 200 A GeV Au + Au collisions that v2/ε is a universal function of multiplicity density (1/S)(dN(ch)/dy) that depends only on the viscosity but not on the model used for computing the initial fireball eccentricity ε. Comparing with measurements we find 1<4π(η/s)(QGP) < 2.5 where the uncertainty range is dominated by model uncertainties for the values of ε used to normalize the measured v2.

  13. Charge-Asymmetry Dependence of Proton Elliptic Flow in 200 GeV Au +Au Collisions

    NASA Astrophysics Data System (ADS)

    Smith, Rachel; STAR Collaboration

    2016-09-01

    The chiral magnetic wave (CMW) is predicted to manifest a finite electric quadrupole moment in the quark-gluon plasma produced in high-energy heavy-ion collisions. This quadrupole moment generates a divergence in the azimuthal anisotropy (v2) of positively and negatively charged particles such that v2(+) < v2(-). This effect is proportional to the apparent charge asymmetry (Ach) of particles in the same rapidity window. The Ach dependence of v 2 has already been observed in the cases of charged pions and kaons. We present preliminary STAR measurements of v 2 for protons and anti-protons as a function of Ach from √sNN = 200 GeV Au +Au collisions for different centrality classes. The results are then compared with the previously reported results of pions and kaons. For the STAR Collaboration.

  14. Beam physics of the 8-GeV H-minus linac

    SciTech Connect

    Carneiro, J.-P.; Mustapha, B.; Ostroumov, P.N.; /Argonne

    2008-11-01

    Fermilab is developing the concept and design of an 8-GeV superconducting H-minus linac with the primary mission of increasing the intensity of the Main Injector for the production of neutrino superbeams. The front-end of the linac up to 420 MeV operates at 325 MHz and accelerates beam from the ion source using a room temperature radio-frequency quadrupole followed by short CH type resonators and superconducting spoke resonators. In the high energy section, the acceleration is provided by the International Linear Collider (ILC)-style superconducting elliptical 1.3 GHz cavities. The beam physics for the linac is presented in this paper using two beam dynamics codes: TRACK and ASTRA.

  15. Beam physics of the 8-GeV H-minus linac.

    SciTech Connect

    Carneiro, J.-P.; Ostroumov, P. N.; Mustapha, B.; Physics; FNAL

    2009-07-21

    Fermilab is developing the concept and design of an 8-GeV superconducting H{sup -} linac with the primary mission of increasing the intensity of the Main Injector for the production of neutrino superbeams. The front-end of the linac up to 420 MeV operates at 325 MHz and accelerates the beam from the ion source using a room temperature radio-frequency quadrupole followed by short CH type resonators and superconducting spoke resonators. In the high-energy section, the acceleration is provided by superconducting elliptical 1.3 GHz cavities similar to the ones developed for the International Linear Collider (ILC). The beam physics for the linac is presented in this paper using two beam dynamics codes: TRACK and ASTRA.

  16. Neutron-induced fission cross-section measurement of 234U with quasi-monoenergetic beams in the keV and MeV range using micromegas detectors

    NASA Astrophysics Data System (ADS)

    Tsinganis, A.; Kokkoris, M.; Vlastou, R.; Kalamara, A.; Stamatopoulos, A.; Kanellakopoulos, A.; Lagoyannis, A.; Axiotis, M.

    2017-09-01

    Accurate data on neutron-induced fission cross-sections of actinides are essential for the design of advanced nuclear reactors based either on fast neutron spectra or alternative fuel cycles, as well as for the reduction of safety margins of existing and future conventional facilities. The fission cross-section of 234U was measured at incident neutron energies of 560 and 660 keV and 7.5 MeV with a setup based on `microbulk' Micromegas detectors and the same samples previously used for the measurement performed at the CERN n_TOF facility (Karadimos et al., 2014). The 235U fission cross-section was used as reference. The (quasi-)monoenergetic neutron beams were produced via the 7Li(p,n) and the 2H(d,n) reactions at the neutron beam facility of the Institute of Nuclear and Particle Physics at the `Demokritos' National Centre for Scientific Research. A detailed study of the neutron spectra produced in the targets and intercepted by the samples was performed coupling the NeuSDesc and MCNPX codes, taking into account the energy spread, energy loss and angular straggling of the beam ions in the target assemblies, as well as contributions from competing reactions and neutron scattering in the experimental setup. Auxiliary Monte-Carlo simulations were performed with the FLUKA code to study the behaviour of the detectors, focusing particularly on the reproduction of the pulse height spectra of α-particles and fission fragments (using distributions produced with the GEF code) for the evaluation of the detector efficiency. An overview of the developed methodology and preliminary results are presented.

  17. INC Model interpretation of the proton induced residual nuclide production cross sections below 2 GeV

    SciTech Connect

    Divadeenam, M.; Ward, T.E.; Spergel, M.S.; Lakatos, S.; Manche, E.P.

    1991-12-31

    For the purposes of interpreting the abundances of various isotopes in meteorites or on lunar and planetary surfaces exposed to fragmentation by cosmic rays, Webber et al. recently reported the measured total elemental and isotopic cross sections with heavy ions as projectiles on H, He, and C targets with beam energies of 0.33 - 1.7 GeV/nucleon. We employ the INC model to predict the fragmentation of the heavy ions in a hydrogen target with the inverse reaction process: proton bombardment of a heavy-ion nucleus leading to spallation products. Charge-changing and mass-changing cross sections are calculated for proton bombardment of an {sup 56}Fe target with beam energies ranging from 0.33 to 1.88 GeV. Total Z-changing and A-changing cross sections in the energy range 0.6 to 1.88 GeV are in excellent agreement with the corresponding experimental data of Webber et al. and Westfall at al., while the agreement below 0.6 GeV proton energy is not as good. The general trend of the Z-changing cross sections are reproduced by the model calculations at each proton incident energy. The interaction of 200-MeV protons with synthetic Stony Meteorite samples was undertaken to explain radionuclide production in a cosmic-ray environment. The BNL Linac 200-MeV-proton beam was used to irradiate synthetic Stony Meteorites to simulate cosmic-ray exposures corresponding to 6.4 and 16.4 million years. Each irradiated sample was analyzed with the help of a high-resolution gamma-ray spectrometer for long-lived radioisotopes. The intranuclear cascade code HETC was employed to simulate the 200-MeV proton bombardment on the meteorite samples to predict the radionuclides {sup 7}Be, {sup 22}Na, {sup 46}Mn, and {sup 56}Co produced in the experimental investigation.

  18. INC Model interpretation of the proton induced residual nuclide production cross sections below 2 GeV

    SciTech Connect

    Divadeenam, M.; Ward, T.E. ); Spergel, M.S.; Lakatos, S.; Manche, E.P. )

    1991-01-01

    For the purposes of interpreting the abundances of various isotopes in meteorites or on lunar and planetary surfaces exposed to fragmentation by cosmic rays, Webber et al. recently reported the measured total elemental and isotopic cross sections with heavy ions as projectiles on H, He, and C targets with beam energies of 0.33 - 1.7 GeV/nucleon. We employ the INC model to predict the fragmentation of the heavy ions in a hydrogen target with the inverse reaction process: proton bombardment of a heavy-ion nucleus leading to spallation products. Charge-changing and mass-changing cross sections are calculated for proton bombardment of an {sup 56}Fe target with beam energies ranging from 0.33 to 1.88 GeV. Total Z-changing and A-changing cross sections in the energy range 0.6 to 1.88 GeV are in excellent agreement with the corresponding experimental data of Webber et al. and Westfall at al., while the agreement below 0.6 GeV proton energy is not as good. The general trend of the Z-changing cross sections are reproduced by the model calculations at each proton incident energy. The interaction of 200-MeV protons with synthetic Stony Meteorite samples was undertaken to explain radionuclide production in a cosmic-ray environment. The BNL Linac 200-MeV-proton beam was used to irradiate synthetic Stony Meteorites to simulate cosmic-ray exposures corresponding to 6.4 and 16.4 million years. Each irradiated sample was analyzed with the help of a high-resolution gamma-ray spectrometer for long-lived radioisotopes. The intranuclear cascade code HETC was employed to simulate the 200-MeV proton bombardment on the meteorite samples to predict the radionuclides {sup 7}Be, {sup 22}Na, {sup 46}Mn, and {sup 56}Co produced in the experimental investigation.

  19. 12 GeV detector technology at Jefferson Lab

    SciTech Connect

    Leckey, John P.; Collaboration: GlueX Collaboration

    2013-04-19

    The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

  20. 12 GeV detector technology at Jefferson Lab

    SciTech Connect

    Leckey, John P.

    2013-04-01

    The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

  1. JLab's Hall A after the 12 GeV upgrade

    SciTech Connect

    John Lerose

    2004-11-14

    An overview is presented of the planned physics program for JLab's Hall A following the 12 GeV upgrade with emphasis on the equipment needed to achieve the desired experimental goals. Results of simulations of sample experiments with anticipated uncertainties are presented.

  2. 7-GeV Advanced Photon Source Conceptual Design Report

    SciTech Connect

    Not Available

    1987-04-01

    During the past decade, synchrotron radiation emitted by circulating electron beams has come into wide use as a powerful, versatile source of x-rays for probing the structure of matter and for studying various physical processes. Several synchrotron radiation facilities with different designs and characteristics are now in regular operation throughout the world, with recent additions in this country being the 0.8-GeV and 2.5-GeV rings of NSLS at Brookhaven National Laboratory. However, none of the operating facilities has been designed to use a low-emittance, high-energy stored beam, together with modern undulator devices, to produce a large number of hard x-ray beams of extremely high brilliance. This document is a proposal to the Department of Energy to construct and operate high-energy synchrotron radiation facility at Argonne National Laboratory. We have now chosen to set the design energy of this facility at 7.0 GeV, with the capability to operate at up to 7.5 GeV.

  3. Nucleon Form Factors experiments with 12 GeV CEBAF

    SciTech Connect

    Wojtsekhowski, B.

    2008-10-13

    A number of precision form factor experiments at high momentum transfer will be performed with the 11 GeV electron beam of CEBAF. We review the approved proposals and the conceptual schemes of several new suggestions. Form factor data will serve as a major input for the construction of a tomographic image of the nucleon.

  4. GeV C. W. electron microtron design report

    SciTech Connect

    Not Available

    1982-05-01

    Rising interest in the nuclear physics community in a GeV C.W. electron accelerator reflects the growing importance of high-resolution short-range nuclear physics to future advances in the field. In this report major current problems are reviewed and the details of prospective measurements which could be made with a GeV C.W. electron facility are discussed, together with their impact on an understanding of nuclear forces and the structure of nuclear matter. The microtron accelerator has been chosen as the technology to generate the electron beams required for the research discussed because of the advantages of superior beam quality, low capital and operating cost and capability of furnishing beams of several energies and intensities simultaneously. A complete technical description of the conceptual design for a 2 GeV double-sided C.W. electron microtron is presented. The accelerator can furnish three beams with independently controlled energy and intensity. The maximum current per beam is 100 ..mu..amps. Although the precise objective for maximum beam energy is still a subject of debate, the design developed in this study provides the base technology for microtron accelerators at higher energies (2 to 6 GeV) using multi-sided geometries.

  5. Inclusive hadron production at 10 GeV

    NASA Astrophysics Data System (ADS)

    Waldi, R.

    1989-12-01

    Recent results of the ARGUS collaboration on inclusive momentum and angular distributions of charged hadrons produced in direct Υ(1S) decays and nonresonant e+e- annihilation at 10 GeV are presented, which allow investigation of quark and gluon fragmentation. The data demonstrate some of the shortcomings of present fragmentation models.

  6. GeV Detection of HESS J0632+057

    NASA Astrophysics Data System (ADS)

    Li, Jian; Torres, Diego F.; Cheng, K.-S.; de Oña Wilhelmi, Emma; Kretschmar, Peter; Hou, Xian; Takata, Jumpei

    2017-09-01

    HESS J0632+057 is the only gamma-ray binary that has been detected at TeV energies, but not at GeV energies yet. Based on nearly nine years of Fermi Large Area Telescope (LAT) Pass 8 data, we report here on a deep search for the gamma-ray emission from HESS J0632+057 in the 0.1–300 GeV energy range. We find a previously unknown gamma-ray source, Fermi J0632.6+0548, spatially coincident with HESS J0632+057. The measured flux of Fermi J0632.6+0548 is consistent with the previous flux upper limit on HESS J0632+057 and shows variability that can be related to the HESS J0632+057 orbital phase. We propose that Fermi J0632.6+0548 is the GeV counterpart of HESS J0632+057. Considering the Very High Energy spectrum of HESS J0632+057, a possible spectral turnover above 10 GeV may exist in Fermi J0632.6+0548, as appears to be common in other established gamma-ray binaries.

  7. The JLAB 12 GeV Energy Upgrade of CEBAF

    SciTech Connect

    Harwood, Leigh H.

    2013-12-01

    This presentation should describe the progress of the 12GeV Upgrade of CEBAF at Jefferson Lab. The status of the upgrade should be presented as well as details on the construction, procurement, installation and commissioning of the magnet and SRF components of the upgrade.

  8. 12 GeV detector technology at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Leckey, John P.; GlueX Collaboration

    2013-04-01

    The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

  9. Promising interpretation of diphoton resonance at 750 GeV

    NASA Astrophysics Data System (ADS)

    Bi, Xiao-Jun; Ding, Ran; Fan, Yizhou; Huang, Li; Li, Chuang; Li, Tianjun; Raza, Shabbar; Wang, Xiao-Chuan; Zhu, Bin

    2016-07-01

    Recently, an excess of events in diphoton channel with invariant mass of about 750 GeV has been reported by the ATLAS and CMS Collaborations. Considering it as a tantalizing hint for new physics beyond the Standard Model (SM), we propose a simple extension of the SM with an additional doublet Higgs H' and a singlet s . We consider the neutral component H0' of H' as the 750 GeV resonance and assume that s is lighter than 2.6 GeV. In particular, H0' can be produced at tree level via q q ¯ production and decay into a pair of s at tree level. Then s can decay into a pair of collimated photons, which cannot be distinguished at the LHC. We show that the diphoton production cross section can be from 3 to 13 fb, the decay width of H0' can be from 30 to 60 GeV, and all the current experimental constraints including dijet constraint can be satisfied.

  10. J/psi production from proton-proton collisions at square root of s=200 GeV.

    PubMed

    Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Drapier, O; Drees, A; Drees, K A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El-Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A K; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; van Hecke, H W; Velkovska, J; Velkovsky, M; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zhou, S J; Zolin, L

    2004-02-06

    J/psi production has been measured in proton-proton collisions at square root of s=200 GeV over a wide rapidity and transverse momentum range by the PHENIX experiment at the Relativistic Heavy Ion Collider. Distributions of the rapidity and transverse momentum, along with measurements of the mean transverse momentum and total production cross section are presented and compared to available theoretical calculations. The total J/psi cross section is 4.0+/-0.6(stat)+/-0.6(syst)+/-0.4(abs) mu b. The mean transverse momentum is 1.80+/-0.23(stat)+/-0.16(syst) GeV/c.

  11. Midrapidity neutral-pion production in proton-proton collisions at square root s = 200 GeV.

    PubMed

    Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Drapier, O; Drees, A; Drees, K A; Du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; Granier De Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A K; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; Van Hecke, H W; Velkovska, J; Velkovsky, M; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zolin, L

    2003-12-12

    The invariant differential cross section for inclusive neutral-pion production in p+p collisions at sqrt[s]=200 GeV has been measured at midrapidity (|eta|<0.35) over the range 1Ion Collider. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. The precision of our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions.

  12. Pion-Kaon correlations in central Au+Au collisions at square root [sNN] = 130 GeV.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gutierrez, T D; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2003-12-31

    Pion-kaon correlation functions are constructed from central Au+Au STAR data taken at sqrt[s(NN)]=130 GeV by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The results suggest that pions and kaons are not emitted at the same average space-time point. Space-momentum correlations, i.e., transverse flow, lead to a space-time emission asymmetry of pions and kaons that is consistent with the data. This result provides new independent evidence that the system created at RHIC undergoes a collective transverse expansion.

  13. Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV.

    PubMed

    Ackermann, K H; Adams, N; Adler, C; Ahammed, Z; Ahmad, S; Allgower, C; Amsbaugh, J; Anderson, M; Anderssen, E; Arnesen, H; Arnold, L; Averichev, G S; Baldwin, A; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Beddo, M; Bekele, S; Belaga, V V; Bellwied, R; Bennett, S; Bercovitz, J; Berger, J; Betts, W; Bichsel, H; Bieser, F; Bland, L C; Bloomer, M; Blyth, C O; Boehm, J; Bonner, B E; Bonnet, D; Bossingham, R; Botlo, M; Boucham, A; Bouillo, N; Bouvier, S; Bradley, K; Brady, F P; Braithwaite, E S; Braithwaite, W; Brandin, A; Brown, R L; Brugalette, G; Byrd, C; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carr, L; Carroll, J; Castillo, J; Caylor, B; Cebra, D; Chatopadhyay, S; Chen, M L; Chen, W; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Chrin, J; Christie, W; Coffin, J P; Conin, L; Consiglio, C; Cormier, T M; Cramer, J G; Crawford, H J; Danilov, V I; Dayton, D; DeMello, M; Deng, W S; Derevschikov, A A; Dialinas, M; Diaz, H; DeYoung, P A; Didenko, L; Dimassimo, D; Dioguardi, J; Dominik, W; Drancourt, C; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Edwards, W R; Efimov, L G; Eggert, T; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Etkin, A; Fachini, P; Feliciano, C; Ferenc, D; Ferguson, M I; Fessler, H; Finch, E; Fine, V; Fisyak, Y; Flierl, D; Flores, I; Foley, K J; Fritz, D; Gagunashvili, N; Gans, J; Gazdzicki, M; Germain, M; Geurts, F; Ghazikhanian, V; Gojak, C; Grabski, J; Grachov, O; Grau, M; Greiner, D; Greiner, L; Grigoriev, V; Grosnick, D; Gross, J; Guilloux, G; Gushin, E; Hall, J; Hallman, T J; Hardtke, D; Harper, G; Harris, J W; He, P; Heffner, M; Heppelmann, S; Herston, T; Hill, D; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Howe, M; Huang, H Z; Humanic, T J; Hümmler, H; Hunt, W; Hunter, J; Igo, G J; Ishihara, A; Ivanshin, Y I; Jacobs, P; Jacobs, W W; Jacobson, S; Jared, R; Jensen, P; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kenney, V P; Khodinov, A; Klay, J; Klein, S R; Klyachko, A; Koehler, G; Konstantinov, A S; Kormilitsyne, V; Kotchenda, L; Kotov, I; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Krupien, T; Kuczewski, P; Kuhn, C; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lakehal-Ayat, L; Lamas-Valverde, J; Lamont, M A; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; LeCompte, T; Leonhardt, W J; Leontiev, V M; Leszczynski, P; LeVine, M J; Li, Q; Li, Q; Li, Z; Liaw, C J; Lin, J; Lindenbaum, S J; Lindenstruth, V; Lindstrom, P J; Lisa, M A; Liu, H; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Lopiano, D; Love, W A; Lutz, J R; Lynn, D; Madansky, L; Maier, R; Majka, R; Maliszewski, A; Margetis, S; Marks, K; Marstaller, R; Martin, L; Marx, J; Matis, H S; Matulenko, Y A; Matyushevski, E A; McParland, C; McShane, T S; Meier, J; Melnick, Y; Meschanin, A; Middlekamp, P; Mikhalin, N; Miller, B; Milosevich, Z; Minaev, N G; Minor, B; Mitchell, J; Mogavero, E; Moiseenko, V A; Moltz, D; Moore, C F; Morozov, V; Morse, R; de Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Ngo, T; Nguyen, M; Nguyen, T; Nikitin, V A; Nogach, L V; Noggle, T; Norman, B; Nurushev, S B; Nussbaum, T; Nystrand, J; Odyniec, G; Ogawa, A; Ogilvie, C A; Olchanski, K; Oldenburg, M; Olson, D; Ososkov, G A; Ott, G; Padrazo, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Pentia, M; Perevotchikov, V; Peryt, W; Petrov, V A; Pinganaud, W; Pirogov, S; Platner, E; Pluta, J; Polk, I; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Puskar-Pasewicz, J; Rai, G; Rasson, J; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J; Renfordt, R E; Retiere, F; Ridiger, A; Riso, J; Ritter, H G; Roberts, J B; Roehrich, D; Rogachevski, O V; Romero, J L; Roy, C; Russ, D; Rykov, V; Sakrejda, I; Sanchez, R; Sandler, Z; Sandweiss, J; Sappenfield, P; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Scheblien, J; Scheetz, R; Schlueter, R; Schmitz, N; Schroeder, L S; Schulz, M; Schüttauf, A; Sedlmeir, J; Seger, J; Seliverstov, D; Seyboth, J; Seyboth, P; Seymour, R; Shakaliev, E I; Shestermanov, K E; Shi, Y; Shimanskii, S S; Shuman, D; Shvetcov, V S; Skoro, G; Smirnov, N; Smykov, L P; Snellings, R; Solberg, K; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Stone, N; Stone, R; Strikhanov, M; Stringfellow, B; Stroebele, H; Struck, C; Suaide, A A; Sugarbaker, E; Suire, C; Symons, T J; Takahashi, J; Tang, A H; Tarchini, A; Tarzian, J; Thomas, J H; Tikhomirov, V; Szanto De Toledo, A; Tonse, S; Trainor, T; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T; Underwood, D G; Vakula, I; Van Buren, G; VanderMolen, A M; Vanyashin, A; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Visser, G; Voloshin, S A; Vu, C; Wang, F; Ward, H; Weerasundara, D; Weidenbach, R; Wells, R; Wells, R; Wenaus, T; Westfall, G D; Whitfield, J P; Whitten, C; Wieman, H; Willson, R; Wilson, K; Wirth, J; Wisdom, J; Wissink, S W; Witt, R; Wolf, J; Wood, L; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yokosawa, A; Yurevich, V I; Zanevski, Y V; Zhang, J; Zhang, W M; Zhu, J; Zimmerman, D; Zoulkarneev, R; Zubarev, A N

    2001-01-15

    Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

  14. Ion heating in an auroral potential structure

    NASA Astrophysics Data System (ADS)

    Anastasiadis, A.; Daglis, I. A.; Tsironis, C.

    2004-06-01

    We investigate the interaction of O+ ions with a one-dimensional potential well, using Hamiltonian formulation. Heating of plasma originating in the terrestrial ionosphere plays a catalytic role in solar-driven magnetic storms, which dissipate energy globally within the magnetosphere of the earth. An interesting candidate for ionospheric plasma heating is a potential well located at auroral arcs in the high-latitude magnetosphere. We consider a potential with an exponential form, having a characteristic length Lx. The oxygen ions drift towards the auroral arc in the presence of a constant magnetic field Bz and a constant electric field Ey. The orbits of individual ions for different initial conditions - phase angle and kinetic energy - are traced. Our results show that, depending upon the initial conditions, test particles can be either accelerated or decelerated. Furthermore, we perform a parametric study for the interactions of mono-energetic and Maxwellian type of initial ion distribution - using random phase angle injection of the particles - with respect to our main model parameter, the characteristic length of the potential Lx. We conclude that for characteristic lengths comparable to twice the ion gyroradius, the O+ population is accelerated.

  15. Detailed Experimental Study of Ion Acceleration by Interaction of an Ultra-Short Intense Laser with an Underdense Plasma

    PubMed Central

    Kahaly, S.; Sylla, F.; Lifschitz, A.; Flacco, A.; Veltcheva, M.; Malka, V.

    2016-01-01

    Ion acceleration from intense (Iλ2 > 1018 Wcm−2 μm2) laser-plasma interaction is experimentally studied within a wide range of He gas densities. Focusing an ultrashort pulse (duration  ion plasma period) on a newly designed submillimetric gas jet system, enabled us to inhibit total evacuation of electrons from the central propagation channel reducing the radial ion acceleration associated with ponderomotive Coulomb explosion, a mechanism predominant in the long pulse scenario. New ion acceleration mechanism have been unveiled in this regime leading to non-Maxwellian quasi monoenergetic features in the ion energy spectra. The emitted nonthermal ion bunches show a new scaling of the ion peak energy with plasma density. The scaling identified in this new regime differs from previously reported studies. PMID:27531755

  16. Detailed Experimental Study of Ion Acceleration by Interaction of an Ultra-Short Intense Laser with an Underdense Plasma

    NASA Astrophysics Data System (ADS)

    Kahaly, S.; Sylla, F.; Lifschitz, A.; Flacco, A.; Veltcheva, M.; Malka, V.

    2016-08-01

    Ion acceleration from intense (Iλ2 > 1018 Wcm‑2 μm2) laser-plasma interaction is experimentally studied within a wide range of He gas densities. Focusing an ultrashort pulse (duration  ion plasma period) on a newly designed submillimetric gas jet system, enabled us to inhibit total evacuation of electrons from the central propagation channel reducing the radial ion acceleration associated with ponderomotive Coulomb explosion, a mechanism predominant in the long pulse scenario. New ion acceleration mechanism have been unveiled in this regime leading to non-Maxwellian quasi monoenergetic features in the ion energy spectra. The emitted nonthermal ion bunches show a new scaling of the ion peak energy with plasma density. The scaling identified in this new regime differs from previously reported studies.

  17. Oncogenic transformation of C3H 10T1/2 cells by acute and protracted exposures to monoenergetic neutrons.

    PubMed

    Miller, R C; Hall, E J

    1991-10-01

    An in vitro assay was used to assess cell killing and induction of neoplastic transformation in C3H 10T1/2 cells exposed to X rays and a range of monoenergetic neutrons administered at various dose rates. Curves for cell survival and induction of neoplastic transformation showed nonlinearity for cells exposed to acute graded doses of X rays, while irradiation of cells with 0.05 to 1.5 Gy of 0.23-, 0.35-, 0.45-, 0.70-, 0.96-, 5.90-, and 13.7-MeV neutrons resulted in a linear response as a function of dose for both neoplastic transformation and killing. When compared to results obtained with 250-kVp X rays, all neutron energies were more effective at both cell killing and induction of neoplastic transformation. When expressed as maximum biological effectiveness (RBEM), both cell survival and induction of neoplastic transformation showed an initial increase with neutron energy (maximal at 0.35 MeV), followed by a decrease in effectiveness with further increases in energy. These responses are consistent with microdosimetric predictions in that recoil protons from neutron interaction are shifted to lower lineal energies as neutron energies increase. To examine the effects of temporal distribution of dose on neutron-induced neoplastic transformation, cells were exposed to either a single dose or five equal dose fractions spread over 8 h. As a function of dose for single or fractionated exposures to 0.5 Gy or 0.23-, 0.35-, 0.45-, 5.9-, or 13.7-MeV neutrons, neither a sparing nor an enhancing effect was seen with survival. Similarly, the frequency of induction of neoplastic transformation was independent of dose fractionation for all but 5.9-MeV neutrons. The enhancing effects of exposure to fractionated doses of 5.9-MeV neutrons were further studied by comparing exposures for a range of doses given singly, in five fractions over 8 h, or continuously for 8 h. Results reaffirm the enhancing effects of dose fractionation on the induction of oncogenic transformation for 5

  18. The RHIC polarized H- ion source

    NASA Astrophysics Data System (ADS)

    Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Steski, D.

    2016-02-01

    A novel polarization technique had been successfully implemented for the Relativistic Heavy Ion Collider (RHIC) polarized H- ion source upgrade to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gaseous ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically pumped Rb vapor. The use of high-brightness primary beam and large cross sections of charge-exchange cross sections resulted in production of high intensity H- ion beam of 85% polarization. The source very reliably delivered polarized beam in the RHIC Run-2013 and Run-2015. High beam current, brightness, and polarization resulted in 75% polarization at 23 GeV out of Alternating Gradient Synchrotron (AGS) and 60%-65% beam polarization at 100-250 GeV colliding beams in RHIC.

  19. Investigation of the ion beryllium surface interaction

    SciTech Connect

    Guseva, M.I.; Birukov, A.Yu.; Gureev, V.M.

    1995-09-01

    The self -sputtering yield of the Be was measured. The energy dependence of the Be self-sputtering yield agrees well with that calculated by W. Eckstein et. al. Below 770 K the self-sputtering yield is temperature independent; at T{sub irr}.> 870 K it increases sharply. Hot-pressed samples at 370 K were implanted with monoenergetic 5 keV hydrogen ions and with a stationary plasma (flux power {approximately} 5 MW/m{sup 2}). The investigation of hydrogen behavior in beryllium shows that at low doses hydrogen is solved, but at doses {ge} 5x10{sup 22} m{sup -2} the bubbles and channels are formed. It results in hydrogen profile shift to the surface and decrease of its concentration. The sputtering results in further concentration decrease at doses > 10{sup 25}m{sup -2}.

  20. Design studies of high-luminoisty ring-ring- eletron-ion collider at CEBAF.

    SciTech Connect

    Bogacz, A.; Brindza, P.; Bruell, A.; Cardman, L.; Delayen, J.; Ostroumov, P.; Derbenev, Y.; Ent, R.; Evtushenko, P.; Grames, J.; Hutton, A.; Krafft, G.; Li, R.; Merminga, L.; Musson, J.; Poelker, M.; Thomas, A.; Wojteshowski, B.; Yunn, B.; Zhang, Y.; Fischer, W.; Montag, C.; Dudnikov, V.; Belov, A.; Derenchuk, V.; Physics; Jefferson Lab.; BNL; BTG; INR; IUCF

    2007-08-01

    Experimental studies of fundamental structure of nucleons require an electron-ion collider of a center-of-mass energy up to 90 GeV at luminosity up to 10{sup 35} cm{sup -2}s{sup -1} with both beams polarized. A CEBAF-based collider of 9 GeV electrons/positrons and 225 GeV ions is envisioned to meet this science need and as a next step for CEBAF after the planned 12 GeV energy upgrade of the fixed target program. A ring-ring scheme of this collider developed recently takes advantage of the existing polarized electron CW beam from the CEBAF and a green-field design of an ion complex with electron cooling. We present a conceptual design and report design studies of this high-luminosity collider.

  1. Identified particle distributions in pp and Au+Au collisions at square root of (sNN)=200 GeV.

    PubMed

    Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gutierrez, T D; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; de Toledo, A Szanto; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2004-03-19

    Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

  2. Science and status of the Electron Ion Collider

    NASA Astrophysics Data System (ADS)

    Deshpande, A.

    The US Nuclear Science Advisory Committee (NSAC) recently recommended the construction of a high-luminosity, high-energy Electron Ion Collider (EIC), with polarized beams capable of colliding polarized electrons with polarized proton and light ion beams, and with any nucleus. The s range between 40GeV and 140GeV, and luminosity range from 1033‑34cm‑2s‑1 were recommended. It is anticipated that under the current guidance from the DOE, the collider could become operational in the second half of the 2020’s. This paper summarizes its science and the scope of this over all project.

  3. Why is GeV physics relevant in the age of the LHC?

    SciTech Connect

    Pennington, Michael R.

    2014-02-01

    The contribution that Jefferson Lab has made, with its 6 GeV electron beam, and will make, with its 12 GeV upgrade, to our understanding of the way the fundamental interactions work, particularly strong coupling QCD, is outlined. The physics at the GeV scale is essential even in TeV collisions.

  4. Energy response of GR-200A thermoluminescence dosemeters to 60Co and to monoenergetic synchrotron radiation in the energy range 28-40 keV.

    PubMed

    Emiro, F; Di Lillo, F; Mettivier, G; Fedon, C; Longo, R; Tromba, G; Russo, P

    2016-01-01

    The response of LiF:Mg,Cu,P thermoluminescence dosemeters (type GR-200A) to monoenergetic radiation of energy 28, 35, 38 and 40 keV was evaluated with respect to irradiation with a calibrated (60)Co gamma-ray source. High-precision measurements of the relative air kerma response performed at the SYRMEP beamline of the ELETTRA synchrotron radiation facility (Trieste, Italy) showed a significant deviation of the average response to low-energy X-rays from that to (60)Co, with an over-response from 6 % (at 28 keV) to 22 % (at 40 keV). These data are not consistent with literature data for these dosemeters, where model predictions gave deviation from unity of the relative air kerma response of about 10 %. The authors conclude for the need of additional determinations of the low-energy relative response of GR-200A dosemeters, covering a wider range of monoenergetic energies sampled at a fine energy step, as planned in future experiments by their group at the ELETTRA facility.

  5. Surface sealing using self-assembled monolayers and its effect on metal diffusion in porous low-k dielectrics studied using monoenergetic positron beams

    NASA Astrophysics Data System (ADS)

    Uedono, Akira; Armini, Silvia; Zhang, Yu; Kakizaki, Takeaki; Krause-Rehberg, Reinhard; Anwand, Wolfgang; Wagner, Andreas

    2016-04-01

    Surface sealing effects on the diffusion of metal atoms in porous organosilicate glass (OSG) films were studied by monoenergetic positron beams. For a Cu(5 nm)/MnN(3 nm)/OSG(130 nm) sample fabricated with pore stuffing, C4F8 plasma etch, unstuffing, and a self-assembled monolayer (SAM) sealing process, it was found that pores with cubic pore side lengths of 1.1 and 3.1 nm coexisted in the OSG film. For the sample without the SAM sealing process, metal (Cu and Mn) atoms diffused from the top Cu/MnN layer into the OSG film and were trapped by the pores. As a result, almost all pore interiors were covered with those metals. For the sample damaged by an Ar/C4F8 plasma etch treatment before the SAM sealing process, SAMs diffused into the OSG film, and they were preferentially trapped by larger pores. The cubic pore side length in these pores containing self-assembled molecules was estimated to be 0.7 nm. Through this work, we have demonstrated that monoenergetic positron beams are a powerful tool for characterizing capped porous films and the trapping of atoms and molecules by pores.

  6. Microdosimetry of monoenergetic neutrons

    SciTech Connect

    Srdoc, D.; Marino, S.A.

    1993-12-31

    Tissue spheres 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 {mu}m in diameter were simulated using a wall-less spherical counter filled with a propane-based tissue-equivalent gas. Microdosimetric spectra corresponding to these site sizes were measured for five neutron energies (0.22, 0.44, 1.5, 6, and 14 MeV) and the related mean values {bar Y}{sub F} and {bar Y}{sub D} were calculated for several site sizes and neutron energies. An elaborate calibration technique combining soft x-rays, a {sup 55}Fe photon source, and a {sup 244}Cm collimated source of alpha particles was used throughout the measurement. The spectra and their mean values are compared with theoretically calculated values for ICRU tissue. The agreement between the calculated and the measured data is good in spite of a systematic discrepancy, which could be attributed, in part, to the difference in elemental composition between the tissue-equivalent gas and plastic used in the counter, and the ICRU standard tissue used in the calculations.

  7. Microdosimetry of monoenergetic neutrons.

    PubMed

    Srdoc, D; Marino, S A

    1996-10-01

    Tissue spheres 0.25, 0.5, 1.0, 2.0, 4.0 and 8.0 micron in diameter were simulated using a wall-less spherical counter filled with propane-based tissue-equivalent gas. Microdosimetric spectra corresponding to these site sizes were measured for five neutron energies (0.22, 0.44, 1.5, 6 and 14 MeV) and the related mean values /yF and /yD were calculated for several site sizes and neutron energies. An elaborate calibration technique combining soft X rays, an 55Fe photon source and a collimated 244Cm alpha-particle source was used throughout the measurements. The spectra and their mean values are compared with theoretically calculated values for ICRU standard tissue. The agreement between the calculated and the measured data is good in spite of a systematic discrepancy, which could be attributed, in part, to the difference in elemental composition between the tissue-equivalent gas and plastic used in the counter and the ICRU standard tissue used in the calculations.

  8. Multiplicity and Transverse Momentum Distributions of Charged Particles in Proton - Anti-proton Collisions at $\\sqrt{s} = 630$ GeV and 1800 GeV

    SciTech Connect

    Sekiguchi, Masaki

    1988-10-01

    We have measured the multiplicity and transverse momentum distributions of charged particles produced in proton-antiproton collisions at center of mass energies of 630 and 1800 GeV. This is the first measurement of this kind at the center of mass of 1800 GeV, which is the highest energy available today. Data are obtained for the pseudorapidity $\\mid \\eta \\mid \\le$ 3.0 and for the transverse momentum down to 50 MeV/c. The number of events analyzed is 2.7 x $10^3$ for 630 GeV and 2.5 x $10^4$ for 1800 GeV....

  9. Meson Spectroscopy at JLab@12 GeV

    SciTech Connect

    Celentano, Andrea

    2013-03-01

    Meson, being the simplest hadronic bound system, is the ideal "laboratory" to study the interaction between quarks, to understand the role of the gluons inside hadrons and to investigate the origin of color confinement. To perform such studies it is important to measure the meson spectrum, with precise determination of resonance masses and properties, looking for rare qbar q states and for unconventional mesons with exotic quantum numbers (i.e. mesons with quantum numbers that are not compatible with a qbar q structure). With the imminent advent of the 12 GeV upgrade of Jefferson Lab a new generation of meson spectroscopy experiments will start: "Meson-Ex" in Hall B and "GLUEX" in Hall D. Both will use photo-production to explore the spectrum of mesons in the light-quark sector, in the energy range of few GeVs.

  10. Intensity of primary electrons above 10 GeV

    NASA Technical Reports Server (NTRS)

    Freier, P.; Gilman, C.; Waddington, C. J.

    1975-01-01

    A nuclear emulsion-spark chamber-counter electron telescope has been flown on a balloon at 3.5 g/sq cm residual pressure over Palestine, Texas, where the vertical cutoff is 4.5 GeV. The spark chamber pictures permitted the elimination of about 50% of the events whose counter signatures alone would qualify them as electrons. Of those events identified as 'electron-like' by counters and spark chambers, only 43% turn out to be electrons when found in the emulsion. The resulting intensities are among the lowest currently reported and are in good agreement with earlier results. The differential intensity in the region 8-40 GeV is measured.

  11. Scaled simulations of a 10 GeV accelerator

    SciTech Connect

    Cormier-Michel, Estelle; Geddes, C. G. R.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.; Bruhwiler, D. L.; Paul, K.; Cowan, B.

    2009-01-22

    Laser plasma accelerators are able to produce high quality electron beams from 1 MeV to 1 GeV. The next generation of plasma accelerator experiments will likely use a multi-stage approach where a high quality electron bunch is first produced and then injected into an accelerating structure. In this paper we present scaled particle-in-cell simulations of a 10 GeV stage in the quasi-linear regime. We show that physical parameters can be scaled to be able to perform these simulations at reasonable computational cost. Beam loading properties and electron bunch energy gain are calculated. A range of parameter regimes are studied to optimize the quality of the electron bunch at the output of the stage.

  12. The 750 GeV Diphoton Excess and SUSY

    NASA Astrophysics Data System (ADS)

    Heinemeyer, S.

    The LHC experiments ATLAS and CMS have reported an excess in the diphoton spectrum at ˜750 GeV. At the same time the motivation for Supersymmetry (SUSY) remains unbowed. Consequently, we review briefly the proposals to explain this excess in SUSY, focusing on "pure" (N)MSSM solutions. We then review in more detail a proposal to realize this excess within the NMSSM. In this particular scenario a Higgs boson with mass around 750 GeV decays to two light pseudo-scalar Higgs bosons. Via mixing with the pion these pseudo-scalars decay into a pair of highly collimated photons, which are identified as one photon, thus resulting in the observed signal.

  13. Scaled simulations of a 10 GeV accelerator

    SciTech Connect

    Cormier-Michel, Estelle; Geddes, C.G.R; Esarey, E.; Schroeder, C.B.; Bruhwiler, D.L.; Paul, K.; Cowan, B.; Leemans, W.P.

    2008-09-08

    Laser plasma accelerators are able to produce high quality electron beams from 1 MeV to 1 GeV. The next generation of plasma accelerator experiments will likely use a multi-stage approach where a high quality electron bunch is first produced and then injected into an accelerating structure. In this paper we present scaled particle-in-cell simulations of a 10 GeV stage in the quasi-linear regime. We show that physical parameters can be scaled to be able to perform these simulations at reasonable computational cost. Beam loading properties and electron bunch energy gain are calculated. A range of parameter regimes are studied to optimize the quality of the electron bunch at the output of the stage.

  14. Study of the laser-plasma acceleration of ion beams with enhanced quality: The effects of nanostructured targets

    NASA Astrophysics Data System (ADS)

    Fazeli, Reza

    2017-06-01

    Production of high-quality ion beams by intense laser-plasma interactions represents a rapidly evolving field of interest. In this paper, a nanostructured target is proposed to generate laser-driven quasi-monoenergetic ion beams with considerably reduced energy spread and enhanced peak energy. Linearly polarized, 40-fs laser pulses of intensity 8.5 × 1020 W cm-2 were considered to irradiate simple carbon foil and nanostructured targets. The proposed target consists of a thin layer of relatively high-Z atom (Ti) with a depression on its back surface which is filled by a nanosize disc of a low-Z atom (C). Reliable and reproducible results of multi-parametric Particle-in-Cell simulations show that by using a composed nanostructured target with optimum physical properties, a quasi-monoenergetic ion beam can be generated with a narrow band energy spectrum peaking at energies higher than 20 MeV. In addition, the forward-accelerated beam of low-Z carbon ions exhibits a considerably reduced transverse emittance in comparison with the ion beam obtained in the condition of a simple foil. The proposed nanostructured target can efficiently contribute to the generation of high-quality ion beams which are critical in newly growing applications and physics of laser-plasma accelerators.

  15. Sources of GeV Photons and the Fermi Results

    NASA Astrophysics Data System (ADS)

    Dermer, Charles D.

    This chapter presents the elaborated lecture notes on Sources of GeV Photons and the Fermi Results given by Charles D. Dermer at the 40th Saas-Fee Advanced Course on "Astrophysics at Very High Energies". The Fermi Gamma-ray Space Telescope made important discoveries and established new results in various areas of astrophysics: from our solar system to remote gamma-ray bursts, from pulsar physics to limits on dark matter and Lorentz invariance violations. The author gives a broad overview of these results by discussing GeV instrumentation and the GeV sky as seen by Fermi, the Fermi catalogs on gamma-ray sources, pulsars and active galactic nuclei, relativistic jet physics and blazars, gamma-rays from cosmic rays in the Galaxy, from star-forming galaxies and from clusters of galaxies, the diffuse extra-galactic gamma-ray background, micro-quasars, radio galaxies, the extragalactic background light, gamma-ray bursts, Fermi acceleration, ultra-high energy cosmic rays, and black holes.

  16. S5 0716+714: GeV variability study

    DOE PAGES

    Rani, B.; Krichbaum, T. P.; Lott, B.; ...

    2013-02-19

    The GeV observations by Fermi-LAT give us the opportunity to characterize the high-energy emission (100 MeV–300 GeV) variability properties of the BL Lac object S5 0716+714. In this study, we performed flux and spectral analysis of more than 3 year long (August 2008 to April 2012) Fermi-LAT data of the source. During this period, the source exhibits two different modes of flux variability with characteristic timescales of ~75 and ~140 days, respectively. In addition, we also notice that the flux variations are characterized by a weak spectral hardening. The GeV spectrum of the source shows a clear deviation from amore » simple power law, and is better explained by a broken power law. Similar to other bright Fermi blazars, the break energy does not vary with the source flux during the different activity states. Finally, we discuss several possible scenarios to explain the observed spectral break.« less

  17. Conceptual Design for a 1-GeV IFEL Accelerator

    NASA Astrophysics Data System (ADS)

    Kimura, W. D.; Musumeci, P.; Quimby, D. C.; Gottschalk, S. C.; Pellegrini, C.

    2004-12-01

    A conceptual design for a multistaged 1-GeV IFEL laser-driven accelerator (laser linac) was developed using the Staged Electron Laser Acceleration (STELLA) inverse free electron laser (IFEL) model created at STI Optronics. A comparison with the UCLA TREDI model yields good agreement with the STELLA model. The 1-GeV IFEL laser linac consists of an IFEL buncher for forming microbunches and four IFEL acceleration stages. Electrons enter the laser linac from a conventional microwave-driven linac (51 MeV). The acceleration stages are driven by 10-TW laser beams at 1.06-μm. It is found good trapping occurs as the electrons are accelerated; however, refocusing of the e-beam between acceleration stages is needed to control detrapping effects. The energy spread of the trapped electrons is also small. This design exercise was in support of the task placed upon the EM Structure-Based Accelerators Working Group at the 2004 Advanced Accelerator Concepts Workshop. It demonstrates that a 1-GeV IFEL laser linac is feasible with present technology.

  18. Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector

    SciTech Connect

    Pace, D. C. Fisher, R. K.; Van Zeeland, M. A.; Pipes, R.

    2014-11-15

    New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. These calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.

  19. Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector

    DOE PAGES

    Pace, D. C.; Pipes, R.; Fisher, R. K.; ...

    2014-08-05

    New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signaturemore » spanning across 50-140 keV. As a result, these calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.« less

  20. First measurements of the ion energy distribution at the divertor strike point during DIII-D disruptions

    SciTech Connect

    Parks, P.B.; Brooks, N.H.; West, W.P.; Wong, C.P.C.; Bastasz, R.; Wampler, W.R.; Whyte, D.

    1995-12-01

    Plasma/wall interaction studies are being carried out using the Divertor Materials Exposure System (DiMES) on DIII-D. The objective of the experiment is to determine the kinetic energy and flux of deuterium ions reaching the divertor target during argon-induced radiative disruptions. The experiment utilizes a special slotted ion analyzer mounted over a Si sample to collect the fast charge-exchange (CX) deuterium neutrals emitted within the recycled cold neutral layer (CNL) which serves as a CX target for the incident ions. A theoretical interpretation of the experiment reveals a strong forward pitch-angle dependence in the approaching ion distribution function. The depth distribution of the trapped D in the Si sample was measured using low-energy direct recoil spectroscopy. Comparison with the TRIM code using monoenergetic ions indicated that the best fit to the data was obtained for an ion energy of 100 eV.

  1. Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector

    SciTech Connect

    Pace, D. C.; Pipes, R.; Fisher, R. K.; Van Zeeland, M. A.

    2014-08-05

    New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. As a result, these calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.

  2. Ultra-relativistic ion acceleration in the laser-plasma interactions

    SciTech Connect

    Huang Yongsheng; Wang Naiyan; Tang Xiuzhang; Shi Yijin; Xueqing Yan

    2012-09-15

    An analytical relativistic model is proposed to describe the relativistic ion acceleration in the interaction of ultra-intense laser pulses with thin-foil plasmas. It is found that there is a critical value of the ion momentum to make sure that the ions are trapped by the light sail and accelerated in the radiation pressure acceleration (RPA) region. If the initial ion momentum is smaller than the critical value, that is in the classical case of RPA, the potential has a deep well and traps the ions to be accelerated, as the same described before by simulation results [Eliasson et al., New J. Phys. 11, 073006 (2009)]. There is a new ion acceleration region different from RPA, called ultra-relativistic acceleration, if the ion momentum exceeds the critical value. In this case, ions will experience a potential downhill. The dependence of the ion momentum and the self-similar variable at the ion front on the acceleration time has been obtained. In the ultra-relativistic limit, the ion momentum at the ion front is proportional to t{sup 4/5}, where t is the acceleration time. In our analytical hydrodynamical model, it is naturally predicted that the ion distribution from RPA is not monoenergetic, although the phase-stable acceleration mechanism is effective. The critical conditions of the laser and plasma parameters which identify the two acceleration modes have been achieved.

  3. Identified high-pT spectra in Cu+Cu collisions at sqrt sNN=200 GeV

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    We report new results on identified (anti)proton and charged pion spectra at large transverse momenta (3 < p{sub T} < 10 GeV/c) from Cu+Cu collisions at {radical}s{sub NN} = 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-p{sub T} and the anomalous baryon to meson enhancement at intermediate transverse momenta. Both phenomena could be attributed to the creation of a new form of QCD matter. The results presented here bridge the system size gap between the available pp and Au+Au data, and allow the detailed exploration for the on-set of the novel features. Comparative analysis of all available 200 GeV data indicates that the system size is a major factor determining both the magnitude of the hadron spectra suppression at large transverse momenta and the relative baryon to meson enhancement.

  4. Centrality dependence of charged hadron transverse momentum spectra in d+Au collisions at {radical}{ovr{sup S}NN} = 200 GeV.

    SciTech Connect

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; George, N.; Wuosmaa, A. H.; PHOBOS Collaboration; Physics; BNL; Massachusetts Inst. of Tech.

    2003-08-15

    We have measured transverse momentum distributions of charged hadrons produced in Au+Au collisions at {radical}{ovr S{sub NN}} = 62.4 GeV. The spectra are presented for transverse momenta 0.25 < p{sub T} < 4.5 GeV/c, in a pseudo-rapidity range of 0.2 < {eta} < 1.4. The nuclear modification factor R{sub AA} is calculated relative to p+p data at the same collision energy as a function of collision centrality. For 2 < p{sub T} < 4.5 GeV/c, R{sub AA} is found to be significantly larger than in Au+Au collisions at {radical}{ovr S{sub NN}} = 130 and 200 GeV. In contrast to the large change in R{sub AA}, we observe a very similar centrality evolution of the p{sub T} spectra at {radical}{ovr S{sub NN}} = 62.4 GeV and 200 GeV. The dynamical origin of this surprising factorization of energy and centrality dependence of particle production in heavy ion collisions remains to be understood.

  5. Ion cyclotron and spin-flip emissions from fusion products in tokamaks

    SciTech Connect

    Arunasalam, V.; Greene, G.J.; Young, K.M.

    1993-02-01

    Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T [perpendicular] [ne] T[parallel]and with appreciable drift velocity along the confining magnetic field. Single dressed'' test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between kinetic or causal instabilities'' and hydrodynamic instabilities'' are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k[parallel] = 0 for k[parallel] [ne] 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an inverted'' population of states.

  6. Ion cyclotron and spin-flip emissions from fusion products in tokamaks

    SciTech Connect

    Arunasalam, V.; Greene, G.J.; Young, K.M.

    1993-02-01

    Power emission by fusion products of tokamak plasmas in their ion cyclotron range of frequencies (ICRF) and at their spin-flip resonance frequency is calculated for some specific model fusion product velocity-space distribution functions. The background plasma of say deuterium (D) is assumed to be in equilibrium with a Maxwellian distribution both for the electrons and ions. The fusion product velocity distributions analyzed here are: (1) A monoenergetic velocity space ring distribution. (2) A monoenergetic velocity space spherical shell distribution. (3) An anisotropic Maxwellian distribution with T {perpendicular} {ne} T{parallel}and with appreciable drift velocity along the confining magnetic field. Single ``dressed`` test particle spontaneous emission calculations are presented first and the radiation temperature for ion cyclotron emission (ICE) is analyzed both for black-body emission and nonequilibrium conditions. Thresholds for instability and overstability conditions are then examined and quasilinear and nonlinear theories of the electromagnetic ion cyclotron modes are discussed. Distinctions between ``kinetic or causal instabilities`` and ``hydrodynamic instabilities`` are drawn and some numerical estimates are presented for typical tokamak parameters. Semiquantitative remarks are offered on wave accessibility, mode conversion, and parametric decay instabilities as possible for spatially localized ICE. Calculations are carried out both for k{parallel} = 0 for k{parallel} {ne} 0. The effects of the temperature anisotropy and large drift velocities in the parallel direction are also examined. Finally, proton spin-flip resonance emission and absorption calculations are also presented both for thermal equilibrium conditions and for an ``inverted`` population of states.

  7. K*0 production in Cu + Cu and Au + Au collisions at sNN=62.4 GeV and 200 GeV

    NASA Astrophysics Data System (ADS)

    Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Alekseev, I.; Alford, J.; Anderson, B. D.; Anson, C. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Barnby, L. S.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bonner, B. E.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bridgeman, A.; Bruna, E.; Bueltmann, S.; Bunzarov, I.; Burton, T. P.; Cai, X. Z.; Caines, H.; Calderon de La Barca Sanchez, M.; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, P.; Clarke, R. F.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Davila Leyva, A.; de Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Derevschikov, A. A.; Derradi de Souza, R.; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunlop, J. C.; Dutta Mazumdar, M. R.; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Evdokimov, O.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E. J.; Geromitsos, A.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Gupta, A.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heinz, M.; Heppelmann, S.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Huang, B.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jena, C.; Jin, F.; Jones, C. L.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kauder, K.; Keane, D.; Kechechyan, A.; Kettler, D.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Koroleva, L.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Krueger, K.; Krus, M.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, L.; Li, N.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Lukashov, E. V.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; Matulenko, Yu. A.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitrovski, M. K.; Mohanty, B.; Mondal, M. M.; Morozov, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldag, E. W.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Powell, C. B.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Sahoo, R.; Sakai, S.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sangaline, E.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Staszak, D.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van Leeuwen, M.; van Nieuwenhuizen, G.; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.

    2011-09-01

    We report on K*0 production at midrapidity in Au + Au and Cu + Cu collisions at sNN=62.4 and 200 GeV collected by the Solenoid Tracker at the Relativistic Heavy Ion Collider detector. The K*0 is reconstructed via the hadronic decays K*0→K+π- and K*0¯→K-π+. Transverse momentum, pT, spectra are measured over a range of pT extending from 0.2 GeV/c up to 5 GeV/c. The center-of-mass energy and system size dependence of the rapidity density, dN/dy, and the average transverse momentum, , are presented. The measured N(K*0)/N(K) and N(φ)/N(K*0) ratios favor the dominance of rescattering of decay daughters of K*0 over the hadronic regeneration for the K*0 production. In the intermediate pT region (2.0

  8. The primary cosmic ray electron spectrum from 10 GeV to about 200 GeV

    NASA Technical Reports Server (NTRS)

    Silverberg, R. F.; Ormes, J. F.; Balasubrahmanyan, V. K.; Ryan, M. J.

    1971-01-01

    An ionization spectrometer consisting of 10.8 radiation lengths of tungsten and 35 radiation lengths of iron has been used to determine the energy spectrum of cosmic ray electrons above 10 GeV. The spectrometer was calibrated with electrons from 5.4 to 18 GeV and then flown at an altitude of 6 gm-cm/2 for 16 hours. Separation of electron initiated events from proton events was achieved by utilizing starting point distributions, the shower development in tungsten, and the energy deposited in the large thickness of iron absorber. The exponent of the differential energy spectrum of the electrons is -3.1 + or - 0.2 while the exponent of the background is consistent with the proton exponent of -2.7 + or -0.2.

  9. Multiple collision effects on the antiproton production by high energy proton (100 GeV - 1000 GeV)

    SciTech Connect

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    Antiproton production rates which take into account multiple collision are calculated using a simple model. Methods to reduce capture of the produced antiprotons by the target are discussed, including geometry of target and the use of a high intensity laser. Antiproton production increases substantially above 150 GeV proton incident energy. The yield increases almost linearly with incident energy, alleviating space charge problems in the high current accelerator that produces large amounts of antiprotons.

  10. Graphene treatment using a very low energy Ar+ ion beam for residue removal.

    PubMed

    Min, Kyoung Seok; Kim, Ki Seok; Kim, Kyoung Nam; Mishra, Anurag; Yeom, Geun Young

    2014-12-01

    The effect of Ar+ ion energy on the removal of the polymethyl methacrylate (PMMA) residue remaining on the chemical vapor deposited (CVD) graphene surface without damaging the graphene surface was investigated. Stable and low energy Ar+ ion beams having a mono-energetic energy distribution with a peak energy of 7.5 eV or 11.5 eV could be formed by using a two-grid magnetically enhanced ICP ion gun with and without the application of 25 Gauss axial magnetic field, respectively, while controlling the Ar gas flow rate. When the CVD graphene treatment was performed with the Ar+ ions having the ion energy peak at 7.5 eV (with the magnetic field) and 11.5 eV (without the magnetic field), the blue shift of Raman G peak from p-type doped to intrinsic graphene indicating the removal of residue on the graphene surface could be observed for both conditions, however, the graphene treated at 11.5 eV (without the magnetic field) showed the increase of the defect while that treated at 7.5 eV (with the magnetic field) showed no significant change of the defect. It is believed that, for the treatment of CVD graphene, possibly due to the low binding energy area such as grain boundaries and domains in the CVD graphene, low energy ions with less than the energy of 10 eV is required not to damage the graphene surface, and a magnetically enhanced ICP ion gun which can provide stable and low energy Ar+ ions with a mono-energetic ion energy distribution with a peak of 7.5 eV can be applicable to the residue removal on the graphene surface.

  11. INTERACTION REGION DESIGN FOR THE ELECTRON-ION COLLIDER ERHIC.

    SciTech Connect

    MONTAG, C.; PARKER, B.; TEPIKIAN, S.; ET AL.

    2005-05-16

    To facilitate the study of collisions between 10 GeV polarized electrons and 100 GeV/u heavy ions or 250 GeV polarized protons at luminosities in the 10{sup 33} cm{sup -2} sec{sup -1} range (e-p case), adding a 10 GeV electron storage ring to the existing RHIC complex has been proposed. The interaction region of this electron-ion collider eRHIC has to provide the required low-beta focusing, while simultaneously accommodating the synchrotron radiation fan generated by beam separation close to the interaction point, which is particularly challenging. The latest design status of the eRHIC interaction region will be presented.

  12. Experimental investigation of ion-ion recombination at atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Franchin, A.; Ehrhart, S.; Leppä, J.; Nieminen, T.; Gagné, S.; Schobesberger, S.; Wimmer, D.; Duplissy, J.; Riccobono, F.; Dunne, E.; Rondo, L.; Downard, A.; Bianchi, F.; Kupc, A.; Tsagkogeorgas, G.; Lehtipalo, K.; Manninen, H. E.; Almeida, J.; Amorim, A.; Wagner, P. E.; Hansel, A.; Kirkby, J.; Kürten, A.; Donahue, N. M.; Makhmutov, V.; Mathot, S.; Metzger, A.; Petäjä, T.; Schnitzhofer, R.; Sipilä, M.; Stozhkov, Y.; Tomé, A.; Kerminen, V.-M.; Carslaw, K.; Curtius, J.; Baltensperger, U.; Kulmala, M.

    2015-02-01

    We present the results of laboratory measurements of the ion-ion recombination coefficient at different temperatures, relative humidities and concentrations of ozone and sulfur dioxide. The experiments were carried out using the Cosmics Leaving OUtdoor Droplets (CLOUD) chamber at CERN, the walls of which are made of conductive material, making it possible to measure small ions. We produced ions in the chamber using a 3.5 GeV c-1 beam of positively-charged pions (π+) from the CERN Proton Synchrotron (PS) and with galactic cosmic rays, when the PS was switched off. The range of the ion production rate varied from 2 to 100 cm-3s-1, covering the typical range of ionization throughout the troposphere. The temperature ranged from -55 to 20 °C, the relative humidity from 0 to 70%, the SO2 concentration from 0 to 40 ppb, and the ozone concentration from 200 to 700 ppb. At 20 °C and 40% RH, the retrieved ion-ion recombination coefficient was (2.3 ± 0.7) × 10-6cm3s-1. We observed no dependency of the ion-ion recombination coefficient on ozone concentration and a weak variation with sulfur dioxide concentration. However, we found a strong dependency of the ion-ion recombination coefficient on temperature. We compared our results with three different models and found an overall agreement for temperatures above 0 °C, but a disagreement at lower temperatures. We observed a strong dependency of the recombination coefficient on relative humidity, which has not been reported previously.

  13. Extended conversion coefficients for use in radiation protection of the embryo and fetus against external neutrons from 10 MeV to 100 GeV.

    PubMed

    Chen, Jing

    2006-03-01

    External neutron exposure is of concern in the environment and in some workplaces. Dose assessments for neutrons frequently rely on fluence-to-absorbed dose conversion coefficients. A problem of concern in radiation protection is exposure of pregnant women to ionizing radiation because of the high radiosensitivity of the embryo and fetus. While neutron fluence-to-dose conversion coefficients for adults are recommended in ICRP publications and ICRU reports, conversion coefficients for embryos and fetuses are not given in the publications. This study uses the Monte Carlo code MCNPX to determine mean absorbed doses to the embryo and fetus when the mother is exposed to neutron fields. A previous study has dealt with neutrons from 1 eV to 10 MeV. In this study, monoenergetic neutrons ranging from 10 MeV to 100 GeV are considered. The irradiation geometries include antero-posterior, postero-anterior, lateral, rotational, and isotropic. At each of these standard irradiation geometries, absorbed doses to the fetal brain and body are calculated for the embryo of 8 wk and the fetus of 3, 6, or 9 mo. Neutron fluence-to-absorbed dose conversion coefficients are derived for the four prenatal ages. The results showed that the fetus at about 3 mo of prenatal age should receive more radiation protection to prevent long-term brain damage. During prenatal life, the fetus generally receives the highest absorbed dose per unit neutron fluence for antero-posterior irradiation. In cases where the irradiation geometry is not specified or not adequately known, conversion coefficients of AP-irradiation can therefore be used in a conservative dose assessment of fetus exposure to external neutrons.

  14. Ultralow energy ion beam surface modification of low density polyethylene.

    PubMed

    Shenton, Martyn J; Bradley, James W; van den Berg, Jaap A; Armour, David G; Stevens, Gary C

    2005-12-01

    Ultralow energy Ar+ and O+ ion beam irradiation of low density polyethylene has been carried out under controlled dose and monoenergetic conditions. XPS of Ar+-treated surfaces exposed to ambient atmosphere show that the bombardment of 50 eV Ar+ ions at a total dose of 10(16) cm(-2) gives rise to very reactive surfaces with oxygen incorporation at about 50% of the species present in the upper surface layer. Using pure O+ beam irradiation, comparatively low O incorporation is achieved without exposure to atmosphere (approximately 13% O in the upper surface). However, if the surface is activated by Ar+ pretreatment, then large oxygen contents can be achieved under subsequent O+ irradiation (up to 48% O). The results show that for very low energy (20 eV) oxygen ions there is a dose threshold of about 5 x 10(15) cm(-2) before surface oxygen incorporation is observed. It appears that, for both Ar+ and O+ ions in this regime, the degree of surface modification is only very weakly dependent on the ion energy. The results suggest that in the nonequilibrium plasma treatment of polymers, where the ion flux is typically 10(18) m(-2) s(-1), low energy ions (<50 eV) may be responsible for surface chemical modification.

  15. Test ion acceleration in a dynamic planar electron sheath

    NASA Astrophysics Data System (ADS)

    Basko, M. M.

    2007-03-01

    New exact results are obtained for relativistic acceleration of test positive ions in the laminar zone of a planar electron sheath evolving from an initially mono-energetic electron distribution. The electron dynamics is calculated against the background of motionless foil ions. The limiting gamma-factor γp∞ of accelerated ions is shown to be determined primarily by the values of the ion-electron charge-over-mass ratio μ=meZp/mp and the initial gamma-factor γ0 of the accelerated electrons. For μ> 1/8 a test ion always overtakes the electron front and attains γp∞> γ0. For μ< 1/8 a test ion can catch up with the electron front only when γ0 is above a certain critical value γcr, which for μ≪1 can most often be evaluated as γ_{cr} = ({1}/{4}) μexpleft(μ^{-1}-1right). In this model the protons and heavier test ions, for which γcr> 10398 is enormous, always lag behind the front edge of the electron sheath and have γp∞< γ0; for their maximum energy an appropriate intermediate asymptotic formula is derived. The domain of applicability of the laminar-zone results is analyzed in detail.

  16. Annealing behaviors of vacancy-type defects near interfaces between metal contacts and GaN probed using a monoenergetic positron beam

    SciTech Connect

    Uedono, Akira Yoshihara, Nakaaki; Fujishima, Tatsuya; Piedra, Daniel; Palacios, Tomás; Ishibashi, Shoji; Sumiya, Masatomo; Laboutin, Oleg; Johnson, Wayne

    2014-08-04

    Vacancy-type defects near interfaces between metal contacts and GaN grown on Si substrates by metal organic chemical vapor deposition have been studied using a monoenergetic positron beam. Measurements of Doppler broadening spectra of the annihilation radiation for Ti-deposited GaN showed that optically active vacancy-type defects were introduced below the Ti/GaN interface after annealing at 800 °C. Charge transition of those defects due to electron capture was observed and was found to correlate with a yellow band in the photoluminescence spectrum. The major defect species was identified as vacancy clusters such as three to five Ga-vacancies coupled with multiple nitrogen-vacancies. The annealing behaviors of vacancy-type defects in Ti-, Ni-, and Pt-deposited GaN were also examined.

  17. A pulsed, mono-energetic and angular-selective UV photo-electron source for the commissioning of the KATRIN experiment

    NASA Astrophysics Data System (ADS)

    Behrens, J.; Ranitzsch, P. C.-O.; Beck, M.; Beglarian, A.; Erhard, M.; Groh, S.; Hannen, V.; Kraus, M.; Ortjohann, H.-W.; Rest, O.; Schlösser, K.; Thümmler, T.; Valerius, K.; Wierman, K.; Wilkerson, J. F.; Winzen, D.; Zacher, M.; Weinheimer, C.

    2017-06-01

    The KATRIN experiment aims to determine the neutrino mass scale with a sensitivity of 200 {meV/c^2} (90% C. L.) by a precision measurement of the shape of the tritium β -spectrum in the endpoint region. The energy analysis of the decay electrons is achieved by a MAC-E filter spectrometer. To determine the transmission properties of the KATRIN main spectrometer, a mono-energetic and angular-selective electron source has been developed. In preparation for the second commissioning phase of the main spectrometer, a measurement phase was carried out at the KATRIN monitor spectrometer where the device was operated in a MAC-E filter setup for testing. The results of these measurements are compared with simulations using the particle-tracking software "Kassiopeia", which was developed in the KATRIN collaboration over recent years.

  18. Chromosome aberrations induced in vitro in human lymphocytes by monoenergetic 2.5 MeV neutrons and 60Co gamma rays.

    PubMed

    Hellin, H; Paulsen, A; Liskien, H; Decat, G; Wambersie, A; Léonard, A; Baugnet-Mahieu, L

    1990-08-01

    The aim of the present experiments was to evaluate the relative biological effectiveness (RBE) of monoenergetic 2.5 MeV neutrons, in view of the scarcity of data on the RBE of neutrons in this energy range. Human peripheral blood lymphocytes from two donors were exposed to doses of neutrons ranging from 0.005 Gy to 0.5 Gy. Gamma rays produced by a telecobalt therapy unit were used as reference radiation. RBE values were of the same order of magnitude, whatever was the model of the dose-response curve chosen for the neutrons (linear or linear-quadratic). As expected, RBE increased markedly with decreasing doses and went beyond 30 at a dose level of 0.2 Gy. The present results, compared with RBE values obtained with neutrons of higher energy (6.5, 14 and 21 MeV), confirm that low energy neutrons are more effective in producing genetic effects, especially at low doses.

  19. Characterization of Hundreds of MeV 7Li(p,n) Quasi-Monoenergetic Neutron Source at RCNP Using a Proton Recoil Telescope and TOF Technique

    NASA Astrophysics Data System (ADS)

    Hagiwara, Masayuki; Iwamoto, Yosuke; Iwase, Hiroshi; Yashima, Hiroshi; Satoh, Daiki; Matsumoto, Tetsuro; Masuda, Akihiko; Nakane, Yoshihiro; Tamii, Atsushi; Shima, Tatsushi; Hatanaka, Kichiji; Nakamura, Takashi

    The peak neutron fluence of a quasi-monoenergetic 7Li(p,n) neutron source at RCNP of Osaka University have been measured for four incident proton energies between 100 and 300 MeV, using a proton recoil telescope (PRT) with event selection by a time-of-flight technique. We deduced the cross section of the peak neutron production reaction, 7Li(p,n0,1)7Be, at 0° and compared with that previously obtained with a time-of-flight (TOF) method employing an organic liquid scintillator. The results obtained with different methods are in agreement within their uncertainties and generally consistent with the other experimental data in several hundreds of MeV region.

  20. Transportation of high-current ion and electron beams in the accelerator drift gap in the presence of an additional electron background

    NASA Astrophysics Data System (ADS)

    Karas', V. I.; Kornilov, E. A.; Manuilenko, O. V.; Tarakanov, V. P.; Fedorovskaya, O. V.

    2015-12-01

    The dynamics of a high-current ion beam propagating in the drift gap of a linear induction accelerator with collective focusing is studied using 3D numerical simulations in the framework of the full system of the Vlasov-Maxwell equations (code KARAT). The ion beam is neutralized by a comoving electron beam in the current density and, partially, in space charge, since the velocities of electrons and ions differ substantially. The dynamics of the high-current ion beam is investigated for different versions of additional neutralization of its space charge. It is established that, for a given configuration of the magnetic field and in the presence of a specially programmed injection of additional electrons from the boundary opposite to the ion injection boundary, the angular divergence of the ion beam almost vanishes, whereas the current of the ion beam at the exit from the accelerator drift gap changes insignificantly and the beam remains almost monoenergetic.

  1. Transportation of high-current ion and electron beams in the accelerator drift gap in the presence of an additional electron background

    SciTech Connect

    Karas’, V. I. Kornilov, E. A.; Manuilenko, O. V.; Tarakanov, V. P.; Fedorovskaya, O. V.

    2015-12-15

    The dynamics of a high-current ion beam propagating in the drift gap of a linear induction accelerator with collective focusing is studied using 3D numerical simulations in the framework of the full system of the Vlasov–Maxwell equations (code KARAT). The ion beam is neutralized by a comoving electron beam in the current density and, partially, in space charge, since the velocities of electrons and ions differ substantially. The dynamics of the high-current ion beam is investigated for different versions of additional neutralization of its space charge. It is established that, for a given configuration of the magnetic field and in the presence of a specially programmed injection of additional electrons from the boundary opposite to the ion injection boundary, the angular divergence of the ion beam almost vanishes, whereas the current of the ion beam at the exit from the accelerator drift gap changes insignificantly and the beam remains almost monoenergetic.

  2. Yields of nuclear fragments in the interactions of carbon nuclei with a beryllium target at a projectile energy of 0.6 GeV per nucleon

    NASA Astrophysics Data System (ADS)

    Abramov, B. M.; Alexeev, P. N.; Borodin, Yu. A.; Bulychjov, S. A.; Gudima, K. K.; Dukhovskoy, I. A.; Krutenkova, A. P.; Kulikov, V. V.; Martemianov, M. A.; Matsyuk, M. A.; Mashnik, S. G.; Turdakina, E. N.; Khanov, A. I.

    2016-09-01

    The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T 0 = 0.6 GeV per nucleon on a berylliumtarget were measured in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion-ion interactions: BC, INCL++, LAQGSM03.03, and QMD.

  3. eRHIC, the BNL design for a future Electron-Ion Collider

    NASA Astrophysics Data System (ADS)

    Roser, Thomas

    2016-03-01

    With the addition of a 20 GeV polarized electron accelerator to the existing Brookhaven Relativistic Heavy Ion Collider (RHIC), the world's only high energy heavy ion and polarized proton collider, a future eRHIC facility will be able to produce polarized electron-nucleon collisions at center-of-mass energies of up to 145 GeV and cover the whole science case as outlined in the Electron-Ion Collider White Paper and endorsed by the 2015 Nuclear Physics Long Range Plan with high luminosity. The presentation will describe the eRHIC design concepts and recent efforts to reduce the technical risks of the project.

  4. Dual-energy computed tomography in patients with cutaneous malignant melanoma: Comparison of noise-optimized and traditional virtual monoenergetic imaging.

    PubMed

    Martin, Simon S; Wichmann, Julian L; Weyer, Hendrik; Albrecht, Moritz H; D'Angelo, Tommaso; Leithner, Doris; Lenga, Lukas; Booz, Christian; Scholtz, Jan-Erik; Bodelle, Boris; Vogl, Thomas J; Hammerstingl, Renate

    2017-10-01

    The aim of this study was to investigate the impact of noise-optimized virtual monoenergetic imaging (VMI+) reconstructions on quantitative and qualitative image parameters in patients with cutaneous malignant melanoma at thoracoabdominal dual-energy computed tomography (DECT). Seventy-six patients (48 men; 66.6±13.8years) with metastatic cutaneous malignant melanoma underwent DECT of the thorax and abdomen. Images were post-processed with standard linear blending (M_0.6), traditional virtual monoenergetic (VMI), and VMI+ technique. VMI and VMI+ images were reconstructed in 10-keV intervals from 40 to 100keV. Attenuation measurements were performed in cutaneous melanoma lesions, as well as in regional lymph node, subcutaneous and in-transit metastases to calculate objective signal-to-noise (SNR) and contrast-to-noise (CNR) ratios. Five-point scales were used to evaluate overall image quality and lesion delineation by three radiologists with different levels of experience. Objective indices SNR and CNR were highest at 40-keV VMI+ series (5.6±2.6 and 12.4±3.4), significantly superior to all other reconstructions (all P<0.001). Qualitative image parameters showed highest values for 50-keV and 60-keV VMI+ reconstructions (median 5, respectively; P≤0.019) regarding overall image quality. Moreover, qualitative assessment of lesion delineation peaked in 40-keV VMI+ (median 5) and 50-keV VMI+ (median 4; P=0.055), significantly superior to all other reconstructions (all P<0.001). Low-keV noise-optimized VMI+ reconstructions substantially increase quantitative and qualitative image parameters, as well as subjective lesion delineation compared to standard image reconstruction and traditional VMI in patients with cutaneous malignant melanoma at thoracoabdominal DECT. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Noise-Optimized Virtual Monoenergetic Dual-Energy CT Improves Diagnostic Accuracy for the Detection of Active Arterial Bleeding of the Abdomen.

    PubMed

    Martin, Simon S; Wichmann, Julian L; Scholtz, Jan-Erik; Leithner, Doris; D'Angelo, Tommaso; Weyer, Hendrik; Booz, Christian; Lenga, Lukas; Vogl, Thomas J; Albrecht, Moritz H

    2017-09-01

    To evaluate diagnostic accuracy of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique for detection of active arterial abdominal bleeding on dual-energy (DE) CT angiography compared with standard image reconstruction. DE CT angiography data sets of 71 patients (46 men; age 63.6 y ± 13.3) with suspected arterial bleeding of the abdomen or pelvis were reconstructed with standard linearly blended (F_0.5), VMI+, and traditional virtual monoenergetic imaging (VMI) algorithms in 10-keV increments from 40 to 100 keV. Attenuation measurements were performed in the descending aorta, area of hemorrhage, and feeding artery to calculate contrast-to-noise ratios (CNRs) in patients with active arterial bleeding. Based on quantitative image quality results, the best series for each reconstruction technique were chosen to analyze the diagnostic performance of 3 blinded radiologists. DE CT angiography showed acute arterial bleeding in 36 patients. Mean CNR was superior in 40-keV VMI+ compared with VMI series (all P < .001), which showed highest CNRs in 70-keV VMI and F_0.5 (21.6 ± 7.9, 12.9 ± 4.7, and 10.4 ± 3.6) images. Area under the curve analysis for detection of arterial bleeding showed significantly superior (P < .001) results for 40-keV VMI+ (0.963) compared with 70-keV VMI (0.775) and F_0.5 (0.817) series. Diagnostic accuracy in patients with active arterial bleeding of the abdomen can be significantly improved using VMI+ reconstructions at 40 keV compared with standard linearly blended and traditional VMI series in DE CT angiography. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  6. Noise-optimized virtual monoenergetic dual-energy computed tomography: optimization of kiloelectron volt settings in patients with gastrointestinal stromal tumors.

    PubMed

    Martin, Simon S; Pfeifer, Sophia; Wichmann, Julian L; Albrecht, Moritz H; Leithner, Doris; Lenga, Lukas; Scholtz, Jan-Erik; Vogl, Thomas J; Bodelle, Boris

    2017-03-01

    The aim of this study was to evaluate the impact of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique on quantitative and qualitative image analysis in patients with gastrointestinal stromal tumors (GISTs) at dual-energy computed tomography (DECT) of the abdomen. Forty-five DECT datasets of 21 patients (14 men; 63.7 ± 9.2 years) with GISTs were reconstructed with the standard linearly blended (M_0.6) and VMI+ and traditional virtual monoenergetic (VMI) algorithm in 10-keV increments from 40 to 100 keV. Attenuation measurements were performed in GIST lesions and abdominal metastases to calculate objective signal-to-noise (SNR) and contrast-to-noise ratios (CNR). Five-point scales were used to evaluate overall image quality, lesion delineation, image sharpness, and image noise. Quantitative image parameters peaked at 40-keV VMI+ series (SNR 27.8 ± 13.0; CNR 26.3 ± 12.7), significantly superior to linearly blended (SNR 16.8 ± 7.3; CNR 13.6 ± 6.9) and all VMI series (all P < 0.001). Qualitative image parameters were highest for 60-keV VMI+ reconstructions regarding overall image quality and image sharpness (median 5, respectively; P ≤ 0.023). Qualitative assessment of lesion delineation peaked in 40 and 50-keV VMI+ series (median 5, respectively). Image noise was superior in 90 and 100-keV VMI and VMI+ reconstructions (all medians 5). Low-keV VMI+ reconstructions significantly increase SNR and CNR of GISTs and improve quantitative and qualitative image quality of abdominal DECT datasets compared to traditional VMI and standard linearly blended image series.

  7. Possible Contrast Media Reduction with Low keV Monoenergetic Images in the Detection of Focal Liver Lesions: A Dual-Energy CT Animal Study.

    PubMed

    Chung, Yong Eun; You, Je Sung; Lee, Hye-Jeong; Lim, Joon Seok; Lee, Hye Sun; Baek, Song-Ee; Kim, Myeong-Jin

    2015-01-01

    To investigate the feasibility of dual-energy CT for contrast media (CM) reduction in the diagnosis of hypervascular and hypovascular focal liver lesions (FLL). The Institutional Animal Care and Use Committee approved this study. VX2 tumors were implanted in two different segments of the liver in 13 rabbits. After 2 weeks, two phase contrast enhanced CT scans including the arterial phase (AP) and portal-venous phase (PVP) were performed three times with 24-hour intervals with three different concentrations of iodine, 300 (I(300)), 150 (I(150)) and 75 mg I/mL (I(75)). The mean HU and standard deviation (SD) were measured in the liver, the hypervascular portion of the VX2 tumor which represented hypervascular tumors, and the central necrotic area of the VX2 tumor which represented hypovascular tumors in 140 kVp images with I(300) as a reference standard and in monoenergetic images (between 40 keV and 140 keV) with I(150) and I(75). The contrast-to-noise ratio (CNR) for FLLs and the ratio of the CNRs (CNR(ratio)) between monoenergetic image sets with I(150) and I(75), and the reference standard were calculated. For hypervascular lesions, the CNR(ratio) was not statistically different from 1.0 between 40 keV and 70 keV images with I(150), whereas the CNR(ratio) was significantly lower than 1.0 in all keV images with I(75). For hypovascular lesions, the CNR(ratio) was similar to or higher than 1.0 between 40 keV and 80 keV with I(150) and between 40 keV and 70 keV with I(75).. With dual-energy CT, the total amount of CM might be halved in the diagnosis of hypervascular FLLs and reduced to one-fourth in the diagnosis of hypovascular FLLs, while still preserving CNRs.

  8. Possible Contrast Media Reduction with Low keV Monoenergetic Images in the Detection of Focal Liver Lesions: A Dual-Energy CT Animal Study

    PubMed Central

    Chung, Yong Eun; You, Je Sung; Lee, Hye-Jeong; Lim, Joon Seok; Lee, Hye Sun; Baek, Song-Ee; Kim, Myeong-Jin

    2015-01-01

    Objective To investigate the feasibility of dual-energy CT for contrast media (CM) reduction in the diagnosis of hypervascular and hypovascular focal liver lesions (FLL). Subjects and Methods The Institutional Animal Care and Use Committee approved this study. VX2 tumors were implanted in two different segments of the liver in 13 rabbits. After 2 weeks, two phase contrast enhanced CT scans including the arterial phase (AP) and portal-venous phase (PVP) were performed three times with 24-hour intervals with three different concentrations of iodine, 300 (I300), 150 (I150) and 75 mg I/mL (I75). The mean HU and standard deviation (SD) were measured in the liver, the hypervascular portion of the VX2 tumor which represented hypervascular tumors, and the central necrotic area of the VX2 tumor which represented hypovascular tumors in 140kVp images with I300 as a reference standard and in monoenergetic images (between 40keV and 140keV) with I150 and I75. The contrast-to-noise ratio (CNR) for FLLs and the ratio of the CNRs (CNRratio) between monoenergetic image sets with I150 and I75, and the reference standard were calculated. Results For hypervascular lesions, the CNRratio was not statistically different from 1.0 between 40keV and 70keV images with I150, whereas the CNRratio was significantly lower than 1.0 in all keV images with I75. For hypovascular lesions, the CNRratio was similar to or higher than 1.0 between 40keV and 80keV with I150 and between 40keV and 70keV with I75. Conclusions With dual-energy CT, the total amount of CM might be halved in the diagnosis of hypervascular FLLs and reduced to one-fourth in the diagnosis of hypovascular FLLs, while still preserving CNRs. PMID:26203652

  9. SU-F-18C-04: A Combination of Monoenergetic Reconstruction and Stoichiometric Calibration for Tissue Characterization Using Dual Energy Computed Tomography

    SciTech Connect

    Bedwani, S; Tremblay, J; Bouchard, H

    2014-06-15

    Purpose: Dual energy computed tomography (DECT) pre-reconstruction methods require the prior knowledge of the X-ray source spectrum to allow extracting physical parameters needed for radiation therapy dose calculation, such as electron density (ED) and the effective atomic number (EAN). While DECT stoichiometric calibration may provide reliable performance for typical radiation therapy clinical conditions, it is yet to be adapted to prereconstruction methods. The presence of noise and inaccurate spectrum description may lead to systematic errors and artifacts which compromise the accuracy of treatment planning. Methods: A new technique is investigated which consists in applying a DECT stoichiometric calibration method to a set of monoenergetic images obtained with a DECT prereconstruction method. To evaluate the performance of this extended method, a simulation environment is developed to generate DECT scans under well controlled conditions, to reconstruct monoenergetic images of a tissue-equivalent phantom from transformed sinograms and to extract ED and EAN maps using a DECT formalism. Result: Under simulated clinical conditions, the accuracy in determining ED with the extended method versus a pre-reconstruction method alone is shown to be better than 0.35% versus 0.5%, respectively. In the presence of a realistic noise level, EAN determination presents a relative mean error that drops from 2.5% to 0.5% once the calibration is applied. Considering a spectrum alteration by a 1 mm Cu layer, EAN errors are up to 30% for the pre-reconstruction method alone versus less than 3% for the extended method. Conclusion: This study shows that combining pre-reconstruction DECT methods with a stoichiometric calibration considerably improves the accuracy and reliability of tissue characterization for radiation therapy in a clinical context. The presented method could potentially be adapted as gold standard for dose calculation methods based on DECT.

  10. Potential clinical impact of laser-accelerated beams in cancer ion therapy

    NASA Astrophysics Data System (ADS)

    Obcemea, Ceferino

    2016-09-01

    In this article, I present three advantages of plasma-accelerated ion beams for cancer therapy. I discuss how: 1. low-emittance and well-collimated beams are advantageous in proximal normal tissue-sparing; 2. highly-peaked quasi-monoenergetic beams are ideal for fast energy selection and switching in Pencil Beam Scanning (PBS) as a treatment delivery; 3. high fluence and ultra-short pulse delivery produce collective excitations in the medium and enhance the stopping power. This in turn produces denser ionization track signatures (spurs, blobs, etc.) in target tumors, higher linear energy transfer, higher Bragg peak, and higher radiobiological effectiveness at the micro-level.

  11. Ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.

    1984-01-01

    A magnetic filter for an ion source reduces the production of undesired ion species and improves the ion beam quality. High-energy ionizing electrons are confined by the magnetic filter to an ion source region, where the high-energy electrons ionize gas molecules. One embodiment of the magnetic filter uses permanent magnets oriented to establish a magnetic field transverse to the direction of travel of ions from the ion source region to the ion extraction region. In another embodiment, low energy 16 eV electrons are injected into the ion source to dissociate gas molecules and undesired ion species into desired ion species.

  12. The Jefferson Lab 12 GeV Upgrade

    SciTech Connect

    R.D. McKeown

    2011-10-01

    A major upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility is in progress. Construction began in 2008 and the project should be completed in 2015. The upgrade includes doubling the energy of the electron beam to 12 GeV, the addition of a new fourth experimental hall, and new experimental equipment in three of the experimental halls. A brief overview of this upgrade project is presented along with some highlights of the anticipated experimental program.

  13. GeV Gamma-Ray Astronomy with GLAST

    SciTech Connect

    Kamae, T

    2004-05-11

    GLAST is NASA's next major mission to observe the gamma ray sky with unprecedented sensitivity in the energy range between 20 MeV and 300 GeV. The collaboration consisting of institutions in the US, France, Italy, Sweden and Japan is now building the engineering model to demonstrate validity of the flight model design. They will proceed to the flight model construction in the fall of 2002 which will be launched in March 2006. The instrument and science of GLAST Large Area Telescope will be described briefly here.

  14. High energy electrons beyond 100 GEV observed by emulsion chamber

    NASA Technical Reports Server (NTRS)

    Nishimura, J.; Fujii, M.; Yoshida, A.; Taira, T.; Aizu, H.; Nomura, Y.; Kobayashi, T.; Kazuno, M.; Nishio, A.; Golden, R. L.

    1986-01-01

    Much efforts have been expended to observe the spectrum of electrons in the high energy region with large area emulsion chambers exposed at balloon altitudes, and now 15 electrons beyond 1 TeV have been observed. The observed integral flux at 1 TeV is (3.24 + or - 0.87)x10(-5)/sq m sec sr. The statistics of the data around a few hundred GeV are also improving by using new shower detecting films of high sensitivity. The astrophysical significance of the observed spectrum are discussed for the propagation of electrons based on the leaky box and the nested leaky box model.

  15. 750 GeV threshold to a new particle world

    NASA Astrophysics Data System (ADS)

    Jain, Samarth; Margaroli, Fabrizio; Moretti, Stefano; Panizzi, Luca

    2017-01-01

    We show how an excess in the diphoton channel can be the effect of neither a resonance nor an end point in a cascade decay, but rather of a threshold for virtual production of a pair of extra quarks, each with half of peak invariant mass, onsetting in both the g g -initiated production and the γ γ -induced decay of an off-shell Z boson. For our analysis we consider as a paradigmatic example the 750 GeV excess previously seen at the end of 2015 with the run 2 data of the LHC but not confirmed with 2016 data.

  16. Total width of 125 GeV Higgs boson.

    PubMed

    Barger, Vernon; Ishida, Muneyuki; Keung, Wai-Yee

    2012-06-29

    By using the LHC and Tevatron measurements of the cross sections to various decay channels relative to the standard model Higgs boson, the total width of the putative 125 GeV Higgs boson is determined as 6.1(-2.9)(+7.7) MeV. We describe a way to estimate the branching fraction for the Higgs-boson decay to dark matter. We also discuss a no-go theorem for the γγ signal of the Higgs boson at the LHC.

  17. Fluence-to-absorbed-dose conversion coefficients for neutron beams from 0.001 eV to 100 GeV calculated for a set of pregnant female and fetus models

    NASA Astrophysics Data System (ADS)

    Taranenko, Valery; Xu, X. George

    2008-03-01

    Protection of fetuses against external neutron exposure is an important task. This paper reports a set of absorbed dose conversion coefficients for fetal and maternal organs for external neutron beams using the RPI-P pregnant female models and the MCNPX code. The newly developed pregnant female models represent an adult female with a fetus including its brain and skeleton at the end of each trimester. The organ masses were adjusted to match the reference values within 1%. For the 3 mm cubic voxel size, the models consist of 10-15 million voxels for 35 organs. External monoenergetic neutron beams of six standard configurations (AP, PA, LLAT, RLAT, ROT and ISO) and source energies 0.001 eV-100 GeV were considered. The results are compared with previous data that are based on simplified anatomical models. The differences in dose depend on source geometry, energy and gestation periods: from 20% up to 140% for the whole fetus, and up to 100% for the fetal brain. Anatomical differences are primarily responsible for the discrepancies in the organ doses. For the first time, the dependence of mother organ doses upon anatomical changes during pregnancy was studied. A maximum of 220% increase in dose was observed for the placenta in the nine months model compared to three months, whereas dose to the pancreas, small and large intestines decreases by 60% for the AP source for the same models. Tabulated dose conversion coefficients for the fetus and 27 maternal organs are provided.

  18. Fluence-to-absorbed dose conversion coefficients for use in radiological protection of embryo and foetus against external exposure to electrons from 10 MeV TO 10 GeV.

    PubMed

    Chen, Jing

    2008-04-01

    Electrons as primary and more often as secondary radiation exist commonly in the environment and workplaces. No conversion coefficients are yet available, in the literature, for use in radiological protection of embryo and foetus against external exposure to electrons. This study uses mathematical models developed by the Radiation Protection Bureau, Health Canada, for the embryo of 8 wk and for the foetus of 3, 6, and 9 mo. Monte Carlo code MCNPX is used to determine mean absorbed doses to the embryo and foetus when the mother is exposed to external electron fields. Monoenergetic electrons ranging from 10 MeV to 10 GeV were considered. The irradiation geometries include antero-posterior (AP), postero-anterior (PA), lateral (LAT), rotational (ROT), isotropic (ISO), and top-down (TOP). At each of these irradiation geometries, absorbed doses to the foetal brain and body were calculated for the embryo of 8 wk and the foetus of 3, 6, and 9 mo. Electron fluence-to-absorbed dose conversion coefficients were derived for the four prenatal ages.

  19. Ion-Ion Neutralization.

    DTIC Science & Technology

    1980-12-31

    ion flow tube (SIFT) experiments have been given in previous publications and so only the essential features and tho.;e detail:. specific to the present...rapidly, essentially at the gas kinetic limiting rate within the accuracy of the experimental data (1 30% on the measured rate coefficients). The...the various negative ions remained essentially invariant along the length of the plasma column. The data in Table C show that ". for all of the

  20. J /ψ production at low pT in Au + Au and Cu + Cu collisions at √sNN =200 GeV with the STAR detector

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Powell, C. B.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-08-01

    The J /ψ pT spectrum and nuclear modification factor (RAA) are reported for pT<5GeV /c and |y|<1 from 0% to 60% central Au +Au and Cu +Cu collisions at √sNN =200GeV at STAR. A significant suppression of pT-integrated J /ψ production is observed in central Au +Au events. The Cu +Cu data are consistent with no suppression, although the precision is limited by the available statistics. RAA in Au +Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with pT. The data are compared to high-pT STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low pT are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration.

  1. Measurement of the midrapidity transverse energy distribution from square root of [(s)NN] = 130 GeV Au + Au collisions at RHIC.

    PubMed

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; El Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, D; Kochetkov, V; Koehler, D; Kohama, T; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Palounek, A P; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S

    2001-07-30

    The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such that / remains relatively constant as a function of centrality. The energy density calculated via Bjorken's prescription for the 2% most central Au+Au collisions at square root[s(NN)] = 130 GeV is at least epsilon(Bj) = 4.6 GeV/fm(3), which is a factor of 1.6 larger than found at sqrt[s(NN)] = 17.2 GeV ( Pb+Pb at CERN).

  2. An observation of cosmic ray positrons from 10-20 GeV

    NASA Technical Reports Server (NTRS)

    Mueller, D.; Tang, J.

    1985-01-01

    A balloon flight of the University of Chicago electron telescope was performed. Making use of the east-west asymmetry in the geomagnetic cut off rigidity, the cosmic ray positrons and negatrons were separated over the range 10 GeV to 20 GeV. The positron to electron ratio, e+/(e++e-), was measured to be 17% + or - 5%, significantly higher than the ratio measured in the 1 GeV to 10 GeV range by other experiments. This increase appears to suggest that either a primary component of positrons become significant above 10 GeV, or that the spectrum of primary negatrons decreases above 10 GeV more sharply than that of secondary positrons.

  3. Measurements of e p →e'π+π-p' cross sections with CLAS at 1.40 GeV GeV and 2.0 GeV2GeV2

    NASA Astrophysics Data System (ADS)

    Isupov, E. L.; Burkert, V. D.; Carman, D. S.; Gothe, R. W.; Hicks, K.; Ishkhanov, B. S.; Mokeev, V. I.; Adhikari, K. P.; Adhikari, S.; Adikaram, D.; Akbar, Z.; Amaryan, M. J.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Cao, T.; Celentano, A.; Charles, G.; Chetry, T.; Ciullo, G.; Clark, L.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fersch, R.; Filippi, A.; Fleming, J. A.; Forest, T. A.; Garçon, M.; Gavalian, G.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Gleason, C.; Golovatch, E.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Heddle, D.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Jenkins, D.; Jiang, H.; Joo, K.; Joosten, S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Kunkel, M.; Lanza, L.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; McKinnon, B.; Mineeva, T.; Mirazita, M.; Montgomery, R. A.; Movsisyan, A.; Munevar, E.; Munoz Camacho, C.; Murdoch, G.; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Paolone, M.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Phelps, W.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ripani, M.; Riser, D.; Ritchie, B. G.; Rizzo, A.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Sharabian, Y. G.; Simonyan, A.; Skorodumina, Iu.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stankovic, I.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tian, Ye; Torayev, B.; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Wei, X.; Wood, M. H.; Zachariou, N.; Zhang, J.; CLAS Collaboration

    2017-08-01

    This paper reports new exclusive cross sections for e p →e'π+π-p' using the CLAS detector at Jefferson Laboratory. These results are presented for the first time at photon virtualities 2.0 GeV2GeV2 in the center-of-mass energy range 1.4 GeV GeV, which covers a large part of the nucleon resonance region. Using a model developed for the phenomenological analysis of electroproduction data, we see strong indications that the relative contributions from the resonant cross sections at W <1.74 GeV increase with Q2. These data considerably extend the kinematic reach of previous measurements. Exclusive e p →e'π+π-p' cross section measurements are of particular importance for the extraction of resonance electrocouplings in the mass range above 1.6 GeV.

  4. Ion acceleration with radiation pressure in quantum electrodynamic regimes

    NASA Astrophysics Data System (ADS)

    Del Sorbo, Dario; Blackman, David R.; Capdessus, Remi; Small, Kristina; Slade-Lowther, Cody; Luo, Wen; Duff, Matthew J.; Robinson, Alexander P. L.; McKenna, Paul; Sheng, Zheng-Ming; Pasley, John; Ridgers, Christopher P.

    2017-05-01

    The radiation pressure of next generation high-intensity lasers could efficiently accelerate ions to GeV energies. However, nonlinear quantum-electrodynamic effects play an important role in the interaction of these lasers with matter. We show that these quantum-electrodynamic effects lead to the production of a critical density pair-plasma which completely absorbs the laser pulse and consequently reduces the accelerated ion energy and efficiency by 30-50%.

  5. STANDARDIZATION OF CEBAF 12 GEV UPGRADE CAVITY TESTING

    SciTech Connect

    Tiffany Bass, G. Davis, Christiana Wilson, Mircea Stirbet

    2012-07-01

    CEBAF 12GeV upgrade project includes 80 new 7-cell cavities to form 10 cryomodules. Each cavity underwent RF qualification at 2.07K using a high power accelerating gradient test and an HOM survey in Jefferson Lab's Vertical Testing Area (VTA) before cavity string assembly. In order to ensure consistently high quality data, updated cavity testing procedures and analysis were implemented and used by a group of VTA operators. For high power tests, a cavity testing procedure was developed and used in conjunction with a LabVIEW program to collect the test data. Additionally while the cavity was at 2.07K, an HOM survey was performed using a network analyzer and a combination of Excel and Mathematica programs. Data analysis was standardized and an online logbook, Pansophy, was used for data storage and mining. The Pansophy system allowed test results to be easily summarized and searchable across all cavity tests. In this presentation, the CEBAF 12GeV upgrade cavity testing procedure, method for data analysis, and results reporting results will be discussed.

  6. Upgrading the CEBAF Accelerator to 12 GeV

    SciTech Connect

    Leigh Harwood

    2006-07-01

    Jefferson Lab is preparing to upgrade its 6 GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12 GeV. The doubled energy will significantly extend research reach of the three existing experimental Halls A, B and C, and the upgrade will add scientific capability, with a newly constructed hall, Hall D. Areas of special initial interest are reactions at high xBjorken, GPD's and exotic hybrid mesons. The present linacs will have their acceleration roughly doubled through the addition of 10 new cryomodules which will perform at {approx}5 times the original specification for CEBAF. The cryogenics plant will be roughly doubled and new rf systems will be installed for the new cryomodules. The beam transport system will strongly leverage existing hardware but must be enhanced with new power supplies, one new recirculation arc, and a beamline to the new Hall D. A brief description of the scope for the various accelerator subsystems will be given as well as the status of the project as a whole.

  7. Galactic Diffuse Gamma Ray Emission Is Greater than 10 Gev

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.; White, Nicholas E. (Technical Monitor)

    2000-01-01

    AGILE and Gamma-ray Large Area Telescope (GLAST) are the next high-energy gamma-ray telescopes to be flown in space. These instruments will have angular resolution about 5 times better than Energetic Gamma-Ray Experiment Telescope (EGRET) above 10 GeV and much larger field of view. The on-axis effective area of AGILE will be about half that of EGRET, whereas GLAST will have about 6 times greater effective area than EGRET. The capabilities of ground based very high-energy telescopes are also improving, e.g. Whipple, and new telescopes, e.g. Solar Tower Atmospheric Cerenkov Effect Experiment (STACEE), Cerenkov Low Energy Sampling and Timing Experiment (CELESTE), and Mars Advanced Greenhouse Integrated Complex (MAGIC) are expected to have low-energy thresholds and sensitivities that will overlap the GLAST sensitivity above approximately 10 GeV. In anticipation of the results from these new telescopes, our current understanding of the galactic diffuse gamma-ray emission, including the matter and cosmic ray distributions is reviewed. The outstanding questions are discussed and the potential of future observations with these new instruments to resolve these questions is examined.

  8. 12 GeV Upgrade Project - Cryomodule Production

    SciTech Connect

    J. Hogan, A. Burrill, G.K. Davis, M.A. Drury, M. Wiseman

    2012-07-01

    The Thomas Jefferson National Accelerator Facility (Jefferson Lab) is producing ten 100+MV SRF cryomodules (C100) as part of the CEBAF 12 GeV Upgrade Project. Once installed, these cryomodules will become part of an integrated accelerator system upgrade that will result in doubling the energy of the CEBAF machine from 6 to 12 GeV. This paper will present a complete overview of the C100 cryomodule production process. The C100 cryomodule was designed to have the major components procured from private industry and assembled together at Jefferson Lab. In addition to measuring the integrated component performance, the performance of the individual components is verified prior to being released for production and assembly into a cryomodule. Following a comprehensive cold acceptance test of all subsystems, the completed C100 cryomodules are installed and commissioned in the CEBAF machine in preparation of accelerator operations. This overview of the cryomodule production process will include all principal performance measurements, acceptance criterion and up to date status of current activities.

  9. Study of rare processes induced by 209-Gev muons

    SciTech Connect

    Smith, W.H.

    1981-05-01

    Analysis of dimuon final states from 1.4 x 10/sup 11/ positive and 2.9 x 10/sup 10/ negative 209-Gev muons in a magnetized iron calorimeter has set a lower limit of 9 Gev/c/sup 2/ on the mass of a heavy neutral muon (M/sup 0/), and a 90%-confidence level upper limit of sigma(..mu..N..-->..b anti bX)B(b anti b..--> mu..X)<2.9 x 10/sup -36/ cm/sup 2/ for the production of bottom hadrons by muons. The dimuon mass spectrum from 102,678 trimuon final states places a 90%-confidence level upper limit for the muoproduction of upsilon states: sigma(..mu..N..--> mu.. UPSILON X)B(UPSILON..--> mu../sup +/..mu../sup -/)<22 x 10/sup -39/ cm/sup 2/. In addition, analysis of 71 rare multimuon events, including 4- and 5-muon final states, is presented.

  10. SPECTRAL ANALYSIS OF FERMI -LAT BLAZARS ABOVE 50 GEV

    DOE PAGES

    Domínguez, Alberto; Ajello, Marco

    2015-11-04

    We present an analysis of the intrinsic (unattenuated by the extragalactic background light, EBL) power-law spectral indices of 128 extragalactic sources detected up to z ~ 2 with the Fermi-Large Area Telescope (LAT) at very high energies (VHEs, E ≥50 GeV). The median of the intrinsic index distribution is 2.20 (versus 2.54 for the observed distribution). We also analyze the observed spectral breaks (i.e., the difference between the VHE and high energy, HE, 100 MeV ≤ E ≤ 300 GeV, spectral indices). The Fermi-LAT has now provided a large sample of sources detected both at VHE and HE with comparablemore » exposure that allows us to test models of extragalactic γ-ray photon propagation. We find that our data are compatible with simulations that include intrinsic blazar curvature and EBL attenuation. There is also no evidence of evolution with redshift of the physics that drives the photon emission in high-frequency synchrotron peak (HSP) blazars. This makes HSP blazars excellent probes of the EBL.« less

  11. 750 GeV diphotons from supersymmetry with Dirac gauginos

    NASA Astrophysics Data System (ADS)

    Cohen, Timothy; Kribs, Graham D.; Nelson, Ann E.; Ostdiek, Bryan

    2016-07-01

    Motivated by the recent excess in the diphoton invariant mass near 750 GeV, we explore a supersymmetric extension of the Standard Model that includes the minimal set of superpartners as well as additional Dirac partner chiral superfields in the adjoint representation for each gauge group. The bino partner pseudoscalar is identified as the 750 GeV resonance, while superpotential interactions between it and the gluino (wino) partners yield production via gluon fusion (decay to photon pairs) at one-loop. The gauginos and these additional adjoint superpartners are married by a Dirac mass and must also have Majorana masses. While a large wino partner Majorana mass is necessary to explain the excess, the gluino can be approximately Dirac-like, providing benefits consistent with being both "supersoft" (loop corrections to the scalar masses from Dirac gauginos are free of logarithmic enhancements) and "supersafe" (the experimental limits on the squark/gluino masses can be relaxed due to the reduced production rate). Consistency with the measured Standard Model-like Higgs boson mass is imposed, and a numerical exploration of the parameter space is provided. Models that can account for the diphoton excess are additionally characterized by having couplings that can remain perturbative up to very high scales, while remaining consistent with experimental constraints, the Higgs boson mass, and an electroweak scale which is not excessively fine-tuned.

  12. 125 GeV Technidilaton at the LHC

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Shinya

    The technidilaton (TD) is a composite scalar predicted in walking technicolor (WTC), arising as a pseudo Nambu-Goldstone boson associated with the spontaneous breaking of the approximate scale invariance. Due to the Nambu-Goldstone boson's nature, the TD can be as light as the LHC boson that has been discovered at around 125 GeV. We discuss the size of the TD mass and the coupling properties relevant to the LHC study. It turns out that the TD couplings to the standard model (SM) particles take the same form as those of the SM Higgs boson, except the essentially distinguishable two ingredients: i) the overall coupling strengths set by the decay constant related to the spontaneous breaking of the scale invariance, which is in general not equal to the electroweak scale; ii) the couplings to photons and gluons which can include extra contributions from technifermion loops and hence can be enhanced compared to the SM Higgs case. To be concrete, we take the one-family technicolor model to explore the TD LHC phenomenology at 125 GeV. It is shown that the TD gives the signal consistent with the currently reported LHC data, notably can explain the excess in the diphoton channel, due to the extra contributions to digluon and diphoton couplings coming from the one-family technifermion loops.

  13. PROTON-4He Elastic Scattering at ~ 1 GeV

    NASA Astrophysics Data System (ADS)

    Khan, Z. A.; Singh, Minita

    Based on the (spin-independent) Sugar-Blanckenbecler eikonal expansion for the T-matrix, we parametrize the (spin-dependent) NN amplitude (SNN) which successfully describes the pp and pn elastic scattering observables at ~ 1 GeV up to the available momentum transfers. Using SNN, we calculate the differential cross-section, polarization, and spin-rotation function of ~ 1 GeV protons on 4He within the framework of the Glauber model. The analysis also includes the phase variation in the NN amplitude. It is found that the use of SNN, in comparision with the usually parametrized one-term amplitude, improves the agreement with the experimental data. The introduction of a global phase variation provides only a slight improvement over the results with a constant phase. However, if we allow different phases in the central- and spin-dependent parts of the NN amplitude, the agreement with the polarization data improves further without affecting the differential cross-section results.

  14. Detector development for Jefferson Lab's 12GeV Upgrade

    SciTech Connect

    Qiang, Yi

    2015-05-01

    Jefferson Lab will soon finish its highly anticipated 12 GeV Upgrade. With doubled maximum energy, Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) will enable a new experimental program with substantial discovery potential, addressing important topics in nuclear, hadronic and electroweak physics. In order to take full advantage of the high energy, high luminosity beam, new detectors are being developed, designed and constructed to fit the needs of different physics topics. The paper will give an overview of various new detector technologies to be used for 12 GeV experiments. It will then focus on the development of two solenoid-based spectrometers, the GlueX and SoLID spectrometers. The GlueX experiment in Hall D will study the complex properties of gluons through exotic hybrid meson spectroscopy. The GlueX spectrometer, a hermetic detector package designed for spectroscopy and the associated partial wave analysis, is currently in the final stage of construction. Hall A, on the other hand, is developing the SoLID spectrometer to capture the 3D image of the nucleon from semi-inclusive processes and to study the intrinsic properties of quarks through mirror symmetry breaking. Such a spectrometer will have the capability to handle very high event rates while still maintaining a large acceptance in the forward region.

  15. Detector development for Jefferson Lab's 12GeV Upgrade

    DOE PAGES

    Qiang, Yi

    2015-05-01

    Jefferson Lab will soon finish its highly anticipated 12 GeV Upgrade. With doubled maximum energy, Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) will enable a new experimental program with substantial discovery potential, addressing important topics in nuclear, hadronic and electroweak physics. In order to take full advantage of the high energy, high luminosity beam, new detectors are being developed, designed and constructed to fit the needs of different physics topics. The paper will give an overview of various new detector technologies to be used for 12 GeV experiments. It will then focus on the development of two solenoid-based spectrometers,more » the GlueX and SoLID spectrometers. The GlueX experiment in Hall D will study the complex properties of gluons through exotic hybrid meson spectroscopy. The GlueX spectrometer, a hermetic detector package designed for spectroscopy and the associated partial wave analysis, is currently in the final stage of construction. Hall A, on the other hand, is developing the SoLID spectrometer to capture the 3D image of the nucleon from semi-inclusive processes and to study the intrinsic properties of quarks through mirror symmetry breaking. Such a spectrometer will have the capability to handle very high event rates while still maintaining a large acceptance in the forward region.« less

  16. Commissioning of the 123 MeV injector for 12 GeV CEBAF

    SciTech Connect

    Wang, Yan; Hofler, Alicia S.; Kazimi, Reza

    2015-09-01

    The upgrade of CEBAF to 12GeV included modifications to the injector portion of the accelerator. These changes included the doubling of the injection energy and relocation of the final transport elements to accommodate changes in the CEBAF recirculation arcs. This paper will describe the design changes and the modelling of the new 12GeV CEBAF injector. Stray magnetic fields have been a known issue for the 6 GeV CEBAF injector, the results of modelling the new 12GeV injector and the resulting changes implemented to mitigate this issue are described in this paper. The results of beam commissioning of the injector are also presented.

  17. Galactic antiprotons of 0.2-2 GeV energy

    NASA Technical Reports Server (NTRS)

    Bogomolov, E. A.; Vasilyev, G. I.; Iodko, M. G.; Krutkov, S. Y.; Lubyanaya, N. D.; Romanov, V. A.; Stepanov, S. V.; Shulakova, M. S.

    1985-01-01

    Balloon measurements of the galactic antiproton flux in the energy range 0.2 GeV to 2 GeV are presented. The experiments were carried out in the summer of 1984 with magnet spectrometers flown at a residual pressure of approximately 10 g sq cm and cut off rigidity of approximately 0.6 GV. An upper limit for the antiproton to proton flux ratio has been obtained of antiproton/proton (0.2 GeV to 2 GeV) less than 5 x .0001.

  18. Effects on axial momentum spread on the electron-ion two-stream instability in high-intensity ion beams

    SciTech Connect

    R. Davidso; H. Qin

    2000-06-15

    Use is made of the Vlasov-Maxwell equations to describe the electron-ion two-stream instability driven by the directed axial motion of a high-intensity ion beam propagating through a stationary population of (unwanted) background electrons. The ion beam is treated as continuous in the z-direction, and the electrons are electrostatically confined in the transverse direction by the space-charge potential produced by the excession charge. The analysis is carried out for arbitrary beam intensity, consistent with transverse confinement of the beam particles, and arbitrary fractional charge neutralization by the background electrons. For the case of overlapping step-function ion and electron density profiles, corresponding to monoenergetic electrons and ions in the transverse direction, detailed stability properties are calculated, including the important effects of an axial momentum spread, over a wide range of system parameters for dipole perturbations with azimuthal mode number l=1. The two-stream instability growth rate is found to increase with increasing beam intensity, increasing fractional charge neutralization, and decreasing proximity of the conducting wall. It is shown that Landau damping associated with a modest axial momentum spread of the beam ions and background electrons has a strong stabilizing influence on the instability.

  19. Baryon stopping in heavy-ion collisions at Elab = 2A-200A GeV

    NASA Astrophysics Data System (ADS)

    Ivanov, Yu. B.; Blaschke, D.

    2016-08-01

    It is argued that an irregularity in the baryon stopping is a natural consequence of the onset of deconfinement occurring in the compression stage of a nuclear collision. It is an effect of the softest point inherent in an equation of state (EoS) with a deconfinement transition. In order to illustrate this effect, calculations within the three-fluid model were performed with three different EoSs: a purely hadronic EoS, an EoS with a first-order phase transition and a third one with a smooth crossover transition. It is demonstrated that this irregularity is a very robust signal of the first-order phase transition that survives under acceptance conditions of the NICA MPD experiment.

  20. Reconstruction of K*+/-(892) in Au +Au Collisions at √sNN = 200 GeV

    NASA Astrophysics Data System (ADS)

    Zheng, He; STAR Collaboration

    2016-09-01

    The Relativistic Heavy Ion Collider (RHIC) produces a hot, dense and deconfined Quantum ChromoDynamics (QCD) medium, called the quark-gluon plasma (QGP), with Au +Au collisions at √sNN = 200 GeV. The K*+/-(892) resonance is a short-lived particle with a lifetime shorter than the expected lifetime of the QGP. The K* production may provide an effective tool to probe the QGP properties, such as strangeness enhancement. Experimentally, K*+/- analysis is difficult and less studied previously because of large combinatorial background. In recent years, improvements in data sample statistics and particle identification capability promise better K*+/- measurements. In this presentation, we report the reconstruction of K*+/- resonance via the hadronic decay channel K*+/- (892) ->KS0π+/- as a function of transverse momentum (pT) up to 5 GeV/c for various collision centrality classes. The data are Au +Au collisions at √sNN = 200 GeV collected in the year 2011 run from the STAR experiment. Physics implications of our measurements will also be discussed. For the STAR collaboration.

  1. Hypernuclear production cross section in the reaction of 6Li + 12C at 2 A GeV

    NASA Astrophysics Data System (ADS)

    Rappold, C.; Saito, T. R.; Bertini, O.; Bianchin, S.; Bozkurt, V.; Kim, E.; Kavatsyuk, M.; Ma, Y.; Maas, F.; Minami, S.; Nakajima, D.; Özel-Tashenov, B.; Yoshida, K.; Achenbach, P.; Ajimura, S.; Aumann, T.; Ayerbe Gayoso, C.; Bhang, H. C.; Caesar, C.; Erturk, S.; Fukuda, T.; Göküzüm, B.; Guliev, E.; Hoffmann, J.; Ickert, G.; Ketenci, Z. S.; Khaneft, D.; Kim, M.; Kim, S.; Koch, K.; Kurz, N.; Le Fèvre, A.; Mizoi, Y.; Nungesser, L.; Ott, W.; Pochodzalla, J.; Sakaguchi, A.; Schmidt, C. J.; Sekimoto, M.; Simon, H.; Takahashi, T.; Tambave, G. J.; Tamura, H.; Trautmann, W.; Voltz, S.; Yoon, C. J.

    2015-07-01

    Hypernuclear production cross sections have been deduced for the first time with induced reaction of heavy ion beam on fixed target and by means of the invariant mass method by the HypHI Collaboration exploiting the reaction of 6Li + 12C at 2 A GeV or √{sNN} = 2.70 GeV. A production cross section of 3.9 ± 1.4 μb for 3ΛH and of 3.1 ± 1.0 μb for 4ΛH respectively in the projectile rapidity region was inferred as well as the total production cross section of the Λ hyperon was measured and found to be equal to 1.7 ± 0.8 mb. A global fit based on a Bayesian approach was performed in order to include and propagate statistical and systematic uncertainties. Production ratios of 3ΛH/4ΛH, 3ΛH/Λ and 4ΛH/Λ were included in the inference procedure. The strangeness population factors S3 and S4 of 3ΛH and 4ΛH respectively were extracted. In addition, the multiplicities of the Λ hyperon, 3ΛH, and 4ΛH together with the rapidity and transversal momentum density distributions of the observed hypernuclei were extracted and reported.

  2. Simulation of 1 GeV laser wakefield accelerator experiments and scaling to 10 GeV

    NASA Astrophysics Data System (ADS)

    Cormier-Michel, Estelle; Geddes, C. G. R.; Isaacs, W. A.; Stinus, N.; Esarey, E.; Schroeder, C. B.; Leemans, W. P.; Bruhwiler, D. L.; Cary, J. R.

    2007-11-01

    Recent laser-plasma accelerator experiments at LBNL have demonstrated the production of high quality 0.5 and 1.0 GeV electron beams.ootnotetextW.P. Leemans et al., Nature Physics 2, 696 (2006) In these experiments, the 10-40 TW laser pulse was guided in a 3 cm long capillary discharge plasma channel. Particle-In-Cell (PIC) simulations provide information not accessible from experiments on the nonlinear laser-plasma interaction that governs the accelerator internal dynamics. Simulations show that high quality electron bunches are formed by self-trapping of electrons in the wake, followed by loading of the wake by the trapped bunch, creating a bunch of electrons isolated in phase space. A narrow energy spread beam is then obtained by extracting the bunch as it outran the accelerating phase of the wake. Simulations in 2D and 3D showing details on the electron bunch, wakefield, and laser evolution are presented and compared to experimental results. Simulations on scaling these experiments to the 10 GeV level are also presented.

  3. Hadron Correlations at Energies from GeV to TeV

    NASA Astrophysics Data System (ADS)

    Kittel, W.

    One of the central issues in High Energy Physics is the close interchange between Theory and Experiment. Ever since I know Andrzej Bia{\\l}as, I know him as one of the theorists most interested in experimental data. This has naturally led to continuous fruitful contacts. Even though we have been working somehow together since about 1968, we so far have only one single publication in common. This was back in 1969 and it was on means to efficiently study what we then called (exclusive) Multihadron Final States. At that time this meant 3- or at best 4-particle final states of two-hadron collisions at cms energies of some 4 GeV (not TeV!). The field of multiparticle dynamics was in fact the domain of Polish high-energy physicists. The first of a very successful (and still lasting) series of annual International Symposia on Multiparticle Dynamics was organized in Paris in 1970, but essentially by Polish physicists. Andrzej himself was not attending, but it was he who organized the third in these series in (of course) Zakopane. Since heavy ion-collisions, another field of major interest for Andrzej, will be covered by others, I here will restrict myself mainly to the collisions of two elementary particles.

  4. Pion and kaon structure functions at 12 GeV JLab and EIC

    NASA Astrophysics Data System (ADS)

    Horn, Tanja

    2017-01-01

    Pions and kaons are, along with protons and neutrons, the main building blocks of nuclear matter. They are connected to the Goldstone modes of dynamical chiral symmetry breaking, the mechanism thought to generate all hadron mass in the visible universe. The distribution of the fundamental constituents, the quarks and gluons, is expected to be different in pions, kaons, and nucleons. However, experimental data are sparse. As a result, there has been persistent doubt about the behavior of the pion's valence quark structure function at large Bjorken-x and virtually nothing is known about the contribution of gluons. A 12 GeV JLab experiment using tagged DIS may contribute to the resolution of the former. The Electron-Ion Collider with an acceptance optimized for forward physics could provide access to structure functions over a larger kinematic region. This would allow for measurements testing if the origin of mass is encoded in the differences of gluons in pions, kaons, and nucleons, and measurements testing assumptions used in the extraction of structure functions and the pion and kaon form factors. Electroweak measurements at an EIC would also potentially allow to disentangle the role of quark flavors at high x. In this talk we will discuss the prospects of such measurements. Supported in part by NSF grants PHY-1306227 and PHY-1306418.

  5. Measurement of the inclusive charm cross section at 4.03 GeV and 4.14 GeV in e(+)e(-) annihilations

    NASA Astrophysics Data System (ADS)

    Blum, Ira Kenneth

    1999-12-01

    The charm hadronic cross section at s = 4.03 GeV and s = 4.14 GeV has been measured with the Beijing Spectrometer. The measurement was made using 22.3 pb-1 of e+e- data collected at 4.03 GeV and 1.9 pb-1 of e+e- data collected at 4.14 GeV. Inclusive observed cross sections for the production of D0 and D+ and differential momentum spectra for D0 and D + are presented at both energies. Observed cross sections were radiatively corrected to obtain tree level cross sections and RD. Measurements of R were obtained from RD and an extrapolation of R from below the charm threshold.

  6. The temperature and ion energy dependence of deuterium retention in lithium films

    NASA Astrophysics Data System (ADS)

    Buzi, Luxherta; Koel, Bruce E.; Skinner, Charles H.

    2016-10-01

    Lithium conditioning of plasma facing components in magnetic fusion devices has improved plasma performance and lowered hydrogen recycling. For applications of lithium in future high heat flux and long pulse duration machines it is important to understand and parameterize deuterium retention in lithium. This work presents surface science studies of deuterium retention in lithium films as a function of surface temperature, incident deuterium ion energy and flux. Initial experiments are performed on thin (3-30 ML) lithium films deposited on a single crystal molybdenum substrate to avoid effects due to grain boundaries, intrinsic defects and impurities. A monoenergetic and mass-filtered deuterium ion beam was generated in a differentially pumped Colutron ion gun. Auger electron spectroscopy and X-ray photoelectron spectroscopy were used to identify the elemental composition and temperature programmed desorption was used to measure the deuterium retention under the different conditions. Support was provided through DOE Contract Number DE-AC02-09CH11466.

  7. Radiation-Pressure Acceleration of Ion Beams from Nanofoil Targets: The Leaky Light-Sail Regime

    SciTech Connect

    Qiao, B.; Zepf, M.; Borghesi, M.; Dromey, B.; Geissler, M.; Karmakar, A.; Gibbon, P.

    2010-10-08

    A new ion radiation-pressure acceleration regime, the 'leaky light sail', is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10{sup 19} W/cm{sup 2}. 100 MeV proton beams are obtained by increasing the intensities to 2x10{sup 20} W/cm{sup 2}.

  8. Radiation-pressure acceleration of ion beams from nanofoil targets: the leaky light-sail regime.

    PubMed

    Qiao, B; Zepf, M; Borghesi, M; Dromey, B; Geissler, M; Karmakar, A; Gibbon, P

    2010-10-08

    A new ion radiation-pressure acceleration regime, the "leaky light sail," is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10¹⁹  W/cm². 100 MeV proton beams are obtained by increasing the intensities to 2 × 10²⁰  W/cm².

  9. Azimuthal anisotropy of the identified charged hadrons in Au+Au collisions at √SNN = 39 - 200 GeV at RHIC

    NASA Astrophysics Data System (ADS)

    Vdovkina, S. S.

    2017-01-01

    A new form of nuclear matter, where quarks and gluons are deconfined and interact strongly with each other, is produced in heavy ion collisions at the relativistic heavy ion collider (RHIC). Azimuthal anisotropies of particle distributions relative to the symmetry plane in high energy heavy ion collisions are used to characterize the collision dynamics. The results of measurements of the azimuthal anisotropy parameters vn (n=2,3) of identified charged hadrons (pions, kaons and protons) in Au+Au collisions at √SNN = 39, 62.4 and 200 GeV are presented and discussed. The energy dependence of the difference between the flow of the particles and their anti-particles are discussed as well.

  10. Yields of nuclear fragments in the interactions of carbon nuclei with a beryllium target at a projectile energy of 0.6 GeV per nucleon

    SciTech Connect

    Abramov, B. M.; Alexeev, P. N.; Borodin, Yu. A.; Bulychjov, S. A.; Gudima, K. K.; Dukhovskoy, I. A.; Krutenkova, A. P. Kulikov, V. V.; Martemianov, M. A.; Matsyuk, M. A.; Mashnik, S. G.; Turdakina, E. N.; Khanov, A. I.

    2016-09-15

    The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T{sub 0} = 0.6 GeV per nucleon on a berylliumtarget were measured in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD.

  11. The chemical composition of cosmic ray nuclei above 1.3 GeV per nucleus and 23 GeV per nucleus

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; Osborn, R. W.

    1974-01-01

    Measurements made with a balloon-borne counter telescope are reported. The telescope was flown from Palestine, Tex., during the fall of 1971 for a total of 10 hours under an average residual atmospheric depth of 4.4 g per sq cm. The data analysis indicates that the integral flux ratios above 1.3 GeV per nucleus and 23 GeV per nucleus are consistent with energy independence.

  12. Value of a noise-optimized virtual monoenergetic reconstruction technique in dual-energy CT for planning of transcatheter aortic valve replacement.

    PubMed

    Martin, Simon S; Albrecht, Moritz H; Wichmann, Julian L; Hüsers, Kristina; Scholtz, Jan-Erik; Booz, Christian; Bodelle, Boris; Bauer, Ralf W; Metzger, Sarah C; Vogl, Thomas J; Lehnert, Thomas

    2017-02-01

    To evaluate objective and subjective image quality of a noise-optimized virtual monoenergetic imaging (VMI+) reconstruction technique in dual-energy computed tomography (DECT) angiography prior to transcatheter aortic valve replacement (TAVR). Datasets of 47 patients (35 men; 64.1 ± 10.9 years) who underwent DECT angiography of heart and vascular access prior to TAVR were reconstructed with standard linear blending (F_0.5), VMI+, and traditional monoenergetic (VMI) algorithms in 10-keV intervals from 40-100 keV. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of 564 arterial segments were evaluated. Subjective analysis was rated by three blinded observers using a Likert scale. Mean SNR and CNR were highest in 40 keV VMI+ series (SNR, 27.8 ± 13.0; CNR, 26.3 ± 12.7), significantly (all p < 0.001) superior to all VMI series, which showed highest values at 70 keV (SNR, 18.5 ± 7.6; CNR, 16.0 ± 7.4), as well as linearly-blended F_0.5 series (SNR, 16.8 ± 7.3; CNR, 13.6 ± 6.9). Highest subjective image quality scores were observed for 40, 50, and 60 keV VMI+ reconstructions (all p > 0.05), significantly superior to all VMI and standard linearly-blended images (all p < 0.01). Low-keV VMI+ reconstructions significantly increase CNR and SNR compared to VMI and standard linear-blending image reconstruction and improve subjective image quality in preprocedural DECT angiography in the context of TAVR planning. • VMI+ combines increased contrast with reduced image noise. • VMI+ shows substantially less image noise than traditional VMI. • 40-keV reconstructions show highest SNR/CNR of the aortic and iliofemoral access route. • Observers overall prefer 60 keV VMI+ images. • VMI+ DECT imaging helps improve image quality for TAVR planning.

  13. Virtual Monoenergetic Imaging and Iodine Perfusion Maps Improve Diagnostic Accuracy of Dual-Energy Computed Tomography Pulmonary Angiography With Suboptimal Contrast Attenuation.

    PubMed

    Leithner, Doris; Wichmann, Julian L; Vogl, Thomas J; Trommer, Jesko; Martin, Simon S; Scholtz, Jan-Erik; Bodelle, Boris; De Cecco, Carlo N; Duguay, Taylor; Nance, John W; Schoepf, U Joseph; Albrecht, Moritz H

    2017-11-01

    The aim of this study was to investigate the impact of virtual monoenergetic imaging (VMI+) and dual-energy computed tomography perfusion maps (DECT-PMs) on reader confidence and diagnostic accuracy in dual-energy computed tomography pulmonary angiography (DE-CTPA) studies with suboptimal contrast attenuation, compared with standard linearly blended reconstruction series. Dual-energy computed tomography pulmonary angiography examinations with suboptimal contrast attenuation of 68 patients with suspected pulmonary embolism (PE) were included in this institutional review board-approved retrospective study. Virtual monoenergetic imaging series at 40 keV, DECT-PM, and linearly blended images (M_0.6, 60% 90-kV spectrum) were reconstructed. Contrast-to-noise ratio and signal-to-noise ratio within the pulmonary trunk were calculated. Four independent radiologists assessed the presence of PE and their diagnostic confidence using 3 DE-CTPA reconstruction protocols: protocol 1, M_0.6 images; protocol 2, M_0.6 series and DECT-PM; and protocol 3, M_0.6, DECT-PM, and VMI+ series. Receiver operating characteristic (ROC) analysis was performed. Fourteen patients showed central and 29 segmental PE. Greater contrast-to-noise ratio and signal-to-noise ratio values were measured in VMI+ series at 40 keV in comparison to M_0.6 images (P < 0.001). Diagnostic accuracy for segmental PE detection was as follows: protocol 1 (69.1%); protocol 2 (86.8%); and protocol 3 (92.6%). Protocol 3 resulted in a significantly greater area under the curve for diagnosing segmental PE (0.991, P ≤ 0.033), compared with protocol 1 and 2 (0.897 and 0.951, respectively), and provided the highest diagnostic confidence (P < 0.001). A reconstruction protocol including 40-keV VMI+ series and DECT-PM improves reader confidence and diagnostic accuracy for segmental PE detection compared with standard M_0.6 images in DE-CTPA with suboptimal contrast attenuation.

  14. Comprehensive Comparison of Virtual Monoenergetic and Linearly Blended Reconstruction Techniques in Third-Generation Dual-Source Dual-Energy Computed Tomography Angiography of the Thorax and Abdomen.

    PubMed

    Albrecht, Moritz H; Trommer, Jesko; Wichmann, Julian L; Scholtz, Jan-Erik; Martin, Simon S; Lehnert, Thomas; Vogl, Thomas J; Bodelle, Boris

    2016-09-01

    The aim of this study was to perform an objective and subjective image analysis of traditional and advanced noise-optimized virtual monoenergetic imaging (VMI) algorithms and standard linearly blended images in third-generation dual-source dual-energy computed tomography angiography (DE-CTA) of the thorax and abdomen. Thoracoabdominal DE-CTA examinations of 55 patients (36 male; mean age, 64.2 ± 12.7 years) were included in this retrospective institutional review board-approved study. Dual-energy computed tomography angiography data were reconstructed using standard linearly blended M_0.6 (merging 60% low kiloelectron volt [90 kV] with 40% high kiloelectron volt [150 kV] spectrum), traditional (VMI), and advanced VMI (VMI+) algorithms. Monoenergetic series were calculated ranging from 40 to 120 keV with 10 keV increments. Attenuation and standard deviation of 8 arteries and various anatomical landmarks of the thorax and abdomen were measured to calculate contrast-to-noise ratio values. Two radiologists subjectively assessed image quality, contrast conditions, noise, and visualization of small arterial branches using 5-point Likert scales. Vascular attenuation of VMI and VMI+ series showed a gradual increase from high to low kiloelectron volt levels without significant differences between both algorithms (P < 0.894). VMI+ 40-keV series showed the highest contrast-to-noise ratio for both thoracic and abdominal DE-CTA (P < 0.001), albeit revealing higher noise than M_0.6 images (objectively and subjectively, P < 0.001) and were rated best for visualization of small arterial branches in the subjective analysis (P < 0.109). Substantially increased noise was found for VMI 40 and 50 keV series compared with all other reconstructions (objectively and subjectively, P < 0.001). VMI+ images at 100 keV+ were rated best regarding image noise (P < 0.843), whereas VMI+ reconstructions at 70 keV were found to have superior subjective image quality (P < 0.031) compared with other

  15. Advanced image-based virtual monoenergetic dual-energy CT angiography of the abdomen: optimization of kiloelectron volt settings to improve image contrast.

    PubMed

    Albrecht, Moritz H; Scholtz, Jan-Erik; Hüsers, Kristina; Beeres, Martin; Bucher, Andreas M; Kaup, Moritz; Martin, Simon S; Fischer, Sebastian; Bodelle, Boris; Bauer, Ralf W; Lehnert, Thomas; Vogl, Thomas J; Wichmann, Julian L

    2016-06-01

    To compare quantitative image quality parameters in abdominal dual-energy computed tomography angiography (DE-CTA) using an advanced image-based (Mono+) reconstruction algorithm for virtual monoenergetic imaging and standard DE-CTA. Fifty-five patients (36 men; mean age, 64.2 ± 12.7 years) who underwent abdominal DE-CTA were retrospectively included. Mono + images were reconstructed at 40, 50, 60, 70, 80, 90 and 100 keV levels and as standard linearly blended M_0.6 images (60 % 100 kV, 40 % 140 kV). The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) of the common hepatic (CHA), splenic (SA), superior mesenteric (SMA) and left renal arteries (LRA) were objectively measured. Mono+ DE-CTA series showed a statistically superior CNR for 40, 50, 60, 70 and 80 keV (P < 0.031) compared to M_0.6 images for all investigated arteries except SMA at 80 keV (P = 0.08). CNR at 40 keV revealed a mean relative increase of 287.7 % compared to linearly blended images among all assessed arteries (P < 0.001). SNR of Mono+ images was consistently significantly higher at 40, 50, 60 and 70 keV compared to M_0.6 for CHA and SA (P < 0.009). Compared to linearly blended images, Mono+ reconstructions at low keV levels of abdominal DE-CTA datasets significantly improve quantitative image quality. • Mono+ combines increased attenuation with reduced image noise compared to standard DE-CTA. • Mono+ shows superior contrast-to-noise ratios at low keV compared to linearly-blended images. • Contrast-to-noise ratio in monoenergetic DE-CTA peaks at 40 keV. • Mono+ reconstructions significantly improve quantitative image quality at low keV levels.

  16. EXTERNAL INVERSE COMPTON SPECTRA FOR MONOENERGETIC AND BLACKBODY PHOTON FIELDS UPSCATTERED BY A POWER-LAW ELECTRON DISTRIBUTION WITH A FINITE ENERGY RANGE

    SciTech Connect

    Fouka, M.; Ouichaoui, S. E-mail: souichaoui@usthb.dz

    2011-08-20

    We have calculated the inverse Compton (IC) integrated spectral power within the Thomson limit for a monoenergetic isotropic photon field upscattered off highly relativistic electrons assuming an isotropic power-law distribution of the latter, N({gamma}) = C{gamma}{sup -p}, with Lorentz parameter values {gamma}{sub 1} < {gamma} < {gamma}{sub 2}. Our interest was essentially focused on the case of a finite energy range (finite {gamma}{sub 2}) possibly having realistic applications in high-energy astrophysical sites, mainly relativistic shock regions. To this end, we have defined and derived a dimensionless parametric function, F{sub p} (z{sub 1}, {eta}), with variables z{sub 1} = {epsilon}{sub 1}/4{gamma}{sup 2}{sub 1}{epsilon} and {eta} = {gamma}{sub 2}/{gamma}{sub 1}. This result was used to derive the IC-integrated spectral power for an upscattered blackbody (BB) photon field using a dimensionless parametric function, W{sub p} ({xi}, {eta}), with variable {xi} = {epsilon}{sub 1}/4{gamma}{sup 2}{sub 1} kT. Asymptotic forms of this function have been derived for three energy ranges, i.e., {xi} << 1, 1 << {xi} << {eta}{sup 2}, and {xi} >> {eta}{sup 2}. Then, a characteristic value, {eta}{sub c}(p, {epsilon}) with {epsilon} << 1, of parameter {eta} was defined such that the middle range asymptotic form of W{sub p} ({xi}, {eta}) could be valid and good when {eta} {approx}> {eta}{sub c}(p, {epsilon}), by deriving an approximate expression of this particular value for {epsilon} = 10{sup -3}. The resulting spectra featured by a high-energy cutoff in the case of low values of the ratio {eta} can be discussed at least for a population of short gamma-ray bursts (GRBs), those best described by the cutoff power-law model with a low-energy spectral index, {alpha} {approx} 0. Furthermore, it is suggested that for GRB spectra with {alpha} < -1/2 pertaining to the prompt emission phase, the IC is a likely emission mechanism for both monoenergetic and BB photon fields if one

  17. External Inverse Compton Spectra for Monoenergetic and Blackbody Photon Fields Upscattered by a Power-law Electron Distribution with a Finite Energy Range

    NASA Astrophysics Data System (ADS)

    Fouka, M.; Ouichaoui, S.

    2011-08-01

    We have calculated the inverse Compton (IC) integrated spectral power within the Thomson limit for a monoenergetic isotropic photon field upscattered off highly relativistic electrons assuming an isotropic power-law distribution of the latter, N(γ) = Cγ-p , with Lorentz parameter values γ1 < γ < γ2. Our interest was essentially focused on the case of a finite energy range (finite γ2) possibly having realistic applications in high-energy astrophysical sites, mainly relativistic shock regions. To this end, we have defined and derived a dimensionless parametric function, Fp (z 1, η), with variables z 1 = epsilon1/4γ2 1epsilon and η = γ2/γ1. This result was used to derive the IC-integrated spectral power for an upscattered blackbody (BB) photon field using a dimensionless parametric function, Wp (ξ, η), with variable ξ = epsilon1/4γ2 1 kT. Asymptotic forms of this function have been derived for three energy ranges, i.e., ξ Lt 1, 1 Lt ξ Lt η2, and ξ Gt η2. Then, a characteristic value, η c (p, ɛ) with ɛ Lt 1, of parameter η was defined such that the middle range asymptotic form of Wp (ξ, η) could be valid and good when η >~ η c (p, ɛ), by deriving an approximate expression of this particular value for ɛ = 10-3. The resulting spectra featured by a high-energy cutoff in the case of low values of the ratio η can be discussed at least for a population of short gamma-ray bursts (GRBs), those best described by the cutoff power-law model with a low-energy spectral index, α ≈ 0. Furthermore, it is suggested that for GRB spectra with α < -1/2 pertaining to the prompt emission phase, the IC is a likely emission mechanism for both monoenergetic and BB photon fields if one assumes that the former photon field could exist specifically in the GRB environment. Various suitable astrophysical applications are presented and discussed.

  18. Nucleon Form Factors above 6 GeV

    DOE R&D Accomplishments Database

    Taylor, R. E.

    1967-09-01

    This report describes the results from a preliminary analysis of an elastic electron-proton scattering experiment... . We have measured cross sections for e-p scattering in the range of q{sup 2} from 0.7 to 25.0 (GeV/c){sup 2}, providing a large region of overlap with previous measurements. In this experiment we measure the cross section by observing electrons scattered from a beam passing through a liquid hydrogen target. The scattered particles are momentum analyzed by a magnetic spectrometer and identified as electrons in a total absorption shower counter. Data have been obtained with primary electron energies from 4.0 to 17.9 GeV and at scattering angles from 12.5 to 35.0 degrees. In general, only one measurement of a cross section has been made at each momentum transfer.

  19. Leptogenesis via the 750 GeV pseudoscalar

    NASA Astrophysics Data System (ADS)

    Kusenko, Alexander; Pearce, Lauren; Yang, Louis

    2016-06-01

    Recently the ATLAS and CMS Collaborations have reported evidence of a diphoton excess which may be interpreted as a pseudoscalar boson S with a mass around 750 GeV. To explain the diphoton excess, such a boson is coupled to the Standard Model gauge fields via S F F ˜ operators. In this work, we consider the implications of this state for early universe cosmology; in particular, the S field can acquire a large vacuum expectation value due to quantum fluctuations during inflation. During reheating, it then relaxes to its equilibrium value, during which time the same operators introduced to explain the diphoton excess induce a nonzero chemical potential for baryon and lepton number. Interactions such as those involving right-handed neutrinos allow the system to develop a nonzero lepton number and, therefore, this state may also be responsible for the observed cosmological matter-antimatter asymmetry.

  20. 50x50 GeV Muon Collider Beam Collimation

    SciTech Connect

    A.I. Drozhdin, C.J. Johnstone, N.V. Mokhov, A.A. Garen and V.M. Biryukov

    1999-04-14

    A summary of different techniques and systems to scrape beam halo in a 50 x 50 GeV {mu}{sup +}{mu}{sup -} collider is presented. Such systems are installed in a special utility section with optics specifically designed to meet both the requirements of the scraping system and of injection. Results froma realistic Monte Carlo simulation (STRUCT-MARS) show that a system consisting of steel absorbers several meters in length suppresses halo-induced backgrounds in the collider detector by more than three orders of magnitude. The heat load in superconducting magnets near the scraper system can be reduced to tolerable levels by appropriate collimator design and location. This reduction applies to both injection and collider mode of operation. Also discussed is extraction of halo particles using electrostatic deflectors and bent crys-tals, although neither appears to be effective for a muon collider at this energy.

  1. Pressure Safety of JLAB 12GeV Upgrade Cryomodule

    SciTech Connect

    Cheng, Gary; Wiseman, Mark A.; Daly, Ed

    2009-11-01

    This paper reviews pressure safety considerations, per the US Department of Energy (DOE) 10CFR851 Final Rule [1], which are being implemented during construction of the 100 Megavolt Cryomodule (C100 CM) for Jefferson Lab’s 12 GeV Upgrade Project. The C100 CM contains several essential subsystems that require pressure safety measures: piping in the supply and return end cans, piping in the thermal shield and the helium headers, the helium vessel assembly which includes high RRR niobium cavities, the end cans, and the vacuum vessel. Due to the vessel sizes and pressure ranges, applicable national consensus code rules are applied. When national consensus codes are not applicable, equivalent design and fabrication approaches are identified and implemented. Considerations for design, material qualification, fabrication, inspection and examination are summarized. In addition, JLAB’s methodologies for implementation of the 10 CFR 851 requirements are described.

  2. GLAST: GeV Astronomy in a Multiwavelength Context

    SciTech Connect

    Thompson, D

    2004-06-14

    The GLAST Large Area Telescope (LAT), successor to EGRET on the Compton Observatory, will play an important role in multiwavelength studies during the second half of this decade. Operating at energies between 20 MeV and greater than 300 GeV with sensitivity 30 or more times greater than that of EGRET, the LAT will offer good spatial and time resolution over a large (> 2 sr) field of view. The LAT will bring insight to the whole range of high-energy gamma-ray phenomena, including bursts, active galactic nuclei, pulsars, supernova remnants, diffuse emission, and unidentified sources. In essentially all cases, the maximum scientific return will come from coordinated (although not necessarily simultaneous) multiwavelength observations. Particularly with its planned scanning mode of operation, GLAST will have full sky coverage on relatively short time scales. The LAT team looks forward to cooperating with observers at other wavelengths.

  3. 1-GeV Linac Upgrade Study at Fermilab

    SciTech Connect

    Popovic, M., Moretti, A., Noble, R., Schmidt, C. W., FNAL

    1998-09-01

    A linac injector for a new proton source complex at Fermilab is assumed to have a kinetic energy of 1 GeV. This linac would be sized to accelerate 100 mA of H{sup -} beam in a 200 microsecond pulse at a 15 Hz repetition rate. This would be adequate to produce {approximately}10{sup 14} protons per pulse allowing for future improvements of the new proton source complex. An alternate proposal is to add 600 MeV of side coupled cavity linac at 805 MHz to the existing 400 MeV Linac. This addition may either be in a new location or use the present Booster tunnel. A discussion of these possibilities will be given.

  4. Charmed meson lifetimes from 20 GeV photoproduction

    SciTech Connect

    Brau, J.E.

    1985-01-01

    A sample of 134 events containing 159 visible multiprong charm decays has been obtained from the 20 GeV charm photoproduction experiment at the SLAC Hybrid Facility. Following a selection procedure which ensures high and uniform detection efficiency for selected events, 47 charged, 46 neutral and five topologically ambiguous decays remain. These decays yield preliminary lifetimes of ..pi../sub D/sup +-// = (9.2 +- 1.5 +- 0.5) x 10/sup -13/ secs ..pi../sub D//sup 0/ approx. = (6.1 +- 1.1 +- 0.4) x 10/sup -13/ secs and a ratio (phi/sub D/sup +-//)/(tau/sub D/sup 0//) = 1.5/sub -0.3//sup +0.6/ +- 0.1. One fully reconstructed four-body D/sup 0/ decay has a proper flight time of 55 x 10/sup -13/ seconds. 5 refs., 4 figs.

  5. 750 GeV messenger of dark conformal symmetry breaking

    NASA Astrophysics Data System (ADS)

    Davoudiasl, Hooman; Zhang, Cen

    2016-03-01

    The tentative hints for a diphoton resonance at a mass of ˜750 GeV from the ATLAS and CMS experiments at the LHC may be interpreted as first contact with a "dark" sector with a spontaneously broken conformal symmetry. The implied TeV scale of the dark sector may be motivated by the interaction strength required to accommodate a viable thermal relic dark matter (DM) candidate. We model the conformal dynamics using a Randall-Sundrum-type five-dimensional geometry whose IR boundary is identified with the dynamics of the composite dark sector, while the Standard Model (SM) matter content resides on the UV boundary, corresponding to "elementary" fields. We allow the gauge fields to reside in the five-dimensional bulk, which can be minimally chosen to be S U (3 )c×U (1 )Y. The "dark" radion is identified as the putative 750 GeV resonance. Heavy vectorlike fermions, often invoked to explain the diphoton excess, are not explicitly present in our model and are not predicted to appear in the spectrum of TeV scale states. Our minimal setup favors scalar DM of O (TeV ) mass. A generic expectation in this scenario, suggested by DM considerations, is the appearance of vector bosons at ˜ few TeV, corresponding to the gluon and hypercharge Kaluza-Klein (KK) modes that couple to UV boundary states with strengths that are suppressed uniformly compared to their SM values. Our analysis suggests that these KK modes could be within the reach of the LHC in the coming years.

  6. Scaling properties of hyperon production in Au+Au collisions at square root [sNN]=200 GeV.

    PubMed

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