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Sample records for antiprotons beam applied

  1. Low energy antiproton beams

    NASA Astrophysics Data System (ADS)

    Klapisch, R.

    1992-04-01

    It was the invention of stochastic cooling by S. Van Meer that has allowed antiproton beams to become a powerful tool for the physicist. As a byproduct of the high energy proton-antiproton collider, a versatile low-energy facility, LEAR has been operating at CERN since 1984. The facility and its characteristics will be described as well as examples of its use for studying fundamental properties of the antiproton and for topics in atomic, nuclear and particle Physics.

  2. Antiproton source beam position system

    NASA Astrophysics Data System (ADS)

    Bagwell, T.; Holmes, S.; McCarthy, J.; Webber, R.

    1984-05-01

    The TeV I Beam Position Monitor (BPM) system is designed to provide a useful diagnostic tool during both the commissioning and operational phases of the antiproton source. The design goal is to provide single turn beam position information for intensities of 1 x 10 to the 9th particles, and multi-turn (closed orbit) information for beam intensities of 1 x 10 to the 7th particles, both with submillimeter resolution. It is anticipated that the system will be used during commissioning for establishing the first turn through the debuncher and accumulator, for aligning injection orbits, for providing information necessary to correct closed orbits, and for measuring various machine parameters (tunes, dispersion, apertures, and chromaticity). During normal antiproton operation the system will be used to monitor the beam position throughout the accumulation process.

  3. An alternative for polarized antiproton beams

    NASA Astrophysics Data System (ADS)

    Grzonka, Dieter; Kilian, Kurt; Möhl, Dieter; Oelert, Walter; Sefzick, Thomas

    2012-12-01

    Presently the most popular way to prepare high quality polarized antiproton beams is the so called spin filter method. The feasibility of the method has been proven for a proton beam and measurements of the spin dependent interaction of antiprotons have been proposed by the PAX collaboration. Another well known source for polarized antiprotons is the bar{Λ} decay which was used at FERMILAB in the only experiment performed so far with polarized antiprotons. An alternative approach for polarized antiproton beams may be the production process itself. If the produced antiprotons show polarization it would be rather simple to handle a polarized antiproton beam in the existing antiproton collector and cooler at CERN just like in the unpolarized case.

  4. An alternative for polarized antiproton beams

    NASA Astrophysics Data System (ADS)

    Grzonka, Dieter; Kilian, Kurt; Möhl, Dieter; Oelert, Walter; Sefzick, Thomas

    Presently the most popular way to prepare high quality polarized antiproton beams is the so called spin filter method. The feasibility of the method has been proven for a proton beam and measurements of the spin dependent interaction of antiprotons have been proposed by the PAX collaboration. Another well known source for polarized antiprotons is the bar{Λ} decay which was used at FERMILAB in the only experiment performed so far with polarized antiprotons. An alternative approach for polarized antiproton beams may be the production process itself. If the produced antiprotons show polarization it would be rather simple to handle a polarized antiproton beam in the existing antiproton collector and cooler at CERN just like in the unpolarized case.

  5. Ways to make polarized antiproton beams

    NASA Astrophysics Data System (ADS)

    Grzonka, D.; Kilian, K.; Möhl, D.; Oelert, W.; Sefzick, T.

    2011-05-01

    For producing polarized antiproton beams the so called spin filter method is normally discussed. The method has been proven by the FILTEX collaboration with a proton beam and detailed studies are presently performed by the PAX collaboration at COSY. A well known source for polarized antiprotons is the antilambda decay. It was used in the only experiment with polarized antiprotons so far at FERMILAB. Furthermore the antiproton production process itself, if showing polarization, would be by far the simplest and best way to get polarized beams because one could use the existing antiproton facility. Up to now production has never been investigated in detail.

  6. Ways to Make Polarized Antiproton Beams

    NASA Astrophysics Data System (ADS)

    Kilian, K.; Grzonka, D.; Möhl, D.; Oelert, W.

    For making polarized antiproton beams the so called filter method is normally discussed. It is based on the depletion of one spin component due to the spin dependent interaction if a stored beam passes a polarized target. The method has been proven by the FILTEX collaboration and detailed studies are presently performed by the PAX collaboration. Another source for polarized antiprotons is the antilambda decay as it was used in the only experiment with polarized antiprotons so far at FERMILAB. Furthermore the antiproton production process itself if showing polarisation, would be by far the best way to get polarized bar p. It can be assumed to result from a quasi-free proton-nucleon collison. Up to now it has never been investigated in detail. In such a hadronic interaction the antiprotons may have substantial polarisation which would simplify the preparation of a polarized antiproton beam drastically. It is proposed to measure the polarisation of antiprotons produced in a fixed target experiment.

  7. Antiproton beam polarizer using a dense polarized target

    SciTech Connect

    Wojtsekhowski, Bogdan

    2011-05-01

    We describe considerations regarding the spin filtering method for the antiproton beam. The proposed investigation of the double polarization cross section for antiproton to nucleon interaction is outlined. It will use a single path of the antiproton beam through a dense polarized target, e.g. 3He or CH2, followed by a polarimeter.

  8. The antiproton cell experiment—do antiprotons offer advantages over other particle beam modalities?

    NASA Astrophysics Data System (ADS)

    Sellner, Stefan; Boll, Rebecca; Caccia, Massimo; Negrini, Loretta; Straße, Tina; Tegami, Sara; Holzscheiter, Michael H.

    2012-12-01

    The use of heavy charged particles for cancer therapy has the potential for a significant improvement of the therapeutic window compared to standard X-ray treatments. This is due to the improved energy deposition profile, exhibiting a well-defined peak at a depth in target controllable by the initial energy of the beam. Particles heavier than protons in addition show an increase in biological effectiveness. Compared to protons or heavy ions, antiprotons deposit additional annihilation energy, mostly by low energy recoils, resulting in an increase of dose and also adding a component with high biological effectiveness in the target region. The relative magnitude of the physical energy deposition of antiprotons compared to protons was measured at Low Energy Antiproton Ring (LEAR) by A. Sullivan, but no study of the biological effect had been conducted prior to the Antiproton Cell Experiment (AD-4/ACE) experiment at CERN. The special conditions found at CERN present significant challenges, but also offer unique opportunities. 500 ns pulses of antiprotons are extracted from the Antiproton Decelerator (AD) at 500 MeV/c momentum. Biological cell samples are irradiated and clonogenic survival fractions are measured for various doses. To extract biological efficiency, the physical dose deposition is obtained by Monte-Carlo calculations in conjunction with shot-by-shot monitoring of the incoming beam intensity and profile using a silicon pixel detector. Also imaging of the pions resulting from antiproton annihilations in the target using silicon pixel detector technology to determine the actual range in more complex targets with strong variations in material densities was carried out. The feasibility of this technique using a novel arrangement of the detector was demonstrated. This paper describes the ACE experiment and focuses on the different detector activities within the AD-4/ACE collaboration, explaining the experimental set-up, physical and biological methods used

  9. The antiproton cell experiment—do antiprotons offer advantages over other particle beam modalities?

    NASA Astrophysics Data System (ADS)

    Sellner, Stefan; Boll, Rebecca; Caccia, Massimo; Negrini, Loretta; Straße, Tina; Tegami, Sara; Holzscheiter, Michael H.

    The use of heavy charged particles for cancer therapy has the potential for a significant improvement of the therapeutic window compared to standard X-ray treatments. This is due to the improved energy deposition profile, exhibiting a well-defined peak at a depth in target controllable by the initial energy of the beam. Particles heavier than protons in addition show an increase in biological effectiveness. Compared to protons or heavy ions, antiprotons deposit additional annihilation energy, mostly by low energy recoils, resulting in an increase of dose and also adding a component with high biological effectiveness in the target region. The relative magnitude of the physical energy deposition of antiprotons compared to protons was measured at Low Energy Antiproton Ring (LEAR) by A. Sullivan, but no study of the biological effect had been conducted prior to the Antiproton Cell Experiment (AD-4/ACE) experiment at CERN. The special conditions found at CERN present significant challenges, but also offer unique opportunities. 500 ns pulses of antiprotons are extracted from the Antiproton Decelerator (AD) at 500 MeV/c momentum. Biological cell samples are irradiated and clonogenic survival fractions are measured for various doses. To extract biological efficiency, the physical dose deposition is obtained by Monte-Carlo calculations in conjunction with shot-by-shot monitoring of the incoming beam intensity and profile using a silicon pixel detector. Also imaging of the pions resulting from antiproton annihilations in the target using silicon pixel detector technology to determine the actual range in more complex targets with strong variations in material densities was carried out. The feasibility of this technique using a novel arrangement of the detector was demonstrated. This paper describes the ACE experiment and focuses on the different detector activities within the AD-4/ACE collaboration, explaining the experimental set-up, physical and biological methods used

  10. Transverse instability of the antiproton beam in the Recycler Ring

    SciTech Connect

    Prost, L.R.; Bhat, C.M.; Burov, A.; Crisp, J.; Eddy, N.; Hu, M.; Shemyakin, A.; /Fermilab

    2011-03-01

    The brightness of the antiproton beam in Fermilab's 8 GeV Recycler ring is limited by a transverse instability. This instability has occurred during the extraction process to the Tevatron for large stacks of antiprotons even with dampers in operation. This paper describes observed features of the instability, introduces the threshold phase density to characterize the beam stability, and finds the results to be in agreement with a resistive wall instability model. Effective exclusion of the longitudinal tails from Landau damping by decreasing the depth of the RF potential well is observed to lower the threshold density by up to a factor of two.

  11. A beam sweeping system for the Fermilab antiproton production target

    SciTech Connect

    Bieniosek, F.M.

    1993-08-01

    In the Main Injector era beam intensities high enough to damage the antiproton production target will be available. In order to continue to operate with a tightly-focused primary beam spot on the target, and thus maintain yield, it will be necessary to spread the hot spot on the target by use of a beam sweeping system. This report summarizes the requirements for such a system, and addresses the issues involved in the design of a sweeping system.

  12. Commissioning of polarized-proton and antiproton beams at Fermilab

    SciTech Connect

    Yokosawa, A.

    1988-05-04

    The author described the polarized-proton and polarized-antiproton beams up to 200 GeV/c at Fermilab. The beam line, called MP, consists of the 400-m long primary and 350-m long secondary beam line followed by 60-m long experimental hall. We discuss the characteristics of the polarized beams. The Fermilab polarization projects are designated at E-581/704 initiated and carried out by an international collaboration, Argonne (US), Fermilab (US), Kyoto-Kyushu-Hiroshima-KEK (Japan), LAPP (France), Northwestern University (US), Los Alamos Laboratory (US), Rice (US), Saclay (France), Serpukhov (USSR), INFN Trieste (Italy), and University of Texas (US).

  13. Antiprotons

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Segre, Emilio; Wiegand, Clyde

    1955-11-29

    Since the development of Dirac's theory of the electron and the brilliant confirmation of one of its most startling predictions by the discovery of the positron by Anderson, it has been assumed most likely that the proton would also have its charge conjugate, the antiproton. The properties that define the antiproton are: (a) charge equal to the electron charge (also in sign); (b) mass equal to the proton mass; (c) stability against spontaneous decay; (d) ability to annihilate by interaction with a proton or neutron, probably generating pions and releasing in some manner the energy 2 mc{sup 2}; (e) generation in pairs with ordinary nucleons; (f) magnetic moment equal but opposite to that of the proton; (g) fermion of spin 1/2. Not all these properties are independent, but all might ultimately be subjected to experiment.

  14. Generating a Reduced-energy Antiproton beam using Channeling Electrostatic elements (GRACE)

    NASA Astrophysics Data System (ADS)

    Lawler, Gerard; Pacifico, Nicola; Aegis Collaboration

    2016-03-01

    A device was designed for Generating a Reduced-energy Antiproton-beam using Channeling Electrostatic elements (GRACE). A series of einzel lenses and electrodes are used to create a slow beam of antiprotons with tunable mean energy (0 to 16 keV with root mean squared value below 20%) using antiprotons (mean energy of 5 MeV) from the Antiproton Decelerator (AD) at CERN. Degrader foil is in place, so GRACE further deflects the beam bunches away from the annihilation products, focusing them on a 14 mm x 14 mm detector. Manufacturing parameters were found using simulations written in C++. The device is currently in use by the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) collaboration at CERN, which seeks to measure the sign of the gravitational constant for antimatter by performing interferometry studies on an antihydrogen beam. GRACE delivers on the order of 10 events per beam bunch from the AD. Antiprotons will eventually be used together with a pulse of positronium atoms to make antihydrogen atoms with horizontal velocity. GRACE is being used to perform intermediary experiments concerning interferometry of antiprotons, an important stepping stone on the way to measuring the sign of gravity. Special thanks to Boston University Undergraduate Research Opportunities Program, Lawrence Sulak, and Michael Doser.

  15. Non-Gaussian beam dynamics in low energy antiproton storage rings

    NASA Astrophysics Data System (ADS)

    Resta-López, J.; Hunt, J. R.; Welsch, C. P.

    2016-10-01

    In low energy antiproton facilities, where electron cooling is fundamental, the cooling forces together with heating phenomena causing emittance blow-up, such as Intra Beam Scattering (IBS), result in highly non-Gaussian beam distributions. In these cases, a precise simulation of IBS effects is essential to realistically evaluate the long term beam evolution, taking into account the non-Gaussian characteristics of the beam. Here, we analyse the beam dynamics in the Extra Low ENergy Antiproton ring (ELENA), which is a new small synchrotron currently being constructed at CERN to decelerate antiprotons to energies as low as 100 keV. Simulations are performed using the code BETACOOL, comparing different models of IBS.

  16. A new antiproton beam transfer scheme without coalescing

    SciTech Connect

    Weiren Chou et al.

    2003-06-04

    An effective way to increase the luminosity in the Fermilab Tevatron collider program Run2 is to improve the overall antiproton transfer efficiency. During antiproton coalescing in the Main Injector (MI), about 10-15% particles get lost. This loss could be avoided in a new antiproton transfer scheme that removes coalescing from the process. Moreover, this scheme would also eliminate emittance dilution due to coalescing. This scheme uses a 2.5 MHz RF system to transfer antiprotons from the Accumulator to the Main Injector. It is then followed by a bunch rotation in the MI to shorten the bunch length so that it can be captured by a 53 MHz RF bucket. Calculations and ESME simulations show that this scheme works. No new hardware is needed to implement this scheme.

  17. First Observation of a (1,0) Mode Frequency Shift of an Electron Plasma at Antiproton Beam Injection

    NASA Astrophysics Data System (ADS)

    Kuroda, N.; Mohri, A.; Torii, H. A.; Nagata, Y.; Shibata, M.

    2014-07-01

    The frequency shift of the center-of-mass oscillation, known as the (1,0) mode, of a trapped electron plasma and, furthermore, its time evolution were observed during the cooling of an injected antiproton beam for the first time. Here, antiprotons mixed with the electrons did not follow faster electron oscillations but contributed to the modification of the effective potential. The time evolution of the plasma temperature, deduced from the frequency shift of the excited (3,0) mode, suggested that there was an abnormal energy deposition of the antiproton beam in the electron plasma before thermalization.

  18. Using time separation of signals to obtain independent proton and antiproton beam position measurements around the Tevatron

    SciTech Connect

    Webber, R.; /Fermilab

    2005-05-01

    Independent position measurement of the counter-circulating proton and antiproton beams in the Tevatron, never supported by the original Tevatron Beam Position Monitor (BPM) system, presents a challenge to upgrading that system. This paper discusses the possibilities and complications of using time separation of proton and antiproton signals at the numerous BPM locations and for the dynamic Tevatron operating conditions. Results of measurements using one such method are presented.

  19. Advanced space propulsion study - antiproton and beamed-power propulsion. Final report, 1 May 1986-30 June 1987

    SciTech Connect

    Forward, R.L.

    1987-10-01

    The contract objective was to monitor the research at the forefront of physics and engineering to discover new spacecraft-propulsion concepts. The major topics covered were antiproton-annihilation propulsion, laser thermal propulsion, laser-pushed lightsails, tether transportation systems, solar sails, and metallic hydrogen. Five papers were prepared and are included as appendices. They covered 1) pellet, microwave, and laser-beamed power systems for interstellar transport; 2) a design for a near-relativistic laser-pushed lightsail using near-term laser technology; 3) a survey of laser thermal propulsion, tether transportation systems, antiproton annihilation propulsion, exotic applications of solar sails, and laser-pushed interstellar lightsails; 4) the status of antiproton annihilation propulsion as of 1986, and 5) the prospects for obtaining antimatter ions heavier than antiprotons. Two additional appendices contain the first seven issues of the Mirror Matter Newsletter concerning the science and technology of antimatter, and an annotated bibliography of antiproton science and technology.

  20. Simulation studies of the beam cooling process in presence of heating effects in the Extra Low ENergy Antiproton ring (ELENA)

    NASA Astrophysics Data System (ADS)

    Resta-López, J.; Hunt, J. R.; Karamyshev, O.; Welsch, C. P.

    2015-05-01

    The Extra Low ENergy Antiproton ring (ELENA) is a small synchrotron equipped with an electron cooler, which is currently being constructed at CERN to further decelerate antiprotons from the Antiproton Decelerator (AD) from 5.3 MeV to energies as low as 100 keV. At such low energies it is very important to carefully take contributions from electron cooling and beam heating mechanisms (e.g. on the residual gas and intrabeam scattering) into account. Detailed investigations into the ion kinetics under consideration of effects from electron cooling and heating sources have been carried out, and the equilibrium phase space dimensions of the beam have been computed, based on numerical simulations using the code BETACOOL. The goal is to provide a consistent explanation of the different physical effects acting on the beam in ELENA.

  1. CERN antiproton target: Hydrocode analysis of its core material dynamic response under proton beam impact

    NASA Astrophysics Data System (ADS)

    Martin, Claudio Torregrosa; Perillo-Marcone, Antonio; Calviani, Marco; Muñoz-Cobo, José-Luis

    2016-07-01

    Antiprotons are produced at CERN by colliding a 26 GeV /c proton beam with a fixed target made of a 3 mm diameter, 55 mm length iridium core. The inherent characteristics of antiproton production involve extremely high energy depositions inside the target when impacted by each primary proton beam, making it one of the most dynamically demanding among high energy solid targets in the world, with a rise temperature above 2000 °C after each pulse impact and successive dynamic pressure waves of the order of GPa's. An optimized redesign of the current target is foreseen for the next 20 years of operation. As a first step in the design procedure, this numerical study delves into the fundamental phenomena present in the target material core under proton pulse impact and subsequent pressure wave propagation by the use of hydrocodes. Three major phenomena have been identified, (i) the dominance of a high frequency radial wave which produces destructive compressive-to-tensile pressure response (ii) The existence of end-of-pulse tensile waves and its relevance on the overall response (iii) A reduction of 44% in tensile pressure could be obtained by the use of a high density tantalum cladding.

  2. Search for Polarization Effects in the Antiproton Production Process

    DOE PAGES

    Grzonka, D.; Kilian, K.; Ritman, J.; ...

    2015-01-01

    For the production of a polarized antiproton beam, various methods have been suggested including the possibility that antiprotons may be produced polarized which will be checked experimentally. The polarization of antiprotons produced under typical conditions for antiproton beam preparation will be measured at the CERN/PS. If the production process creates some polarization, a polarized antiproton beam could be prepared by a rather simple modification of the antiproton beam facility. The detection setup and the expected experimental conditions are described.

  3. The Antiproton-Nucleon Annihilation Process (Antiproton Collaboration Experiment)

    DOE R&D Accomplishments Database

    Barkas, W. H.; Birge, R. W.; Chupp, W. W.; Ekspong, A. G.; Goldhaber, G.; Goldhaber, S.; Heckman, H. H.; Perkins, D. H.; Sandweiss, J.; Segre, E.; Smith, F. M.; Stork, D. H.; Rossum, L. Van; Amaldi, E.; Baroni, G.; Castagnoli, C.; Franzinetti, C.; Manfredini, A.

    1956-09-10

    In the exposure to a 700-MeV/c negative particle beam, 35 antiproton stars have been found. Of these antiprotons, 21 annihilate in flight and three give large-angle scatters ({Theta} > 15 , T{sub P-} > 50 Mev), while 14 annihilate at rest. From the interactions in flight we obtain the total cross section for antiproton interaction.

  4. Formation spectra of charmed meson-nucleus systems using an antiproton beam

    NASA Astrophysics Data System (ADS)

    Yamagata-Sekihara, J.; Garcia-Recio, C.; Nieves, J.; Salcedo, L. L.; Tolos, L.

    2016-03-01

    We investigate the structure and formation of charmed meson-nucleus systems, with the aim of understanding the charmed meson-nucleon interactions and the properties of the charmed mesons in the nuclear medium. The D bar mesic nuclei are of special interest, since they have tiny decay widths due to the absence of strong decays for the D bar N pair. Employing an effective model for the D bar N and DN interactions and solving the Klein-Gordon equation for D bar and D in finite nuclei, we find that the D--11B system has 1s and 2p mesic nuclear states and that the D0-11B system binds in a 1s state. In view of the forthcoming experiments by the PANDA and CBM Collaborations at the future FAIR facility and the J-PARC upgrade, we calculate the formation spectra of the [D--11B] and [D0-11B] mesic nuclei for an antiproton beam on a 12C target. Our results suggest that it is possible to observe the 2pD- mesic nuclear state with an appropriate experimental setup.

  5. Development of an optical transition radiation detector for profile monitoring of antiproton and proton beams at FNAL

    SciTech Connect

    Scarpine, V.E.; Lindenmeyer, C.W.; Tassotto, G.R.; Lumpkin, A.H.; /Argonne

    2005-05-01

    Optical transition radiation (OTR) detectors are being developed at Fermi National Accelerator Laboratory (FNAL) as part of the collider Run II upgrade program and as part of the NuMI primary beam line. These detectors are designed to measure 150 GeV antiprotons as well as 120 GeV proton beams over a large range of intensities. Design and development of an OTR detector capable of measuring beam in both directions down to beam intensities of {approx}5e9 particles for nominal beam sizes are presented. Applications of these OTR detectors as an on-line emittance monitor for both antiproton transfers and reverse-injected protons, as a Tevatron injection profile monitor, and as a high-intensity beam profile monitor for NuMI are discussed. In addition, different types of OTR foils are being evaluated for operation over the intensity range of {approx}5e9 to 5e13 particles per pulse, and these are described.

  6. Antiproton charge radius

    NASA Astrophysics Data System (ADS)

    Crivelli, P.; Cooke, D.; Heiss, M. W.

    2016-09-01

    The upcoming operation of the extra low energy antiprotons ring at CERN, the upgrade of the antiproton decelerator (AD), and the installation in the AD hall of an intense slow positron beam with an expected flux of 1 08 e+ /s will open the possibility for new experiments with antihydrogen (H ¯). Here we propose a scheme to measure the Lamb shift of H ¯. For four months of data taking, we anticipate an uncertainty of 100 ppm. This will provide a test of C P T and the first determination of the antiproton charge radius at the level of 10%.

  7. Erratum: Simulation studies of the beam cooling process in presence of heating effects in the Extra Low ENergy Antiproton ring (ELENA) Erratum: Simulation studies of the beam cooling process in presence of heating effects in the Extra Low ENergy Antiproton ring (ELENA)

    NASA Astrophysics Data System (ADS)

    Resta-López, J.; Hunt, J. R.; Karamyshev, O.; Welsch, C. P.

    2015-08-01

    The Extra Low ENergy Antiproton ring (ELENA) is a small synchrotron equipped with an electron cooler, which is currently being constructed at CERN to further decelerate antiprotons from the Antiproton Decelerator (AD) from 5.3 MeV to energies as low as 100 keV . At such low energies it is very important to carefully take contributions from electron cooling and beam heating mechanisms (e.g. on the residual gas and intrabeam scattering) into account. Detailed investigations into the ion kinetics under consideration of effects from electron cooling and heating sources have been carried out, and the equilibrium phase space dimensions of the beam have been computed, based on numerical simulations using the code BETACOOL. The goal is to provide a consistent explanation of the different physical effects acting on the beam in ELENA.

  8. PHYSICS WITH ULTRA-LOW ENERGY ANTIPROTONS

    SciTech Connect

    M. HOLZSCHEITER

    2001-02-01

    In this report the author describes the current status of the antiproton deceleration (AD) facility at CERN, and highlights the physics program with ultra-low energy antiproton at this installation. He also comments on future possibilities provided higher intensity antiproton beams become available at Fermilab, and review possibilities for initial experiments using direct degrading of high energy antiprotons in material has been developed and proven at CERN.

  9. Report on Operation of Antiproton Decelerator

    SciTech Connect

    Belochitskii, Pavel

    2006-03-20

    The Antiproton Decelerator (AD) at CERN operates for physics since 1999. The 3.5 GeV/c antiprotons produced in the target by a 26 GeV/c proton beam coming from CERN PS. Since the experiments need a low energy antiprotons, beam is decelerated in the AD down to an extraction momentum of 100 MeV/c. Due to significant emittance blow up during deceleration, as well as tight requirements from experiments on extracted beam sizes, efficient compression of beam phase space is indispensable. Two cooling systems, stochastic and electron are used in AD. The progress in machine performance is reviewed, along with plans for the future. Special emphasis is given to the proposed new extra low energy antiproton ring (ELENA) for deceleration of antiproton beam further down to an energy of 100 keV (momentum 13.7 MeV/c), which would allow much higher antiproton capture rate with significantly higher beam density.

  10. Proceedings of the 10 May 1989 Antiproton Technology Workshop: Addendum

    NASA Astrophysics Data System (ADS)

    Nordley, Gerald D.

    1989-09-01

    Antiprotons are particles of antimatter which release highly penetrating radiation when they are stopped in normal matter. According to presentations at the Antiproton Technology Workshop this radiation can be used, in very small quantities, to image objects and determine their composition and density. In larger amounts, the radiation could be used to kill cancer tumors or produce highly localized heating and shock waves. Titles of presentations include: Stopping Power of MeV Proton and Antiproton Beams; Recent Simulation Results of ASTER; Pbar Testing of Hydrogen Effects in Sealed Carbon-Carbon Composites; Potential for Antiprotons in Radiation Oncology; Prospects for a Commercial Antiproton Source; Prospects for Exciting Extreme States in Nuclear Matter with Intense Antiproton Beams; Status of AL Studies Relating to condensed Antimatter; Electromagnetic Traps for Atomic Antihydrogen; Antihydrogen Production; Antiproton Catalyzed Fusion; Antiproton Induced Fusion Reaction; Modeling Antiproton-Plasma Interactions; Introduction to CP Violation Studies with Pbars; and Antiproton Production Calculation by the Multistring Model VENUS.

  11. Antiproton production for Tevatron

    SciTech Connect

    Azhgirey, I.L.; Mokhov, N.V.; Striganov, S.I. . Inst. Fiziki Vysokikh Ehnergij)

    1991-03-01

    Needs to improve the Fermilab Pbar Source for the Tevatron Upgrade and discrepancies in predictions of the antiproton yields have forced us to develop the production model based on the modern data and to incorporate this model to the current version of MARS10 code. The inclusive scheme of this code with the use of statistical weights allows the production of antiprotons to be enhanced within the phase space region of interest, which is extremely effective for optimization of Pbar Source parameters and for developing of such an idea as a beam sweeping system. Antiproton production model included in the modified version of our Monte Carlo program MARS10M for the inclusive simulation of hadronic cascades, as for other particles throughout the program, is based on a factorization approach for hadron-nucleus differential cross-section. To describe antiproton inclusive spectra in pp-collisions a phenomenological model has been used modified in the low-Pt region. The antiproton production in pion-nucleon interactions is described in the frame of our simple phenomenological model based on the modern data. In describing of the of antiproton production cross-sections ratio in hadron-nucleus and hadron-nucleon collisions the ideas of soft hadronization of color strings and all the present experimental data have been used. Some comparisons of our model with experimental data are presented in the wide intervals of initial momenta, antiproton kinematical variables and nuclei. In all the cases the agreement is pretty good what gives us an assurance in the consequent studies carried out for the Fermilab Pbar Source. The results of such study are presented in this paper.

  12. ASTER: Imaging with antiprotons

    SciTech Connect

    Muratore, R.

    1988-01-01

    Antiprotons are of great promise in biomedical research and in practical biomedical and industrial applications. It is likely that antiprotons will be of far greater utility in the next century than x-rays have been in this century. Antiprotonic STEReography (ASTER), a 3-D photography-like imaging technique, is basic to most of the foreseen applications. This dissertation explores realistic models of ASTER analytically, numerically, and with computer simulations. It carries the understanding of ASTER further than previous work, and its models are adaptable to more powerful computers. In particular, ASTER is portrayed as a robust alternative to the ambiguities inherent in the imaging techniques used in x-ray computer tomography, CT. The scattering of the antiprotons lateral to their initial direction is the limiting factor in ASTERs ability to resolve fine anatomical details. This lateral scattering is calculated with a mathematical term ignored in previous studies, which overestimate the scattering of heavy charged particles in homogeneous media. Optimization techniques are explored and found to provide twice the resolution for a given radiation dose, and to reduce the needed detector size. Proper choice of orientation of the antiproton beam is shown to improve the resolution/dose ratio by an order of magnitude. Comparison of simulated ASTER scans with actual CT scans shows that ASTER imparts about one to two orders of magnitude less dose than that imparted by CT at comparable resolutions. The scanned targets include a random pattern. The target and the image are shown to be more correlated as the number of antiprotons used is increased. Finally, the future of ASTER is considered: further computer simulations are suggested, and implications for medicine and industry are discussed.

  13. Past, present and future low energy antiproton facilities at CERN

    NASA Astrophysics Data System (ADS)

    Bartmann, W.; Belochitskii, P.; Breuker, H.; Butin, F.; Carli, C.; Eriksson, T.; Maury, S.; Oelert, W.; Pasinelli, S.; Tranquille, G.

    2014-05-01

    Low energy antiprotons are available for physics experiments at CERN since the 1980s and have been used by a large variety of experiments. The Low Energy Antiproton Ring LEAR has been constructed as a complementary use of antiprotons available at that time for high energy physics and delivered beam to experiments mainly using slow extraction. After completion of LEAR exploitation, the Antiproton Decelerator (AD) was constructed (adaptation of the existing Antiproton Collector, AC) to allow for a simpler low energy antiproton scheme (only one accelerator operated with Antiprotons) with fast extraction well suited for trap experiments. The Extra Low ENergy Antiproton ring ELENA is a small synchrotron presently constructed to further decelerate antiprotons from the AD in a controlled manner, and to reduce emittances with the help of an electron cooler to improve the capture efficiencies of existing experiments and allow for additional ones.

  14. Antiproton annihilation dynamics in the Gasdynamic Fusion Rocket

    SciTech Connect

    Kammash, T.; Lee, M.

    1996-03-01

    The use of antiprotons to initiate the fusion reactions in the Gasdynamic Fusion Rocket (GDFR) is examined as potential replacement of the neutral beam injection system often cited in connection with fusion power reactors. The effectiveness of this approach depends critically, however, on the ability of the antiprotons to penetrate the plasma and reach the center of the engine without undergoing many annihilation reactions along the way. Using expressions for the annihilation rate per unit distance and the stopping power of antiprotons in a fully ionized hydrogenous plasma we calculate the annihilation distribution and the fraction of antiprotons that reach the central region in a relatively cold deuterium-tritium plasma. We apply these results to a rocket engine 16 m in length and containing plasma with 10{sup 16} cm{sup {minus}3} density, and we find that well over 90{percent} of the annihilations take place within a few centimeters from the midplane of the engine when the initial plasma temperature is 20 eV. Under these conditions we find that about 10{sup {minus}5} grams per second of antiprotons injected at an energy of about 4 MeV are required to ignite the plasma in this rocket engine. {copyright} {ital 1996 American Institute of Physics.}

  15. Antiproton Powered Gas Core Fission Rocket

    SciTech Connect

    Kammash, Terry

    2005-02-06

    Extensive research in recent years has demonstrated that 'at rest' annihilation of antiprotons in the uranium isotope U238 leads to fission at nearly 100% efficiency. The resulting highly-ionizing, energetic fission fragments can heat a suitable medium to very high temperatures, making such a process particularly suitable for space propulsion applications. Such an ionized medium, which would serve as a propellant, can be confined by a magnetic field during the heating process, and subsequently ejected through a magnetic nozzle to generate thrust. The gasdynamic mirror (GDM) magnetic configuration is especially suited for this application since the underlying confinement principle is that the plasma be of such density and temperature as to make the ion-ion collision mean free path shorter than the plasma length. Under these conditions the plasma behaves like a fluid, and its escape from the system is analogous to the flow of a gas into vacuum from a vessel with a hole. For the system we propose we envisage radially injecting atomic or U238 plasma beam at a pre-determined position and axially pulsing an antiproton beam which upon interaction with the uranium target gives rise to near isotropic ejection of fission fragments with a total mass of 212 amu and total energy of about 160 MeV. These particles, along with the annihilation products (i.e. pions and muons) will heat the background U238 gas - inserted into the chamber just prior to the release of the antiproton - to one keV temperature. Preliminary analysis reveals that such a propulsion system can produce a specific impulse of about 3000 seconds at a thrust of about 50 kN. When applied to a round trip Mars mission, we find that such a journey can be accomplished in about 142 days with 2 days of thrusting and requiring only one gram of antiprotons to achieve it.

  16. Uncoupled thermoelasticity solutions applied on beam dumps

    NASA Astrophysics Data System (ADS)

    Ouzia, A.; Antonakakis, T.

    2016-06-01

    In particle accelerators the process of beam absorption is vital. At CERN particle beams are accelerated at energies of the order of TeV. In the event of a system failure or following collisions, the beam needs to be safely absorbed by dedicated protecting blocks. The thermal shock caused by the rapid energy deposition within the absorbing block causes thermal stresses that may rise above critical levels. The present paper provides a convenient expression of such stresses under hypotheses described hereafter. The temperature field caused by the beam energy deposition is assumed to be Gaussian. Such a field models a non-diffusive heat deposition. These effects are described as thermoelastic as long as the stresses remain below the proportional limit and can be analytically modeled by the coupled equations of thermoelasticity. The analytical solution to the uncoupled thermoelastic problem in an infinite domain is presented herein and matched with a finite unit radius sphere. The assumption of zero diffusion as well as the validity of the match with a finite geometry is quantified such that the obtained solutions can be rigorously applied to real problems. Furthermore, truncated series solutions, which are not novel, are used for comparison purposes. All quantities are nondimensional and the problem reduces to a dependence of five dimensionless parameters. The equations of elasticity are presented in the potential formulation where the shear potential is assumed to be nil due to the source being a gradient and the absence of boundaries. Nevertheless equivalent three-dimensional stresses are computed using the compressive potential and optimized using standard analytical optimization methods. An alternative algorithm for finding the critical points of the three-dimensional stress function is presented. Finally, a case study concerning the proton synchrotron booster dump is presented where the aforementioned analytical solutions are used and the preceding assumptions

  17. Results of head-on beam-beam compensation studies at the Tevatron

    SciTech Connect

    Valishev, A.; Stancari, G.; /Fermilab

    2011-03-01

    At the Tevatron collider, we studied the feasibility of suppressing the antiproton head-on beam-beamtune spread using a magnetically confined 5-keV electron beam with Gaussian transverse profile overlapping with the circulating beam. When electron cooling of antiprotons is applied in regular Tevatron operations, the head-on beam-beam effect on antiprotons is small. Therefore, we first focused on the operational aspects, such as beam alignment and stability, and on fundamental observations of tune shifts, tune spreads, lifetimes, and emittances. We also attempted two special collider stores with only 3 proton bunches colliding with 3 antiproton bunches, to suppress long-range forces and enhance head-on effects. We present here the results of this study and a comparison between numerical simulations and observations, in view of the planned application of this compensation concept to RHIC.

  18. Measurement of interaction between antiprotons

    NASA Astrophysics Data System (ADS)

    The Star Collaboration; Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; 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, J. 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, 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, 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, B.; Huang, H. Z.; 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.; Klein, S.; 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, Z. M.; Li, Y.; Li, W.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R.; Ma, Y. G.; Ma, L.; 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.; 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.; 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.; Roy, A.; 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, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; 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, Z.; Sun, X. M.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; 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, G.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, Y.; Wang, F.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, H.; Xu, N.; Xu, Z.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Z.; Zhang, J.; Zhang, S.; Zhang, X. P.; Zhang, J.; Zhang, Y.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2015-11-01

    One of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton-antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton-proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.

  19. Conceptual Design of an Antiproton Generation and Storage Facility

    SciTech Connect

    Peggs, Stephen

    2006-10-24

    The Antiproton Generation and Storage Facility (AGSF) creates copious quantities of antiprotons, for bottling and transportation to remote cancer therapy centers. The first step in the generation and storage process is to accelerate an intense proton beam down the Main Linac for injection into the Main Ring, which is a Rapid Cycling Synchrotron that accelerates the protons to high energy. The beam is then extracted from the ring into a transfer line and into a Proton Target. Immediately downstream of the target is an Antiproton Collector that captures some of the antiprotons and focuses them into a beam that is transported sequentially into two antiproton rings. The Precooler ring rapidly manipulates antiproton bunches from short and broad (in momentum) to long and thin. It then performs some preliminary beam cooling, in the fraction of a second before the next proton bunch is extracted from the Main Ring. Pre-cooled antiprotons are passed on to the Accumulator ring before the next antiprotons arrive from the target. The Accumulator ring cools the antiprotons, compressing them into a dense state that is convenient for mass storage over many hours. Occasionally the Accumulator ring decelerates a large number of antiprotons, injecting them into a Deceleration Linac that passes them into a waiting Penning trap.

  20. Antiproton fast ignition for Inertial Confinement Fusion

    SciTech Connect

    Perkins, L.J.

    1997-10-24

    With 180MJ/{micro}g, antiprotons offer the highest stored energy per unit mass of any known entity. We investigate the use of antiprotons to promote fast ignition in an ICF capsule and seek high gains with only modest compression of the main fuel. Unlike standard fast ignition where the ignition energy is supplied by an energetic, short pulse laser, the energy here is supplied through the ionization energy deposited when antiprotons annihilate at the center of a compressed fuel capsule. In the first of two candidate fast ignition schemes, the antiproton package is delivered by a low energy external ion beam. In the second, ''autocatalytic'' scheme, the antiprotons are pre-emplaced at the center of the capsule prior to compression. In both schemes, we estimate that {approximately}3x10{sup 13} antiprotons are required to initiate fast ignition in a typical ICF capsule and show that incorporation of a thin, heavy metal shell is desirable to enhance energy deposition in the igniter zone. In addition to obviating the need for a second energetic fast laser and vulnerable final optics, this scheme would achieve central without reliance on laser channeling through halo plasma or houlrahm debris. However, in addition to the unknowns involved in the storage and manipulation of antiprotons at low energy, the other large uncertainty for the practicality of such a scheme is the ultimate efficiency of antiproton production in, an external, optimized facility.

  1. Beam-Energy Dependence of the Directed Flow of Protons, Antiprotons, and Pions in Au+Au Collisions

    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

    2014-04-01

    Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y =0) are reported in √sNN =7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

  2. Beam-energy dependence of the directed flow of protons, antiprotons, and pions in Au+Au collisions.

    PubMed

    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

    2014-04-25

    Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

  3. Practical Uses of Antiprotons

    NASA Astrophysics Data System (ADS)

    Jackson, Gerald P.

    The production of commercial quantities of antiprotons has been a reality for many years now. The deceleration and trapping of antiprotons is a relatively new activity, but has been sufficiently proven to be translated into a business enterprise. Now that NASA has a portable Penning trap for transporting antiprotons, all the elements are in place to begin the commercial distribution of antiprotons. The list of potential customers for antiprotons is continuously growing, with detailed market analyses already performed on some medical and propulsion applications. In this paper these applications are reviewed, along with their appetite for antiprotons and the steps needed to bring them to market.

  4. Physics with antiprotons at P¯ANDA

    NASA Astrophysics Data System (ADS)

    Mochalov, V.

    2013-12-01

    The P¯ANDA collaboration (anti-Proton ANnihilations at DArmstadt) is a next generation hadron physics experiment to be operated at the future Facility for Antiproton and Ion Research (FAIR) at Darmstadt, Germany. It will use intensive cooled antiproton beams with a momentum between 1.5 GeV/c and 15 GeV/c. The P¯ANDA detector is a state-of-the-art internal target detector allowing the detection and identification of neutral and charged particles almost in the whole solid angle.

  5. Measurement of interaction between antiprotons

    DOE PAGES

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

    2015-11-04

    In this paper, one of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by themore » STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton–antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton–proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.« less

  6. Measurement of interaction between antiprotons

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; 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, J. 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, 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, 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, B.; Huang, H. Z.; 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.; Klein, S.; 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, Z. M.; Li, Y.; Li, W.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R.; Ma, Y. G.; Ma, L.; 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.; 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.; 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.; Roy, A.; 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, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; 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, Z.; Sun, X. M.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; 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, G.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, Y.; Wang, F.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, H.; Xu, N.; Xu, Z.; Yang, Y.; Yang, C.; Yang, S.; Yang, Y.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I. -K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, Z.; Zhang, J.; Zhang, S.; Zhang, X. P.; Zhang, J.; Zhang, Y.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.

    2015-11-04

    In this paper, one of the primary goals of nuclear physics is to understand the force between nucleons, which is a necessary step for understanding the structure of nuclei and how nuclei interact with each other. Rutherford discovered the atomic nucleus in 1911, and the large body of knowledge about the nuclear force that has since been acquired was derived from studies made on nucleons or nuclei. Although antinuclei up to antihelium-4 have been discovered and their masses measured, little is known directly about the nuclear force between antinucleons. Here, we study antiproton pair correlations among data collected by the STAR experiment at the Relativistic Heavy Ion Collider (RHIC), where gold ions are collided with a centre-of-mass energy of 200 gigaelectronvolts per nucleon pair. Antiprotons are abundantly produced in such collisions, thus making it feasible to study details of the antiproton–antiproton interaction. By applying a technique similar to Hanbury Brown and Twiss intensity interferometry, we show that the force between two antiprotons is attractive. In addition, we report two key parameters that characterize the corresponding strong interaction: the scattering length and the effective range of the interaction. Our measured parameters are consistent within errors with the corresponding values for proton–proton interactions. Our results provide direct information on the interaction between two antiprotons, one of the simplest systems of antinucleons, and so are fundamental to understanding the structure of more-complex antinuclei and their properties.

  7. Antiproton physics at BNL

    SciTech Connect

    Lazarus, D.M.

    1992-12-31

    A review of antiproton physics at the brookhaven AGS in past decade is given as well as a description of the present high energy physics program. Existing and potential facilities for antiproton physics at the AGS are discussed and are found to provide useful antiproton intensities over the momentum range proposed for SUPERLEAR in a multiple user environment.

  8. AMS-02 antiprotons reloaded

    SciTech Connect

    Kappl, Rolf; Reinert, Annika; Winkler, Martin Wolfgang E-mail: areinert@th.physik.uni-bonn.de

    2015-10-01

    The AMS-02 collaboration has released preliminary data on the antiproton fraction in cosmic rays. The surprisingly hard antiproton spectrum at high rigidity has triggered speculations about a possible primary antiproton component originating from dark matter annihilations. In this note, we employ newly available AMS-02 boron to carbon data to update the secondary antiproton flux within the standard two-zone diffusion model. The new background permits a considerably better fit to the measured antiproton fraction compared to previous estimates. This is mainly a consequence of the smaller slope of the diffusion coefficient favored by the new AMS-02 boron to carbon data.

  9. Deceleration of Antiprotons in Support of Antiproton Storage/Utilization Research

    SciTech Connect

    Howe, Steven D.; Jackson, Gerald P.; Pearson, J. Boise; Lewis, Raymond A.

    2005-02-06

    Antimatter has the highest energy density known to mankind. Many concepts have been studied that use antimatter for propulsion. All of these concepts require the development of high density storage. H-bar Technologies, under contract with the NASA Marshall Space Flight Center, has undertaken the first step toward development of high density storage. Demonstration of the ability to store antiprotons in a Penning Trap provides the technology to pursue research in alternative storage methods that may lead to eventually to high density concepts. H-bar Technologies has undertaken research activity on the detailed design and operations required to decelerate and redirect the Fermi National Accelerator Laboratory (FNAL) antiproton beam to lay the groundwork for a source of low energy antiprotons. We have performed a detailed assessment of an antiproton deceleration scheme using the FNAL Main Injector, outlining the requirements to significantly and efficiently lower the energy of antiprotons. This task shall require a combination of: theoretical/computation simulations, development of specialized accelerator controls programming, modification of specific Main Injector hardware, and experimental testing of the modified system. Testing shall be performed to characterize the system with a goal of reducing the beam momentum from 8.9 GeV/c to a level of 1 GeV/c or less. We have designed an antiproton degrader system that will integrate with the FNAL decelerated/transferred beam. The degrader shall be designed to maximize the number of low energy antiprotons with a beam spot sized for acceptance by the Mark I test hardware.

  10. Photo-Production of Proton Antiproton Pairs

    SciTech Connect

    Paul Eugenio; Burnham Stokes

    2007-02-01

    Results are reported on the reaction gammap --> ppp-bar . A high statistic data set was obtained at the Thomas Jefferson National Accelerator Facility utilizing the CLAS detector and a tagged photon beam of 4.8 to 5.2 GeV incident on a liquid hydrogen target. The focus of this study was to search for possible intermediate resonances which decay to proton-antiproton. Both final state protons were detected in the CLAS apparatus whereas the antiproton was identified via missing mass. General features of the data are presented along with results on narrow and broad resonance studies.

  11. Anti-hydrogen production with positron beam ion trap

    SciTech Connect

    Itahashi, Takahisa

    2008-08-08

    In low-energy antiproton physics, it is advantageous to be able to manipulate anti-particles as freely as normal particles. A robust production and storage system for high-quality positrons and antiprotons would be a substantial advance for the development of anti-matter science. The idea of electron beam ion trap could be applied for storage of anti-particle when the electron beam could be replaced by the positron beam. The bright positron beam would be brought about using synchrotron radiation source with a superconducting wiggler. The new scheme for production of anti-particles is proposed by using new accelerator technologies.

  12. Antiproton catalyzed fusion

    SciTech Connect

    Morgan, D.L. Jr.; Perkins, L.J.; Haney, S.W.

    1995-05-15

    Because of the potential application to power production, it is important to investigate a wide range of possible means to achieve nuclear fusion, even those that may appear initially to be infeasible. In antiproton catalyzed fusion, the negative antiproton shields the repulsion between the positively charged nuclei of hydrogen isotopes, thus allowing a much higher level of penetration through the repulsive Coulomb barrier, and thereby greatly enhancing the fusion cross section. Because of their more compact wave function, the more massive antiprotons offer considerably more shielding than do negative muons. The effects of the shielding on fusion cross sections are most predominate, at low energies. If the antiproton could exist in the ground state with a nucleus for a sufficient time without annihilating, the fusion cross sections are so enhanced that at room temperature energies, values up to about 1,000 barns (that for d+t) would be possible. Unfortunately, the cross section for antiproton annihilation with the incoming nucleus is even higher. A model that provides an upper bound for the fusion to annihilation cross section for all relevant energies indicates that each antiproton will catalyze no more than about one fusion. Because the energy required to make one antiproton greatly exceeds the fusion energy that is released, this level of catalysis is far from adequate for power production.

  13. Polarized Antiprotons - The Quest For A Missing Tool

    SciTech Connect

    Steffens, Erhard

    2009-08-04

    After termination of the LEAR facility in 1996 and the restriction of the CERN antiproton program to Trap experiments, stored antiprotons at low and medium energies are no longer available for experiments. FAIR at GSI (Darmstadt) will provide intense stored antiproton beams in less than a decade from now. This has renewed the interest in polarized antiprotons originally proposed for LEAR. In August 2007, an International Workshop was organized at the Cockcroft Institute (Daresbury) and methods to polarize stored antiprotons were discussed. In June 2008, a Heraeus Seminar at the Physikzentrum in Bad Honnef dealing with the same subject took place. The results of these workshops will be presented with some historical remarks and an account of the recent developments.

  14. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2013-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  15. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2014-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  16. Hadron Physics with Antiprotons

    SciTech Connect

    Wiedner, Ulrich

    2005-10-26

    The new FAIR facility which comes into operation at GSI in the upcoming years has a dedicated program of utilizing antiprotons for hadron physics. In particular, the planned PANDA experiment belongs to the group of core experiments at the new FAIR facility in Darmstadt/Germany. PANDA will be a universal detector to study the strong interaction by utilizing the annihilation process of antiprotons with protons and nuclear matter. The current paper gives an introduction into the hadron physics with antiprotons and part of the planned physics program with PANDA.

  17. Physics overview of the Fermilab Low Energy Antiproton Facility Workshop

    SciTech Connect

    Chanowitz, M.S.

    1986-05-01

    A physics overview is presented of the Fermilab workshop to consider a possible high flux, low energy antiproton facility that would use cooled antiprotons from the accumulator ring of the Tevatron collider. Two examples illustrate the power of each a facility to produce narrow states at high rates. Physics topics to which such a facility may be applied are reviewed.

  18. Antiproton Trapping for Advanced Space Propulsion Applications

    NASA Technical Reports Server (NTRS)

    Smith, Gerald A.

    1998-01-01

    The Summary of Research parallels the Statement of Work (Appendix I) submitted with the proposal, and funded effective Feb. 1, 1997 for one year. A proposal was submitted to CERN in October, 1996 to carry out an experiment on the synthesis and study of fundamental properties of atomic antihydrogen. Since confined atomic antihydrogen is potentially the most powerful and elegant source of propulsion energy known, its confinement and properties are of great interest to the space propulsion community. Appendix II includes an article published in the technical magazine Compressed Air, June 1997, which describes CERN antiproton facilities, and ATHENA. During the period of this grant, Prof. Michael Holzscheiter served as spokesman for ATHENA and, in collaboration with Prof. Gerald Smith, worked on the development of the antiproton confinement trap, which is an important part of the ATHENA experiment. Appendix III includes a progress report submitted to CERN on March 12, 1997 concerning development of the ATHENA detector. Section 4.1 reviews technical responsibilities within the ATHENA collaboration, including the Antiproton System, headed by Prof. Holzscheiter. The collaboration was advised (see Appendix IV) on June 13, 1997 that the CERN Research Board had approved ATHENA for operation at the new Antiproton Decelerator (AD), presently under construction. First antiproton beams are expected to be delivered to experiments in about one year. Progress toward assembly of the ATHENA detector and initial testing expected in 1999 has been excellent. Appendix V includes a copy of the minutes of the most recently documented collaboration meeting held at CERN of October 24, 1997, which provides more information on development of systems, including the antiproton trapping apparatus. On February 10, 1998 Prof. Smith gave a 3 hour lecture on the Physics of Antimatter, as part of the Physics for the Third Millennium Lecture Series held at MSFC. Included in Appendix VI are notes and

  19. Direct measurements of the stopping power for antiprotons of light and heavy targets

    SciTech Connect

    Mo Uggerho Bluhme, H.; Knudsen, H.; Mikkelsen, U.; Paludan, K.; Morenzoni, E.

    1997-10-01

    Measurements of antiproton stopping powers around the stopping-power maximum are presented for targets of Al, Si, Ti, Cu, Ag, Ta, Pt, and Au. The Low Energy Antiproton Ring antiproton beam of 5.9 MeV is degraded to 50{endash}700 keV, and the energy loss is found by measuring the antiproton velocity before and after the target. Target thicknesses have been determined accurately by weighing and Rutherford backscattering techniques. The antiproton stopping powers are found to be reduced by around 35{percent} for both light and heavy elements near the electronic stopping-power maximum as compared to the equivalent proton stopping power. The antiproton stopping powers and the Barkas effect; that is, the difference in stopping power between protons and antiprotons is compared to theoretical estimates, based on a harmonic-oscillator model and an electron-gas model, and good agreement is obtained. {copyright} {ital 1997} {ital The American Physical Society}

  20. Antiproton compression and radial measurements

    SciTech Connect

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der; Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S.; Cesar, C. L.; Lambo, R.; Silveira, D. M.; Fujiwara, M. C.

    2008-08-08

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  1. Observation of Ultra-Slow Antiprotons using Micro-channel Plate

    SciTech Connect

    Imao, H.; Toyoda, H.; Shimoyama, T.; Kanai, Y.; Mohri, A.; Yamazaki, Y.; Torii, H. A.; Nagata, Y.; Enomoto, Y.; Higaki, H.

    2008-08-08

    Our group ASACUSA-MUSASHI has succeeded in accumulating several million antiprotons and extracting them as monochromatic ultra-slow antiproton beams (10 eV-1 keV) at CERN AD. We have observed ultra-slow antiprotons using micro-channel plates (MCP). The integrated pulse area of the output signals generated when the MCP was irradiated by ultra-slow antiprotons was 6 times higher than that by electrons. As a long-term effect, we also observed an increase in the background rate presumably due to the radioactivation of the MCP surface. Irradiating the antiproton beams on the MCP induces antiproton-nuclear annihilations only on the first layer of the surface. Low-energy and short-range secondary particles like charged nuclear fragments caused by the 'surface nuclear reactions' would be the origin of our observed phenomena.

  2. Antiproton cloud compression in the ALPHA apparatus at CERN

    NASA Astrophysics Data System (ADS)

    Gutierrez, A.; Ashkezari, M. D.; Baquero-Ruiz, M.; Bertsche, W.; Burrows, C.; Butler, E.; Capra, A.; Cesar, C. L.; Charlton, M.; Dunlop, R.; Eriksson, S.; Evetts, N.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Hangst, J. S.; Hardy, W. N.; Hayden, M. E.; Isaac, C. A.; Jonsell, S.; Kurchaninov, L.; Little, A.; Madsen, N.; K. McKenna, J. T.; Menary, S.; Napoli, S. C.; Nolan, P.; Olchanski, K.; Olin, A.; Pusa, P.; Rasmussen, C. Ø.; Robicheaux, F.; Sacramento, R. L.; Sarid, E.; Silveira, D. M.; So, C.; Stracka, S.; Tarlton, J.; Tharp, T. D.; Thompson, R. I.; Tooley, P.; Turner, M.; van der Werf, D. P.; Wurtele, J. S.; Zhmoginov, A. I.

    2015-11-01

    We have observed a new mechanism for compression of a non-neutral plasma, where antiprotons embedded in an electron plasma are compressed by a rotating wall drive at a frequency close to the sum of the axial bounce and rotation frequencies. The radius of the antiproton cloud is reduced by up to a factor of 20 and the smallest radius measured is ˜ 0.2 mm. When the rotating wall drive is applied to either a pure electron or pure antiproton plasma, no compression is observed in the frequency range of interest. The frequency range over which compression is evident is compared to the sum of the antiproton bounce frequency and the system's rotation frequency. It is suggested that bounce resonant transport is a likely explanation for the compression of antiproton clouds in this regime.

  3. Commissioning of Fermilab's electron cooling system for 8-GeV antiprotons

    SciTech Connect

    Nagaitsev, S.; Broemmelsiek, D.; Burov, A.; Carlson, K.; Gattuso, C.; Hu, M.; Kramper, B.; Kroc, T.; Leibfritz, J.; Prost, L.; Pruss, S.; Saewert, G.; Schmidt, C.W.; Shemyakin, A.; Sutherland, M.; Tupikov, V.; Warner, A.; Seletsky, S.; Gai, W.; Kazakevich, Grigory M.; /Novosibirsk, IYF

    2005-05-01

    A 4.3-MeV electron cooling system [1] has been installed at Fermilab in the Recycler antiproton storage ring and is currently being commissioned. The cooling system is designed to assist accumulation of 8.9-GeV/c antiprotons for the Tevatron collider operations. This paper reports on the progress of the electron beam commissioning effort as well as on detailed plans of demonstrating the cooling of antiprotons.

  4. CPT tests with antihydrogen and antiprotonic helium atoms

    NASA Astrophysics Data System (ADS)

    Hayano, Ryugo

    2014-09-01

    Recent progress of the CPT tests with antihydrogen and antiprotonic helium atoms by the ASACUSA collaboration at CERN's antiproton decelerator will be presented. The antiprotonic helium atom (antiproton+electron+helium nucleus) is a serendipitously discovered metastable three-body system, whose energy levels can now be studied by laser spectroscopy techniques to a relative precision of ~10-9. By comparing these precise experimental results with the result of three-body QED calculation, the antiproton-to-electron mass ratio was determined to a relative precision of 1 . 2 ×10-9 . While this can be used as a precise test of the CPT symmetry, CODATA instead assumed the CPT, and combined our results with the proton-to-electron mass ratio measured by the Penning trap method in their adjustment of the fundamental physical constants. In addition to the laser spectroscopy of antiprotonic helium, ASACUSA collaboration also aims at measuring the ground-state hyperfine splitting of antihydrogen using the (anti)-atomic beam method. Extraction of antihydrogen atoms from a ``cusp'' trap has so far been demonstrated. Both of these experiments will benefit from the completing of a new antiproton decelerator-cooler ring called ELENA, which is under construction at CERN.

  5. Composition of the nuclear periphery from antiproton absorption

    NASA Astrophysics Data System (ADS)

    Lubiński, P.; Jastrzȩbski, J.; Trzcińska, A.; Kurcewicz, W.; Hartmann, F. J.; Schmid, W.; von Egidy, T.; Smolańczuk, R.; Wycech, S.

    1998-06-01

    Thirteen targets with mass numbers from 58 to 238 were irradiated with the antiproton beam from the Low Energy Antiproton Ring facility at CERN leading to the formation of antiprotonic atoms of these heavy elements. The antiproton capture at the end of an atomic cascade results in the production of more or less excited residual nuclei. The targets were selected with the criterion that both reaction products with one nucleon less than the proton and neutron number of the target be radioactive. The yield of these radioactive products after stopped-antiproton annihilation was determined using gamma-ray spectroscopy techniques. This yield is related to the proton and neutron density in the target nucleus at a radial distance corresponding to the antiproton annihilation site. The experimental data clearly indicate the existence of a neutron-rich nuclear periphery, a ``neutron halo,'' strongly correlated with the target neutron separation energy Bn and observed for targets with Bn<10 MeV. For two-target nuclei 106Cd and 144Sm, with larger neutron binding energies, a proton-rich nuclear periphery was observed. Most of the experimental data are in reasonable agreement with calculations based on current antiproton-nucleus and pion-nucleus interaction potentials and on nuclear densities deduced with the help of the Hartree-Fock-Bogoliubov approach. This approach was, however, unable to account for the 106Cd and 144Sm results.

  6. Antiproton-boosted microfission

    SciTech Connect

    Lewis, R.A.; Newton, R.; Smith, G.A. ); Kanzleiter, R.J. )

    1991-12-01

    The concept of microfission, whereby a small target of fissile material is burned under compression, was introduced nearly 20 years ago; the size of the target is limited by the magnitude of the compression and by the initial number of fissions that start the chain reaction. A burst of antiprotons at maximum compression can allow target size to be significantly reduced. Antiprotons were previously shown to be a strong source of neutrons and pions; under conditions of high density, they enable a significant reduction in burn time and, hence, target size. In this paper, possible applications are discussed, including space propulsion and intense neutron and X-ray sources.

  7. Antiprotons in cosmic rays

    NASA Technical Reports Server (NTRS)

    Balasubrahmanyan, V. K.; Ormes, J. F.; Streitmatter, R. E.

    1987-01-01

    Recent experimental observations and results are discussed. It was found that the approximately 50 antiprotons collected in balloon experiments to date have generated considerable theoretical interest. Clearly, confirmatory experiments and measurements over an extended energy range are required before definite conclusions are drawn. Antiproton measurements have a bearing on astrophysical problems ranging from cosmic ray propagation to issues of cosmological import. The next generation of balloon experiments and the Particle Astrophysics Magnet Facility being discussed for operation on NASA's space station should provide data and insights of highest interest.

  8. Measurement of proton and anti-proton intensities in the Tevatron Collider

    SciTech Connect

    Stephen Pordes et al.

    2003-06-04

    This paper describes the techniques used to measure the intensities of the proton (p) and anti-proton ({bar p}) beams in the Tevatron collider. The systems provide simultaneous measurements of the intensity of the 36 proton and 36 antiproton bunches and their longitudinal profiles.

  9. Sub-Femtosecond Correlated Dynamics Probed with Antiprotons

    SciTech Connect

    Welsch, C. P.; Kuehnel, K. U.; Schroeter, C. D.; Ullrich, J.

    2008-08-08

    Low-energy antiprotons are the ideal and perhaps the only tool to study in detail correlated quantum dynamics of few-electron systems in the femto and sub-femtosecond time regime. Unfortunately cooled beams of antiprotons with the necessary beam quality and luminosity are not yet available and cannot be provided with present scientific infrastructures. In order to pave the way for a next-generation low-energy antiproton facility, challenging developments in both, storing and imaging techniques have been launched at MPI-K. A novel ultra-low energy storage ring (USR) to be integrated at the proposed facility for low-energy antiproton and ion research (FLAIR) is being developed to provide electron-cooled beams of antiprotons and possibly highly charged ions in the energy range between 300 and 20 keV/q, maybe even approaching the sub keV regime. To allow for kinematically complete investigations for a variety of different collision processes, a reaction microscope shall be integrated in the ring thus achieving unprecedented luminosities. In this contribution, the present status of experiments in comparison with theory is highlighted and the layout of the USR as well as of the in-ring and an external single-pass reaction microscope is presented.

  10. Electron cooling of 8-GeV antiprotons at Fermilab's Recycler: Results and operational implications

    SciTech Connect

    Prost, L.R.; Broemmelsiek, D.; Burov, Alexey V.; Carlson, K.; Gattuso, C.; Hu, M.; Kroc, T.; Leibfritz, J.; Nagaitsev, S.; Pruss, S.; Saewert, G.; Schmidt, C.W.; Shemyakin, A.; Sutherland, M.; Tupikov, V.; Warner, A.; /Fermilab

    2006-05-01

    Electron cooling of 8 GeV antiprotons at Fermilab's Recycler storage ring is now routinely used in the collider operation. It requires a 0.1-0.5 A, 4.3 MeV dc electron beam and is designed to increase the longitudinal phase-space density of the circulating antiproton beam. This paper briefly describes the characteristics of the electron beam that were achieved to successfully cool antiprotons. Then, results from various cooling force measurements along with comparison to a nonmagnetized model are presented. Finally, operational aspects of the implementation of electron cooling at the Recycler are discussed, such as adjustments to the cooling rate and the influence of the electron beam on the antiproton beam lifetime.

  11. Observation of Antiprotons

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Segre, Emilio; Wiegand, Clyde; Ypsilantis, Thomas

    1955-10-19

    One of the striking features of Dirac's theory of the electron was the appearance of solutions to his equations which required the existence of an antiparticle, later identified as the positron. The extension of the Dirac theory to the proton requires the existence of an antiproton, a particle which bears to the proton the same relationship as the positron to the electron. However, until experimental proof of the existence of the antiproton was obtained, it might be questioned whether a proton is a Dirac particle in the same sense as is the electron. For instance, the anomalous magnetic moment of the proton indicates that the simple Dirac equation does not give a complete description of the proton.

  12. The Fermilab Antiproton Source Design Report April, 1981

    SciTech Connect

    None, None

    1981-04-01

    The purpose of the Fermilab Antiproton source is to provide at least $10^{11}$ cooled, accumulated antiprotons for acceleration in the Main Ring and Tevatron for colliding-beams experiments with 1-TeV protons. This will provide the highest available energy in the world for particle-physics experiments through at least the 1980's. Collisions at 2 TeV in the center of mass will provide a unique experimental tool in a new energy range. The design of the Antiproton Source has been carried out by the Colliding Beams Department of the Accelerator Division in collaboration with Argonne National Laborator.y, Lawrence Berkeley Laboratory, the Institute of Nuclear Physics at Novosibirsk, and the University of Wisconsin...

  13. Large amounts of antiproton production by heavy ion collision

    SciTech Connect

    Takahashi, Hiroshi; Powell, J.

    1987-01-01

    To produce large amounts of antiprotons, on the order of several grams/year, use of machines to produce nuclear collisions are studied. These can be of either proton-proton, proton-nucleus and nucleus-nucleus in nature. To achieve high luminosity colliding beams, on the order of 10/sup 41/ m/cm/sup 2/, a self-colliding machine is required, rather than a conventional circular colliding type. The self-colliding machine can produce additional antiprotons through successive collisions of secondary particles, such as spectator nucleons. A key problem is how to collect the produced antiprotons without capture by beam nuclei in the collision zone. Production costs for anti-matter are projected for various energy source options and technology levels. Dedicated facilities using heavy ion collisions could produce antiproton at substantially less than 1 million $/milligram. With co-production of other valuable products, e.g., nuclear fuel for power reactors, antiproton costs could be reduced to even lower values.

  14. Simulated annealing algorithm applied in adaptive near field beam shaping

    NASA Astrophysics Data System (ADS)

    Yu, Zhan; Ma, Hao-tong; Du, Shao-jun

    2010-11-01

    Laser beam shaping is required in many applications for improving the efficiency of the laser systems. In this paper, the near field beam shaping based on the combination of simulated annealing algorithm and Zernike polynomials is demonstrated. Considering phase distribution can be represented by the expansion of Zernike polynomials, the problem of searching appropriate phase distribution can be changed into a problem of optimizing a vector made up of Zernike coefficients. The feasibility of this method is validated theoretically by translating the Gaussian beam into square quasi-flattop beam in the near field. Finally, the closed control loop system constituted by phase only liquid crystal spatial light modulator and simulated annealing algorithm is used to prove the validity of the technique. The experiment results show that the system can generate laser beam with desired intensity distributions.

  15. Physics at CERN’s Antiproton Decelerator

    NASA Astrophysics Data System (ADS)

    Hori, M.; Walz, J.

    2013-09-01

    The Antiproton Decelerator (AD) facility of CERN began operation in 1999 to serve experiments for studies of CPT invariance by precision laser and microwave spectroscopy of antihydrogen (Hbar ) and antiprotonic helium (pbar He) atoms. The first 12 years of AD operation saw cold Hbar synthesized by overlapping clouds of positrons (e+) and antiprotons (pbar ) confined in magnetic Penning traps. Cold Hbar was also produced in collisions between Rydberg positronium (Ps) atoms and pbar . Ground-state Hbar was later trapped for up to ˜1000 s in a magnetic bottle trap, and microwave transitions excited between its hyperfine levels. In the pbar He atom, deep ultraviolet transitions were measured to a fractional precision of (2.3-5)×10-9 by sub-Doppler two-photon laser spectroscopy. From this the antiproton-to-electron mass ratio was determined as M/me=1836.1526736(23), which agrees with the p value known to a similar precision. Microwave spectroscopy of pbar He yielded a measurement of the pbar magnetic moment with a precision of 0.3%. More recently, the magnetic moment of a single pbar confined in a Penning trap was measured with a higher precision, as μ=-2.792845(12)μ in nuclear magnetons. Other results reviewed here include the first measurements of the energy loss (-dE/dx) of 1-100 keV pbar traversing conductor and insulator targets; the cross sections of low-energy (<10 keV) pbar ionizing atomic and molecular gas targets; and the cross sections of 5 MeV pbar annihilating on various target foils via nuclear collisions. The biological effectiveness of pbar beams destroying cancer cells was measured as a possible method for radiological therapy. New experiments under preparation attempt to measure the gravitational acceleration of Hbar or synthesize H. Several other future experiments will also be briefly described.

  16. Antiproton production in heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Jacak, B. V.

    In high energy p-p and alpha-alpha collisions, baryons are observed predominantly at rapidities near those of target and projectile; the mean rapidity shift of projectile and target nucleons is approximately one unit. In the central rapidity region, the number of baryons is quite small. In fact, the number of baryons and antibaryons is rather similar, indicating that most of these baryons are CREATED particles rather than projectile and target fragments. Antibaryon production is of interest in heavy ion collisions as enhanced antiquark production has been predicted as a potential signature of quark-gluon plasma formation. Antibaryons also provide a sensitive probe of the hadronic environment, via annihilation and/or mean field effects upon their final distributions. However, the collision dynamics also affect the baryon and antibaryon distributions. Baryons are more shifted toward midrapidity in nucleus-nucleus and p-p nucleus collisions than in p-p collisions, increasing the probability of annihilating the antibaryons. The interpretation of antibaryon yields is further complicated by collective processes which may take place in the dense hadronic medium formed in nucleus-nucleus collisions. Jahns and coworkers have shown that multistep processes can increase antibaryon production near threshold. Antiproton production is clearly very interesting, but is sensitive to a combination of processes taking place in the collision. The final number of observed antiprotons depends on the balance between mechanisms for extra antiproton production beyond those from the individual nucleon-nucleon collisions and annihilation with surrounding baryons. We can hope to sort out these things by systematic studies, varying the system size and beam energy. I will review what is known about antiproton production at both the AGS and SPS, and look at trends going from p-p to p-nucleus to nucleus-nucleus collisions.

  17. ANTIPROTONS PRODUCED IN SUPERNOVA REMNANTS

    SciTech Connect

    Berezhko, E. G.; Ksenofontov, L. T.

    2014-08-20

    We present the energy spectrum of an antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNRs). The model includes the reacceleration of antiprotons already existing in the interstellar medium as well as the creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shocks. It is shown that the production of antiprotons in SNRs produces a considerable effect in their resultant energy spectrum, making it essentially flatter above 10 GeV so that the spectrum at TeV energies increases by a factor of 5. The calculated antiproton spectrum is consistent with the PAMELA data, which correspond to energies below 100 GeV. As a consistency check, we have also calculated within the same model the energy spectra of secondary nuclei and show that the measured boron-to-carbon ratio is consistent with the significant SNR contribution.

  18. Proceedings of the Workshop on Antiproton Technology Held in Brookhaven National Laboratory on 10 May 1989. Addendum

    DTIC Science & Technology

    1989-09-01

    GROUP SUB-GROUP Antiproton Beams, Imaging, NDA/NDE, Radiotherapy, Condensed _2 07 Antimatter , CP Violation 20 084, 19. ABSTRACT (Continue on reverse if...experiments proposed by workshop participantC. Antiprotons are particles of antimatter which release highly penetroting radiation when they are stopped in...Clinic Medical Cen. Prospects for a Commercial Antiproton Source 46 Brian Von Herzen, Antimatter Technology Corp Prospects for Exciting Extreme States

  19. Photon and dilepton production at the Facility for Proton and Anti-Proton Research and beam-energy scan at the Relativistic Heavy-Ion Collider using coarse-grained microscopic transport simulations

    NASA Astrophysics Data System (ADS)

    Endres, Stephan; van Hees, Hendrik; Bleicher, Marcus

    2016-05-01

    We present calculations of dilepton and photon spectra for the energy range Elab=2 A to35 A GeV which will be available for the Compressed Baryonic Matter (CBM) experiment at the future Facility for Proton and Anti-Proton Research (FAIR). The same energy regime will also be covered by phase II of the beam-energy scan at the Relativistic Heavy-Ion Collider (RHIC-BES). Coarse-grained dynamics from microscopic transport calculations of the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) model is used to determine temperature and chemical potentials, which allows for the use of dilepton and photon-emission rates from equilibrium quantum-field-theory calculations. The results indicate that nonequilibrium effects, the presence of baryonic matter, and the creation of a deconfined phase might show up in specific manners in the measurable dilepton invariant-mass spectra and in the photon transverse-momentum spectra. However, as the many influences are difficult to disentangle, we argue that the challenge for future measurements of electromagnetic probes will be to provide a high precision with uncertainties much lower than in previous experiments. Furthermore, a systematic study of the whole energy range covered by CBM at FAIR and RHIC-BES is necessary to discriminate between different effects, which influence the spectra, and to identify possible signatures of a phase transition.

  20. Antiproton Annihilation Propulsion

    DTIC Science & Technology

    1985-09-01

    hadrons with transverse momentum 0.5-2.5 GeV/c in 70-GeV proton- nucleus collisions ," Soy. J. Nucl. Phys. 31, 343-346 (1980). 1- 1 6 B.E. Balakin and A.N...particle physics experiments including measurements of the production spectrum of hadrons (including antiprotons) in the collision of 70 GeV protons with...electromagnetic fields on the nucleation process, including the precursor phase where two, three, and multiple -molecule collisions produce the dendritic

  1. Collisional and Spectroscopic Studies of Exotic Atoms Using Ultra-Slow Antiprotons

    SciTech Connect

    Torii, H. A.; Toyoda, H.; Kuroda, N.; Nagata, Y.; Yamazaki, Y.; Imao, H.; Varentsov, V. L.

    2009-07-10

    Antiproton, the antiparticle of proton, is a unique projectile in the study of atomic collision physics, which can be treated theoretically either as a 'negative proton' or a 'heavy electron'. Atomic capture of an antiproton will result in formation of a highly excited exotic atom. Antiprotonic helium atom has been studied intensively by means of precision laser spectroscopy, which has led to a stringent determination of antiproton mass and charge to a level of ppb. Comparison of these values with those of proton gives one of the best tests of CPT invariance, the most fundamental symmetry in physics. However, the dynamic processes of antiproton capture remain unclarified, except for some indirect information given by those optical and X-ray observations. With an aim to produce an antiproton beam at atomic-physics energies for 'pure' collision experiments, we have so far developed techniques to decelerate, cool and confine antiprotons in vacuo, using a sequential combination of the Antiproton Decelerator (AD) at CERN, a Radio-Frequency Quadrupole Decelerator (RFQD), and an electromagnetic trap. Our recent success in stable extraction of monoenergetic ultra-slow antiprotons, about 3x10{sup 5} in number available every 5 minutes, has opened up the possibility to study ionization and atomic capture processes between an antiproton thus provided as a beam and an atom prepared in the form of a supersonic gas-jet target, at an unprecedented low energy from 10 eV to 1 keV under the single-collision condition. Our design and strategy of the cross-beam experiments are discussed.

  2. Experimental Studies of Compensation of Beam-Beam Effects with Tevatron Electron Lenses

    SciTech Connect

    Shiltsev, V.; Alexahin, Yu.; Bishofberger, Kip; Kamerdzhiev, V.; Parkhomchuk, V.; Reva, V.; Solyak, N.; Wildman, D.; Zhang, X.-L.; Zimmermann, F.; /Fermilab /Los Alamos /Novosibirsk, IYF /CERN

    2008-02-01

    Applying the space-charge forces of a low-energy electron beam can lead to a significant improvement of the beam-particle lifetime limit arising from the beam-beam interaction in a high-energy collider [1]. In this article we present the results of various beam experiments with 'electron lenses', novel instruments developed for the beam-beam compensation at the Tevatron, which collides 980-GeV proton and antiproton beams. We study the dependencies of the particle betatron tunes on the electron beam current, energy and position; we explore the effects of electron-beam imperfections and noises; and we quantify the improvements of the high-energy beam intensity and the collider luminosity lifetime obtained by the action of the Tevatron Electron Lenses.

  3. Status of antiproton accumulation and cooling at Fermilab's Recycler

    SciTech Connect

    Prost, L.R.; Bhat, C.M.; Broemmelsiek, D.; Burov, A.; Carlson, K.; Crisp, J.; Derwent, P.; Eddy, N.; Gattuso, C.; Hu, M.; Pruss, S.; /Fermilab

    2009-08-01

    The Recycler ring is an 8 GeV permanent magnet storage ring where antiprotons are accumulated and prepared for Fermilab's Tevatron Collider program. With the goal of maximizing the integrated luminosity delivered to the experiments, storing, cooling and extracting antiprotons with high efficiency has been pursued. Over the past two years, while the average accumulation rate doubled, the Recycler continued to operate at a constant level of performance thanks to changes made to the Recycler Electron Cooler (energy stability and regulation, electron beam optics), RF manipulations and operating procedures. In particular, we discuss the current accumulation cycle in which {approx} 400 x 10{sup 10} antiprotons are accumulated and extracted to the Tevatron every {approx}15 hours.

  4. Ion Beam Analysis applied to laser-generated plasmas

    NASA Astrophysics Data System (ADS)

    Cutroneo, M.; Macková, A.; Havranek, V.; Malinsky, P.; Torrisi, L.; Kormunda, M.; Barchuk, M.; Ullschmied, J.; Dudzak, R.

    2016-04-01

    This paper presents the research activity on Ion Beam Analysis methods performed at Tandetron Laboratory (LT) of the Institute of Nuclear Physics AS CR, Rez, Czech Republic. Recently, many groups are paying attention to implantation by laser generated plasma. This process allows to insert a controllable amount of energetic ions into the surface layers of different materials modifying the physical and chemical properties of the surface material. Different substrates are implanted by accelerated ions from plasma through terawatt iodine laser, at nominal intensity of 1015 W/cm2, at the PALS Research Infrastructure AS CR, in the Czech Republic. This regime of the laser matter interaction generates, multi-MeV proton beams, and multi-charged ions that are tightly confined in time (hundreds ps) and space (source radius of a few microns). These ion beams have a much lower transverse temperature, a much shorter duration and a much higher current than those obtainable from conventional accelerators. The implementation of protons and ions acceleration driven by ultra-short high intensity lasers is exhibited by adopting suitable irradiation conditions as well as tailored targets. An overview of implanted targets and their morphological and structural characterizations is presented and discussed.

  5. Applying CLIPS to control of molecular beam epitaxy processing

    NASA Technical Reports Server (NTRS)

    Rabeau, Arthur A.; Bensaoula, Abdelhak; Jamison, Keith D.; Horton, Charles; Ignatiev, Alex; Glover, John R.

    1990-01-01

    A key element of U.S. industrial competitiveness in the 1990's will be the exploitation of advanced technologies which involve low-volume, high-profit manufacturing. The demands of such manufacture limit participation to a few major entities in the U.S. and elsewhere, and offset the lower manufacturing costs of other countries which have, for example, captured much of the consumer electronics market. One such technology is thin-film epitaxy, a technology which encompasses several techniques such as Molecular Beam Epitaxy (MBE), Chemical Beam Epitaxy (CBE), and Vapor-Phase Epitaxy (VPE). Molecular Beam Epitaxy (MBE) is a technology for creating a variety of electronic and electro-optical materials. Compared to standard microelectronic production techniques (including gaseous diffusion, ion implantation, and chemical vapor deposition), MBE is much more exact, though much slower. Although newer than the standard technologies, MBE is the technology of choice for fabrication of ultraprecise materials for cutting-edge microelectronic devices and for research into the properties of new materials.

  6. Comparison of electromagnetic and hadronic models generated using Geant 4 with antiproton dose measured in CERN.

    PubMed

    Tavakoli, Mohammad Bagher; Reiazi, Reza; Mohammadi, Mohammad Mehdi; Jabbari, Keyvan

    2015-01-01

    After proposing the idea of antiproton cancer treatment in 1984 many experiments were launched to investigate different aspects of physical and radiobiological properties of antiproton, which came from its annihilation reactions. One of these experiments has been done at the European Organization for Nuclear Research known as CERN using the antiproton decelerator. The ultimate goal of this experiment was to assess the dosimetric and radiobiological properties of beams of antiprotons in order to estimate the suitability of antiprotons for radiotherapy. One difficulty on this way was the unavailability of antiproton beam in CERN for a long time, so the verification of Monte Carlo codes to simulate antiproton depth dose could be useful. Among available simulation codes, Geant4 provides acceptable flexibility and extensibility, which progressively lead to the development of novel Geant4 applications in research domains, especially modeling the biological effects of ionizing radiation at the sub-cellular scale. In this study, the depth dose corresponding to CERN antiproton beam energy by Geant4 recruiting all the standard physics lists currently available and benchmarked for other use cases were calculated. Overall, none of the standard physics lists was able to draw the antiproton percentage depth dose. Although, with some models our results were promising, the Bragg peak level remained as the point of concern for our study. It is concluded that the Bertini model with high precision neutron tracking (QGSP_BERT_HP) is the best to match the experimental data though it is also the slowest model to simulate events among the physics lists.

  7. The Early Antiproton Work [Nobel Lecture

    DOE R&D Accomplishments Database

    Chamberlain, O.

    1959-12-15

    Early work on the antiproton, particularly that part which led to the first paper on the subject, is described. Conclusions that can be drawn purely from the existence of the antiproton are discussed. (W.D.M.)

  8. Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

    1957-07-22

    In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

  9. ELENA antiproton facility

    NASA Astrophysics Data System (ADS)

    Bartmann, Wolfgang; Belochitskii, Pavel; Breuker, Horst; Butin, François Carli, Christian; Eriksson, Tommy; Maury, Stephen; Oelert, Walter; Pasinelli, Sergio; Tranquille, Gerard

    The following sections are included: * Motivation to build ELENA * From initial ideas to machine project * Choice of ELENA extraction energy * ELENA layout and optics * ELENA cycle * Beam extraction and main machine parameters * Beam instrumentation * ELENA transfer lines * ELENA experimental areas * Conclusion * References

  10. Compression of Antiproton Clouds for Antihydrogen Trapping

    SciTech Connect

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Bertsche, W.; Butler, E.; Charlton, M.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der; Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S.; Cesar, C. L.; Lambo, R.; Silveira, D. M.; Fujiwara, M. C.; Gill, D. R.

    2008-05-23

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.

  11. Applying the laser beam for reconstruction of the upper airway

    NASA Astrophysics Data System (ADS)

    Kukwa, Andrzej; Tulibacki, Marek P.; Wojtowicz, Piotr; Dudziec, Katarzyna; Oledzka, Iwona

    2000-11-01

    The authors present their own experience in restoration of the upper airway using a different source of high power laser. There are many patients with a stricture of the upper airway. One of the most common cause insufficiency of this is nosal polyps. Surgical treatment of polyps till now is not sufficiently effective. For this reason we work out a Nd:YAG laser applying technique that let us to reduce a hospitalization time with elongation of an asymptotic period of our patients. Nd:YAG energy we apply for conchoplasty benefiting of its profound coagulation as a distinctive role. This type of laser is very useful in removing of granulation tissue from different areas of the upper airway. Other applications of Nd:YAG laser in our hands is very useful for: coagulation of vessels in Kisselbach area, especially in Rendou-Osler's diseases, resection of the nosal Septo-turbinate adhesions, treatment of hemangiomas and small papillomas in nasal cavity, diminishing of the hypertrophied mucosa in the nasopharyngeal space as well as, reduction of the uvula and soft palate in OSAS patients. In our department we use a Nd:YAG for treatment of precancerous and early stages of cancer and for a palliation procedures in an advanced cancer infiltration in mouth, pharynx and laryngeal region. For treatment removing of cicatrix tissue in a larynx and trachea we use to use a Holm: YAG laser their very superficial penetration of tissues is used for a coagulation of small vessels too let us to resect it without bleeding from a bony and mucosa tissue, as a fragments maxillary sinus wall, nosal septum crest or spine with resection of the posterior pole of a turbinate. Both laser are conveyed by fiberoptic, to reach a pathological changes in many plans, places for this reason we are able to continuously work on a new its applications.

  12. Enhancing trappable antiproton populations through deceleration and frictional cooling

    SciTech Connect

    Zolotorev, M.; Sessler, A.; Penn, G.; Wurtele, J. S.; Charman, A. E.

    2012-03-01

    CERN currently delivers antiprotons for trapping experiments with the Antiproton Decelerator (AD), which slows the antiprotons down to about 5 MeV.This energy is currently too high for direct trapping, and thick foils are used to slow down the beam to energies which can be trapped.To allow further deceleration to $\\sim 100 \\;\\mbox{keV}$, CERN is initiating the construction of ELENA,consisting of a ring which will combine RF deceleration and electron cooling capabilities. We describe a simple frictionalcooling scheme that can serve to provide significantly improved trapping efficiency, either directly from the AD or first usinga standard deceleration mechanism (induction linac or RFQ). This scheme could be implemented in a short time.The device itself is short in length, uses accessible voltages, and at reasonable cost could serve in the interim beforeELENA becomes operational, or possibly in lieu of ELENA for some experiments. Simple theory and simulations provide a preliminary assessment of theconcept and its strengths and limitations, and highlight important areas for experimental studies, in particular to pin down the level of multiplescattering for low-energy antiprotons. We show that the frictional cooling scheme can provide a similar energy spectrum to that of ELENA,but with higher transverse emittances.

  13. Doubly Strange Hypernuclei Physics with antiprotons at PANDA

    SciTech Connect

    Szymanska, K.; Iazzi, F.

    2010-04-26

    The study of the double hypernuclei will be possible inside the future facility FAIR. A new technique for their production was recently proposed, based on high intensity antiproton beams in connection with a two-target set-up, for the future PANDA experiment at HESR. In particular, the production technique and optimized parameters for the primary target where the hyperon XI{sup -} is produced as well as the expected rates for the stoped XI{sup -} will be discussed.

  14. Antiproton induced DNA damage: proton like in flight, carbon-ion like near rest

    PubMed Central

    Kavanagh, J. N.; Currell, F. J.; Timson, D. J.; Savage, K. I.; Richard, D. J.; McMahon, S. J.; Hartley, O.; Cirrone, G. A. P.; Romano, F.; Prise, K. M.; Bassler, N.; Holzscheiter, M. H.; Schettino, G.

    2013-01-01

    Biological validation of new radiotherapy modalities is essential to understand their therapeutic potential. Antiprotons have been proposed for cancer therapy due to enhanced dose deposition provided by antiproton-nucleon annihilation. We assessed cellular DNA damage and relative biological effectiveness (RBE) of a clinically relevant antiproton beam. Despite a modest LET (~19 keV/μm), antiproton spread out Bragg peak (SOBP) irradiation caused significant residual γ-H2AX foci compared to X-ray, proton and antiproton plateau irradiation. RBE of ~1.48 in the SOBP and ~1 in the plateau were measured and used for a qualitative effective dose curve comparison with proton and carbon-ions. Foci in the antiproton SOBP were larger and more structured compared to X-rays, protons and carbon-ions. This is likely due to overlapping particle tracks near the annihilation vertex, creating spatially correlated DNA lesions. No biological effects were observed at 28–42 mm away from the primary beam suggesting minimal risk from long-range secondary particles. PMID:23640660

  15. Segmented scintillation detectors with silicon photomultiplier readout for measuring antiproton annihilations

    SciTech Connect

    Sótér, A.; Todoroki, K.; Kobayashi, T.; Barna, D.; Horváth, D.; Hori, M.

    2014-02-15

    The Atomic Spectroscopy and Collisions Using Slow Antiprotons experiment at the Antiproton Decelerator (AD) facility of CERN constructed segmented scintillators to detect and track the charged pions which emerge from antiproton annihilations in a future superconducting radiofrequency Paul trap for antiprotons. A system of 541 cast and extruded scintillator bars were arranged in 11 detector modules which provided a spatial resolution of 17 mm. Green wavelength-shifting fibers were embedded in the scintillators, and read out by silicon photomultipliers which had a sensitive area of 1 × 1 mm{sup 2}. The photoelectron yields of various scintillator configurations were measured using a negative pion beam of momentum p ≈ 1 GeV/c. Various fibers and silicon photomultipliers, fiber end terminations, and couplings between the fibers and scintillators were compared. The detectors were also tested using the antiproton beam of the AD. Nonlinear effects due to the saturation of the silicon photomultiplier were seen at high annihilation rates of the antiprotons.

  16. INDEPENDENT COMPONENT ANALYSIS (ICA) APPLIED TO LONG BUNCH BEAMS IN THE LOS ALAMOS PROTON STORAGE RING

    SciTech Connect

    Kolski, Jeffrey S.; Macek, Robert J.; McCrady, Rodney C.; Pang, Xiaoying

    2012-05-14

    Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis (PCA), which is the BSS foundation of the well known model independent analysis (MIA), ICA is more robust to noise, coupling, and nonlinearity. ICA of turn-by-turn beam position data has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch and discuss the source signals identified as betatron motion and longitudinal beam structure.

  17. Review of the High Performance Antiproton Trap (HiPAT) Experiment

    NASA Technical Reports Server (NTRS)

    Martin, James J.; Lewis, Raymond A.; Pearson, J. Boise; Sims, W. Herb; Chakrabarti, Suman; Fant, Wallace E.; McDonald, Stan

    2003-01-01

    Many space propulsion concepts exist that use matter-antimatter reactions. Current antiproton production rates are enough to conduct proof-of-principle evaluation of these concepts. One enabling technology for such experiments is portable storage of low energy antiprotons, to transport antiprotons to experimental facilities. To address this need, HiPAT is being developed, with a design goal of containing 10(exp 12) particles for up to 18 days. HiPAT is a Penning-Malmberg trap with a 4 Tesla superconductor, 20kV electrodes, radio frequency (RF) network, and 10(exp -13) Torr vacuum. 'Normal' matter is being used to evaluate the system. An electron beam ionizes background gas in situ, and particle beams are captured dynamically. The experiment examines ion storage lifetimes, RF plasma diagnostics, charge exchange with background gases, and dynamic ion beam capture.

  18. Focused Ion Beam Milling Applied in Future Tunable-Wavelength Nano-LED’s Fabrication

    DTIC Science & Technology

    2010-01-07

    When this method was applied in light emitting diodes ( LED ) devices, a single pillar or arrays of pillars comprising InGaN /GaN multiple quantum wells...applied the Focused Ion Beam milling technique directly on InGaN /GaN MQW LED wafers. By setting up different bitmaps for patterning, various...patterned 1D nano-pillar arrays were fabricated directly on the InGaN /GaN MQW LED wafer by Gallium (Ga+) beam milling. Figure 2 shows various bitmaps that

  19. Tevatron beam-beam compensation project progress

    SciTech Connect

    Shiltsev, V.; Zhang, X.L.; Kuznetsov, G.; Pfeffer, H.; Saewert, G.; Zimmermann, F.; Tiunov, M.; Bishofberger, K.; Bogdanov, I.; Kashtanov, E.; Kozub, S.; Sytnik, V.; Tkachenko, L.; /Serpukhov, IHEP

    2005-05-01

    In this paper, we report the progress of the Tevatron Beam-Beam Compensation (BBC) project [1]. Electron beam induced proton and antiproton tuneshifts have been reported in [2], suppression of an antiproton emittance growth has been observed, too [1]. Currently, the first electron lens (TEL1) is in operational use as the Tevatron DC beam cleaner. We have made a lot of the upgrades to improve its stability [3]. The 2nd Tevatron electron lens (TEL2) is under the final phase of development and preparation for installation in the Tevatron.

  20. Synthetic aperture technique applied to a multi-beam echo sounder

    NASA Astrophysics Data System (ADS)

    Asada, Akira; Yabuki, Tetsuichiro

    2001-04-01

    We are developing a synthetic aperture technique using a Sea Beam 2000 multi-beam echo sounder to observe subsea crustal movements for earthquake studies. Augmented by the Kinematic GPS and a motion sensor, the synthetic aperture technique was successfully applied to the Sea Beam 2000 with a 12 kHz frequency acoustic signal. The 4.3-meter long projector produces a transmission fan beam in alongtrack beamwidth of 2 degrees, but a synthesis of the data achieved about 37 m aperture length, equivalent to a 0.3 degrees alongtrack beamwidth. Bathymetry measurements at the water depth of 900 m obtained through the synthetic aperture processing show considerable improvement of the signal-to-noise ratio and reveal detailed features of the seafloor.

  1. The Facility for Antiproton and Ion Research FAIR Cosmic Matter in the Laboratory

    NASA Astrophysics Data System (ADS)

    Stoecker, H.; Sturm, C.

    2011-07-01

    Cosmic matter in the laboratory - a broad spectrum of unprecedented fore-front research becomes available at the Facility for Antiproton and Ion Research, FAIR. The new facility will be constructed within the next seven years adjacent to the existing accelerator complex of the GSI Helmholtz Centre for Heavy Ion Research at Darmstadt/Germany. On October 4th, 2010, nine countries signed the international agreement on the construction of FAIR which will start in 2012. First beam will be delivered in 2017/2018 providing worldwide unique accelerator and experimental facilities. This will open the way for a large variety of experiments in hadron, nuclear, atomic and plasma physics as well as applied sciences which will be briefly described in this article. A few more details will be given on heavy-ion collisions providing a tool to study strongly interacting matter under extreme conditions.

  2. Antiproton powered propulsion with magnetically confined plasma engines

    NASA Technical Reports Server (NTRS)

    Lapointe, Michael R.

    1989-01-01

    The reaction of the matter-antimatter annihilation, with its specific energy being over 250 times the specific energy released in nuclear fusion, is considered as an energy source for spacecraft propulsion. A concept of a magnetically confined pulsed plasma engine is described. In this concept, antiproton beams are injected axially into a pulsed magnetic mirror system, where they annihilate with an initially neutral hydrogen gas; the resulting charge annihilation products transfer energy to the hydrogen propellant, which is then exhausted through one end of the pulsed mirror system to provide thrust. Numerical simulations were developed to calculate the annihilation rate of antiprotons in hydrogen and to follow the resulting ion, muon, and electron/positron number density evolutions.

  3. Antiproton powered propulsion with magnetically confined plasma engines

    SciTech Connect

    Lapointe, M.R.

    1989-01-01

    The reaction of the matter-antimatter annihilation, with its specific energy being over 250 times the specific energy released in nuclear fusion, is considered as an energy source for spacecraft propulsion. A concept of a magnetically confined pulsed plasma engine is described. In this concept, antiproton beams are injected axially into a pulsed magnetic mirror system, where they annihilate with an initially neutral hydrogen gas; the resulting charge annihilation products transfer energy to the hydrogen propellant, which is then exhausted through one end of the pulsed mirror system to provide thrust. Numerical simulations were developed to calculate the annihilation rate of antiprotons in hydrogen and to follow the resulting ion, muon, and electron/positron number density evolutions. 22 refs.

  4. Proposed OTR Measurements of 120-GeV Protons and Antiprotons at FNAL

    NASA Astrophysics Data System (ADS)

    Scarpine, V. E.; Tassotto, G. R.; Lumpkin, A. H.

    2004-11-01

    Fermi National Accelerator Laboratory (FNAL) is developing optical transition radiation (OTR) detectors for beam diagnostics for their 120-GeV proton and antiproton transfer lines. As part of a collaboration to enhance the luminosity for the FNAL collider RUN II program, the quality of the proton and antiproton beams, as they are transported from the main injector (MI) to the Tevatron, will be characterized using OTR imaging techniques. A prototype detector in air has already successfully acquired OTR images of 120-GeV protons upstream of the antiproton production target. This result demonstrates that (i) the Ti and Al thin foil screens survive the 5 × 1012 proton beam spills, (ii) OTR is sufficient to image lower intensity antiproton beams, and (iii) the images provide two-dimensional information and higher resolution than the present multi-wire profile monitors in the transport lines. Beam bombardment effects on the Al screen and radiation effects on the lenses, filters and cameras have been evaluated for the prototype system for over 1 × 1019 120-GeV protons and will also be presented. An in-vacuum OTR station is being designed for the transport lines with adjustments to the optical components as warranted by the beam characteristics and anticipated radiation environment.

  5. Antiproton Production by CR on Air Nuclei

    NASA Technical Reports Server (NTRS)

    Maskalenko, I. V.; Mashnik, S. G.

    2003-01-01

    Recent measurements of the cosmic ray (CR) antiproton flux have been shown to challenge existing CR propagation models. In particular, the conventional reacceleration model designed to match secondary/primary nuclei ratios produces too few antiprotons. Recently there appear some indications that the atmospheric contribution to antiproton production is considerably underestimated, which implies that antiproton CR flux might be lower. This may be the primary reason of the discrepancy discovered in CR propagation. We use the Los Alamos version of the Quark-Gluon String Model code LAQGSM together with available data on antiproton production on nuclei to analyse the accuracy of existing parameterizations of antiproton production cross section. The LAQGSM model has been shown to reproduce well nuclear reactions and hadronic data in the range 0.01-800 GeV/nucleon.

  6. Anitproton-matter interactions in antiproton applications

    NASA Technical Reports Server (NTRS)

    Morgan, David L., Jr.

    1990-01-01

    By virtue of the highly energetic particles released when they annihilate in matter, antiprotons have a variety of potentially important applications. Among others, these include remote 3-D density and composition imaging of the human body and also of thick, dense materials, cancer therapy, and spacecraft propulsion. Except for spacecraft propulsion, the required numbers of low energy antiprotons can be produced, stored, and transported through reliance on current or near term technology. Paramount to these applications and to fundamental research involving antiprotons is knowledge of how antiprotons interact with matter. The basic annihilation process is fairly well understood, but the antiproton annihilation and energy loss rates in matter depend in complex ways on a number of atomic processes. The rates, and the corresponding cross sections, were measured or are accurately predictable only for limited combinations of antiproton kinetic energy and material species.

  7. Cosmic ray antiprotons at high energies

    NASA Astrophysics Data System (ADS)

    Winkler, Martin Wolfgang

    2017-02-01

    Cosmic ray antiprotons provide a powerful tool to probe dark matter annihilations in our galaxy. The sensitivity of this important channel is, however, diluted by sizable uncertainties in the secondary antiproton background. In this work, we improve the calculation of secondary antiproton production with a particular focus on the high energy regime. We employ the most recent collider data and identify a substantial increase of antiproton cross sections with energy. This increase is driven by the violation of Feynman scaling as well as by an enhanced strange hyperon production. The updated antiproton production cross sections are made publicly available for independent use in cosmic ray studies. In addition, we provide the correlation matrix of cross section uncertainties for the AMS-02 experiment. At high energies, the new cross sections improve the compatibility of the AMS-02 data with a pure secondary origin of antiprotons in cosmic rays.

  8. Antiproton cooling in the Fermilab Recycler Ring

    SciTech Connect

    Nagaitsev, S.; Bolshakov, A.; Broemmelsiek, D.; Burov, Alexey V.; Carlson, K.; Gattuso, C.; Hu, M.; Kazakevich, G.; Kramper, B.; Kroc, T.; Leibfritz, J.; Prost, L.; Pruss, S.; Saewert, G; Schmidt, C.W.; Seletskiy, S.; Shemyakin, A.; Sutherland, M.; Tupikov, V.; Warner, A.; Zenkevich, P.; /Fermilab /Moscow, ITEP /Novosibirsk, IYF /Rochester U.

    2005-12-01

    The 8.9-GeV/c Recycler antiproton storage ring is equipped with both stochastic and electron cooling systems. These cooling systems are designed to assist accumulation of antiprotons for the Tevatron collider operations. In this paper we report on an experimental demonstration of electron cooling of high-energy antiprotons. At the time of writing this report, the Recycler electron cooling system is routinely used in collider operations. It has helped to set recent peak luminosity records.

  9. Cooling of Stored Beams

    SciTech Connect

    Mills, F.

    1986-06-10

    Beam cooling methods developed for the accumulation of antiprotons are being employed to assist in the performance of experiments in Nuclear and Particle Physics with ion beams stored in storage rings. The physics of beam cooling, and the ranges of utility of stochastic and electron cooling are discussed in this paper.

  10. Overview of the High Performance Antiproton (HiPAT) Experiment

    NASA Technical Reports Server (NTRS)

    Martin, James J.; Sims, William H.; Chakrabarti, Suman; Pearson, Boise; Fant, Wallace E.; Lewis, Raymond A.; Rodgers, Stephen (Technical Monitor)

    2002-01-01

    The annihilation of matter with antimatter represents the highest energy density of any known reaction, producing 10(exp 8) MJ/g, approximately 10 orders of magnitude more energy per unit mass than chemical based combustion. To take the first step towards using this energy for propulsion applications the NASA MSFC Propulsion Research Center (PRC) has initiated a research activity examining the storage of low energy antiprotons. Storage was identified as a key enabling technology since it builds the experience base necessary to understand the handling of antiprotons for virtually all utilization and high-density storage concepts. To address this need, a device referred to as the High Performance Antiproton Trap (HiPAT) is under development at the NASA MSFC PRC. The HiPAT is an electromagnetic system (Penning-Malmberg design) consisting of a 4 Tesla superconductor, a high voltage confinement electrode system (operation up to 20 KV), and an ultra high vacuum test section (operating in the 10(exp -12) torr range). The system was designed to be portable with an ultimate goal of maintaining 10(exp 12) charged particles with a half-life of 18 days. Currently, this system is being experimentally evaluated using normal matter ions which are cheap to produce and relatively easy to handle. These normal ions provide a good indication of overall trap behavior, with the exception of assessing annihilation losses. The ions are produced external to HiPAT using two hydrogen ion sources, with adjustable beam energy and current. Ion are transported in a beam line and controlled through the use of electrostatic optics. These optics serve to both focus and gate the incoming ions, providing microsecond-timed pulses that are dynamically captured by cycling the HiPAT electric containment field like a 'trap door'. The layout of this system more closely simulates the operations expected at an actual antiproton production facility where 'packets' of antiprotons with pulse widths measured in

  11. On the Utility of Antiprotons as Drivers for Inertial Confinement Fusion

    SciTech Connect

    Perkins, L J; Orth, C D; Tabak, M

    2003-10-20

    By contrast to the large mass, complexity and recirculating power of conventional drivers for inertial confinement fusion (ICF), antiproton annihilation offers a specific energy of 90MJ/{micro}g and thus a unique form of energy packaging and delivery. In principle, antiproton drivers could provide a profound reduction in system mass for advanced space propulsion by ICF. We examine the physics underlying the use of antiprotons ({bar p}) to drive various classes of high-yield ICF targets by the methods of volumetric ignition, hotspot ignition and fast ignition. The useable fraction of annihilation deposition energy is determined for both {bar p}-driven ablative compression and {bar p}-driven fast ignition, in association with 0-D and 1-D target burn models. Thereby, we deduce scaling laws for the number of injected antiprotons required per capsule, together with timing and focal spot requirements. The kinetic energy of the injected antiproton beam required to penetrate to the desired annihilation point is always small relative to the deposited annihilation energy. We show that heavy metal seeding of the fuel and/or ablator is required to optimize local deposition of annihilation energy and determine that a minimum of {approx}3x10{sup 15} injected antiprotons will be required to achieve high yield (several hundred megajoules) in any target configuration. Target gains - i.e., fusion yields divided by the available p - {bar p} annihilation energy from the injected antiprotons (1.88GeV/{bar p}) - range from {approx}3 for volumetric ignition targets to {approx}600 for fast ignition targets. Antiproton-driven ICF is a speculative concept, and the handling of antiprotons and their required injection precision - temporally and spatially - will present significant technical challenges. The storage and manipulation of low-energy antiprotons, particularly in the form of antihydrogen, is a science in its infancy and a large scale-up of antiproton production over present supply

  12. Antiproton limits on decaying gravitino dark matter

    SciTech Connect

    Delahaye, Timur; Grefe, Michael E-mail: michael.grefe@uam.es

    2013-12-01

    We derive 95 % CL lower limits on the lifetime of decaying dark matter in the channels Zν, Wℓ and hν using measurements of the cosmic-ray antiproton flux by the PAMELA experiment. Performing a scan over the allowed range of cosmic-ray propagation parameters we find lifetime limits in the range of 8 × 10{sup 28} s to 5 × 10{sup 25} s for dark matter masses from roughly 100 GeV to 10 TeV. We apply these limits to the well-motivated case of gravitino dark matter in scenarios with bilinear violation of R-parity and find a similar range of lifetime limits for the same range of gravitino masses. Converting the lifetime limits to constraints on the size of the R-parity violating coupling we find upper limits in the range of 10{sup −8} to 8 × 10{sup −13}.

  13. Applying a polynomial formula to photon beam output and equivalent square field.

    PubMed

    Chen, F S

    1990-01-01

    The polynomial formula proposed by Chen [Med. Phys. 15, 348 (1988)] in calculating the electron beam output from a Therac 20 linear accelerator has been applied to generating the output factor of various machines with photon energies ranging from 100 kVp to 18 MeV. The calculated outputs are within 1% of the measured values. This formula can be very useful to the physicist in preparing an output table of photon beams or electron beams for a therapeutic unit. An equation is derived from this formula to calculate the equivalent square. The derivation shows that only under special circumstances is the equivalent square field equivalent to 2ab/(a + b); otherwise the equivalent square field depends on the formula's parameters as well as the sides of the rectangular field. These parameters, in turn, are dependent on the photon energy, the medium irradiated, and the collimator design.

  14. Applying a polynomial formula to photon beam output and equivalent square field

    SciTech Connect

    Chen, F. )

    1990-05-01

    The polynomial formula proposed by Chen (Med. Phys. {bold 15}, 348 (1988)) in calculating the electron beam output from a Therac 20 linear accelerator has been applied to generating the output factor of various machines with photon energies ranging from 100 kVp to 18 MeV. The calculated outputs are within 1% of the measured values. This formula can be very useful to the physicist in preparing an output table of photon beams or electron beams for a therapeutic unit. An equation is derived from this formula to calculate the equivalent square. The derivation shows that only under special circumstances is the equivalent square field equivalent to 2{ital ab}/({ital a}+{ital b}); otherwise the equivalent square field depends on the formula's parameters as well as the sides of the rectangular field. These parameters, in turn, are dependent on the photon energy, the medium irradiated, and the collimator design.

  15. Development of an applied-magnetic-field diode for ion-beam-transport experiments

    SciTech Connect

    Young, F.C.; Neri, J.M.; Boller, J.R.

    1996-12-31

    An applied-magnetic-field ion diode (ABD) is being developed to study the transport of intense ion beams for light-ion inertial confinement fusion. Initially, the beam from this diode will be used to test the concept of self-pinched transport (SPT). The design goal is diode operation at 1.5 MV and 250-kA total current on the Gamble 2 generator at NRL. For SPT experiments, the beam is extracted from the diode and focused into a transport channel. The ATHETA code is used to calculate B-field configurations in the diode and ion-beam trajectories. Shaping of the anode surface to aim the beam and to counteract focusing due to self B-field and solenoidal-lens effects results in a convex anode surface. Most of the beam can be focused within a spot size of 1.4-cm diameter at 65 cm from the anode. The B-field is generated with inner and outer cathode coils connected in series and driven by a 100-{micro}s risetime, 50-kA pulse. A shunt inductor in parallel with the outer coil is used to control the ratio of the currents in the two coils. To cancel flux penetration of the aluminum anode by the main B-field, a current pulse of opposite polarity with a 1-ms risetime is applied prior to the main pulse. This current is adjusted to place the B-field separatrix on the ion emission surface in the diode gap, accounting for anode plasma expansion. A grooved-anode flashover source is planned for initial experiments. Preliminary results are presented.

  16. Antiproton powered propulsion with magnetically confined plasma engines

    SciTech Connect

    Lapointe, M.R.

    1989-08-01

    Matter-antimatter annihilation releases more energy per unit mass than any other method of energy production, making it an attractive energy source for spacecraft propulsion. In the magnetically confined plasma engine, antiproton beams are injected axially into a pulsed magnetic mirror system, where they annihilate with an initially neutral hydrogen gas. The resulting charged annihilation products transfer energy to the hydrogen propellant, which is then exhausted through one end of the pulsed mirror system to provide thrust. The calculated energy transfer efficiencies for a low number density (10(14)/cu cm) hydrogen propellant are insufficient to warrant operating the engine in this mode. Efficiencies are improved using moderate propellant number densities (10(16)/cu cm), but the energy transferred to the plasma in a realistic magnetic mirror system is generally limited to less than 2 percent of the initial proton-antiproton annihilation energy. The energy transfer efficiencies are highest for high number density (10(18)/cu cm) propellants, but plasma temperatures are reduced by excessive radiation losses. Low to moderate thrust over a wide range of specific impulse can be generated with moderate propellant number densities, while higher thrust but lower specific impulse may be generated using high propellant number densities. Significant mass will be required to shield the superconducting magnet coils from the high energy gamma radiation emitted by neutral pion decay. The mass of such a radiation shield may dominate the total engine mass, and could severely diminish the performance of antiproton powered engines which utilize magnetic confinement. The problem is compounded in the antiproton powered plasma engine, where lower energy plasma bremsstrahlung radiation may cause shield surface ablation and degradation.

  17. Antiproton powered propulsion with magnetically confined plasma engines

    NASA Technical Reports Server (NTRS)

    Lapointe, Michael R.

    1989-01-01

    Matter-antimatter annihilation releases more energy per unit mass than any other method of energy production, making it an attractive energy source for spacecraft propulsion. In the magnetically confined plasma engine, antiproton beams are injected axially into a pulsed magnetic mirror system, where they annihilate with an initially neutral hydrogen gas. The resulting charged annihilation products transfer energy to the hydrogen propellant, which is then exhausted through one end of the pulsed mirror system to provide thrust. The calculated energy transfer efficiencies for a low number density (10(14)/cu cm) hydrogen propellant are insufficient to warrant operating the engine in this mode. Efficiencies are improved using moderate propellant number densities (10(16)/cu cm), but the energy transferred to the plasma in a realistic magnetic mirror system is generally limited to less than 2 percent of the initial proton-antiproton annihilation energy. The energy transfer efficiencies are highest for high number density (10(18)/cu cm) propellants, but plasma temperatures are reduced by excessive radiation losses. Low to moderate thrust over a wide range of specific impulse can be generated with moderate propellant number densities, while higher thrust but lower specific impulse may be generated using high propellant number densities. Significant mass will be required to shield the superconducting magnet coils from the high energy gamma radiation emitted by neutral pion decay. The mass of such a radiation shield may dominate the total engine mass, and could severely diminish the performance of antiproton powered engines which utilize magnetic confinement. The problem is compounded in the antiproton powered plasma engine, where lower energy plasma bremsstrahlung radiation may cause shield surface ablation and degradation.

  18. Supersonic Molecular Beam Injection Effects on Tokamak Plasma Applied Non-axisymmetric Magnetic Perturbation

    NASA Astrophysics Data System (ADS)

    Han, Hyunsun; in, Y.; Jeon, Y. M.; Hahn, S. H.; Lee, K. D.; Nam, Y. U.; Yoon, S. W.

    2016-10-01

    In KSTAR experiments, the change of tokamak plasma behavior by supersonic molecular beam injection (SMBI) was investigated by applying resonant magnetic perturbations(RMP) that could suppress edge localized modes (ELMs). When the SMBI is applied, the symptom representing ELM suppression by RMP is disappeared. The SMBI acts as a cold pulse on the plasma keeping the total confinement engergy constant. However, it makes plasma density increase and change the plasama collisionality which can play a role in the edge-pedestal build-up processing. This work was supported by Project PG1201-2 and the KSTAR research project funded by Korea Ministry of Science, ICT and Future Planning.

  19. Tevatron anti-proton injection kicker waveform analysis

    SciTech Connect

    Hanna, B.; Finley, D.; /Fermilab

    1996-08-01

    This note describes the measurements of the waveform of the Tevatron antiproton injection kicker using the 150 Gev proton beam. This new horizontal kicker was installed at D48 during the summer of 1995 shutdown. These measurements were taken in two sessions [1] starting on October 10 and October 18, 1995. The measurements use the Tevatron BPM and flying wire systems. This note is a companion to the Tevatron proton injection kicker note published recently [2]. The design specifications for the kicker are given in Dinkel et al. [3].

  20. Development of a novel device for applying uniform doses of electron beam irradiation on carcasses.

    PubMed

    Maxim, Joseph E; Neal, Jack A; Castillo, Alejandro

    2014-01-01

    The Maxim's Electron Scatter Chamber (Maxim Chamber) was developed to obtain uniform dose distribution when applying electron beam (e-beam) irradiation to materials of irregular surface. This was achieved by placing a stainless steel mesh surrounding a cylindrical area where the target sample was placed. Upon contact with the mesh, electrons scatter and are directed onto the target from multiple angles, eliminating the e-beam linearity and resulting in a uniform dose distribution over the target surface. The effect of irradiation in the Maxim Chamber on dose distribution and pathogen reduction was tested on rabbit carcasses to simulate other larger carcasses. The dose uniformity ratio (DUR) on the rabbit carcasses was 1.8, indicating an acceptable dose distribution. On inoculated carcasses, this treatment reduced Escherichia coli O157:H7 by >5 log cycles. These results indicate that carcass irradiation using e-beam is feasible using the Maxim's electron scattering chamber. Appropriate adjustments will be further needed for commercial application on beef and other animal carcasses.

  1. Operating Procedure Changes to Improve Antiproton Production at the Fermilab Tevatron Collider

    SciTech Connect

    Drendel, B.; Morgan, J.P.; Vander Meulen, D.; /Fermilab

    2009-04-01

    Since the start of Fermilab Collider Run II in 2001, the maximum weekly antiproton accumulation rate has increased from 400 x 10{sup 10} Pbars/week to approximately 3,700 x 10{sup 10} Pbars/week. There are many factors contributing to this increase, one of which involves changes to operational procedures that have streamlined and automated Antiproton Source production. Automation has been added to the beam line orbit control, stochastic cooling power level management, and RF settings. In addition, daily tuning efforts have been streamlined by implementing sequencer driven tuning software.

  2. Longitudinal momentum mining of antiprotons at the Fermilab Recycler: past, present and future

    SciTech Connect

    Bhat, C.M.; Chase, B.E.; Gattuso, C.; Joireman, P.W.; /Fermilab

    2007-06-01

    The technique of longitudinal momentum mining (LMM)[1] in the Fermilab Recycler was adopted in early 2005 to extract thirty-six equal intensity and equal 6D-emittance antiproton bunches for proton-antiproton collider operation in the Tevatron. Since that time, several improvements have been made in the Recycler and the mining technique to handle higher intensity beams. Consequently, the Recycler has become a key contributor to the increased luminosity performance observed during Tevatron Run IIb. In this paper, we present an overview of the improvements and the current status of the momentum mining technique.

  3. ELENA: the extra low energy anti-proton facility at CERN

    NASA Astrophysics Data System (ADS)

    Maury, Stephan; Oelert, Walter; Bartmann, Wolfgang; Belochitskii, Pavel; Breuker, Horst; Butin, Francois; Carli, Christian; Eriksson, Tommy; Pasinelli, Sergio; Tranquille, Gerard

    2014-04-01

    At the last LEAP conference in Vancouver 2011 the authors stated that a project "ELENA", as an abbreviation for Extra Low ENergy Antiproton ring and as first discussed in 1982 for LEAR by H. Herr et al., was freshly proposed with a substantial new design and revised layout and that it was under consideration to be built at CERN. ELENA is an upgrade of the Anti-proton Decelerator (AD) at CERN and is devoted to special experiments with physics using low energy anti-protons. The main topics are the anti-hydrogen production and consecutive studies of the features of this anti-matter atom as well as the anti-proton nucleon interaction by testing the QED to high precision. During the last years the project underwent several steps in presentations at different committees at CERN and was finally approved such that the construction has started. ELENA will increase the number of useful anti-protons by about two orders of magnitude and will allow to serve up to four experiments simultaneously. Very first and convincing results from the experiments at the AD have been published recently. For high precision physics, however, it appears to be cumbersome, time consuming and ineffective when collecting the needed large numbers and high densities of anti-proton clouds with the present AD. Both the effectiveness and the availability for additional experiments at this unique facility will drastically increase, when the anti-proton beam of presently 5 MeV kinetic energy is reduced by the additional decelerator ELENA to 100 keV.

  4. Instrumentation for measurement of in-flight annihilations of 130 keV antiprotons on thin target foils

    NASA Astrophysics Data System (ADS)

    Todoroki, K.; Barna, D.; Hayano, R. S.; Aghai-Khozani, H.; Sótér, A.; Corradini, M.; Leali, M.; Lodi-Rizzini, E.; Mascagna, V.; Venturelli, L.; Prest, V.; Vallazza, L.; De Salvador, D.; Hori, M.

    2016-11-01

    We describe the instrumentation for an experiment to measure the cross sections of antiprotons with kinetic energies of 130±10 keV annihilating on carbon, palladium, and platinum target foils of sub-100 nm thicknesses. A 120 ns long pulsed beam containing 105 -106 antiprotons was allowed to traverse the foils, and the signal annihilations that resulted from this were isolated using a time-of-flight method. Backgrounds arose from Rutherford scattering of the antiprotons off the target foils, their annihilations in the target chamber walls, and π → μ → e decay of the charged pions that emerged from the annihilations. Some antiprotons slowed down and annihilated in the contamination on the target surfaces. This reduced the signal-to-background ratio of the measurement.

  5. Secondary antiproton production in relativistic plasmas

    NASA Technical Reports Server (NTRS)

    Dermer, C. D.; Ramaty, R.

    1985-01-01

    The possibility is investigated that the reported excess low energy antiproton component of the cosmic radiation results from proton-proton (p-p) interactions in relativistic plasmas. Because of both target and projectile motion in such plasmas, the antiproton production threshold in the frame of the plasma is much lower than the threshold of antiproton production in cosmic ray interactions with ambient matter. The spectrum of the resultant antiprotons therefore extends to much lower energy than in the cosmic ray case. The antiproton spectrum is calculated for relativistic thermal plasmas and the spectrum is estimated for relativistic nonthermal plasmas. As possible production sites, matter accreting onto compact objects located in the galaxy is considered. Possible overproduction of gamma rays from associated neutral pion production can be avoided if the site is optically thick to the photons but not to the antiprotons. A possible scenario involves a sufficiently large photon density that the neutral pion gamma rays are absorbed by photon-photon pair production. Escape of the antiprotons to the interstellar medium can be mediated by antineutron production.

  6. The bar{P}ANDA Experiment at FAIR — Subatomic Physics with Antiprotons

    NASA Astrophysics Data System (ADS)

    Messchendorp, Johan

    The non-perturbative nature of the strong interaction leads to spectacular phenomena, such as the formation of hadronic matter, color confinement, and the generation of the mass of visible matter. To get deeper insight into the underlying mechanisms remains one of the most challenging tasks within the field of subatomic physics. The antiProton ANnihilations at DArmstadt (bar{P}ANDA) collaboration has the ambition to address key questions in this field by exploiting a cooled beam of antiprotons at the High Energy Storage Ring (HESR) at the future Facility for Antiproton and Ion Research (FAIR) combined with a state-of-the-art and versatile detector. This contribution will address some of the unique features of bar{P}ANDA that give rise to a promising physics program together with state-of-the-art technological developments.

  7. Transversity Measurement with Polarized Proton and Antiproton Interactions at Gsi:. the Pax Experiment

    NASA Astrophysics Data System (ADS)

    Dalpiaz, P. F.

    2006-02-01

    It has recently been suggested by the PAX collaboration that collisions of transversely polarized protons and antiprotons at the GSI-FAIR can be used to determine the nucleon's transversity densities from measurements of the double-spin asymmetry for the Drell-Yan process. The theoretical expectations for this observable are in the 0.3-0.4 range at the FAIR-HESR enrgies. PAX therefore proposes to build a polarized antiproton stored beam suitable for this measurament. Polarized antiprotons will be produced by spin filtering with an internal polarized gas target in a storage ring. The design and performance of the accelerator setup, and of the the detector will be briefly outlined.

  8. Evaluation on Geant4 Hadronic Models for Pion Minus, Pion Plus and Neutron Particles as Major Antiproton Annihilation Products.

    PubMed

    Tavakoli, Mohammad Bagher; Mohammadi, Mohammad Mehdi; Reiazi, Reza; Jabbari, Keyvan

    2015-01-01

    Geant4 is an open source simulation toolkit based on C++, which its advantages progressively lead to applications in research domains especially modeling the biological effects of ionizing radiation at the sub-cellular scale. However, it was shown that Geant4 does not give a reasonable result in the prediction of antiproton dose especially in Bragg peak. One of the reasons could be lack of reliable physic model to predict the final states of annihilation products like pions. Considering the fact that most of the antiproton deposited dose is resulted from high-LET nuclear fragments following pion interaction in surrounding nucleons, we reproduced depth dose curves of most probable energy range of pions and neutron particle using Geant4. We consider this work one of the steps to understand the origin of the error and finally verification of Geant4 for antiproton tracking. Geant4 toolkit version 9.4.6.p01 and Fluka version 2006.3 were used to reproduce the depth dose curves of 220 MeV pions (both negative and positive) and 70 MeV neutrons. The geometry applied in the simulations consist a 20 × 20 × 20 cm(3) water tank, similar to that used in CERN for antiproton relative dose measurements. Different physic lists including Quark-Gluon String Precompound (QGSP)_Binary Cascade (BIC)_HP, the recommended setting for hadron therapy, were used. In the case of pions, Geant4 resulted in at least 5% dose discrepancy between different physic lists at depth close to the entrance point. Even up to 15% discrepancy was found in some cases like QBBC compared to QGSP_BIC_HP. A significant difference was observed in dose profiles of different Geant4 physic list at small depths for a beam of pions. In the case of neutrons, large dose discrepancy was observed when LHEP or LHEP_EMV lists were applied. The magnitude of this dose discrepancy could be even 50% greater than the dose calculated by LHEP (or LHEP_EMV) at larger depths. We found that effect different Geant4 physic list in

  9. Supersonic molecular beam injection effects on tokamak plasma applied non-axisymmetric magnetic perturbation

    NASA Astrophysics Data System (ADS)

    Han, Hyunsun; In, Y.; Jeon, Y. M.; Lee, H. Y.; Hahn, S. H.; Lee, K. D.; Nam, Y. U.; Yoon, S. W.

    2016-08-01

    The change of tokamak plasma behavior by supersonic molecular beam injection (SMBI) was investigated by applying a three-dimensional magnetic perturbation that could suppress edge localized modes (ELMs). From the time trace of decreasing electron temperature and with increasing plasma density keeping the total confined energy constant, the SMBI seems to act as a cold pulse on the plasma. However, the ELM behaviors were changed drastically (i.e., the symptom of ELM suppression has disappeared). The plasma collisionality in the edge-pedestal region could play a role in the change of the ELM behaviors.

  10. Antiproton stopping in atomic targets

    NASA Astrophysics Data System (ADS)

    Bailey, J. J.; Kadyrov, A. S.; Abdurakhmanov, I. B.; Fursa, D. V.; Bray, I.

    2015-08-01

    Stopping powers of antiprotons in H, He, Ne, Ar, Kr, and Xe targets are calculated using a semiclassical time-dependent convergent close-coupling method. The helium target is treated using both frozen-core and multiconfiguration approximations. The electron-electron correlation of the target is fully accounted for in both cases. Double ionization and ionization with excitation channels are taken into account using an independent-event model. The Ne, Ar, Kr, and Xe atom wave functions are described in a model of six p -shell electrons above a frozen Hartree-Fock core with only one-electron excitations from the outer p shell allowed. Results obtained for helium in the multiconfiguration treatment are in better agreement with experimental measurements than other theories.

  11. RF Stabilization for Storage of Antiprotons

    NASA Technical Reports Server (NTRS)

    Pearson, J. Boise; Lewis, Raymond A.

    2005-01-01

    Portable storage of antimatter is an important step in the experimental exploration of antimatter in propulsion applications. The High Performance Antiproton Trap (HiPAT) at NASA Marshall Space Flight Center is a Penning-Malmberg ion trap being developed to trap and store low energy antiprotons for a period of weeks. The antiprotons can then be transported for use in experiments. HiPAT is being developed and evaluated using normal matter, before an attempt is made to store and transport antiprotons. Stortd ions have inherent instabilities that limit the storage lifetime. RF stabilization at cyclotron resonance frequencies is demonstrated over a period of 6 days for normal matter ion clouds. A variety of particles have been stored, including protons, C+ ions, and H2+ ions. Cyclotron resonance frequencies are defined and experimental evidence presented to demonstrate excitation of cyclotron waves in the plasma for all three species of ions.

  12. Electric charges of positrons and antiprotons

    SciTech Connect

    Hughes, R.J. ); Deutch, B.I. )

    1992-07-27

    Tests of the electric charges carried by the positron and antiproton are derived from recent measurements of the cyclotron frequencies of these particles, and from the spectroscopy of exotic atoms in which they are constituents.

  13. D¯ D meson pair production in antiproton-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Shyam, R.; Tsushima, K.

    2016-10-01

    We study the D ¯D (D¯0D0 and D-D+) charm meson pair production in antiproton (p ¯) induced reactions on nuclei at beam energies ranging from threshold to several GeV. Our model is based on an effective Lagrangian approach that has only the baryon-meson degrees of freedom and involves the physical hadron masses. The reaction proceeds via the t -channel exchanges of Λc+, Σc+, and Σc++ baryons in the initial collision of the antiproton with one of the protons of the target nucleus. The medium effects on the exchanged baryons are included by incorporating in the corresponding propagators, the effective charm baryon masses calculated within a quark-meson coupling (QMC) model. The wave functions of the bound proton have been determined within the QMC model as well as in a phenomenological model where they are obtained by solving the Dirac equation with appropriate scalar and vector potentials. The initial- and final-state distortion effects have been approximated by using an eikonal approximation-based procedure. Detailed numerical results are presented for total and double differential cross sections for the D¯0D0 and D-D+ production reactions on 16O and 90Zr targets. It is noted that at p ¯ beam momenta of interest to the P ¯ ANDA experiment, medium effects lead to noticeable enhancements in the charm meson production cross sections.

  14. Electron beam focusing system

    SciTech Connect

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  15. Annihilation of Antiprotons in Heavy Nuclei.

    DTIC Science & Technology

    1986-04-01

    Consideration of matter- antimatter annihilation as an energy source for space propulsion has been taking place over the last several years. For details of...any known possible means of propulsion . The form of antimatter most often considered for annihilation consists of antiprotons, which are the...Emission in Antiproton Annihilation on d and He, Lettere Al Nuovo Cimento 38, 211 (1983). R.L. Forward, Antimatter Propulsion , Journal of the British

  16. Antiproton catalyzed microfission/fusion propulsion

    NASA Technical Reports Server (NTRS)

    Chiang, Pi-Ren; Lewis, Raymond A.; Smith, Gerald A.; Newton, Richard; Dailey, James; Werthman, W. Lance; Chakrabarti, Suman

    1994-01-01

    Inertial confinement fusion (ICF) utilizing an antiproton catalyzed hybrid fission/fusion target is discussed as a potential energy source for interplanetary propulsion. A proof-of-principle experiment underway at Phillips Laboratory, Kirtland AFB and antiproton trapping experiments at CERN, Geneva, Switzerland, are presented. The ICAN propulsion concept is described and results of performance analyses are reviewed. Future work to further define the ICAN concept is outlined.

  17. Modified Penning-Malmberg Trap for Storing Antiprotons

    NASA Technical Reports Server (NTRS)

    Sims, William H.; Martin, James; Lewis, Raymond

    2005-01-01

    A modified Penning-Malmberg trap that could store a small cloud of antiprotons for a relatively long time (weeks) has been developed. This trap is intended for use in research on the feasibility of contemplated future matter/antimatter-annihilation systems as propulsion sources for spacecraft on long missions. This trap is also of interest in its own right as a means of storing and manipulating antiprotons for terrestrial scientific experimentation. The use of Penning-Malmberg traps to store antiprotons is not new. What is new here is the modified trap design, which utilizes state-of-the-art radiofrequency (RF) techniques, including ones that, heretofore, have been used in radio-communication applications but not in iontrap applications. A basic Penning-Malmberg trap includes an evacuated round tube that contains or is surrounded by three or more collinear tube electrodes. A steady axial magnetic field that reaches a maximum at the geometric center of the tube is applied by an external source, and DC bias voltages that give rise to an electrostatic potential that reaches a minimum at the center are applied to the electrodes. The combination of electric and magnetic fields confines the charged particles (ions or electrons) for which it was designed to a prolate spheroidal central region. However, geometric misalignments and the diffusive cooling process prevent the steady fields of a basic Penning- Malmberg trap from confining the particles indefinitely. In the modified Penning-Malmberg trap, the loss of antiprotons is reduced or eliminated by use of a "rotating-wall" RF stabilization scheme that also heats the antiproton cloud to minimize loss by matter/antimatter annihilation. The scheme involves the superposition of a quadrupole electric field that rotates about the cylindrical axis at a suitably chosen radio frequency. The modified Penning-Malmberg trap (see Figure 1) includes several collinear sets of electrodes inside a tubular vacuum chamber. Each set

  18. Physics Results from the Antiproton Experiment (APEX) at Fermilab

    DOE Data Explorer

    APEX Collaboration

    Is Antimatter stable? The APEX experiment searches for the decay of antiprotons at the Fermilab Antiproton Accumulator. Observation of antiproton decay would indicate a violation of the CPT theorem, which is one of the most fundamental theorems of modern physics. The best laboratory limits on antiproton decay come from the APEX experiment which achieved a sensitivity to antiproton lifetimes up to of order 700,000 years for the most sensitive decay modes. Antiproton lifetimes in this range could arise from CPT violation at the Planck scale.[copied from http://www-apex.fnal.gov/] This website presents published results from the APEX Test Experiment (T861) and from the E868 Experiment. Limits were placed on six antiproton decay modes with a muon in the final state and on seven antiproton decay modes with an electron in the final state. See also the summary table and plot and the APEX picture gallery.

  19. Computer control of RF-manipulations in the CERN antiproton accumulator

    SciTech Connect

    Johnson, R.; van der Meer, S.; Pedersen, F.; Shering, G.

    1983-08-01

    The CERN antiproton accumulator uses a conventional RF system for bunched beam manipulation within the ring. Several different manipulations are needed, often in close succession, so a fast, reliable and accurate method of switching between them is required. This has led to an unconventional computerized beam control system. For a desired set of beam manipulations, the computer calculates the needed voltage and frequency as functions of time, using a mathematical model of the beam and lattice. These are then loaded into function generators which subsequently operate independently of the computer. The RF system, a dual gap, ferrite loaded cavity driven by a 4CX25000 power tetrode, has three main uses: the stacking process to accumulate the antiprotons, the unstacking process to make the accumulated antiprotons available for extraction, and a variety of test and measurement purposes. Two digital function generators control voltage and frequency in the cavity. The voltage function is logarithmic and is fed into an AVC loop which contains a logarithmic detector and modulator to provide high voltage for stacking and low voltage for unstacking. The frequency function controls a 10 to 30 kHz quadrature VCO which is mixed with the output of a quadrature synthesizer producing an 1840 to 1860 kHz frequency range. RF phase and magnet noise were harmful while manipulating low emittance proton and antiproton bunches. A high-pass phase loop acquires beam cavity phase; adding AC corrections to the frequency program eliminated this problem. The cavity tune is maintained by a tuning loop acting on a DC ferrite base. Schematics are provided.

  20. The Facility for Antiproton and Ion Research Fair

    NASA Astrophysics Data System (ADS)

    Stöecker, H.; Sturm, C.

    2012-01-01

    On October 4th, 2010, nine countries signed the international agreement on the construction of the Facility for Antiproton and Ion Research FAIR. The new facility is going to be constructed within the next eight years adjacent to the existing accelerator complex of the GSI Helmholtz Centre for Heavy Ion Research at Darmstadt/Germany, expanding the research goals and technical possibilities substantially. Providing a broad spectrum of unprecedented fore-front research at worldwide unique accelerator and experimental facilities, FAIR will open the way for a large variety of experiments in hadron, nuclear, atomic and plasma physics as well as applied sciences which will be briefly described in this article.

  1. Study of doubly strange systems using stored antiprotons

    NASA Astrophysics Data System (ADS)

    Singh, B.; Erni, W.; Krusche, B.; Steinacher, M.; Walford, N.; Liu, B.; Liu, H.; Liu, Z.; Shen, X.; Wang, C.; Zhao, J.; Albrecht, M.; Erlen, T.; Fink, M.; Heinsius, F.; Held, T.; Holtmann, T.; Jasper, S.; Keshk, I.; Koch, H.; Kopf, B.; Kuhlmann, M.; Kümmel, M.; Leiber, S.; Mikirtychyants, M.; Musiol, P.; Mustafa, A.; Pelizäus, M.; Pychy, J.; Richter, M.; Schnier, C.; Schröder, T.; Sowa, C.; Steinke, M.; Triffterer, T.; Wiedner, U.; Ball, M.; Beck, R.; Hammann, C.; Ketzer, B.; Kube, M.; Mahlberg, P.; Rossbach, M.; Schmidt, C.; Schmitz, R.; Thoma, U.; Urban, M.; Walther, D.; Wendel, C.; Wilson, A.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Patel, B.; Czyzycki, W.; Domagala, M.; Filo, G.; Jaworowski, J.; Krawczyk, M.; Lisowski, E.; Lisowski, F.; Michałek, M.; Poznański, P.; Płażek, J.; Korcyl, K.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Szczurek, A.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Biernat, J.; Kamys, B.; Kistryn, S.; Korcyl, G.; Krzemien, W.; Magiera, A.; Moskal, P.; Psyzniak, A.; Rudy, Z.; Salabura, P.; Smyrski, J.; Strzempek, P.; Wronska, A.; Augustin, I.; Böhm, R.; Lehmann, I.; Nicmorus Marinescu, D.; Schmitt, L.; Varentsov, V.; Al-Turany, M.; Belias, A.; Deppe, H.; Dzhygadlo, R.; Ehret, A.; Flemming, H.; Gerhardt, A.; Götzen, K.; Gromliuk, A.; Gruber, L.; Karabowicz, R.; Kliemt, R.; Krebs, M.; Kurilla, U.; Lehmann, D.; Löchner, S.; Lühning, J.; Lynen, U.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schwarz, C.; Schwiening, J.; Täschner, A.; Traxler, M.; Ugur, C.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fechtchenko, A.; Fedunov, A. G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Y. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Olshevskiy, A.; Perevalova, E.; Piskun, A. A.; Pocheptsov, T.; Pontecorvo, G.; Rodionov, V.; Rogov, Y.; Salmin, R.; Samartsev, A.; Sapozhnikov, M. G.; Shabratova, G.; Skachkov, N. B.; Skachkova, A. N.; Strokovsky, E. A.; Suleimanov, M.; Teshev, R.; Tokmenin, V.; Uzhinsky, V.; Vodopyanov, A.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Böhm, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Dobbs, S.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Akishina, V.; Kisel, I.; Kozlov, G.; Pugach, M.; Zyzak, M.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Biguenko, K.; Brinkmann, K.; Di Pietro, V.; Diehl, S.; Dormenev, V.; Drexler, P.; Düren, M.; Etzelmüller, E.; Galuska, M.; Gutz, E.; Hahn, C.; Hayrapetyan, A.; Kesselkaul, M.; Kühn, W.; Kuske, T.; Lange, J. S.; Liang, Y.; Metag, V.; Nanova, M.; Nazarenko, S.; Novotny, R.; Quagli, T.; Reiter, S.; Rieke, J.; Rosenbaum, C.; Schmidt, M.; Schnell, R.; Stenzel, H.; Thöring, U.; Ullrich, M.; Wagner, M. N.; Wasem, T.; Wohlfarth, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Loehner, H.; Messchendorp, J.; Schakel, P.; Smit, H.; Tiemens, M.; van der Weele, J. C.; Veenstra, R.; Vejdani, S.; Dutta, K.; Kalita, K.; Kumar, A.; Roy, A.; Sohlbach, H.; Bai, M.; Bianchi, L.; Büscher, M.; Cao, L.; Cebulla, A.; Dosdall, R.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Lehrach, A.; Nellen, R.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Prencipe, E.; Pütz, J.; Ritman, J.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Zambanini, A.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Isaksson, L.; Achenbach, P.; Corell, O.; Denig, A.; Distler, M.; Hoek, M.; Karavdina, A.; Lauth, W.; Liu, Z.; Merkel, H.; Müller, U.; Pochodzalla, J.; Schlimme, S.; Sfienti, C.; Thiel, M.; Ahmadi, H.; Ahmed, S.; Bleser, S.; Capozza, L.; Cardinali, M.; Dbeyssi, A.; Deiseroth, M.; Feldbauer, F.; Fritsch, M.; Fröhlich, B.; Jasinski, P.; Kang, D.; Khaneft, D.; Klasen, R.; Leithoff, H. H.; Lin, D.; Maas, F.; Maldaner, S.; Martìnez Rojo, M.; Marta, M.; Michel, M.; Mora Espì, M. C.; Morales Morales, C.; Motzko, C.; Nerling, F.; Noll, O.; Pflüger, S.; Pitka, A.; Rodríguez Piñeiro, D.; Sanchez Lorente, A.; Steinen, M.; Valente, R.; Weber, T.; Zambrana, M.; Zimmermann, I.; Fedorov, A.; Korjik, M.; Missevitch, O.; Boukharov, A.; Malyshev, O.; Marishev, I.; Balanutsa, P.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Chandratre, V.; Datar, V.; Dutta, D.; Jha, V.; Kumawat, H.; Mohanty, A. K.; Parmar, A.; Roy, B.; Sonika, G.; Fritzsch, C.; Grieser, S.; Hergemöller, A. K.; Hetz, B.; Hüsken, N.; Khoukaz, A.; Wessels, J. P.; Khosonthongkee, K.; Kobdaj, C.; Limphirat, A.; Srisawad, P.; Yan, Y.; Barnyakov, M.; Barnyakov, A. Yu.; Beloborodov, K.; Blinov, A. E.; Blinov, V. E.; Bobrovnikov, V. S.; Kononov, S.; Kravchenko, E. A.; Kuyanov, I. A.; Martin, K.; Onuchin, A. P.; Serednyakov, S.; Sokolov, A.; Tikhonov, Y.; Atomssa, E.; Kunne, R.; Marchand, D.; Ramstein, B.; Van de Wiele, J.; Wang, Y.; Boca, G.; Costanza, S.; Genova, P.; Montagna, P.; Rotondi, A.; Abramov, V.; Belikov, N.; Bukreeva, S.; Davidenko, A.; Derevschikov, A.; Goncharenko, Y.; Grishin, V.; Kachanov, V.; Kormilitsin, V.; Levin, A.; Melnik, Y.; Minaev, N.; Mochalov, V.; Morozov, D.; Nogach, L.; Poslavskiy, S.; Ryazantsev, A.; Ryzhikov, S.; Semenov, P.; Shein, I.; Uzunian, A.; Vasiliev, A.; Yakutin, A.; Tomasi-Gustafsson, E.; Roy, U.; Yabsley, B.; Belostotski, S.; Gavrilov, G.; Izotov, A.; Manaenkov, S.; Miklukho, O.; Veretennikov, D.; Zhdanov, A.; Makonyi, K.; Preston, M.; Tegner, P.; Wölbing, D.; Bäck, T.; Cederwall, B.; Rai, A. K.; Godre, S.; Calvo, D.; Coli, S.; De Remigis, P.; Filippi, A.; Giraudo, G.; Lusso, S.; Mazza, G.; Mignone, M.; Rivetti, A.; Wheadon, R.; Balestra, F.; Iazzi, F.; Introzzi, R.; Lavagno, A.; Olave, J.; Amoroso, A.; Bussa, M. P.; Busso, L.; De Mori, F.; Destefanis, M.; Fava, L.; Ferrero, L.; Greco, M.; Hu, J.; Lavezzi, L.; Maggiora, M.; Maniscalco, G.; Marcello, S.; Sosio, S.; Spataro, S.; Birsa, R.; Bradamante, F.; Bressan, A.; Martin, A.; Calen, H.; Ikegami Andersson, W.; Johansson, T.; Kupsc, A.; Marciniewski, P.; Papenbrock, M.; Pettersson, J.; Schönning, K.; Wolke, M.; Galnander, B.; Diaz, J.; Pothodi Chackara, V.; Chlopik, A.; Kesik, G.; Melnychuk, D.; Slowinski, B.; Trzcinski, A.; Wojciechowski, M.; Wronka, S.; Zwieglinski, B.; Bühler, P.; Marton, J.; Steinschaden, D.; Suzuki, K.; Widmann, E.; Zmeskal, J.; Gerl, Jürgen; Kojouharov, Ivan; Kojouharova, Jasmina

    2016-10-01

    Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P ‾ ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ--atoms will be feasible and even the production of Ω--atoms will be within reach. The latter might open the door to the | S | = 3 world in strangeness nuclear physics, by the study of the hadronic Ω--nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions.

  2. Automatic steering corrections to minimize injection oscillations in the Fermilab Antiproton Source rings

    SciTech Connect

    Harding, D.J.; Riddiford, A.W.

    1989-03-01

    Missteering of particle beam at injection into a circular accelerator produces coherent betatron oscillations. The beam position monitor system in the Antiproton Source at Fermilab can measure the beam position on each turn around the ring during these oscillations. From the amplitude and phase of the oscillations, corrections to the beamline steering are calculated to remove the oscillations. The analysis includes the case where the horizontal and vertical tunes are quite strongly coupled. This technique has proved to be valuable both in operation of the Fermilab Collider and as an analytical tool. 4 refs., 2 figs.

  3. The antiproton interaction with an internal 12C target inside the HESR ring at FAIR

    NASA Astrophysics Data System (ADS)

    Introzzi, R.; Balestra, F.; Lavagno, A.; Scozzi, F.; Younis, H.

    2016-04-01

    In order to fulfill the goal of producing higher rates of doubly strange hyperons, the P¯ANDA collaboration will use the antiproton ring HESR at the future facility FAIR. The low energy hyperon production by an antiproton beam requires to insert a solid target inside the ring. Unwanted side effects of such an insertion are the overwhelming amount of annihilations, which would make the detectors blind, and the fast depletion of the bunch, which circulates inside the ring. The choice of the target material impacts the hyperon production yield: Carbon turned out to provide enough initial hyperon deceleration and keep secondary interactions below a tolerable level. The use of a very thin Diamond target, together with beam steering techniques, seems to be a satisfactory solution to the above problems and will be described hereafter.

  4. Facility for Antiproton and Ion Research, FAIR, at the GSI site

    SciTech Connect

    Rosner, Guenther

    2006-11-17

    FAIR is a new large-scale particle accelerator facility to be built at the GSI site in Germany. The research pursued at FAIR will cover a wide range of topics in nuclear and hadron physics, as well as high density plasma physics, atomic and antimatter physics, and applications in condensed matter physics and biology. The working horse of FAIR will be a 1.1km circumference double ring of rapidly cycling 100 and 300Tm synchrotrons, which will be used to produce high intensity secondary beams of short-lived radioactive ions or antiprotons. A subsequent suite of cooler and storage rings will deliver heavy ion and antiproton beams of unprecedented quality. Large experimental facilities are presently being designed by the NUSTAR, PANDA, PAX, CBM, SPARC, FLAIR, HEDgeHOB and BIOMAT collaborations.

  5. Testing CPT Invariance with Antiprotonic Helium Atoms

    SciTech Connect

    Horvath, Dezso

    2008-08-08

    The structure of matter is related to symmetries at every level of study. CPT symmetry is one of the most important laws of field theory: it states the invariance of physical properties when one simultaneously changes the signs of the charge and of the spatial and time coordinates of free elementary particles. Although in general opinion CPT symmetry is not violated in Nature, there are theoretical attempts to develop CPT-violating models. The Antiproton Decelerator at CERN has been built to test CPT invariance. The ASACUSA experiment compares the properties of particles and antiparticles by studying the antiprotonic helium atom via laser spectroscopy and measuring the mass, charge and magnetic moment of the antiproton as compared to those of the proton.

  6. Cosmic ray antiprotons from nearby cosmic accelerators

    NASA Astrophysics Data System (ADS)

    Joshi, Jagdish C.; Gupta, Nayantara

    2015-05-01

    The antiproton flux measured by PAMELA experiment might have originated from Galactic sources of cosmic rays. These antiprotons are expected to be produced in the interactions of cosmic ray protons and nuclei with cold protons. Gamma rays are also produced in similar interactions inside some of the cosmic accelerators. We consider a few nearby supernova remnants observed by Fermi LAT. Many of them are associated with molecular clouds. Gamma rays have been detected from these sources which most likely originate in decay of neutral pions produced in hadronic interactions. The observed gamma ray fluxes from these SNRs are used to find out their contributions to the observed diffuse cosmic ray antiproton flux near the earth.

  7. The Darmstadt Antiproton Project (PANDA) at the High Energy Storage Ring at GSI

    SciTech Connect

    Peters, Klaus J.

    2002-11-20

    Recently GSI presented the plans for a major new international research facility. A key feature of this new facility will be the delivery of intense, high-quality secondary beams which embody the production of antiprotons. For the antiproton beams a 50 Tm storage ring is planned, including electron and stochastic cooling, will be able to handle antiproton beams in the momentum range from 1.5 up to 15 GeV/c. The design luminosity is 2 x 10{sup 32} cm{sup -2} s{sup -1}. The PANDA Experiment will take place at an internal target and will cover the aspects of the structure of hadrons and the properties of hadronic matter in the corresponding energy range. The main topics to be addressed are: Spectroscopy of charmonium; Search for charmed hybrids and glueballs; Interaction of open and hidden charm with nucleons and nuclei; Single and double hypernuclei; Open charm spectroscopy; CP-Violation in the charm sector; Deeply Virtual Comptom Scattering, etc. The major part of the experimental program will make use of a general purpose detector PANDA. The concept of this detector is presented.

  8. Proceedings of the Antiproton Science and Technology Workshop Held in Santa Monica, California on 6-9 October 1987

    DTIC Science & Technology

    1988-07-01

    Beams, BNL 52082 (1987). - -24-- Proceedings of the Rand Second Antiproton Conf . October 6-9, 1987, Santa Monica, CA LOW ENERGY ANTIPROTON...Energy Sources of Strangeness, (UC-Santa Cruz, 1983) AlP Conf . Proc. No. 102, Particles and Fields Subseries No. 31 (ALP, N.Y., 1983), ed. by T...0.5 10.0 00 p production . 013 .25 .015 1/oe/d~dp Acceptance (irmm-mrad) 100-200 20 Collection device pulsed target lithium lens ? fithium/plosma lem

  9. Transverse characterization of focused Bessel beams with angular momentum applied to study degree of coherence

    NASA Astrophysics Data System (ADS)

    He, Xi; Wu, Fengtie; Chen, Ziyang; Pu, Jixiong; Chavez-Cerda, Sabino

    2016-05-01

    The transverse focusing properties at the ‘pseudo-focal’ plane of coherent Bessel beams with angular momentum are analyzed in detail. The transverse magnification of the central dark region of Bessel beams at this pseudo-focal plane is derived for the first time by calculating the ratio of the magnitude of the transverse components of the corresponding wave vectors before and after the focusing lens. We test our results experimentally with coherent laser Bessel beams and excellent agreement is observed. Then, an LED light source is used to generate Bessel beams. By modifying the coherence of the LED light source, we observe that by reducing coherence a smaller and shallower central dark region of Bessel beams with angular momentum is produced at the pseudo-focal plane. This technique can be used as a method to characterize the degree of coherence of vortex beams.

  10. Computer Simulation of Antiproton RF Stacking in the Precooler Ring

    SciTech Connect

    Takayama, K.; Ruggiero, A.G.

    1981-01-16

    It has been recently proposed a scheme to produce a high-intensity antiproton beam in a precooler ring with functions of both stochastic cooling and accumulating. According to this scheme 13 batches from {bar p}-target are stacked and precooled on the stacking orbit every Main Ring cycle. After that the precooled beam is transported in a second storage ring (the Accumulator) and cooled for several hours together with previous {bar p} batches. As alternative it has also been proposed to decelerate each precooler pulse down to 200 MeV at which energy it can be transferred in a modified Electron Cooling Ring for storage and further cooling. The sequence of stacking operations in the Precooler consists of (1) injecting a P beam pulse onto the injection orbit, capturing it by standing-by RF buckets, rotating the bunch in the stationary RF buckets, and reducing the bucket height so that the stationary bucket will surround tightly the bunch, (2) decelerating to the stacking orbit and (3) finally turning off the RF adiabatically, allowing the beam to debunch. This sequence is repeated 13 times to build up a complete stack every Main Ring cycle. The above steps require fairly complicated manipulations of RF system parameters. The 13 {bar P}-batches are separated by 100 msec from each other for target heating considerations. In the present study, the above sequence of stacking is investigated by numerical simulation.

  11. High intensity proton injector for facility of antiproton and ion research

    SciTech Connect

    Berezov, R. Brodhage, R.; Fils, J.; Hollinger, R.; Ivanova, V.; Chauvin, N.; Delferriere, O.; Tuske, O.; Ullmann, C.

    2016-02-15

    The high current ion source with the low energy beam transport (LEBT) will serve as injector into the proton LINAC to provide primary proton beam for the production of antiprotons. The pulsed ion source developed and built in CEA/Saclay operates with a frequency of 2.45 GHz based on ECR plasma production with two coils with 87.5 mT magnetic field necessary for the electron cyclotron resonance. The compact LEBT consists of two solenoids with a maximum magnetic field of 500 mT including two integrated magnetic steerers to adjust the horizontal and vertical beam positions. The total length of the compact LEBT is 2.3 m and was made as short as possible to reduced emittance growth along the beam line. To measure ion beam intensity behind the pentode extraction system, between solenoids and at the end of the beam line, two current transformers and a Faraday cup are installed. To get information about the beam quality and position, the diagnostic chamber with different equipment will be installed between the two solenoids. This article reports the current status of the proton injector for the facility of antiproton and ion research.

  12. High intensity proton injector for facility of antiproton and ion research.

    PubMed

    Berezov, R; Brodhage, R; Chauvin, N; Delferriere, O; Fils, J; Hollinger, R; Ivanova, V; Tuske, O; Ullmann, C

    2016-02-01

    The high current ion source with the low energy beam transport (LEBT) will serve as injector into the proton LINAC to provide primary proton beam for the production of antiprotons. The pulsed ion source developed and built in CEA/Saclay operates with a frequency of 2.45 GHz based on ECR plasma production with two coils with 87.5 mT magnetic field necessary for the electron cyclotron resonance. The compact LEBT consists of two solenoids with a maximum magnetic field of 500 mT including two integrated magnetic steerers to adjust the horizontal and vertical beam positions. The total length of the compact LEBT is 2.3 m and was made as short as possible to reduced emittance growth along the beam line. To measure ion beam intensity behind the pentode extraction system, between solenoids and at the end of the beam line, two current transformers and a Faraday cup are installed. To get information about the beam quality and position, the diagnostic chamber with different equipment will be installed between the two solenoids. This article reports the current status of the proton injector for the facility of antiproton and ion research.

  13. Conceptual Design Report. Antiproton - Proton Collider Upgrade 20 GeV Rings. Technical Components and Civil Construction May, 1988

    SciTech Connect

    1988-05-01

    This report contains a description of the design and cost estimate of two new 20 GeV rings which will be required to support the upgrade of the Fermilab Collider with a luminosity goal of 5x10 31 cm-2s-1. The new rings include an antiproton post-accumulator, denoted the Antiproton Super Booster (ASB), and a proton post-booster, denoted the Proton Super Booster (PSB). The siting of the rings is shown in Figure I-1. Both rings are capable of operation at 20 GeV, eliminating the need for ever again injecting beam into the Main Ring below transition, and significantly enhancing Main Ring performance. The Antiproton Super Booster is designed to accept and accumulate up to 4x1012 antiprotons from the existing Antiproton Accumulator, and deliver them to the Main Ring at 20 GeV for acceleration and injection into the Collider. It is also designed to accept diluted antiprotons from the Main Ring at 20 GeV for recooling. The PSB accepts 8.9 GeV protons from the existing Booster and accelerates them to 20 GeV for injection into the Main Ring. The PSB is designed to operate at 5 Hz. The siting shown in Figure I-1 has the attractive feature that it removes all Main Ring injection hardware from the AO straight section, opening the possibility of installing a third proton-antiproton interaction region in the Tevatron Collider.

  14. Creating flat-top X-ray beams by applying surface profiles of alternating curvature to deformable piezo bimorph mirrors

    PubMed Central

    Sutter, John P.; Alcock, Simon G.; Kashyap, Yogesh; Nistea, Ioana; Wang, Hongchang; Sawhney, Kawal

    2016-01-01

    Beam shaping is becoming increasingly important for synchrotron X-ray applications. Although routine for visible light lasers, this is challenging for X-rays due to the limited source coherence and extreme optical tolerances required for the shaping mirrors. In deliberate defocusing, even surface errors <5 nm r.m.s. introduce damagingly large striations into the reflected beam. To counteract such problems, surface modifications with alternating concave and convex curvature on equal segments were polished onto the surface of non-active mirrors of fixed curvature. Such optics are useful for providing a fixed size of X-ray beam, but do not provide the adaptability required by many experiments. In contrast, deformable piezo bimorph mirrors permit a continuous range of X-ray beam sizes and shapes. A new theory is developed for applying non-periodic modifications of alternating curvature to optical surfaces. The position and length of the segments may be freely chosen. For the first time, surface modifications of alternating curvature are applied to bimorph mirrors to generate non-Gaussian X-ray beam profiles of specified width. The new theory’s freedom is exploited to choose the segments to match the polishing errors of medium wavelength (>10 mm) and the piezos’ influence on the mirror’s figure. Five- and seven-segment modifications of alternating curvature are calculated and verified by visible light and X-ray metrology. The latter yields beam profiles with less striation than those made by defocusing. Remaining beam striations are explained by applying geometrical optics to the deviations from the ideal surface modifications of alternating curvature. PMID:27787239

  15. Creating flat-top X-ray beams by applying surface profiles of alternating curvature to deformable piezo bimorph mirrors.

    PubMed

    Sutter, John P; Alcock, Simon G; Kashyap, Yogesh; Nistea, Ioana; Wang, Hongchang; Sawhney, Kawal

    2016-11-01

    Beam shaping is becoming increasingly important for synchrotron X-ray applications. Although routine for visible light lasers, this is challenging for X-rays due to the limited source coherence and extreme optical tolerances required for the shaping mirrors. In deliberate defocusing, even surface errors <5 nm r.m.s. introduce damagingly large striations into the reflected beam. To counteract such problems, surface modifications with alternating concave and convex curvature on equal segments were polished onto the surface of non-active mirrors of fixed curvature. Such optics are useful for providing a fixed size of X-ray beam, but do not provide the adaptability required by many experiments. In contrast, deformable piezo bimorph mirrors permit a continuous range of X-ray beam sizes and shapes. A new theory is developed for applying non-periodic modifications of alternating curvature to optical surfaces. The position and length of the segments may be freely chosen. For the first time, surface modifications of alternating curvature are applied to bimorph mirrors to generate non-Gaussian X-ray beam profiles of specified width. The new theory's freedom is exploited to choose the segments to match the polishing errors of medium wavelength (>10 mm) and the piezos' influence on the mirror's figure. Five- and seven-segment modifications of alternating curvature are calculated and verified by visible light and X-ray metrology. The latter yields beam profiles with less striation than those made by defocusing. Remaining beam striations are explained by applying geometrical optics to the deviations from the ideal surface modifications of alternating curvature.

  16. Two-beam coupling gain in undoped GaAs with applied dc electric field and moving grating

    NASA Technical Reports Server (NTRS)

    Liu, Duncan T. H.; Cheng, Li-Jen; Chiou, Arthur E.; Yeh, Pochi

    1989-01-01

    Experimental results of two-beam coupling gain efficiency in an undoped, semiinsulating GaAs crystal are reported. The highest gain coefficient measured is about 4.5/cm under the condition of an applied electric field of 13 kV/cm and a grating periodicity of 20 microns. The experimental results and theoretical calculations are in reasonable agreement with each other.

  17. Mathematical modelling of the beam under axial compression force applied at any point - the buckling problem

    NASA Astrophysics Data System (ADS)

    Magnucka-Blandzi, Ewa

    2016-06-01

    The study is devoted to stability of simply supported beam under axial compression. The beam is subjected to an axial load located at any point along the axis of the beam. The buckling problem has been desribed and solved mathematically. Critical loads have been calculated. In the particular case, the Euler's buckling load is obtained. Explicit solutions are given. The values of critical loads are collected in tables and shown in figure. The relation between the point of the load application and the critical load is presented.

  18. Kickers and power supplies for the Fermilab Tevatron I antiproton source

    SciTech Connect

    Castellano, T.; Bartoszek, L.; Tilles, E.; Petter, J.; McCarthy, J.

    1985-05-01

    The Fermilab Antiproton Source Accumulator and Debuncher rings require 5 kickers in total. These range in design from conventional ferrite delay line type magnets, with ceramic beam tubes to mechanically complex shuttered kickers situated entirely in the Accumulator Ring's 10/sup -10/ torr vacuum. Power supplies are thyratron switched pulse forming networks that produce microsecond width pulses of several kiloamps with less than 30 nanoseconds rise and fall times. Kicker and power supply design requirements for field strength, vacuum, rise and fall time, timing and magnetic shielding of the stacked beam in the accumulator by the eddy current shutter will be discussed. 8 refs., 3 figs., 2 tabs.

  19. Laser-electron beam interaction applied to optical amplifiers and oscillators

    NASA Technical Reports Server (NTRS)

    Pantell, R. H.; Piestrup, M. A.

    1976-01-01

    Momentum modulation of a relativistic electron beam by a Nd:YAG laser is demonstrated. The electrons, at 100 MeV energy, interact with the laser light in helium gas at standard temperature and pressure. At an angle of 6.55 mrad between the two wavevectors, corresponding to the Cerenkov angle, a given electron remains in a field of constant phase as it passes through the light beam. The experimental arrangement is illustrated showing the trajectories of the electron and light. The particle momentum is measured by a mass spectrometer, and the angle between the wavevectors is controlled by a rotatable mirror. Experimental results indicate that momentum modulation of an electron beam may be used for amplification. A possible configuration for an optical klystron is illustrated.

  20. An antiproton catalyst for inertial confinement fusion propulsion

    NASA Technical Reports Server (NTRS)

    Lewis, Raymond A.; Newton, Richard; Smith, Gerald A.; Toothacker, William S.; Kanzleiter, Randall J.

    1990-01-01

    This paper discusses the concept of an inertial confinement fusion propulsion system involving an antiproton catalyst (for antiproton-induced fission). It is argued that, when the two processes, fusion and antimatter annihilation, are combined into one system, a viable candidate propulsion system for planetary exploration emerges. It is shown that as much as 7.6 GW of power, well within the requrements for interplanetary travel, can be achieved using existing driver technologies and available quantities of antiprotons.

  1. Engineering Challenges in Antiproton Triggered Fusion Propulsion

    SciTech Connect

    Cassenti, Brice; Kammash, Terry

    2008-01-21

    During the last decade antiproton triggered fusion propulsion has been investigated as a method for achieving high specific impulse, high thrust in a nuclear pulse propulsion system. In general the antiprotons are injected into a pellet containing fusion fuel with a small amount of fissionable material (i.e., an amount less than the critical mass) where the products from the fission are then used to trigger a fusion reaction. Initial calculations and simulations indicate that if magnetically insulated inertial confinement fusion is used that the pellets should result in a specific impulse of between 100,000 and 300,000 seconds at high thrust. The engineering challenges associated with this propulsion system are significant. For example, the antiprotons must be precisely focused. The pellet must be designed to contain the fission and initial fusion products and this will require strong magnetic fields. The fusion fuel must be contained for a sufficiently long time to effectively release the fusion energy, and the payload must be shielded from the radiation, especially the excess neutrons emitted, in addition to many other particles. We will review the recent progress, possible engineering solutions and the potential performance of these systems.

  2. Antiproton nucleus potentials from global fits to antiprotonic X-rays and radiochemical data

    NASA Astrophysics Data System (ADS)

    Friedman, E.; Gal, A.; Mareš, J.

    2005-11-01

    We report on global fits of optical-model parameters to 90 data points for p¯ X-rays and 17 data points of radiochemical data put together. By doing separate fits to the two kinds of data it is possible to determine phenomenologically the radial region where the absorption of antiprotons takes place and to obtain neutron densities which represent the average behaviour over the periodic table. A finite-range attractive and absorptive p¯-nuclear isoscalar potential fits the data well. Self-consistent dynamical calculations within the RMF model demonstrate that the polarization of the nucleus by the atomic antiproton is negligible.

  3. Elastic scattering, polarization and absorption of relativistic antiprotons on nuclei

    NASA Astrophysics Data System (ADS)

    Larionov, A. B.; Lenske, H.

    2017-01-01

    We perform Glauber model calculations of the antiproton-nucleus elastic and quasielastic scattering and absorption in the beam momentum range ∼ 0.5 ÷ 10 GeV / c. A good agreement of our calculations with available LEAR data and with earlier Glauber model studies of the p bar A elastic scattering allows us to make predictions at the beam momenta of ∼10 GeV/c, i.e. at the regime of the PANDA experiment at FAIR. The comparison with the proton-nucleus elastic scattering cross sections shows that the diffractive minima are much deeper in the p bar A case due to smaller absolute value of the ratio of the real-to-imaginary part of the elementary elastic amplitude. Significant polarization signal for p bar A elastic scattering at 10 GeV/c is expected. We have also revealed a strong dependence of the p bar A absorption cross section on the slope parameter of the transverse momentum dependence of the elementary p bar N amplitude. The p bar A optical potential is discussed.

  4. Preliminary results on time-resolved ion beam induced luminescence applied to the provenance study of lapis lazuli

    NASA Astrophysics Data System (ADS)

    Czelusniak, C.; Palla, L.; Massi, M.; Carraresi, L.; Giuntini, L.; Re, A.; Lo Giudice, A.; Pratesi, G.; Mazzinghi, A.; Ruberto, C.; Castelli, L.; Fedi, M. E.; Liccioli, L.; Gueli, A.; Mandò, P. A.; Taccetti, F.

    2016-03-01

    This work will present preliminary results concerning the use of time-resolved ion beam induced luminescence applied to provenance studies of lapis lazuli. Measurements were performed at the pulsed beam facility at LABEC laboratory in Florence. Lapis lazuli is a semi-precious gemstone, used as ornament since the early civilizations that can be found in few places on Earth. The importance of this work lies in understanding the origin of various samples of lapis lazuli, from which it may be possible to gain insight into trade routes from ancient times. The samples studied in this work originated from Chile, Afghanistan, Tajikistan, Myanmar, and Siberia. The stones were irradiated with 3 MeV protons and the resulting luminescence was detected by a photomultiplier tube, whose output was acquired using a sampling digitizer VME module (CAEN/V1720). Wavelength discrimination was performed at 430 nm utilizing a range of beam currents. The results showed that, by changing the beam current intensity, one can study different features of lapis lazuli, and this may aid in distinguishing lapis lazuli from different provenances.

  5. A fast parallel Poisson solver on irregular domains applied to beam dynamics simulations

    SciTech Connect

    Adelmann, A. Arbenz, P. Ineichen, Y.

    2010-06-20

    We discuss the scalable parallel solution of the Poisson equation within a Particle-In-Cell (PIC) code for the simulation of electron beams in particle accelerators of irregular shape. The problem is discretized by Finite Differences. Depending on the treatment of the Dirichlet boundary the resulting system of equations is symmetric or 'mildly' nonsymmetric positive definite. In all cases, the system is solved by the preconditioned conjugate gradient algorithm with smoothed aggregation (SA) based algebraic multigrid (AMG) preconditioning. We investigate variants of the implementation of SA-AMG that lead to considerable improvements in the execution times. We demonstrate good scalability of the solver on distributed memory parallel processor with up to 2048 processors. We also compare our iterative solver with an FFT-based solver that is more commonly used for applications in beam dynamics.

  6. Thermal Imaging Applied to Cryocrystallography: Cryocooling and Beam Heating (Part I)

    NASA Technical Reports Server (NTRS)

    Snell, Edward; Bellamy, Henry; Rosenbaum, Gerd; vanderWoerd, Mark; Kazmierczak, Michael

    2006-01-01

    Thermal imaging provides a non-invasive method to study both the cryocooling process and the heating due to the X-ray beam interaction with a sample. The method has been used successfully to image cryocooling in a number of experimental situations, i.e. cooling as a function of sample volume and as a function of cryostream orientation. Although there are experimental limitations to the method, it has proved a powerful technique to aid cryocrystallography development. Due to the rapid spatial temperature information provided about the sample it is also a powerful tool in the testing of mathematical models. Recently thermal imaging has been used to measure the temperature distribution on both a model and typical crystal samples illuminated with an X-ray beam produced by an undulator. A brief overview of thermal imaging and previous results will be presented. In addition, a detailed description of the calibration and experimental aspects of the beam heating measurements will be described. This will complement the following talk on the mathematical modeling and analysis of the results.

  7. Applied Focused Ion Beam Techniques for Sample Preparation of Astromaterials for Integrated Nano-Analysis

    SciTech Connect

    Graham, G A; Teslich, N E; Kearsley, A T; Stadermann, F J; Stroud, R M; Dai, Z R; Ishii, H A; Hutcheon, I D; Bajt, S; Snead, C J; Weber, P K; Bradley, J P

    2007-02-20

    Sample preparation is always a critical step in study of micrometer sized astromaterials available for study in the laboratory, whether their subsequent analysis is by electron microscopy or secondary ion mass spectrometry. A focused beam of gallium ions has been used to prepare electron transparent sections from an interplanetary dust particle, as part of an integrated analysis protocol to maximize the mineralogical, elemental, isotopic and spectroscopic information extracted from one individual particle. In addition, focused ion beam techniques have been employed to extract cometary residue preserved on the rims and walls of micro-craters in 1100 series aluminum foils that were wrapped around the sample tray assembly on the Stardust cometary sample collector. Non-ideal surface geometries and inconveniently located regions of interest required creative solutions. These include support pillar construction and relocation of a significant portion of sample to access a region of interest. Serial sectioning, in a manner similar to ultramicrotomy, is a significant development and further demonstrates the unique capabilities of focused ion beam microscopy for sample preparation of astromaterials.

  8. Radiation Therapy Photon Beams Dose Conformation According to Dose Distribution Around Intracavitary-Applied Brachytherapy Sources

    SciTech Connect

    Jurkovic, Slaven Zauhar, Gordana; Faj, Dario; Radojcic, Deni Smilovic; Svabic, Manda

    2010-04-01

    Intracavitary application of brachytherapy sources followed by external beam radiation is essential for the local treatment of carcinoma of the cervix. Due to very high doses to the central portion of the target volume delivered by brachytherapy sources, this part of the target volume must be shielded while being irradiated by photon beams. Several shielding techniques are available, from rectangular block and standard cervix wedge to more precise, customized step wedge filters. Because the calculation of a step wedge filter's shape was usually based on effective attenuation coefficient, an approach that accounts, in a more precise way, for the scattered radiation, is suggested. The method was verified under simulated clinical conditions using film dosimetry. Measured data for various compensators were compared to the numerically determined sum of the dose distribution around brachytherapy sources and one of compensated beam. Improvements in total dose distribution are demonstrated, using our method. Agreement between calculation and measurements were within 3%. Sensitivity of the method on sources displacement during treatment has also been investigated.

  9. Antiproton-nucleus electromagnetic annihilation as a way to access the proton timelike form factors

    NASA Astrophysics Data System (ADS)

    Fonvieille, H.; Karmanov, V. A.

    2009-11-01

    Contrary to the reaction bar{{p}} p rightarrow e + e - with a high-momentum incident antiproton on a free target proton at rest, in which the invariant mass M of the e + e - pair is necessarily much larger than the bar{{p}} p mass 2 m , in the reaction bar{{p}} d rightarrow e + e - n the value of M can take values near or below the bar{{p}} p mass. In the antiproton-deuteron electromagnetic annihilation, this allows to access the proton electromagnetic form factors in the timelike region of q2 near the bar{{p}} p threshold. We estimate the cross-section dσ _{bar pd to e^ + e^ - n} /dmathcal{M} for an antiproton beam momentum of 1.5GeV/ c. We find that near the bar{{p}} p threshold this cross-section is about 1pb/MeV. The case of heavy-nuclei target is also discussed. Elements of experimental feasibility are presented for the process bar{{p}} d rightarrow e + e - n in the context of the overline{{P}} ANDA project.

  10. The universe in the laboratory - Nuclear astrophysics opportunity at the facility for antiproton and ion research

    SciTech Connect

    Langanke, K.

    2014-05-09

    In the next years the Facility for Antiproton and Ion Research FAIR will be constructed at the GSI Helmholtzze-ntrum für Schwerionenforschung in Darmstadt, Germany. This new accelerator complex will allow for unprecedented and pathbreaking research in hadronic, nuclear, and atomic physics as well as in applied sciences. This manuscript will discuss some of these research opportunities, with a focus on supernova dynamics and nucleosynthesis.

  11. Progress in Antiproton Production at the Fermilab Tevatron Collider

    SciTech Connect

    Pasquinelli, Ralph J.; Drendel, Brian; Gollwitzer, Keith; Johnson, Stan; Lebedev, Valeri; Leveling, Anthony; Morgan, James; Nagaslaev, Vladimir; Peterson, Dave; Sondgeroth, Alan; Werkema, Steve; /Fermilab

    2009-04-01

    Fermilab Collider Run II has been ongoing since 2001. During this time peak luminosities in the Tevatron have increased from approximately 10 x 10{sup 30} cm{sup -2}sec{sup -1} to 300 x 10{sup 30} cm{sup 02}sec{sup -1}. A major contributing factor in this remarkable performance is a greatly improved antiproton production capability. Since the beginning of Run II, the average antiproton accumulation rate has increased from 2 x 10{sup 10}{anti p}/hr to about 24 x 10{sup 10}{anti p}/hr. Peak antiproton stacking rates presently exceed 28 x 10{sup 10}{anti p}/hr. The antiproton stacking rate has nearly doubled since 2005. It is this recent progress that is the focus of this paper. The process of transferring antiprotons to the Recycler Ring for subsequent transfer to the collider has been significantly restructured and streamlined, yielding additional cycle time for antiproton production. Improvements to the target station have greatly increased the antiproton yield from the production target. The performance of the Antiproton Source stochastic cooling systems has been enhanced by upgrades to the cooling electronics, accelerator lattice optimization, and improved operating procedures. In this paper, we will briefly report on each of these modifications.

  12. Antiproton-hydrogen atom rearrangement-annihilation cross section

    SciTech Connect

    Morgan, D.L. Jr.

    1986-08-22

    For antiproton energies of several eV or less, annihilation in matter occurs through atomic rearrangement processes in which the antiproton becomes bound to a nucleus prior to annihilation. Existing calculations of the antiproton-hydrogen atom rearrangement cross section are semiclassical and employ the Born-Oppenheimer approximation. They also employ various arguments in regard to the behavior of the system when the Born-Oppenheimer approximation breaks down at small antiproton-proton separations. These arguments indicate that rearrangement is essentially irreversible. In the present study, a detailed investigation was made of the antiproton-hydrogen atom system when the Born-Oppenheimer approximation breaks down. The results of this study indicate that the previous arguments were approximately correct, but that there is a significant probability for rearrangement reversing prior to annihilation. This probability is estimated to be about 20%. 8 refs., 4 figs., 2 tabs.

  13. Intensity-Frontier Antiproton Physics with The Antiproton Annihilation Spectrometer (TAPAS) at Fermilab

    SciTech Connect

    Apollinari, Giorgio; Asner, David M.; Baldini, Wander; Bartoszek, Larry; Broemmelsiek, Daniel R.; Brown, Charles N.; Chakravorty, Alak; Colas, Paul; Derwent, Paul; Drutskoy, Alexey; Fortner, Michael; /Northern Illinois U. /Saclay /Indian Inst. Tech., Hyderabad

    2011-11-01

    The Fermilab Antiproton Source is the world's most intense source of antimatter. With the Tevatron program now behind us, this unique facility can help make the case for Fermilab's continued accelerator operations. The Antiproton Source can be used for unique, dedicated antimatter studies, including medium-energy {bar p}-annihilation experiments. We propose to assemble a powerful, yet cost-effective, solenoidal magnetic spectrometer for antiproton-annihilation events, and to use it at the Fermilab Antiproton Accumulator to measure the charm production cross section, study rare hyperon decays, search for hyperon CP asymmetry, precisely measure the properties of several charmonium and nearby states, and make the first measurements of the Drell-Yan continuum in medium-energy antiproton annihilation. Should the charm production cross section be as large as some have proposed, we will also be able to measure D{sup 0}-{bar D}{sup 0} mixing with high precision and discover (or sensitively limit) charm CP violation. The observation of charm or hyperon CP violation would be evidence for physics beyond the Standard Model, with possible implications for the origin of the baryon asymmetry of the universe - the question of what happened to all the antimatter that must have been produced in the Big Bang. The experiment will be carried out by an international collaboration and will require some four years of running time. As possibly the sole hadron experiment in progress at Fermilab during that time, it will play an important role in maintaining a broad particle physics program at Fermilab and in the U.S. It will thus help us to continue attracting creative and capable young people into science and technology, and introducing them to the important technologies of accelerators, detectors, and data acquisition and analysis - key roles in society that accelerator-based particle physics has historically played.

  14. AMS-02 antiprotons: implications for dark matter

    NASA Astrophysics Data System (ADS)

    Boudaud, Mathieu

    2016-05-01

    Using the updated proton and helium fluxes just released by the Ams-02 experiment we reevaluate the secondary astrophysical antiproton to proton ratio and its uncertainties, and compare it with the ratio preliminarly reported by AMS-02. We find no unambiguous evidence for a significant excess with respect to expectations. Yet, some preference for a flatter energy dependence of the diffusion coefficient (with respect to the Med benchmark often used in the literature) starts to emerge. Finally, we provide a first assessment of the room left for exotic components such as Galactic Dark Matter annihilation, deriving new stringent constraints.

  15. Stability of the Helium-Antiproton System

    NASA Technical Reports Server (NTRS)

    Drachman, Richard J.

    2006-01-01

    In the course of their Born-Oppenheimer calculations of this system Todd and Armour noted that the lowest-lying state closely resembles the hydrogen negative ion, since the antiproton lies very close to the helium nucleus and shields one unit of nuclear charge. In the present paper this observation will be taken seriously to produce a variationally correct estimate of the total energy of this system, along with a similar estimate of the energy of the once-ionized system. The nonadiabatic effect of exactly treating the reduced masses improves the results.

  16. Ion beam divergence from unstable fluctuations in applied-[ital B] diodes

    SciTech Connect

    Sudan, R.N.; Longcope, D.W. )

    1993-05-01

    An electron plasma oscillation driven unstable by ion streaming is identified with the low-frequency mode observed in QUICKSILVER [[ital Computational] [ital Physics], edited by A. Tenner (World Scientific, Singapore, 1991), pp. 475--482] numerical simulations. This mode heats the electrons along the magnetic field and is ultimately stabilized by the thermal spread. A quasilinear theory determines the saturation level of the fluctuations, the ion divergence, and the ion energy and momentum spread as they exit the diode. The ion divergence is predicted to be independent of the ion mass for fixed diode voltage and scales as the product of the effective gap and the ion beam enhancement factor over Child--Langmuir current.

  17. Potential for a Near Term Very Low Energy Antiproton Source at Brookhaven National Laboratory.

    DTIC Science & Technology

    1989-04-01

    Source; Beam 0 07 Deceleration; Antiproton Production Rates - I)= 20 08 19. ABSTRACT (Continue on reverse if necessary and identify by block number) 7...CLASSIFICATION rIUNCLASSIFIED/UNLIMITED 0 SAME AS RPT. 03 DTIC USERS Unclassified 22a. NAME OF RESPONSIBLE INDIVIDUAL 22b. TELEPHONE (Include Area Code) 22c...1979) 13F/i1.5 x1 0 PROTONS (Collected at 3.5 GeV/c) WITHOUR COOLING 108 07 1 6 I 102 0 T (MeV) 4 BNL- 39142 AGSIAD/ 87-1 AGS SUPERCONDUCTING

  18. The use of the Fermilab antiproton Accumulator in medium energy physics experiments

    SciTech Connect

    Bharadwaj, V.; Church, M.; Harms, E.; Hsueh, S.Y.; Kells, W.; MacLachlan, J.; Marsh, W.; McCarthy, J.; Pastrone, N.; Peoples, J.

    1988-06-07

    The Fermilab antiprotron Accumulator has been modified for use in a medium energy experiment. The experiment is conducted with circulating antiproton beam of momentum between 6.7 GeV/c and 3.7 GeV/c colliding with protons from an internal gas jet. Antiprotons are accumulated at the normal momentum of 8.9 GeV/c and then decelerated to the appropriate energy. It is necessary to cool the beam continually during the time it is colliding with the gas jet. The experiment requires new provisions for the control of magnet power supplies and low level rf system and modifications of the cooling system and high level energy systems to permit variable energy operation. Transition must be crossed to decelerate the beam below 5 GeV/c; because the deceleration is very slow, transition can not be crossed in a conventional manner. This paper will describe the required changes to the Accumulator and operating experience with protons. 8 refs., 2 figs., 1 tab.

  19. Ion Dynamic Capture Experiments With The High Performance Antiproton Trap (HiPAT)

    NASA Technical Reports Server (NTRS)

    Martin, James; Lewis, Raymond; Chakrabarti, Suman; Sims, William H.; Pearson, J. Boise; Fant, Wallace E.

    2002-01-01

    To take the first step towards using the energy produced from the matter-antimatter annihilation for propulsion applications, the NASA Marshall Space Flight Center (MSFC) Propulsion Research Center (PRC) has initiated a research activity examining the storage of low energy antiprotons. The High Performance Antiproton Trap (HiPAT) is an electromagnetic system (Penning-Malmberg design) consisting of a 4 Tesla superconductor, a high voltage electrode confinement system, and an ultra high vacuum test section. It has been designed with an ultimate goal of maintaining 10(exp 12) charged particles with a half-life of 18 days. Currently, this system is being evaluated experimentally using normal matter ions that are cheap to produce, relatively easy to handle, and provide a good indication of overall trap behavior (with the exception of assessing annihilation losses). The ions are produced via a positive hydrogen ion source and transported to HiPAT in a beam line equipped with electrostatic optics. The optics serve to both focus and gate the incoming ions, providing microsecond-timed beam pulses that are dynamically captured by cycling the HiPAT forward containment field like a "trap door". Initial dynamic capture experiments have been successfully performed with beam energy and currents set to 1.9 kV and 23 micro-amps, respectively. At these settings up to 2x10(exp 9) ions have been trapped during a single dynamic cycle.

  20. Anti- and Hypermatter Research at the Facility for Antiproton and Ion Research FAIR

    NASA Astrophysics Data System (ADS)

    Steinheimer, J.; Xu, Z.; Rau, P.; Sturm, C.; Stöcker, H.

    2013-07-01

    Within the next six years, the Facility for Antiproton and Ion Research (FAIR) is built adjacent to the existing accelerator complex of the GSI Helmholtz Center for Heavy Ion Research at Darmstadt, Germany. Thus, the current research goals and the technical possibilities are substantially expanded. With its worldwide unique accelerator and experimental facilities, FAIR will provide a wide range of unprecedented fore-front research in the fields of hadron, nuclear, atomic, plasma physics and applied sciences which are summarized in this article. As an example this article presents research efforts on strangeness at FAIR using heavy ion collisions, exotic nuclei from fragmentation and antiprotons to tackle various topics in this area. In particular, the creation of hypernuclei, metastable exotic multi-hypernuclear objects (MEMOs) and antimatter is investigated.

  1. Anti- and Hypermatter Research at the Facility for Antiproton and Ion Research FAIR

    NASA Astrophysics Data System (ADS)

    Steinheimer, J.; Xu, Z.; Gudima, K.; Botvina, A.; Mishustin, I.; Bleicher, M.; Stöcker, H.

    2012-11-01

    Within the next six years, the Facility for Antiproton and Ion Research (FAIR) is built adjacent to the existing accelerator complex of the GSI Helmholtz Center for Heavy Ion Research at Darmstadt, Germany. Thus, the current research goals and the technical possibilities are substantially expanded. With its worldwide unique accelerator and experimental facilities, FAIR will provide a wide range of unprecedented fore-front research in the fields of hadron, nuclear, atomic, plasma physics and applied sciences which are summarized in this article. As an example this article presents research efforts on strangeness at FAIR using heavy ion collisions, exotic nuclei from fragmentation and antiprotons to tackle various topics in this area. In particular, the creation of hypernuclei and antimatter is investigated.

  2. Potential applicability of the Los Alamos Antiproton Research Program to advanced propulsion

    SciTech Connect

    Howe, S.D.; Hynes, M.V.; Prael, R.E.; Stewart, J.D.

    1986-01-01

    The Los Alamos National Laboratory currently has a research program in antimatter interactions. The immediate objective of the program is to develop the low energy antiproton production capabilities at LEAR and the technology to store antiprotons. The initial experimental goal is to measure the gravitational mass of antiprotons. The technology required for the experiment, however, may allow high-density storage concepts to be experimentally investigated. Analysis of antiproton production over the last 30 years indicates that milligram quantities of antiprotons could conceivably be produced early in the next century. Thus, antiproton propulsion concepts may begin to be feasible. Some results of preliminary calculations pertinent to antiproton powered rocket engines will be presented.

  3. Low energy antiproton possibilities at BNL

    SciTech Connect

    Lee, Y.Y.; Lowenstein, D.I.

    1987-01-01

    Antinuclear physics in the energy range of 0 to 20 GeV has long been a mainstay of the high energy physics program at BNL. The emphasis of the experimental program in the last couple of years has however moved to other areas as new facilities in the world have come on line. The initiatives stimulated by the USAF has caused a renewed interest in the low energy capabilities at BNL, which are still very competitive and considerable for the production of low energy antiprotons. A synopsis is given of the present BNL accelerator plans and the near term possibilities for a high yield antiproton production experiment. This paper does not address the longer term facility possibilities of producing ''large'' amounts of antimatter. Parenthetically, even though several aspects of the program are of little interest for this audience, such as the Relativistic Heavy Ion Collider (RHIC) and the Stretcher, it is important to understand their parameters and impact upon various possible antinucleon initiatives at BNL.

  4. Advanced Space Propulsion Study - Antiproton and Beamed Power Propulsion

    DTIC Science & Technology

    1987-10-01

    a new concept for a very high performance laser-puwhed lightsail that uses near-teri high power laser systems to boost very light payloads to terminal...charged pions have a normal half-life of 26 ns. Because they are moving at 94% of the speed of light , however, their lives are lengthened to 70 ns...Given adequate supplies stashed along the way, a light -weight spacesuit, and enough time, Jack would be able to climb into space instead of having to use

  5. 2D potential measurements by applying automatic beam adjustment system to heavy ion beam probe diagnostic on the Large Helical Device

    SciTech Connect

    Shimizu, A. Ido, T.; Kato, S.; Hamada, Y.; Kurachi, M.; Makino, R.; Nishiura, M.; Nishizawa, A.

    2014-11-15

    Two-dimensional potential profiles in the Large Helical Device (LHD) were measured with heavy ion beam probe (HIBP). To measure the two-dimensional profile, the probe beam energy has to be changed. However, this task is not easy, because the beam transport line of LHD-HIBP system is very long (∼20 m), and the required beam adjustment consumes much time. To reduce the probe beam energy adjustment time, an automatic beam adjustment system has been developed. Using this system, required time to change the probe beam energy is dramatically reduced, such that two-dimensional potential profiles were able to be successfully measured with HIBP by changing the probe beam energy shot to shot.

  6. Do angles of obliquity apply to 30 degrees scattered radiation from megavoltage beams?

    PubMed

    Biggs, Peter J; Styczynski, John R

    2008-10-01

    The angle of obliquity is used in radiation shielding calculations to account for the longer path length x rays will see when obliquely incident on the protective barrier. According to the National Council on Radiation Protection and Measurements (NCRP), use of the angle of obliquity is explicitly assumed for primary radiation, so that an angle of obliquity for secondary radiation is never addressed. However, in the example section of the latest report, it specifically recommends against using an angle of obliquity for scattered radiation. To check this assumption, the existence or not of an angle of obliquity for scattered radiation has been investigated for bremsstrahlung x-ray beams of 4, 6, 10, 15, and 18 MV and for barriers consisting of concrete, lead, and steel using a Monte Carlo approach. The MCNP Monte Carlo code, v4.2C, has been used to generate scattered radiation at 30 degrees from a water phantom and incident on a secondary barrier at the same angle relative to the normal to the barrier. The barrier thickness was increased from zero to a thickness sufficient to reduce the fluence (f4 tally) to <10(-3). A transmission curve was created for each energy-barrier material combination by normalizing to zero thickness. The results for the first tenth-value layer (TVL) in concrete (5 energies) show an average angle of obliquity of 21.7 degrees +/- 5.6 degrees , and for the first two TVLs averaged 29.7 degrees +/- 3.9 degrees . The results for the first TVL in lead (3 energies) show an average angle of obliquity of 27.7 degrees +/- 4.0 degrees , and for the first two TVLs averaged 20.5 degrees +/- 5.8 degrees . There are no data in the NCRP reports for 30 degrees scattered radiation attenuated by steel with which to make a comparison.

  7. Evidence for the existence of cosmic-ray antiprotons

    NASA Technical Reports Server (NTRS)

    Golden, R. L.; Horan, S.; Mauger, B. G.; Badhwar, G. D.; Lacy, J. L.; Stephens, S. A.; Daniel, R. R.; Zipse, J. E.

    1979-01-01

    A search for cosmic-ray antiprotons was recently performed with the use of a balloon-borne superconducting-magnet spectrometer. A total of 46 antiproton candidates were observed in the rigidity interval from 5.6 to 12.5 GV/c. Of these events 18.3 are expected to be atmospheric and instrumentation background. The p(-)/p ratio is found to be 0.00052 + or - 0.00015. This ratio is consistent with secondary production of antiprotons in the interstellar medium.

  8. Propagation of Secondary Antiprotons and Cosmic Rays in the Galaxy

    NASA Technical Reports Server (NTRS)

    Moskalenko, I. V.; Strong, A. W.; Mashnik, S. G.; Ormes, J. F.; Jones, F. C.

    2002-01-01

    Recent more accurate antiproton data obtained by the BESS team during the last solar minimum pose a challenge to conventional propagation models of cosmic rays. In particular, the diffusive reacceleration model, which matches well key secondary/primary isotope ratios in cosmic rays, fails to reproduce the secondary antiproton spectrum. Tuning both secondary/primary isotope ratios and antiprotons is possible, but requires artificial breaks in the diffusion coefficient and the injection spectrum of primaries. We will discuss some possibilities to overcome these difficulties in the propagation models. We will present new results of our calculation of CR propagation in the Galaxy using the GALPROP code.

  9. Micro-/nanosized cantilever beams and mass sensors under applied axial tensile/compressive force vibrating in vacuum and viscous fluid

    SciTech Connect

    Stachiv, Ivo; Fang, Te-Hua; Chen, Tao-Hsing

    2015-11-15

    Vibrating micro-/nanosized cantilever beams under an applied axial force are the key components of various devices used in nanotechnology. In this study, we perform a complete theoretical investigation of the cantilever beams under an arbitrary value of the axial force vibrating in a specific environment such as vacuum, air or viscous fluid. Based on the results easy accessible expressions enabling one the fast and highly accurate estimations of changes in the Q-factor and resonant frequencies of beam oscillating in viscous fluid caused by the applied axial force are derived and analyzed. It has been also shown that for beam-to-string and string vibrational regimes the mode shape starts to significantly deviate from the one known for a beam without axial force. Moreover, a linear dependency of the vibrational amplitude in resonance on the dimensionless tension parameter has been found. We revealed that only a large axial force, i.e. the string vibrational regime, significantly improves the Q-factor of beams submerged in fluid, while an increase of the axial force in beam and beam-to-string transition regimes has a negligibly small impact on the Q-factor enhancement. Experiments carried out on the carbon nanotubes and nanowires are in a good agreement with present theoretical predictions.

  10. Conceptual designs for antiproton space propulsion systems

    SciTech Connect

    Cassenti, B.N.

    1989-01-01

    Five conceptual designs for antimatter space propulsion systems were compared in terms of their performance characteristics. The systems examined included solid-core liquid-propellant rockets; magnetically confined gaseous-core rockets using liquid or solid propellants; plasma-core rockets; pion rockets, which are driven directly by the mass annihilation products; and ram-augmented rockets, in which antiproton annihilation is used to heat hydrogen collected in interstellar space. It was found that, in general, as the specific impulse of the propulsion system increases, the thrust decreases. The comparison between designs showed that only fusion rockets have the capability to compete in performance with mass annihilation rockets. For very-high-speed interstellar missions, pion rockets, which can have a specific impulse of 20 million sec (although with a thrust-to-engine mass ratios of only 0.01 G) will offer best performance. 36 refs.

  11. Positrons and Antiprotons in Galactic Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Cowsik, R.

    2016-10-01

    I consider the impact of recent measurements of positron and antiproton spectra in cosmic rays on our understanding of the origins and propagation of cosmic rays, as well as on the annihilation and decay characteristics of particles of Galactic dark matter, from the perspective of current models postulating energy-dependent leakage of cosmic rays from the Galaxy and of the nested leaky-box model, in which the leakage from the Galaxy is independent of energy. The nested leaky-box model provides a straightforward and consistent explanation of the observed spectral intensities, and finds no compelling need for a contribution from the annihilation or decay of Galactic dark matter. Improved observations and modeling efforts are needed to probe the properties of dark matter deeply enough to be significant to particle physics and cosmology.

  12. Fragmentation of methane molecules by antiproton impact

    NASA Astrophysics Data System (ADS)

    Salehzadeh, Arash; Kirchner, Tom

    2016-09-01

    Extending previous work for proton impact, we have investigated the fragmentation of methane molecules due to collisions with antiprotons in the 25 keV to 5 MeV impact energy range. The multi-center nature of the problem is addressed by using a spectral representation of the molecular Hartree-Fock-level Hamiltonian and a single-center expansion of the initially populated molecular orbitals. The two-center basis generator method (TC-BGM) is used for orbital propagation. Electron-removal cross sections obtained from the TC-BGM solutions are complemented with a dynamical decay-route fragmentation model to calculate cross sections for the production of fragment ions. Good agreement with the available experimental data is observed for CH4+,CH3+,CH2+and CH+. Work supported by NSERC, Canada.

  13. A recoil detector for the measurement of antiproton-proton elastic scattering at angles close to 90°

    NASA Astrophysics Data System (ADS)

    Hu, Q.; Bechstedt, U.; Gillitzer, A.; Grzonka, D.; Khoukaz, A.; Klehr, F.; Lehrach, A.; Prasuhn, D.; Ritman, J.; Sefzick, T.; Stockmanns, T.; Täschner, A.; Wuestner, P.; Xu, H.

    2014-10-01

    The design and construction of a recoil detector for the measurement of recoil protons of antiproton-proton elastic scattering at scattering angles close to are described. The performance of the recoil detector has been tested in the laboratory with radioactive sources and at COSY with proton beams by measuring proton-proton elastic scattering. The results of laboratory tests and commissioning with beam are presented. Excellent energy resolution and proper working performance of the recoil detector validate the conceptual design of the KOALA experiment at HESR to provide the cross section data needed to achieve a precise luminosity determination at the PANDA experiment.

  14. Power tests of the Fermilab Lithium Lens for antiproton collection

    SciTech Connect

    Biallas, G.; Dugan, G.; Hangst, J.; Hanson, R.; Hojvat, C.; Lange, F.; Lennox, A.J.; McCarthy, J.

    1983-08-01

    A prototpye Lithium Lens to be used for the collection of antiprotons in the Fermilab Tevatron I project has been constructed. Some of the fabrication details, the procedure for lithium filling and the results of the initial operation are discussed.

  15. Constraining pre-big-bang nucleosynthesis expansion using cosmic antiprotons

    SciTech Connect

    Schelke, Mia; Catena, Riccardo; Fornengo, Nicolao; Masiero, Antonio; Pietroni, Massimo

    2006-10-15

    A host of dark energy models and nonstandard cosmologies predict an enhanced Hubble rate in the early Universe: perfectly viable models, which satisfy big bang nucleosynthesis (BBN), cosmic microwave background and general relativity tests, may nevertheless lead to enhancements of the Hubble rate up to many orders of magnitude. In this paper we show that strong bounds on the pre-BBN evolution of the Universe may be derived, under the assumption that dark matter is a thermal relic, by combining the dark matter relic density bound with constraints coming from the production of cosmic-ray antiprotons by dark matter annihilation in the Galaxy. The limits we derive apply to the Hubble rate around the temperature of dark matter decoupling. For dark matter masses lighter than 100 GeV, the bound on the Hubble rate enhancement ranges from a factor of a few to a factor of 30, depending on the actual cosmological model, while for a mass of 500 GeV the bound falls in the range 50-500. Uncertainties in the derivation of the bounds and situations where the bounds become looser are discussed. We finally discuss how these limits apply to some specific realizations of nonstandard cosmologies: a scalar-tensor gravity model, kination models and a Randall-Sundrum D-brane model.

  16. Beam polarimetry at the SPASCHARM experiment at IHEP U-70 accelerator

    NASA Astrophysics Data System (ADS)

    Bogdanov, A. A.; Chetvertkov, M. A.; Chetvertkova, V. A.; Garkusha, B. I.; Meshchanin, A. P.; Mochalov, V. V.; Nurusheva, M. B.; Nurushev, S. B.; Rykov, V. L.; Runzo, M. F.; Semenov, P. A.; Strikhanov, M. N.; Vasiliev, A. N.; Zapolsky, V. N.

    2017-01-01

    We describe the absolute polarimeters for the beam channel intended to transport polarized proton and antiproton beam at U70 accelerator. The circulating proton beam of 60 GeV/c and intensity 1013 p/cycle is slowly extracted from accelerator. It strakes the external an aluminum target of one interaction length. The emitted on forward direction Λ and \\bar Λ hyperons by parity violating process serve as the source of the polarized protons and antiprotons. In this case we expect to get the polarized antiproton beams in the momentum range 10-40 GeV/c with intensity, approximately 104 – 4x105 antiprotons/cycle, 106 protons/cycle.

  17. The experiment PANDA: physics with antiprotons at FAIR

    NASA Astrophysics Data System (ADS)

    Boca, Gianluigi

    2015-05-01

    PANDA is an experiment that will run at the future facility FAIR, Darmstadt, Germany. A high intensity and cooled antiproton beam will collide on a fixed hydrogen or nuclear target covering center-of-mass energies between 2.2 and 5.5 GeV. PANDA addresses various physics aspects from the low energy non-perturbative region towards the perturbative regime of QCD. With the impressive theoretical developments in this field, e.g. lattice QCD, the predictions are becoming more accurate in the course of time. The data harvest with PANDA will, therefore, be an ideal test bench with the aim to provide a deeper understanding of hadronic phenomena such as confinement and the generation of hadron masses. A variety of physics topics will be covered with PANDA, for example: the formation or production of exotic non-qqbar charm meson states connected to the recently observed XYZ spectrum; the study of gluon-rich matter, such as glueballs and hybrids; the spectroscopy of the excited states of strange and charm baryons, their production cross section and their spin correlations; the behaviour of hadrons in nuclear matter; the hypernuclear physics; the electromagnetic proton form factors in the timelike region. The PANDA experiment is designed to achieve the above mentioned physics goals with a setup with the following characteristics: an almost full solid angle acceptance; excellent tracking capabilities with high resolution (1-2 % at 1 GeV/c in the central region); secondary vertex detection with resolution ≈ 100 microns or better; electromagnetic calorimetry for detections of gammas and electrons up to 10 GeV; good particle identification of charge tracks (electrons, muons, pions, kaons, protons); a dedicated interchangeable central apparatus for the hypernuclear physics; detector and data acquisition system capable of working at 20 MHz interaction rate with an intelligent software trigger that can provide maximum flexibility.

  18. Spin Filtering of Stored (Anti)Protons: from FILTEX to COSY to AD to FAIR

    SciTech Connect

    Nikolaev, Nikolai; Pavlov, Fyodor

    2007-06-13

    We review the theory of spin filtering of stored (anti)protons by multiple passage through the polarized internal target (PIT). Implications for the antiproton polarization buildup in the proposed PAX experiment at FAIR GSI are discussed.

  19. Strangeness production in antiproton annihilation on nuclei

    NASA Astrophysics Data System (ADS)

    Cugnon, J.; Deneye, P.; Vandermeulen, J.

    1990-04-01

    The strangeness production in antiproton annihilation on nuclei is investigated by means of a cascade-type model, within the frame of the conventional picture of the annihilation on a single nucleon followed by subsequent rescattering proceeding in the hadronic phase. The following hadrons are introduced: N, Λ, Σ, Λ¯, π, η, ω, K, and K¯ and, as far as possible, the experimental reaction cross sections are used in our simulation. The numerical results are compared with experimental data up to 4 GeV/c. The Λ¯ yield is correctly reproduced, while the Λ and Ks yields are overestimated in the p¯Ta and p¯Ne cases. On the other hand, the rapidity and perpendicular momentum distributions are well reproduced. It is shown that total strange yield is not very much affected by the associated production taking place during the rescattering process. It is also shown that the Λ/Ks ratio is largely due to the strangeness exchange reactions induced by antikaons. In particular, values of the order of 1 to 3 are expected in the energy range investigated here, independently of the detail of the hadronic phase dynamics. Finally, it is stressed that rapidity distributions are consistent with the rescattering process. Comparison with other works and implications of our results are examined.

  20. A feasibility study of applying cone-beam computed tomography to observe dimensional changes in human alveolar bone*

    PubMed Central

    Li, Bei; Wang, Yao; Li, Jun

    2014-01-01

    The purpose of this study was to demonstrate the feasibility of applying cone-beam computed tomography (CBCT) to observe dimensional changes in human alveolar bone continuously after tooth extraction. Sixty patients were selected from a CBCT database. Each patient had two CBCT scans (CBCT I and CBCT II), one taken before and one taken after implant surgery. A fixed anatomic reference point was used to orient the horizontal slice of the two scans. The alveolar ridge width was measured on the horizontal slice. In each series of CBCT I sagittal slices, the number of slices from the start point to the pulp center of the test tooth was recorded. The tooth length was measured on the sagittal slice. In each series of CBCT II slices, tooth length was measured on a sagittal slice selected based on the number of slices from the start point to the pulp center recorded in CBCT I. Intraobserver reliability, assessed by the intraclass correlation coefficient (ICC), was high. Paired sample t-tests of repeated measurements of both tooth length and alveolar bone width showed no statistically significant differences (P<0.05). This study has proved that projection differences among CBCT scans taken at different time points from one patient can be neglected without affecting the accuracy of millimeter scale measurements. CBCT is a reliable imaging tool for continuously observing dimensional changes in human alveolar bone. PMID:24711360

  1. Medium-Energy Antiproton Physics with the Antiproton Annihilation Spectrometer (TApAS*) at Fermilab

    SciTech Connect

    Bartoszek, Larry; Piacentino, Giovanni M.; Phillips, Thomas J.; Apollinari, Giorgio; Broemmelsiek, Daniel R.; Brown, Charles N.; Christian, David C.; Derwent, Paul; Gollwitzer, Keith; Hahn, Alan; Papadimitriou, Vaia; /Fermilab /INFN, Pisa /Hbar Technologies, West Chicago /Houston U. /IIT, Chicago /IIT, Hyderabad /ITEP /KyungPook National U. /LPI

    2008-01-01

    We propose to assemble a cost-effective, yet powerful, solenoidal magnetic spectrometer for antiproton-annihilation events and use it at the Fermilab Antiproton Accumulator to measure the charm production cross section, study rare hyperon decays, search for hyperon CP asymmetry, and precisely measure the properties of several charmonium and nearby states. Should the charm production cross section be as large as some have proposed, we will also be able to measure D{sup 0}-{bar D}{sup 0} mixing with high precision and discover (or sensitively limit) charm CP violation. The experiment will be carried out by an international collaboration, with installation occurring during the accelerator downtime following the completion of the Tevatron run, and with funding largely from university research grants. The experiment will require some four years of running time. As possibly the sole hadron experiment in progress at Fermilab during that time, it will play an important role in maintaining a broad particle-physics program at Fermilab and in the U.S.

  2. Feasibility of an antiproton catalyzed fission fragment rocket

    SciTech Connect

    Hdinger, D.S.

    1992-03-01

    The purpose of this project was to investigate the feasibility of an antiproton catalyzed fission fragment rocket (FFR). The FFR is characterized by the extraction of fission fragments from the fissile fuel, and the utilization of their kinetic energy for thrust generation. A significant drawback to previous FFR designs was the requirement to maintain a critical nuclear pile as the fission fragment source. The author examined the possibility of replacing the critical pile with a sub-critical pile driven by antiprotons. Recent experiments have revealed that antiprotons stimulate highly energetic fissions in {sup 238}U, with a neutron multiplicity of 13.7 neutrons per fission. This interaction was used as a throttled neutron source. The pile consisted of layers of fissile coated fibers which are designed to allow fission fragments to escape them, where the fragments collide with a fluid. The heated fluid is then ejected from the rocket to provide thrust. The calculations performed indicate that each antiproton injected into the pile can stimulate 8 or more fissions while maintaining a neutron multiplication of less than 0.4. Based on the results seen, the engine design presented is inadequate. Limitations introduced by the reaction fluid far outweigh the simplicity-of-design gained. Despite this, the basic idea of using the antiproton-U interaction as a source of spacecraft propulsion warrants further study.

  3. Trapped antiprotons produced by cosmic rays in the Earth's magnetosphere.

    PubMed

    Pugacheva, G; Gusev, A A; Jayanthi, U B; Schuch, N G; Spjeldvik, W N; Choque, K T

    2004-01-01

    The existence of significant fluxes of antiparticles in the Earth magnetosphere has been predicted on theoretical considerations in this article. These antiparticles (positrons or antiprotons) at several hundred kilometers of altitudes, we believe are not of direct extraterrestrial origin, but are the natural products of nuclear reactions of the high energy primary cosmic rays (CR) and trapped protons (TP) confined in the terrestrial radiation belt, with the constituents of terrestrial atmosphere. Extraterrestrial positrons and antiprotons born in nuclear reactions of the same CR particles passing through only 5-7 g/cm2 of interstellar matter, exhibit lower fluxes compared to the antiprotons born at hundreds of g/cm2 in the atmosphere, which when confined in the magnetic field of the Earth (in any other planet), get accumulated. We present the results of the computations of the antiproton fluxes at 10 MeV to several GeV energies due to CR particle interactions with the matter in the interstellar space, and also with the residual atmosphere at altitudes of approximately 1000 km over the Earth's surface. The estimates show that the magnetospheric antiproton fluxes are greater by two orders of magnitude compared to the extraterrestrial fluxes measured at energies <1-2 GeV.

  4. Precision hadron spectroscopy in the charmonium mass region using antiproton annihilation

    SciTech Connect

    Marton, Johann

    2006-11-17

    In contrast to systems at high momentum transfer where high accuracy predictions based on QCD can be made, several essential phenomena are still quantitatively unsettled in strongly interacting systems with low momentum transfer. These phenomena include quark confinement, existence of hadrons other than mesons and baryons, and the generation of the mass of hadrons. Hadronic states provide an intrinsically ideal system to address these issues. In particular, the spectroscopy of states with charm quark content provide a window of opportunity between the chiral and the heavy quark limits. Such states can be produced in copious numbers in antiproton-proton annihilation at the appropriate energy. Beams of antiprotons with unsurpassed brilliance will be available with momenta between 1.5 and 15 GeV/c at the new FAIR facility in Darmstadt, Germany. The combination of stochastic and electron phase space cooling will allow spectroscopy measurements with about 50 keV mass resolution and up to 1032 cm-2s-1 luminosity. These studies will be performed with the PANDA detector that is to be located inside the High Energy Storage Ring. This general purpose detector is a magnetic spectrometer with nearly 4{pi} acceptance for charged and neutral particles. An overview of the physics program and the detector will be presented.

  5. DESIGN AND SHIELDING OF A BEAM LINE FROM ELENA TO ATRAP USING ELECTROSTATIC QUADRUPOLE LENSES AND BENDS

    SciTech Connect

    Yuri, Yosuke; Lee, Edward P.

    2010-09-01

    The construction of the Extra Low ENergy Antiprotons (ELENA) upgrade to the Antiproton Decelerator (AD) ring has been proposed at CERN to produce a greatly increased current of low-energy antiprotons for various experiments including anti-hydrogen studies. This upgrade involves the addition of a small storage ring and electrostatic beam lines. The 5.3-MeV antiproton beams from AD are decelerated down to 100 keV in the compact ring and transported to each experimental apparatus. In this paper, we describe an electrostatic beam line from the ELENA ring to the ATRAP experimental apparatus and magnetic shielding of the low-energy beam line against the ATRAP superconducting solenoid magnet. A possible rough conceptual design of this system is displayed.

  6. Cartesian beams.

    PubMed

    Bandres, Miguel A; Gutiérrez-Vega, Julio C

    2007-12-01

    A new and very general beam solution of the paraxial wave equation in Cartesian coordinates is presented. We call such a field a Cartesian beam. The complex amplitude of the Cartesian beams is described by either the parabolic cylinder functions or the confluent hypergeometric functions, and the beams are characterized by three parameters that are complex in the most general situation. The propagation through complex ABCD optical systems and the conditions for square integration are studied in detail. Applying the general expression of the Cartesian beams, we also derive two new and meaningful beam structures that, to our knowledge, have not yet been reported in the literature. Special cases of the Cartesian beams are the standard, elegant, and generalized Hermite-Gauss beams, the cosine-Gauss beams, the Lorentz beams, and the fractional order beams.

  7. High-energy antiprotons from old supernova remnants.

    PubMed

    Blasi, Pasquale; Serpico, Pasquale D

    2009-08-21

    A recently proposed model explains the rise in energy of the positron fraction measured by the PAMELA satellite in terms of hadronic production of positrons in aged supernova remnants, and acceleration therein. Here we present a preliminary calculation of the antiproton flux produced by the same mechanism. While the model is consistent with present data, a rise of the antiproton to proton ratio is predicted at high energy, which strikingly distinguishes this scenario from other astrophysical explanations of the positron fraction (such as pulsars). We briefly discuss important implications for dark matter searches via antimatter.

  8. Three-dimensional annihilation imaging of trapped antiprotons.

    PubMed

    Fujiwara, M C; Amoretti, M; Bonomi, G; Bouchta, A; Bowe, P D; Carraro, C; Cesar, C L; Charlton, M; Doser, M; Filippini, V; Fontana, A; Funakoshi, R; Genova, P; Hangst, J S; Hayano, R S; Jørgensen, L V; Lagomarsino, V; Landua, R; Lodi-Rizzini, E; Marchesotti, M; Macri, M; Madsen, N; Manuzio, G; Montagna, P; Riedler, P; Rotondi, A; Rouleau, G; Testera, G; Variola, A; van der Werf, D P; Yamazaki, Y

    2004-02-13

    We demonstrate three-dimensional imaging of antiprotons in a Penning trap, by reconstructing annihilation vertices from the trajectories of the charged annihilation products. The unique capability of antiparticle imaging has allowed, for the first time, the observation of the spatial distribution of the particle loss in a Penning trap. The radial loss of antiprotons on the trap wall is localized to small spots, strongly breaking the azimuthal symmetry expected for an ideal trap. Our observations have important implications for detection of antihydrogen annihilations.

  9. Status of the SPES project, a new tool for fundamental and apply science studies with exotic ion beams at LNL

    NASA Astrophysics Data System (ADS)

    Napoli, D. R.; Andrighetto, A.; Antonini, P.; Bellan, L.; Bellato, M.; Benini, D.; Bermudez, J.; Bisoffi, G.; Boratto, E.; Bortolato, D.; Calabretta, L.; Calderolla, M.; Calore, A.; Campo, D.; Carturan, S.; Cinausero, M.; Comunian, M.; Corradetti, S.; De Angelis, G.; De Ruvo, P. L.; Esposito, J.; Ferrari, L.; Galatá, A.; Gelain, F.; Giacchini, M.; Giacomazzi, P.; Gobbi, C.; Gramegna, F.; Gulmini, M.; Lollo, M.; Lombardi, A.; Maggiore, M.; Manzolaro, M.; Michinelli, R.; Modanese, P.; Moisio, M. F.; Monetti, A.; Mozzi, A.; Palmieri, A.; Pasquato, F.; Pedretti, D.; Pegoraro, R.; Pisent, A.; Poggi, M.; Pranovi, L.; Prete, G.; Roncolato, C.; Rossignoli, M.; Russo, A. D.; Sarchiapone, L.; Scarpa, D.; Silingardi, R.; Dobon, J. J. Valiente; Visentin, E.; Vivian, G.; Zafiropoulos, D.; Prete, G. F.

    2016-07-01

    SPES, a new accelerator facility for both the production of exotic ion beams and radio-pharmaceuticals, is presently being installed at the Laboratori Nazionali di Legnaro in Italy (LNL). The new cyclotron, which will provide high intensity proton beams for the production of the rare isotopes, has been installed and is now in the commissioning phase. We present here the status of the part of the project devoted to the production and acceleration of fission fragments created in the interaction of an intense proton beam on a production target of UCx. The expected SPES radioactive beams intensities, their quality and their maximum energies (up to 11 MeV/A for A=130) will permit to perform forefront research in nuclear structure and nuclear dynamics far from the stability valley. Another low energy section of the facility is foreseen for new and challenging research, both in the nuclear physics and in the material science frameworks.

  10. Overview of the High Performance Antiproton Trap (HiPAT) Experiment

    NASA Technical Reports Server (NTRS)

    Martin, James; Chakrabarti, Suman; Pearson, Boise; Sims, W. Herbert; Lewis, Raymond; Fant, Wallace; Rodgers, Stephen (Technical Monitor)

    2002-01-01

    A general overview of the High Performance Antiproton Trap (HiPAT) Experiment is presented. The topics include: 1) Why Antimatter? 2) HiPAT Applicability; 3) Approach-Goals; 4) HiPAT General Layout; 5) Sizing For Containment; 6) Laboratory Operations; 7) Vacuum System Cleaning; 8) Ion Production Via Electron Gun; 9) Particle Capture Via Ion Sources; 10) Ion Beam Steering/Focusing; 11) Ideal Ion Stacking Sequence; 12) Setup For Dynamic Capture; 13) Dynamic Capture of H(+) Ions; 14) Dynamic Capture; 15) Radio Frequency Particle Detection; 16) Radio Frequency Antenna Modeling; and 17) R.F. Stabilization-Low Frequencies. A short presentation of propulsion applications of Antimatter is also given. This paper is in viewgraph form.

  11. Radiative proton-antiproton annihilation to a lepton pair

    SciTech Connect

    Ahmadov, A. I.; Bytev, V. V.; Kuraev, E. A.; Tomasi-Gustafsson, E.

    2010-11-01

    The annihilation of proton and antiproton to an electron-positron pair, including radiative corrections due to the emission of virtual and real photons is considered. The results are generalized to leading and next-to leading approximations. The relevant distributions are derived and numerical applications are given in the kinematical range accessible to the PANDA experiment at the FAIR facility.

  12. Secondary antiprotons as a Galactic Dark Matter probe

    NASA Astrophysics Data System (ADS)

    Evoli, Carmelo; Gaggero, Daniele; Grasso, Dario

    2015-12-01

    We present a novel determination of the astrophysical uncertainties associated to the secondary antiproton flux originating from cosmic-ray spallation on the interstellar gas. We select a set of propagation models compatible with the recent B/C data from PAMELA, and find those providing minimal and maximal antiproton fluxes in different energy ranges. We use this result to determine the most conservative bounds on relevant Dark Matter (DM) annihilation channels: we find that the recent claim of a DM interpretation of a gamma-ray excess in the Galactic Center region cannot be ruled out by current antiproton data. Finally, we discuss the impact of the recently released preliminary data from AMS-02. In particular, we provide a reference model compatible with proton, helium and B/C spectra from this experiment. Remarkably, the main propagation parameters of this model are in agreement with the best fit presented in our earlier statistical analyses. We also show that the antiproton-to-proton ratio does not exhibit any significant anomaly at high energy with respect to our predictions.

  13. Antiproton Accumulator in the Main Injector era (2)

    SciTech Connect

    Visnjic, V.

    1992-12-01

    By adding a single quadrupole per sextant in the Antiproton Accumulator it is possible to obtain a lattice well suited for higher bandwidth stochastic cooling systems such as those anticipated for the Main Injector era. The lattice proposed here has excellent properties concerning both the lattice functions and the stochastic cooling parameters.

  14. Interpretation of the cosmic ray positron and antiproton fluxes

    NASA Astrophysics Data System (ADS)

    Lipari, Paolo

    2017-03-01

    The spectral shape of cosmic ray positrons and antiprotons has been accurately measured in the broad kinetic energy range 1-350 GeV. In the higher part of this range (E ≳30 GeV ), the e+ and p ¯ are both well described by power laws with spectral indices γe+≃2.77 ±0.02 and γp ¯≃2.78 ±0.04 that are approximately equal to each other and to the spectral index of protons. In the same energy range, the positron-antiproton flux ratio has the approximately constant value 2.04 ±0.04 , that is consistent with being equal to the ratio e+/p ¯ calculated for the conventional mechanism of production, where the antiparticles are created as secondaries in the inelastic interactions of primary cosmic rays with interstellar gas. The positron-antiproton ratio at lower energy is significantly higher (reaching a value e+/p ¯≈100 for E ≈1 GeV ), but, in the entire energy range 1-350 GeV, the flux ratio is consistent with being equal to the ratio of the production rates in the conventional mechanism, as the production of low-energy antiprotons is kinematically suppressed in collisions with a target at rest. These results strongly suggest that cosmic ray positrons and antiprotons have a common origin as secondaries in hadronic interactions. This conclusion has broad implications for the astrophysics of cosmic rays in the Galaxy.

  15. Constraints on particle dark matter from cosmic-ray antiprotons

    SciTech Connect

    Fornengo, N.; Vittino, A.; Maccione, L. E-mail: luca.maccione@lmu.de

    2014-04-01

    Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are strong, setting a lower bound on the dark matter mass of a ''thermal'' relic at about 40–80 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 3–4 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modelling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints.

  16. High-energy (100-keV) e-beam lithography applied for fabrication of deep-submicrometer SAW devices on lithium niobate and quartz

    NASA Astrophysics Data System (ADS)

    Kondek, Christine A.; Poli, Louis C.

    1995-05-01

    Fabricating submicron feature size Surface Acoustic Wave (SAW) devices on Lithium Niobate and Quartz allows one to take advantage of their unique piezoelectric material properties and operate at higher frequencies. With the recent availability of high performance, high energy e-beam nanowriter tools such as the Leica/Phillips EBPG-HR5 resident at this facility, SAW devices with very narrow line/space transducer gratings can be investigated. Utilizing very high energy (100 keV) direct write electron beam lithography (EBL), allows for processing of deep submicron features with an associated wider process latitude. This is specially desirable when applying EBL to high average Z materials such as lithium niobate. A previously presented paper demonstrated 400 and 500 nm line/space interdigitated transducer fingers on quartz and lithium niobate substrates. E-Beam lithography (30 keV) was used with two and three level, positive and negative tone processes respectively. In this current work a bilevel positive tone process is used by the authors, and involves first spinning a preparation of (1:1) ZEP-320-37 (Nagase Chemical) positive e-beam resist. A commercially available conductive polymer known as TQV-501 (Nitto Chemical) is then spun onto the wafer and serves as a charge removal vehicle. The TQV-501 film is removed by the development procedure. Xylene is used as the developer. Contact pads and interdigitated transducer elements are realized by e-beam metal deposition and lift off process. We will show a direct write positive tone process for the fabrication of deep submicron (400 nM and smaller) interdigitated transducer gratings on Lithium Niobate and Quartz substrates. An improved process dose latitude is seen because of the reduced expected proximity effect at high beam energy.

  17. Testing of the stability of intensity modulated beams generated with dynamic multileaf collimation, applied to the MM50 racetrack microtron.

    PubMed

    Dirkx, M L; Heijmen, B J

    2000-12-01

    Recently, we have published a method for the calculation of required leaf trajectories to generate optimized intensity modulated x-ray beams by means of dynamic multileaf collimation [Phys. Med. Biol. 43, 1171-1184 (1998)]. For the MM50 Racetrack Microtron it has been demonstrated that the dosimetric accuracy of this method, in combination with the dose calculation algorithm of the Cadplan 3D treatment planning system, is adequate for a clinical application (within 2% or 0.2 cm). Prior to initiating patient treatment with dynamic multileaf collimation (DMLC), tests have been performed to investigate the stability of DMLC fields generated at the MM50, (i) in time, (ii) subject to gantry rotation and (iii) in case of treatment interrupts, e.g., caused by an error detected by the treatment machine. The stability of relative dose profiles, normalized to a reference point in a relatively flat part of the modulated beam profile, was assessed from measurements with an electronic portal imaging device (EPID), with a linear diode array attached to the collimator and with film. The dose in the reference point was monitored using an ionization chamber. Tests were performed for several intensity modulated fields using 10 and 25 MV photon beams. Based on film measurements for sweeping 0.1 cm leaf gaps it was concluded that in an 80 days period the variation in leaf positioning was within 0.05 cm, without requiring any recalibration. For a uniform 10x10 cm2 field, realized dynamically by a scanning 0.4x10 cm2 slit beam, a maximum variation in slit width of 0.01 cm was derived from ionization chamber measurements, both in time and for gantry rotation. For a clinical example, the dose in the reference point reproduced within 0.2% (1 SD) over a period of 100 days. Apart from regions with very large dose gradients, variations in the relative beam profiles measured with the EPID were generally less than 1% (1 SD). For different gantry angles the dose profiles also reproduced within 1

  18. First observation of dijet events with an antiproton tag at √s = 1.96 TeV using the D0 Forward Proton Detector

    SciTech Connect

    Strang, Michael Allen

    2005-08-01

    The Forward Proton Detector (FPD) is a new sub-system of the D0 detector, a 5000 ton particle physics detector located at the Fermilab Tevatron proton-antiproton collider. The FPD was implemented for the Tevatron Run II and gives access to a wide range of diffractive scattering processes, where one or both of the beam particles remain intact. The analysis described in this thesis makes use of the dipole spectrometer of the FPD to tag outgoing antiprotons in events that have a dijet signature in the central D0 calorimeter. Properties of jets with a diffractive tag signature are compared to jets without such a signature yielding the first observation of tagged diffractive dijets at a 1.96 TeV center-of-mass energy.

  19. Some Torsional-damping Measurements of Laminated Beams as Applied to the Propeller Stall-flutter Problem

    NASA Technical Reports Server (NTRS)

    Heath, Atwood R , Jr

    1953-01-01

    The structural damping in the torsion mode of vibration of a series of untwisted, laminated thin beams simulating propeller blades is presented. The number of lamination were varied, as well as the bonding material and the method of joining lamination. Application of the data to the calculation of the minimum flutter speed of thin propeller blades indicates that appreciable gains in the minimum flutter speed may be obtained for laminated blades using a Cycleweld bond.

  20. Extended Glauber Model of Antiproton-Nucleus Annihilation for All Energies and Mass Numbers

    SciTech Connect

    Lee, Teck-Ghee; Wong, Cheuk-Yin

    2014-01-01

    Previous analytical formulas in the Glauber model for high-energy nucleus-nucleus collisions developed by Wong are utilized and extended to study Antiproton-nucleus annihilations for both high and low energies, after taking into account the effects of Coulomb and nuclear interactions, and the change of the antiproton momentum inside a nucleus. The extended analytical formulas capture the main features of the experimental antiproton-nucleus annihilation cross sections for all energies and mass numbers. At high antiproton energies, they exhibit the granular property for the lightest nuclei and the black-disk limit for the heavy nuclei. At low antiproton energies, they display the effect of the antiproton momentum increase due to the nuclear interaction for the light nuclei, and the effect of the magnification due to the attractive Coulomb interaction for the heavy nuclei.

  1. An assessment of the antiproton-proton option for the SSC

    SciTech Connect

    1986-05-01

    The Conceptual Design Report (CDR) for the Superconducting Super Collider (SSC) describes a proton-proton collider with an energy of 20 TeV per beam and a maximum luminosity of 10{sup 33}cm{sup {minus}2}s{sup {minus}1} per collision point. This directly responds to the recommendation made by the High Energy Physics Advisory Panel to the US Department of Energy and the National Science Foundation in July 1983. That recommendation called for the ``immediate initiation of a multi-TeV high-luminosity proton-proton collider project with the goal of physics experiments at this facility at the earliest Possible date.`` The primary Parameters of the SSC in the Conceptual Design Report have been chosen taking account of both the physics discovery reach of the machine and accelerator physics considerations. The endeavor of the study reported here was to compare the feasibility of an antiproton-proton collider with the proton-proton collider presented in the SSC Conceptual Design Report. The rapid advances in the technology of p{bar p} colliders at CERN and Fermilab suggest that p{bar p} might be a viable alternative to a PP collider (or might be a first stage of an eventual p{bar p} collider). There is Potentially a large cost saving from eliminating one 20 TeV ring of magnets since the protons and antiprotons share the same ring. Following this suggestion, workshops at the University of Chicago and at Snowmass have provided a forum for these ideas. These reports formed the starting point for our study.

  2. Design and optimisation of low heat load liquid helium cryostat to house cryogenic current comparator in antiproton decelerator at CERN

    NASA Astrophysics Data System (ADS)

    Lees, A.; Koettig, T.; Fernandes, M.; Tan, J.

    2017-02-01

    The Cryogenic Current Comparator (CCC) is installed in the low-energy Antiproton Decelerator (AD) at CERN to make an absolute measurement of the beam intensity. Operating below 4.2 K, it is based on a superconducting quantum interference device (SQUID) and employs a superconducting niobium shield to supress magnetic field components not linked to the beam current. The AD contains no permanent cryogenic infrastructure so the local continuous liquefaction of helium using a pulse-tube is required; limiting the available cooling power to 0.69 W at 4.2K. Due to the sensitivity of the SQUID to variations in magnetic fields, the CCC is highly sensitive to mechanical vibration which is limited to a minimum by the support systems of the cryostat. This article presents the cooling system of the cryostat and discusses the design challenges overcome to minimise the transmission of vibration to the CCC while operating within the cryogenic limits imposed by the cooling system.

  3. Antihydrogen formation in collisions of positronium with antiprotons

    NASA Technical Reports Server (NTRS)

    Humberston, J. W.

    1990-01-01

    Antihydrogen, consisting of a positron orbiting around an antiproton, is the simplest few body system consisting entirely of antimatter and as such is of considerable importance in providing additional tests of the validity of charge conjugation invariance. In addition, the nature of the gravitational interaction between matter and antimatter might more readily be investigated for an electrically neutral system than one which is charged. Before such studies can be undertaken the antihydrogen must, of course, be produced by attachment of a positron to an antipositron. Several production mechanisms have been proposed, the two most favored of which are radiative capture (spontaneous or stimulated) and charge exchange in positronium-antiproton collisions. The cross section for radiative capture is very much less than that for charge exchange, so that it might be thought that the latter process is greatly to be preferred. Various calculations of the cross section for the charge exchange process are briefly reviewed.

  4. Selected Papers on Low-Energy Antiprotons and Possible Applications

    SciTech Connect

    Noble, Robert

    1998-09-19

    The only realistic means by which to create a facility at Fermilab to produce large amounts of low energy antiprotons is to use resources which already exist. There is simply too little money and manpower at this point in time to generate new accelerators on a time scale before the turn of the century. Therefore, innovation is required to modify existing equipment to provide the services required by experimenters.

  5. Antihydrogen formation in laser-assisted positron-antiproton scattering

    NASA Astrophysics Data System (ADS)

    Li, Shu-Min; Miao, Yan-Gang; Zhou, Zi-Fang; Chen, Ji; Liu, Yao-Yang

    1998-09-01

    Antihydrogen formation in the laser-assisted positron-antiproton (nonrelativistic) radiative recombination is investigated. The state of incident positron is given by the Coulomb-Volkov wave function. The perturbative dressed wave function of the atom is obtained in the soft-photon approximation. Our calculation shows that for a geometry of laser polarization parallel to the incident direction, the formation cross section of antihydrogen is greatly reduced. Especially at high impact energy, the reduction is remarkable.

  6. Asymmetric antiproton debuncher: No bad mixing, more good mixing

    SciTech Connect

    Visnjic, V.

    1994-07-01

    An asymmetric lattice for the Fermilab Antiproton Debuncher is designed. The lattice has zero mixing between the pickups and the kickers (bad mixing) while the mixing in the rest of the machine (good mixing) can be varied (even during the operation of the machine) in order to optimize the stochastic cooling. As an example, a lattice with zero bad mixing and twice the good mixing is presented. The betatron cooling rate in this lattice is twice its present value.

  7. Physics at the Fermilab Tevatron Proton-Antiproton Collider

    SciTech Connect

    Geer, S.

    1994-08-01

    These lectures discuss a selection of QCD and Electroweak results from the CDF and D0 experiments at the Fermilab Tevatron Proton-Antiproton Collider. Results are presently based on data samples of about 20 pb{sup {minus}1} at a center-of-mass energy of 1.8 TeV. Results discussed include jet production, direct photon production, W mass and width measurements, the triboson coupling, and most exciting of all, evidence for top quark production.

  8. Evaluation of resistive-plate-chamber-based TOF-PET applied to in-beam particle therapy monitoring.

    PubMed

    Torres-Espallardo, I; Diblen, F; Rohling, H; Solevi, P; Gillam, J; Watts, D; España, S; Vandenberghe, S; Fiedler, F; Rafecas, M

    2015-05-07

    Particle therapy is a highly conformal radiotherapy technique which reduces the dose deposited to the surrounding normal tissues. In order to fully exploit its advantages, treatment monitoring is necessary to minimize uncertainties related to the dose delivery. Up to now, the only clinically feasible technique for the monitoring of therapeutic irradiation with particle beams is Positron Emission Tomography (PET). In this work we have compared a Resistive Plate Chamber (RPC)-based PET scanner with a scintillation-crystal-based PET scanner for this application. In general, the main advantages of the RPC-PET system are its excellent timing resolution, low cost, and the possibility of building large area systems. We simulated a partial-ring scanner based on an RPC prototype under construction within the Fondazione per Adroterapia Oncologica (TERA). For comparison with the crystal-based PET scanner we have chosen the geometry of a commercially available PET scanner, the Philips Gemini TF. The coincidence time resolution used in the simulations takes into account the current achievable values as well as expected improvements of both technologies. Several scenarios (including patient data) have been simulated to evaluate the performance of different scanners. Initial results have shown that the low sensitivity of the RPC hampers its application to hadron-beam monitoring, which has an intrinsically low positron yield compared to diagnostic PET. In addition, for in-beam PET there is a further data loss due to the partial ring configuration. In order to improve the performance of the RPC-based scanner, an improved version of the RPC detector (modifying the thickness of the gas and glass layers), providing a larger sensitivity, has been simulated and compared with an axially extended version of the crystal-based device. The improved version of the RPC shows better performance than the prototype, but the extended version of the crystal-based PET outperforms all other options.

  9. Evaluation of resistive-plate-chamber-based TOF-PET applied to in-beam particle therapy monitoring

    NASA Astrophysics Data System (ADS)

    Torres-Espallardo, I.; Diblen, F.; Rohling, H.; Solevi, P.; Gillam, J.; Watts, D.; España, S.; Vandenberghe, S.; Fiedler, F.; Rafecas, M.

    2015-05-01

    Particle therapy is a highly conformal radiotherapy technique which reduces the dose deposited to the surrounding normal tissues. In order to fully exploit its advantages, treatment monitoring is necessary to minimize uncertainties related to the dose delivery. Up to now, the only clinically feasible technique for the monitoring of therapeutic irradiation with particle beams is Positron Emission Tomography (PET). In this work we have compared a Resistive Plate Chamber (RPC)-based PET scanner with a scintillation-crystal-based PET scanner for this application. In general, the main advantages of the RPC-PET system are its excellent timing resolution, low cost, and the possibility of building large area systems. We simulated a partial-ring scanner based on an RPC prototype under construction within the Fondazione per Adroterapia Oncologica (TERA). For comparison with the crystal-based PET scanner we have chosen the geometry of a commercially available PET scanner, the Philips Gemini TF. The coincidence time resolution used in the simulations takes into account the current achievable values as well as expected improvements of both technologies. Several scenarios (including patient data) have been simulated to evaluate the performance of different scanners. Initial results have shown that the low sensitivity of the RPC hampers its application to hadron-beam monitoring, which has an intrinsically low positron yield compared to diagnostic PET. In addition, for in-beam PET there is a further data loss due to the partial ring configuration. In order to improve the performance of the RPC-based scanner, an improved version of the RPC detector (modifying the thickness of the gas and glass layers), providing a larger sensitivity, has been simulated and compared with an axially extended version of the crystal-based device. The improved version of the RPC shows better performance than the prototype, but the extended version of the crystal-based PET outperforms all other options.

  10. Antiproton-hydrogen atom annihilation. Final report, April-December 1985

    SciTech Connect

    Morgan, D.L.

    1986-05-01

    For antiproton energies of several eV or less, annihilation in matter occurs through atomic rearrangement processes in which the antiproton becomes bound to a nucleus prior to annihilation. Annihilation cross sections via rearrangement at such energies are much higher than for direct antiproton-nucleon annihilation and are, therefore, of consequence to antiproton annihilation propulsion of spacecraft. Existing calculations of the antiproton-hydrogen atom rearrangement cross section are semiclassical and employ the Born-Oppenheimer approximation. They also employ various arguments in regard to the behavior of the system when the Born-Oppenheimer approximation breaks down at small antiproton-proton separations. These arguments indicate that rearrangement is essentially irreversible. In this study, a detailed investigation was made of the antiproton-hydrogen atom system when the Born-Oppenheimer approximation breaks down. Results indicate that the previous arguments were approximately correct, but that there is a significant probability for rearrangement reversing prior to annihilation. This probability is estimated to be about 20%. This consequent reduction in annihilation cross section has little or no negative consequences for antiproton annihilation propulsion at the present time. However, because of the approximate nature of this result and because more-accurate values will be required in the future, it is important to conduct an accurate, fully quantum-mechanical calculation of antiproton-hydrogen atom rearrangement.

  11. Spectroscopy of antiprotonic helium atoms and its contribution to the fundamental physical constants

    PubMed Central

    Hayano, Ryugo S.

    2010-01-01

    Antiprotonic helium atom, a metastable neutral system consisting of an antiproton, an electron and a helium nucleus, was serendipitously discovered, and has been studied at CERN’s antiproton decelerator facility. Its transition frequencies have recently been measured to nine digits of precision by laser spectroscopy. By comparing these experimental results with three-body QED calculations, the antiproton-to-electron massratio was determined as 1836.152674(5). This result contributed to the CODATA recommended values of the fundamental physical constants. PMID:20075605

  12. A novel antiproton radial diagnostic based on octupole induced ballistic loss

    SciTech Connect

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der; Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S.; Cesar, C. L.; Lambo, R.; Silveira, D. M.; Fujiwara, M. C.

    2008-03-15

    We report results from a novel diagnostic that probes the outer radial profile of trapped antiproton clouds. The diagnostic allows us to determine the profile by monitoring the time history of antiproton losses that occur as an octupole field in the antiproton confinement region is increased. We show several examples of how this diagnostic helps us to understand the radial dynamics of antiprotons in normal and nested Penning-Malmberg traps. Better understanding of these dynamics may aid current attempts to trap antihydrogen atoms.

  13. Prospects for the Simultaneous Operation of the Tevatron Collider and pp Experiments in the Antiproton Source Accumulator

    SciTech Connect

    Werkema, Steven J.; /Fermilab

    2001-06-07

    This document is a slightly expanded version of a portion of the Proton Driver design report. The Proton Driver group gets the credit for the original idea of running an Accumulator experiment in the BTeV era. The work presented here is a study of the feasibility of this idea. The addition of the Recycler Ring to the Fermilab accelerator complex provides an opportunity to continue the program of {bar p}p physics in the Antiproton Source Accumulator that was started by Fermilab experiments E760 and E835. The operational scenario presented here utilizes the Recycler Ring as an antiproton bank from which the colliders makes 'withdrawals' as needed to maintain the required luminosity in the Tevatron. The Accumulator is only needed to re-supply the bank in between withdrawals. When the {anti p} stacking rate is sufficiently high, and the luminosity requirements of the Collider experiments are sufficiently low, there will be time between Collider fills and subsequent refilling of the recycler to deliver beam to an experiment in the Accumulator. In the scenario envisioned here, the impact of the Accumulator experiment on the luminosity delivered to the Collider experiments is very small. If the Run II antiproton stacking rate goals are met, the operational conditions required for running Accumulator based experiments will be met during the BTeV era. A simple model of the operation of the Fermilab accelerator complex for BTeV and an experiment in the Accumulator has been developed. The model makes predictions of the rate at which luminosity is delivered to BTeV and an Accumulator experiment. This model was used to examine the impact of the proton driver on this experimental program.

  14. Stability of cooled beams

    NASA Astrophysics Data System (ADS)

    Bosser, J.; Carli, C.; Chanel, M.; Madsen, N.; Maury, S.; Möhl, D.; Tranquille, G.

    2000-02-01

    Because of their high density together with extremely small spreads in betatron frequency and momentum, cooled beams are very vulnerable to incoherent and coherent space-charge effects and instabilities. Moreover, the cooling system itself, i.e. the electron beam in the case of e-cooling, presents large linear and non-linear "impedances" to the circulating ion beam, in addition to the usual beam-environment coupling impedances of the storage ring. Beam blow-up and losses, attributed to such effects, have been observed in virtually all the existing electron cooling rings. The adverse effects seem to be more pronounced in those rings, like CELSIUS, that are equipped with a cooler capable of reaching the presently highest energy (100-300 keV electrons corresponding to 180-560 MeV protons). The stability conditions will be revisited with emphasis on the experience gained at LEAR. It will be argued that for all present coolers, three conditions are necessary (although probably not sufficient) for the stability of intense cold beams: (i) operation below transition energy, (ii) active damping to counteract coherent instability, and (iii) careful control of the e-beam neutralisation. An extrapolation to the future "medium energy coolers", planned to work for (anti)protons of several GeV, will also be attempted.

  15. A study of the energy dependence of the underlying event in proton-antiproton collisions

    SciTech Connect

    Aaltonen, T.

    2015-11-23

    We study charged particle production (pT > 0.5 GeV/c, |η| < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of η-Φspace; “toward”, “away”, and “transverse”. Furthermore, the average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the “underlying event”. The transverse region is divided into a MAX and MIN transverse region, which helps separate the “hard component” (initial and final-state radiation) from the “beam-beam remnant” and multiple parton interaction components of the scattering. We found that the center-of-mass energy dependence of the various components of the event are studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

  16. Study of the energy dependence of the underlying event in proton-antiproton collisions

    SciTech Connect

    Nodulman, L.; Aaltonen, T; Albrow, M; Amerio, S.; Amidei, D; Anastassov, A.; Annovi, A; Antos, J; Apollinari, G.; Appel, J A; Arisawa, T

    2015-11-23

    We study charged particle production (p(T) > 0.5 GeV/c, vertical bar eta vertical bar < 0.8) in proton-antiproton collisions at total center-of-mass energies root s = 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of eta - phi space: "toward", "away", and "transverse." The average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the "underlying event." The transverse region is divided into a MAX and MIN transverse region, which helps separate the "hard component" (initial and final-state radiation) from the "beam-beam remnant" and multiple parton interaction components of the scattering. The center-of-mass energy dependence of the various components of the event is studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.

  17. Validation of an optical model applied to the beam down CSP facility at the Masdar Institute Solar Platform

    NASA Astrophysics Data System (ADS)

    Grange, Benjamin; Kumar, Vikas; Torres, Juliana Beltran; Perez, Victor G.; Armstrong, Peter R.; Slocum, Alexander; Calvet, Nicolas

    2016-05-01

    In the framework of the CSPonD Demo project, the optical characterization of the Beam Down Optical Experiment (BDOE) heliostats field is an important step to certify the required power is provided. To achieve this goal, an experiment involving a single heliostat is carried out. The results of the experiment and the comparison with simulated results are presented in this paper. Only the reflection on the heliostat is observed in order to have a better assessment of its optical performance. The heliostat reflectance is modified and the experimental and simulated concentration distribution are confronted. Results indicate that the shapes of the concentration distributions are quite similar, hence validating the optical model respects the geometry of the BDOE. Moreover these results lead to an increase of the optimized heliostat reflectance when the incident angle on the heliostat decreases. Further investigation is required to validate this method with all the individual heliostats of the BDOE solar field.

  18. Antiproton distributions around the Earth, Saturn and Jupiter from cosmic ray driven albedo antineutron decay

    NASA Astrophysics Data System (ADS)

    Spjeldvik, Walther; Bickford, James; Schmitt, William; Spjeldvik, Walther; Martin, Inácio M.; Pugacheva, Galina; Gusev, Anatoly

    In the extended magnetosphere of planets, antiprotons can be produced from the decay of cosmic ray antineutrons which are generated from interactions between cosmic rays and matter located in the vicinity of the planet. The antiproton source function competes with radial transport and losses from interactions with the exosphere, moons, dust, and other particles located in the magnetosphere. Albedo antineutrons generated from pair production followed by shallow angle scattering in the atmosphere are the principal source of antiprotons in the magnetospheres of Earth (about 1015 per year) and Jupiter (about 1018 per year). In comparison, the antiproton source around Saturn is primarily formed from antineutrons which are generated by cosmic ray interactions with its ring system, and this mechanism is estimated to inject approximately 1020 antiprotons per year into its magnetosphere. The source strength around the Jovian planets is reduced due to rigidity cutoff limits which prevent a portion of the cosmic ray flux from reaching all portions of the atmosphere. In the Earth system, the resulting balance of sources, losses and diffusive transport produces an antiproton belt that is roughly co-located with the proton belt with a maximum density near L=1.4 and E˜175 MeV, and we estimate a peak integral equatorial flux of approximately 4000 antiprotons m-2 s-1 . The magnetospheres of Jupiter and Saturn are significantly more complex due to the numerous moons which orbit each planet. The Saturnian moons act as both sources and sinks so that Jovian planets have multiple antiproton radiation belts separated by the orbital locations of the moons. The peak flux around Jupiter is predicted to be primarily interior to its major moons with an intensity of ˜10 antiprotons m-2 s-1 while Saturn's flux peaks around 100 antiprotons m-2 s-1 between the orbits of Janus and Mimas. A comparison of simulations with protons and antiprotons in the Earth's magnetosphere is presented to

  19. A Scintillation Counter System Design To Detect Antiproton Annihilation using the High Performance Antiproton Trap(HiPAT)

    NASA Technical Reports Server (NTRS)

    Martin, James J.; Lewis, Raymond A.; Stanojev, Boris

    2003-01-01

    The High Performance Antiproton Trap (HiPAT), a system designed to hold up to l0(exp 12) charge particles with a storage half-life of approximately 18 days, is a tool to support basic antimatter research. NASA's interest stems from the energy density represented by the annihilation of matter with antimatter, 10(exp 2)MJ/g. The HiPAT is configured with a Penning-Malmberg style electromagnetic confinement region with field strengths up to 4 Tesla, and 20kV. To date a series of normal matter experiments, using positive and negative ions, have been performed evaluating the designs performance prior to operations with antiprotons. The primary methods of detecting and monitoring stored normal matter ions and antiprotons within the trap includes a destructive extraction technique that makes use of a micro channel plate (MCP) device and a non-destractive radio frequency scheme tuned to key particle frequencies. However, an independent means of detecting stored antiprotons is possible by making use of the actual annihilation products as a unique indicator. The immediate yield of the annihilation event includes photons and pie mesons, emanating spherically from the point of annihilation. To "count" these events, a hardware system of scintillators, discriminators, coincident meters and multi channel scalars (MCS) have been configured to surround much of the HiPAT. Signal coincidence with voting logic is an essential part of this system, necessary to weed out the single cosmic ray events from the multi-particle annihilation shower. This system can be operated in a variety of modes accommodating various conditions. The first is a low-speed sampling interval that monitors the background loss or "evaporation" rate of antiprotons held in the trap during long storage periods; provides an independent method of validating particle lifetimes. The second is a high-speed sample rate accumulating information on a microseconds time-scale; useful when trapped antiparticles are extracted

  20. U2 8 + -intensity record applying a H2 -gas stripper cell

    NASA Astrophysics Data System (ADS)

    Barth, Winfried; Adonin, Aleksey; Düllmann, Christoph E.; Heilmann, Manuel; Hollinger, Ralph; Jäger, Egon; Khuyagbaatar, Jadambaa; Krier, Joerg; Scharrer, Paul; Vormann, Hartmut; Yakushev, Alexander

    2015-04-01

    To meet the Facility for Antiproton and Ion Research science requirements higher beam intensity has to be achieved in the present GSI-accelerator complex. For this an advanced upgrade program for the UNILAC is ongoing. Stripping is a key technology for all heavy ion accelerators. For this an extensive research and development program was carried out to optimize for high brilliance heavy ion operation. After upgrade of the supersonic N2 -gas jet (2007), implementation of high current foil stripping (2011) and preliminary investigation of H2 -gas jet operation (2012), recently (2014) a new H2 -gas cell using a pulsed gas regime synchronized with arrival of the beam pulse has been developed. An obviously enhanced stripper gas density as well as a simultaneously reduced gas load for the pumping system result in an increased stripping efficiency, while the beam emittance remains the same. A new record intensity (7.8 emA) for 238U2 8 + beams at 1.4 MeV /u has been achieved applying the pulsed high density H2 stripper target to a high intensity 238U4 + beam from the VARIS ion source with a newly developed extraction system. The experimental results are presented in detail.

  1. 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.

  2. Review of the High Performance Antiproton Trap (HiPAT) Experiment at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Pearson, J. B.; Sims, Herb; Martin, James; Chakrabarti, Suman; Lewis, Raymond; Fant, Wallace

    2003-01-01

    The significant energy density of matter-antimatter annihilation is attractive to the designers of future space propulsion systems, with the potential to offer a highly compact source of power. Many propulsion concepts exist that could take advantage of matter-antimatter reactions, and current antiproton production rates are sufficient to support basic proof-of-principle evaluation of technology associated with antimatter- derived propulsion. One enabling technology for such experiments is portable storage of low energy antiprotons, allowing antiprotons to be trapped, stored, and transported for use at an experimental facility. To address this need, the Marshall Space Flight Center's Propulsion Research Center is developing a storage system referred to as the High Performance Antiproton Trap (HiPAT) with a design goal of containing 10(exp 12) particles for up to 18 days. The HiPAT makes use of an electromagnetic system (Penning- Malmberg design) consisting of a 4 Telsa superconductor, high voltage electrode structure, radio frequency (RF) network, and ultra high vacuum system. To evaluate the system normal matter sources (both electron guns and ion sources) are used to generate charged particles. The electron beams ionize gas within the trapping region producing ions in situ, whereas the ion sources produce the particles external to the trapping region and required dynamic capture. A wide range of experiments has been performed examining factors such as ion storage lifetimes, effect of RF energy on storage lifetime, and ability to routinely perform dynamic ion capture. Current efforts have been focused on improving the FW rotating wall system to permit longer storage times and non-destructive diagnostics of stored ions. Typical particle detection is performed by extracting trapped ions from HiPAT and destructively colliding them with a micro-channel plate detector (providing number and energy information). This improved RF system has been used to detect various

  3. A Framework for Applying Point Clouds Grabbed by Multi-Beam LIDAR in Perceiving the Driving Environment

    PubMed Central

    Liu, Jian; Liang, Huawei; Wang, Zhiling; Chen, Xiangcheng

    2015-01-01

    The quick and accurate understanding of the ambient environment, which is composed of road curbs, vehicles, pedestrians, etc., is critical for developing intelligent vehicles. The road elements included in this work are road curbs and dynamic road obstacles that directly affect the drivable area. A framework for the online modeling of the driving environment using a multi-beam LIDAR, i.e., a Velodyne HDL-64E LIDAR, which describes the 3D environment in the form of a point cloud, is reported in this article. First, ground segmentation is performed via multi-feature extraction of the raw data grabbed by the Velodyne LIDAR to satisfy the requirement of online environment modeling. Curbs and dynamic road obstacles are detected and tracked in different manners. Curves are fitted for curb points, and points are clustered into bundles whose form and kinematics parameters are calculated. The Kalman filter is used to track dynamic obstacles, whereas the snake model is employed for curbs. Results indicate that the proposed framework is robust under various environments and satisfies the requirements for online processing. PMID:26404290

  4. A Framework for Applying Point Clouds Grabbed by Multi-Beam LIDAR in Perceiving the Driving Environment.

    PubMed

    Liu, Jian; Liang, Huawei; Wang, Zhiling; Chen, Xiangcheng

    2015-08-31

    The quick and accurate understanding of the ambient environment, which is composed of road curbs, vehicles, pedestrians, etc., is critical for developing intelligent vehicles. The road elements included in this work are road curbs and dynamic road obstacles that directly affect the drivable area. A framework for the online modeling of the driving environment using a multi-beam LIDAR, i.e., a Velodyne HDL-64E LIDAR, which describes the 3D environment in the form of a point cloud, is reported in this article. First, ground segmentation is performed via multi-feature extraction of the raw data grabbed by the Velodyne LIDAR to satisfy the requirement of online environment modeling. Curbs and dynamic road obstacles are detected and tracked in different manners. Curves are fitted for curb points, and points are clustered into bundles whose form and kinematics parameters are calculated. The Kalman filter is used to track dynamic obstacles, whereas the snake model is employed for curbs. Results indicate that the proposed framework is robust under various environments and satisfies the requirements for online processing.

  5. Trapping of antiprotons -- a first step on the way to antihydrogen

    SciTech Connect

    Holzscheiter, M.H.

    1993-07-01

    A first step towards producing and effectively utilizing antihydrogen atoms consists of trapping antiprotons. The immediate next step must then be to control, i.e. trap the produced antihydrogen. The current state of the art in trapping antiprotons and positrons is reviewed, and the challenges in trapping the resulting neutral particles are discussed.

  6. Abundance of low energy (50-150 MeV) antiprotons in cosmic rays

    NASA Technical Reports Server (NTRS)

    Apparao, K. M. V.; Biswas, S.; Durgaprasad, N.; Stephens, S. A.

    1985-01-01

    The progress is presented of the nuclear emulsion experiment to determine abundance of low energy antiprotons in cosmic rays. No antiprotons have been detected so far at upper limit of p/p less than or similar to 4 x .0001 in the energy range 50 MeV to 15 MeV.

  7. Experimental and computational study of autoresonant injection of antiprotons into positron plasma in antihydrogen production

    NASA Astrophysics Data System (ADS)

    So, Chukman; Wurtele, Jonathan; Fajans, Joel; Friedland, Lazar; Bertsche, William

    2012-10-01

    The injection of antiprotons into positron plasma during antihydrogen synthesis in ALPHA is simulated numerically and compared with experimental measurements. The antiprotons and positrons are initially confined in adjacent axial potential wells in a nested Penning-Malmberg trap. The antiproton plasma is excited autoresonantly and partially injected into the adjacent positron plasma, creating antihydrogen. The excitation and injection process is modeled numerically with a hybrid code in which the antiproton plasma responds to the autoresonant drive fully dynamically, and the positrons respond quasi-statically. The strong axial magnetic field suppresses radial transport on the timescales of interest. The antiproton plasma is thus assumed to consist of concentric cylindrical tubes within which antiprotons move only in the axial direction, and the evolution of the phase space distributions in each tube obeys a one-dimensional Vlasov equation. The antiproton self-field is obtained by solving the Poisson equation in two-dimensions, thereby coupling the tubes. Alternative injection schemes and the effect of varying antiproton number and temperature are also examined.

  8. Electron-beam-induced current measurements with applied bias provide insight to locally resolved acceptor concentrations at p-n junctions

    SciTech Connect

    Abou-Ras, D. Schäfer, N.; Baldaz, N.; Brunken, S.; Boit, C.

    2015-07-15

    Electron-beam-induced current (EBIC) measurements have been employed for the investigation of the local electrical properties existing at various types of electrical junctions during the past decades. In the standard configuration, the device under investigation is analyzed under short-circuit conditions. Further insight into the function of the electrical junction can be obtained when applying a bias voltage. The present work gives insight into how EBIC measurements at applied bias can be conducted at the submicrometer level, at the example of CuInSe{sub 2} solar cells. From the EBIC profiles acquired across ZnO/CdS/CuInSe{sub 2}/Mo stacks exhibiting p-n junctions with different net doping densities in the CuInSe{sub 2} layers, values for the width of the space-charge region, w, were extracted. For all net doping densities, these values decreased with increasing applied voltage. Assuming a linear relationship between w{sup 2} and the applied voltage, the resulting net doping densities agreed well with the ones obtained by means of capacitance-voltage measurements.

  9. Antiprotonic potentials from global fits to the PS209 data

    NASA Astrophysics Data System (ADS)

    Friedman, E.; Gal, A.

    2004-01-01

    The experimental results for strong interaction effects in antiprotonic atoms by the PS209 collaboration consist of high quality data for several sequences of isotopes along the periodic table. Global analysis of these data in terms of a p¯-nucleus optical potential achieves good description of the data using a s-wave finite-range p¯N interaction. Equally good fits are also obtained with a poorly-defined zero-range potential containing a p-wave term.

  10. Multi-ring trap as a reservoir of cooled antiprotons

    SciTech Connect

    Ichioka, T.; Yamazaki, Y.; Higaki, H.; Komaki, K.; Hori, M.; Oshima, N.; Mohri, A.; Kuroki, K.

    1999-12-10

    For the ASACUSA project, a new charged particle trap was designed and constructed. Like a Penning-Malmberg trap, static electric and static magnetic fields are used. Multi-ring electrode is exploited to generate a harmonic potential on the trap axis. It enables the confinement of a number of antiprotons and electrons for the electron cooling. Upon its design, plasma behavior of trapped particle clouds was taken into consideration. As the first step, trap performances have been checked with electrons. Current status are presented.

  11. AMS results on positrons and antiprotons in cosmic rays

    NASA Astrophysics Data System (ADS)

    Kounine, Andrei; AMS Collaboration

    2017-01-01

    AMS-02 is a particle physics detector collecting data on the International Space Station since May 2011. Precision measurements of charged cosmic ray particles have been performed by AMS using a data sample of 85 billion cosmic ray events collected during the first five years of operations on the Station. The latest AMS results on the fluxes and flux ratios of the cosmic ray particles are presented with the emphasis on the measurements of positrons and antiprotons. They show unique features that require accurate theoretical interpretation as to their origin, be it from dark matter collisions or new astrophysical sources. On behalf of AMS.

  12. Evaluation of the Antiproton Flux from the Antineutrino Electron Scattering

    NASA Astrophysics Data System (ADS)

    Alekseev, V. V.; Belotsky, K. M.; Bogomolov, Yu V.; Budaev, R. I.; Dunaeva, O. A.; Kirillov, A. A.; Kuznetsov, A. V.; Laletin, M. N.; Lukyanov, A. D.; Malakhov, V. V.; Mayorov, A. G.; Mayorova, M. A.; Mosichkin, A. F.; Okrugin, A. A.; Rodenko, S. A.; Shitova, A. M.

    2016-02-01

    Recent experiments in high enegry cosmic ray physics, PAMELA and AMS-02, excite a new interest to the mechanisms of generation of galactic antiparticles. In spite of the fact that global picture coincides with the predictions of the standard model, there are some black spots stimulating scientists to involve into research a particularly new physics like dark matter. In the present work, we make an attempt to estimate the impact of standard neutrino processes into the total flux of secondary antiprotons detected by contemporary experiments.

  13. Investigations into beam monitors at the AE bar {g}IS experiment

    NASA Astrophysics Data System (ADS)

    Sosa, A.; Bravin, E.; Harasimowicz, J.; Jeff, A.; Welsch, C. P.

    2014-02-01

    Detailed diagnostic of antiproton beams at low energies is required for essentially all experiments at the Antiproton Decelerator (AD), but will be particularly important for the future Extra Low ENergy Antiproton ring (ELENA) and its keV beam lines to the different experiments. Many monitors have been successfully developed and operated at the AD, but in particular beam profile monitoring remains a challenge. A dedicated beam instrumentation and detector test stand has recently been setup at the AE bar {g}IS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy). Located behind the actual experiment, it allows for parasitic use of the antiproton beam at different energies for testing and calibration. With the aim to explore and validate different candidate technologies for future low energy beam lines, as well as the downstream antihydrogen detector in AE bar {g}IS, measurements have been carried out using Silicon strip and pixel detectors, a purpose-built secondary emission monitor and emulsions. Here, results from measurements and characterization of the different detector types with regard to their future use at the AD complex are presented.

  14. Study of the CHI(1) and CHI(2) States Produced in Antiproton-Proton Annihilations in Fermilab Experiment 760

    NASA Astrophysics Data System (ADS)

    Marques, Jose Laurencio

    A study of the chi_1(^3P _1) and the chi_2(^3P _2) states of charmonium formed in anti-proton -proton annihilations is reported in this dissertation. Performed at Fermi National Accelerator Laboratory, Experiment 760 used an internal molecular hydrogen jet target and circulating beam of momentum cooled antiprotons to conduct energy scans of the two resonances. The small momentum spread of the antiproton beam allowed very precise measurements of both the resonance mass and total width to be made. From a sample of 483 chi_1 and 556 chi_2 events the following resonance parameters have been determined: Gamma_{chi1} = (0.86 +/- 0.14) MeV, Gamma _{chi2} = (2.01 +/- 0.18) MeV, M_{chi1 } = (3510.51 +/- 0.13) MeV/c^2, M_{ chi2} = (3556.03 +/- 0.14) MeV/c^2, Gamma( chi_1to|{p}p)times BR(chi_1to J/psigamma)times BR(J/psito e^+e^-) = (1.22 +/- 0.15) eV, and Gamma( chi_2to|{p}p)times BR(chi_2to J/psigamma)times BR(J/psito e^+e^-) = (1.68 +/- 0.16) eV. The angular distribution for the reaction chi_{1,2}to J/psi+gamma to e^+e^-+gamma was also studied. For the chi_1 resonance, from a sample of 360 events, the radiative decay quadupole amplitude has been found to be a_2 = -0.14 +/- 0.06. For the chi_2, from a sample of 1904 events, the radiative decay quadrupole and octupole amplitudes have been found to be a_2 = -0.15 +/- 0.07 and a_3 = 0.00 +/- 0.05 respectively. The contribution from helicity zero in the formation process of the chi_2 has also been measured, B_sp{0 }{2} = 0.02_sp{ -0.02}{+0.13}..

  15. Perspective Study of Charmonium and Exotics in Antiproton-Proton Annihilation and Proton-Proton Collisions

    NASA Astrophysics Data System (ADS)

    Barabanov, Mikhail; Olsen, Stephen; Vodopyanov, Alexander

    The spectroscopy of exotic states with hidden charm is discussed. Together with charmonium, these provide a good tool for testing theories of the strong interactions including both perturbative and non-perturbative QCD, lattice QCD, potential and other phenomenological models. An elaborated analysis of exotics spectrum is given, and attempts to interpret recent experimentally observed states with masses above the Dbar{D} threshold region are considered. Experimental results from different collaborations (BES, BaBar, Belle, LHCb) are analyzed with special attention given to recently discovered hidden charm states. Some of these states can be interpreted as higher-lying charmonium states and others as tetraquarks with hidden charm. It has been shown that charged/neutral tetraquarks must have their neutral/charge partners with mass values differ by at most a few MeV/c2, hypotheses that tend to coincide with those proposed by Maiani and Polosa. However, measurements of different decay modes are needed before firm conclusions can be made. These data can be derived directly from the experiments using a high quality antiproton beam with momentum up to 15 GeV/c and proton-proton collisions with momentum up to 26 GeV/c.

  16. A study of the energy dependence of the underlying event in proton-antiproton collisions

    DOE PAGES

    Aaltonen, T.

    2015-11-23

    We study charged particle production (pT > 0.5 GeV/c, |η| < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of η-Φspace; “toward”, “away”, and “transverse”. Furthermore, the average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the “underlying event”. The transverse region is divided into a MAX and MIN transverse region, which helps separate the “hard component” (initial and final-state radiation) from the “beam-beammore » remnant” and multiple parton interaction components of the scattering. We found that the center-of-mass energy dependence of the various components of the event are studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV.« less

  17. Precise Measurements of the Cosmic Ray Antiproton Spectrum with BESS Including the Effects of Solar Modulation

    NASA Technical Reports Server (NTRS)

    Mitchell, J. W.; Abe, K.; Anraku, K.; Asaoka, Y.; Fujikawa, M.; Fuke, H.; Haino, S.; Hams, T.; Ikeda, N.; Imori, M.

    2002-01-01

    The Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV in eight flights between 1993 and 2002. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the interstellar gas agree with the BESS antiproton spectrum. Below 1 GeV, the data show a possible excess antiproton flux compared to secondary model predictions, suggesting the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. However, results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, an evolutionary instrument, BESS-Polar, is under construction for polar flight in 2004.

  18. Non-perturbative measurement of low-intensity charged particle beams

    NASA Astrophysics Data System (ADS)

    Fernandes, M.; Geithner, R.; Golm, J.; Neubert, R.; Schwickert, M.; Stöhlker, T.; Tan, J.; Welsch, C. P.

    2017-01-01

    Non-perturbative measurements of low-intensity charged particle beams are particularly challenging to beam diagnostics due to the low amplitude of the induced electromagnetic fields. In the low-energy antiproton decelerator (AD) and the future extra low energy antiproton rings at CERN, an absolute measurement of the beam intensity is essential to monitor the operation efficiency. Superconducting quantum interference device (SQUID) based cryogenic current comparators (CCC) have been used for measuring slow charged beams in the nA range, showing a very good current resolution. But these were unable to measure fast bunched beams, due to the slew-rate limitation of SQUID devices and presented a strong susceptibility to external perturbations. Here, we present a CCC system developed for the AD machine, which was optimised in terms of its current resolution, system stability, ability to cope with short bunched beams, and immunity to mechanical vibrations. This paper presents the monitor design and the first results from measurements with a low energy antiproton beam obtained in the AD in 2015. These are the first CCC beam current measurements ever performed in a synchrotron machine with both coasting and short bunched beams. It is shown that the system is able to stably measure the AD beam throughout the entire cycle, with a current resolution of 30 {nA}.

  19. RF Manipulation and Detection of Protons in the High Performance Antiproton Trap (HiPAT)

    NASA Technical Reports Server (NTRS)

    Martin, James J.; Lewis, Raymond A.; Pearson, J. Boise; Sims, W. Herb; Chakrabarti, Suman; Fant, Wallace E.; McDonald, Stan

    2003-01-01

    The significant energy density of matter-antimatter annihilation is attractive to the designers of future space propulsion systems, with the potential to offer a highly compact source of power. Many propulsion concepts exist that could take advantage of matter-antimatter reactions, and current antiproton production rates are sufficient to support basic proof-of-principle evaluation of technology associated with antimatter-derived propulsion. One enabling technology for such experiments is portable storage of low energy antiprotons, allowing antiprotons to be trapped, stored, and transported for use at an experimental facility.

  20. 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.

  1. Fermilab main injector: High intensity operation and beam loss control

    NASA Astrophysics Data System (ADS)

    Brown, Bruce C.; Adamson, Philip; Capista, David; Chou, Weiren; Kourbanis, Ioanis; Morris, Denton K.; Seiya, Kiyomi; Wu, Guan Hong; Yang, Ming-Jen

    2013-07-01

    From 2005 through 2012, the Fermilab Main Injector provided intense beams of 120 GeV protons to produce neutrino beams and antiprotons. Hardware improvements in conjunction with improved diagnostics allowed the system to reach sustained operation at 400 kW beam power. Transmission was very high except for beam lost at or near the 8 GeV injection energy where 95% beam transmission results in about 1.5 kW of beam loss. By minimizing and localizing loss, residual radiation levels fell while beam power was doubled. Lost beam was directed to either the collimation system or to the beam abort. Critical apertures were increased while improved instrumentation allowed optimal use of available apertures. We will summarize the improvements required to achieve high intensity, the impact of various loss control tools and the status and trends in residual radiation in the Main Injector.

  2. Antineutron and antiproton nuclear interactions at very low energies

    NASA Astrophysics Data System (ADS)

    Friedman, E.

    2014-05-01

    Experimental annihilation cross sections of antineutrons and antiprotons at very low energies are compared. Features of Coulomb focusing are observed for pbar annihilation on protons. Direct comparisons for heavier targets are not straightforward due to lack of overlap between targets and energies of experimental results for pbar and nbar. Nevertheless, the annihilation cross sections for nbar on nuclei cannot be described by an optical potential that fits well all the available data on pbar interactions with nuclei. Comparisons made with the help of this potential reveal in the nbar data features similar to Coulomb focusing. Direct comparisons between nbar and pbar annihilations at very low energies would be possible when pbar cross sections are measured on the same targets and at the same energies as the available cross sections for nbar. Such measurements may be possible in the foreseeable future.

  3. Antiproton stopping in H2 and H2O

    NASA Astrophysics Data System (ADS)

    Bailey, J. J.; Kadyrov, A. S.; Abdurakhmanov, I. B.; Fursa, D. V.; Bray, I.

    2015-11-01

    Stopping powers of antiprotons in H2 and H2O targets are calculated using a semiclassical time-dependent convergent close-coupling method. In our approach the H2 target is treated using a two-center molecular multiconfiguration approximation, which fully accounts for the electron-electron correlation. Double-ionization and dissociative ionization channels are taken into account using an independent-event model. The vibrational excitation and nuclear scattering contributions are also included. The H2O target is treated using a neonization method proposed by C. C. Montanari and J. E. Miraglia [J. Phys. B 47, 015201 (2014), 10.1088/0953-4075/47/1/015201], whereby the ten-electron water molecule is described as a dressed Ne-like atom in a pseudospherical potential. Despite being the most comprehensive approach to date, the results obtained for H2 only qualitatively agree with the available experimental measurements.

  4. Antiproton-annihilation propulsion. Final report, 1 April 1984-31 January 1985

    SciTech Connect

    Forward, R.L.

    1985-09-01

    Antiproton-annihilation propulsion is a new form of space propulsion, where milligrams of antimatter are used to heat tons of reaction fluid to high temperatures. The hot reaction fluid is exhausted from a nozzle to produce high thrust at high specific impulse. This study was to determine the physical, engineering, and economic feasibility of antiproton-annihilation propulsion. The conclusion of the study is that antiproton propulsion is feasible, but expensive. Because the low mass of the antimatter fuel more than compensates for its high price, comparative mission studies show that antimatter fuel can be cost effective in space, where even normal chemical fuel is expensive because its mass must be lifted into orbit before it can be used. Antiproton-annihilation propulsion is mission-enabling, in that it allows missions to be performed that cannot be performed by any other propulsion system.

  5. Beam manipulation and compression using broadband rf systems in the Fermilab Main Injector and Recycler

    SciTech Connect

    G William Foster et al.

    2004-07-09

    A novel method for beam manipulation, compression, and stacking using a broad band RF system in circular accelerators is described. The method uses a series of linear voltage ramps in combination with moving barrier pulses to azimuthally compress, expand, or cog the beam. Beam manipulations can be accomplished rapidly and, in principle, without emittance growth. The general principle of the method is discussed using beam dynamics simulations. Beam experiments in the Fermilab Recycler Ring convincingly validate the concept. Preliminary experiments in the Fermilab Main Injector to investigate its potential for merging two ''booster batches'' to produce high intensity proton beams for neutrino and antiproton production are described.

  6. Can AMS-02 discriminate the origin of an anti-proton signal?

    SciTech Connect

    Pettorino, Valeria; Busoni, Giorgio; Simone, Andrea De; Morgante, Enrico; Riotto, Antonio; Xue, Wei E-mail: giorgio.busoni@sissa.it E-mail: enrico.morgante@unige.ch E-mail: wei.xue@sissa.it

    2014-10-01

    Indirect searches can be used to test dark matter models against expected signals in various channels, in particular antiprotons. With antiproton data available soon at higher and higher energies, it is important to test the dark matter hypothesis against alternative astrophysical sources, e.g. econdaries accelerated in supernova remnants. We investigate the two signals from different dark matter models and different supernova remnant parameters, as forecasted for the AMS-02, and show that they present a significant degeneracy.

  7. BESS-Polar Measurements of Cosmic-Ray Antiprotons and Search for Antihelium

    NASA Astrophysics Data System (ADS)

    Mitchell, John; Yamamoto, Akira

    With its high-precision measurement of the cosmic-ray antiproton spectrum and sensitive search for cosmological antihelium using BESS-Polar II, the US-Japan BESS-Polar Collaboration (Balloon-borne Experiment with a Superconducting Spectrometer - Polar) has finalized its core study of the early Universe using elementary particle measurements. The antiproton spectrum probes possible exotic sources, such as dark-matter candidates. The search for antihelium or heavier antinuclei examines the possibility that antimatter domains remain in the cosmological neighborhood from symmetry breaking processes in the early Universe. Since1993, BESS has carried out eleven high-latitude balloon flights, including two long-duration Antarctic flights, that together have defined the study of antiprotons below 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive reported limits on the existence of antideuterons and antihelium. BESS-Polar II recorded over 4.7 billion cosmic-ray events in 24.5 days of flight over Antarctica during the 2007-2008 Austral Summer, identifying about 8000 antiprotons. These data more than doubled all earlier BESS flights combined and were obtained at very low, near minimum, Solar activity when the low-energy antiproton measurements are most sensitive to a primary source. Depending on energy range, the BESS-Polar II antiproton measurements have 10-20 times the statistics of BESS95+97 data from the previous Solar minimum. Here, we give an overview the results of the long-duration flights of BESS-Polar I (2004) and BESS-Polar II, including antiproton spectra, the energy-dependent ratios of antiprotons to protons, and the limits on the relative abundance of antihelium.

  8. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector

    SciTech Connect

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Joergensen, L. V.; Kerrigan, S. J.; Madsen, N.; Werf, D. P. van der; Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A. P.; Cesar, C. L.; Lambo, R.; Fujiwara, M. C.; Gill, D. R.; Collaboration: ALPHA Collaboration; and others

    2009-12-15

    A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.

  9. Challenging Cosmic Ray Propagation with Antiprotons: Evidence for a "Fresh" Nuclei Component?

    NASA Technical Reports Server (NTRS)

    Moskalenko, Igor V.; Strong, Andrew W.; Mashnik, Stepan G.; Ormes, Jonathan F.

    2002-01-01

    Recent measurements of the cosmic ray (CR) antiproton flux have been shown to challenge existing CR propagation models. It was shown that the reacceleration models designed to match secondary to primary nuclei ratio (e.g., Boron/Carbon) produce too few antiprotons, while the traditional non-reacceleration models can reproduce the antiproton flux but fall short of explaining the low-energy decrease in the secondary to primary nuclei ratio. Matching both the secondary to primary nuclei ratio and antiproton flux requires artificial breaks in the diffusion coefficient and the primary injection spectrum suggesting the need for other approaches. In the present paper we discuss one possibility to overcome these difficulties. Using the measured antiproton flux to fix the diffusion coefficient, we show that the spectra of primary nuclei as measured in the heliosphere may contain a fresh local unprocessed component at low energies, thus decreasing the measured secondary to primary nuclei ratio. A model reproducing antiprotons, B/C ratio, and abundances up to Ni is presented.

  10. P-986 Letter of Intent: Medium-Energy Antiproton Physics at Fermilab

    SciTech Connect

    Asner, David M.; Phillips, Thomas J.; Apollinari, Giorgio; Broemmelsiek, Daniel R.; Brown, Charles N.; Christian, David C.; Derwent, Paul; Gollwitzer, Keith; Hahn, Alan; Papadimitriou, Vaia; Stefanski, Ray; /Fermilab /INFN, Ferrara /Hbar Technol., West Chicago /IIT, Chicago /CHEP, Taegu /Luther Coll. /Michigan U. /Northwestern U. /Notre Dame U. /St. Xavier U., Chicago

    2009-02-05

    Fermilab has long had the world's most intense antiproton source. Despite this, the opportunities for medium-energy antiproton physics at Fermilab have been limited in the past and - with the antiproton source now exclusively dedicated to serving the needs of the Tevatron Collider - are currently nonexistent. The anticipated shutdown of the Tevatron in 2010 presents the opportunity for a world-leading medium-energy antiproton program. We summarize the current status of the Fermilab antiproton facility and review some physics topics for which the experiment we propose could make the world's best measurements. Among these, the ones with the clearest potential for high impact and visibility are in the area of charm mixing and CP violation. Continued running of the Antiproton Source following the shutdown of the Tevatron is thus one of the simplest ways that Fermilab can restore a degree of breadth to its future research program. The impact on the rest of the program will be minor. We request a small amount of effort over the coming months in order to assess these issues in more detail.

  11. New Calculation of Antiproton Production by Cosmic Ray Protons and Nuclei

    NASA Astrophysics Data System (ADS)

    Kachelriess, Michael; Moskalenko, Igor V.; Ostapchenko, Sergey S.

    2015-04-01

    A dramatic increase in the accuracy and statistics of space-borne cosmic ray (CR) measurements has yielded several breakthroughs over the last several years. The most puzzling is the rise in the positron fraction above ∼10 GeV over the predictions of the propagation models assuming pure secondary production. The accuracy of the antiproton production cross section is critical for astrophysical applications and searches for new physics since antiprotons in CRs seem to hold the keys to many puzzles including the origin of those excess positrons. However, model calculations of antiproton production in CR interactions with interstellar gas are often employing parameterizations that are out of date or are using outdated physical concepts. This may lead to an incorrect interpretation of antiproton data which could have broad consequences for other areas of astrophysics. In this work, we calculate antiproton production in pp-, pA-, and AA-interactions using EPOS-LHC and QGSJET-II-04, two of the most advanced Monte Carlo (MC) generators tuned to numerous accelerator data including those from the Large Hadron Collider (LHC). We show that the antiproton yields obtained with these MC generators differ by up to an order of magnitude from yields of parameterizations commonly used in astrophysics.

  12. Centrality and collision system dependence of antiproton production from p+A to Au+Au collisions at AGS energies

    NASA Technical Reports Server (NTRS)

    Sako, H.; Ahle, L.; Akiba, Y.; Ashktorab, K.; Baker, M. D.; Beavis, D.; Britt, H. C.; Chang, J.; Chasman, C.; Chen, Z.; Chu, Y. Y.; Cianciolo, V.; Cole, B. A.; Crawford, H. J.; Cumming, J. B.; Debbe, R.; Dunlop, J. C.; Eldredge, W.; Engelage, J.; Fung, S.-Y.

    1997-01-01

    Antiproton production in heavy ion collisions reflects subtle interplay between initial production and absorption by nucleons. Because the AGS energies (10--20 A(center-dot)GeV/c) are close to the antiproton production threshold, antiproton may be sensitive to cooperative processes such as QGP and hadronic multi-step processes. On the other hand, antiproton has been proposed as a probe of baryon density due to large N(anti N) annihilation cross sections. Cascade models predict the maximum baryon density reaches about 10 times the normal nucleus density in central Au+Au collisions, where the strong antiproton absorption is expected. In this paper, the authors show systematic studies of antiproton production from p+A to Au+Au collisions.

  13. Meson Production in Proton-Proton and Antiproton - Interactions at Center of Mass Energy = 24.3 GEV

    NASA Astrophysics Data System (ADS)

    Singh, Vinay Mohan

    Experiment UA6 measured the inclusive production cross section of pi^0, eta, and omega mesons in the p_{T} range 3.5 to 6.1 GeV/c in the reactions;eqalignno {p + p&to M + Xcrnoalign{hbox {rm and}}|{p} + p& to M + Xcr}where M represents a meson and X any other associated particles, at center of mass energy sqrt{s} = 24.3 GeV. The experiment was located at the CERN SppS collider and utilized a fixed hydrogen gas jet as the target in oppositely circulating proton and antiproton beams of momenta 315 GeV/c. The apparatus could be rotated to select either proton-proton or antiproton-proton interactions. The meson production cross section results were obtained from the analysis of 3.7 inverse picobarns (pb ^{-1}) of pp data collected in 1988 and 3.2 pb^{-1} of pp data collected in 1989. The eta/pi ^0 production ratio is measured to be 0.61 +/- 0.03 +/- 0.07 for pp and 0.62 +/- 0.03 +/- 0.07 for pp. The omega/ pi^0 production ratio is measured to be 0.87 +/- 0.16 +/- 0.13 for pp and 0.84 +/- 0.16 +/- 0.13 for pp. The inclusive pi^0 cross section is determined as a function of p_{T} averaged over the rapidity range 0.6 <= y <= 1.2. Comparison of the production between pp and pp reveals no significant difference. The cross section and production ratios are also compared with results from other experiments and found to be in agreement.

  14. Measurement of inclusive antiprotons from Au+Au collisions at square root of s(NN) = 130 GeV.

    PubMed

    Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chattopadhyay, S; Chen, M L; 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; DeMello, M; Deng, W S; Derevschikov, A A; Didenko, L; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grabski, J; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heffner, M; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Hümmler, H; Igo, G; Ishihara, A; Ivanshin, Y I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; 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; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lynn, D; Majka, R; Margetis, S; Martin, L; Marx, J; Matis, H S; Matulenko, Y A; McShane, T S; Meissner, F; Melnick, Y; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Mutchler, G S; 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; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Platner, E; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Radomski, S; Rai, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Roy, C; Rykov, V; Sakrejda, I; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A; Sugarbaker, E; Suire, C; Sumbera, M; Symons, T J; de Toledo, A S; Szarwas, P; Takahashi, J; Tang, A H; Thomas, J H; Thompson, M; Tikhomirov, V; Trainor, T A; Trentalange, S; Tribble, R E; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vanyashin, A; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Wenaus, T; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

    2001-12-24

    We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at square root of s(NN) = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25antiproton rapidity density is found to scale approximately with the negative hadron multiplicity density.

  15. Partially coherent nonparaxial beams.

    PubMed

    Duan, Kailiang; Lü, Baida

    2004-04-15

    The concept of a partially coherent nonparaxial beam is proposed. A closed-form expression for the propagation of nonparaxial Gaussian Schell model (GSM) beams in free space is derived and applied to study the propagation properties of nonparaxial GSM beams. It is shown that for partially coherent nonparaxial beams a new parameter f(sigma) has to be introduced, which together with the parameter f, determines the beam nonparaxiality.

  16. Impedances and beam stability issues of the Fermilab recycler ring

    SciTech Connect

    Ng, King-Yuen

    1996-04-01

    The Fermilab Recycler Ring (permanent magnets) will be built on top of the Fermilab Main Injector sharing the same tunnel; its main function is to recycle the anti-protons after a store in the Tevatron and to provide storage for them after after accumulation and cooling in the Accumulator. Estimates of coupling impedances show domination by space charge. Examination of longitudinal instabilities shows that microwave instability will not occur if there are only N = 2.53 x 10{sup 12} anti-protons in the beam. Longitudinal coupling-bunch instability during injection stacking does not appear possible because of long bunch lengths/short bunch gaps and lack of sharp resonances. Transverse instability, on the other hand, cannot be Landau damped by the momentum spread in the beam, but it can be cured by a small spread in the betatron tunes (either from space charge or an octupole).

  17. Beam preparation for studying the gravitational behavior of antimatter at rest (GBAR)

    NASA Astrophysics Data System (ADS)

    Lunney, D.; Dupré, P.; Grandemange, P.; Manea, V.; Mortensen, T.; Cabaret, S.; Pitrel, S.; Comini, P.; Debu, P.; Liszkay, L.; Lotrus, P.; Pérez, P.; Rey, J.-M.; Reymond, J.-M.; Ruiz, N.; Sacquin, Y.; Vallage, B.; Brook-Roberge, D.; Hardy, Ph.

    2014-03-01

    The specific antiproton- and positron-beam requirements of the CERN AD-7 experiment, GBAR (Gravitational Behavior of Antimatter at Rest) are presented. GBAR will synthesize antihydrogen ions which will be sympathetically cooled before performing a free-fall experiment on the atom. Antiprotons delivered by CERN's ELENA facility in 100-keV, 300-ns pulses will be electrostatically decelerated and transformed to keV energies using a pulsed drift tube. Positrons are created using a linear electron accelerator and collected into a Penning-Malmberg trap. Descriptions of these ion optical systems are given along with the status.

  18. IBS in a CAM-Dominated Electron Beam

    SciTech Connect

    Burov, A.; Nagaitsev, S.; Shemyakin, A.; Gusachenko, I.

    2006-03-20

    Electron cooling of the 8.9 GeV/c antiprotons in the Recycler ring requires high-quality dc electron beam with the current of several hundred mA and the kinetic energy of 4.3 MeV. That high electron current is attained through beam recirculation (charge recovery). The primary current path is from the magnetized cathode at high voltage terminal to the ground, where the electron beam interacts with the antiproton beam and cooling takes place, and then to the collector in the terminal. The energy distribution function of the electron beam at the collector determines the required collector energy acceptance. Multiple and single intra-beam scattering as well as the dissipation of density micro-fluctuations during the beam transport are studied as factors forming a core and tails of the electron energy distribution. For parameters of the Fermilab electron cooler, the single intra-beam scattering (Touschek effect) is found to be of the most importance.

  19. Experimental study of magnetically confined hollow electron beams in the Tevatron as collimators for intense high-energy hadron beams

    SciTech Connect

    Stancari, G.; Annala, G.; Shiltsev, V.; Still, D.; Valishev, A.; Vorobiev, L.; /Fermilab

    2011-03-01

    Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable losses. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and tested at Fermilab for this purpose. It was installed in one of the Tevatron electron lenses in the summer of 2010. We present the results of the first experimental tests of the hollow-beam collimation concept on 980-GeV antiproton bunches in the Tevatron.

  20. Fermilab Main Injector Beam Position Monitor Upgrade

    NASA Astrophysics Data System (ADS)

    Banerjee, B.; Barker, W.; Bledsoe, S.; Boes, T.; Briegel, C.; Capista, D.; Deuerling, G.; Dysert, R.; Forster, R.; Foulkes, S.; Haynes, W.; Hendricks, B.; Kasza, T.; Kutschke, R.; Marchionni, A.; Olson, M.; Pavlicek, V.; Piccoli, L.; Prieto, P.; Rapisarda, S.; Saewert, A.; Van Bogaert, J.; Votava, M.; Webber, R.; Wendt, M.; Wilcer, N.; Wolbers, S.

    2006-11-01

    An upgrade of the Beam Position Monitor (BPM) signal processing and data acquisition system for the Fermilab Main Injector is described. The Main Injector is a fast cycling synchrotron that accelerates protons or antiprotons from 8 to 150 GeV, Each Main Injector cycle can have a totally different magnet ramp, RF frequency configuration, beam bunch structure, and injection/extraction pattern from the previous cycle. The new BPM system provides the capabilities and flexibility required by the dynamic and complex machine operations. The system offers measurement capability in the 2.5 MHz and 53 MHz channels to detect the range of bunch structures for protons and antiprotons in both wideband (turn-by-turn) and narrowband (closed-orbit) modes. The new BPM read-out system is based on the digital receiver concept and is highly configurable, allowing the signal processing of nearly all Main Injector beam conditions, including the detection of individual batches. An overview of the BPM system in the Main Injector operating environment, some technology details and first beam measurements are presented.

  1. Antiproton constraints on dark matter annihilations from internal electroweak bremsstrahlung

    SciTech Connect

    Garny, Mathias; Ibarra, Alejandro; Vogl, Stefan E-mail: alejandro.ibarra@ph.tum.de

    2011-07-01

    If the dark matter particle is a Majorana fermion, annihilations into two fermions and one gauge boson could have, for some choices of the parameters of the model, a non-negligible cross-section. Using a toy model of leptophilic dark matter, we calculate the constraints on the annihilation cross-section into two electrons and one weak gauge boson from the PAMELA measurements of the cosmic antiproton-to-proton flux ratio. Furthermore, we calculate the maximal astrophysical boost factor allowed in the Milky Way under the assumption that the leptophilic dark matter particle is the dominant component of dark matter in our Universe. These constraints constitute very conservative estimates on the boost factor for more realistic models where the dark matter particle also couples to quarks and weak gauge bosons, such as the lightest neutralino which we also analyze for some concrete benchmark points. The limits on the astrophysical boost factors presented here could be used to evaluate the prospects to detect a gamma-ray signal from dark matter annihilations at currently operating IACTs as well as in the projected CTA.

  2. Saturation of low-energy antiproton annihilation on nuclei

    NASA Astrophysics Data System (ADS)

    Gal, A.; Friedman, E.; Batty, C. J.

    2000-10-01

    Recent measurements of very low-energy (pL<100 MeV//c) /p¯ annihilation on light nuclei reveal apparent suppression of annihilation upon increasing the atomic charge /Z and mass number /A. Using /p¯-nucleus optical potentials Vopt, fitted to /p¯-atom energy-shifts and -widths, we resolve this suppression as due to the strong effective repulsion produced by the very absorptive Vopt. The low-energy /p¯-nucleus wavefunction is kept substantially outside the nuclear surface and the resulting reaction cross section saturates as function of the strength of ImVopt. This feature, for /E>0, parallels the recent prediction, for /E<0, that the level widths of /p¯ atoms saturate and, hence, that /p¯ deeply bound atomic states are relatively narrow. Antiproton annihilation cross sections are calculated at pL=57 MeV//c across the periodic table, and their dependence on /Z and /A is classified and discussed with respect to the Coulomb focussing effect at very low energies.

  3. Direct detection of antiprotons with the Timepix3 in a new electrostatic selection beamline

    NASA Astrophysics Data System (ADS)

    Pacifico, N.; Aghion, S.; Alozy, J.; Amsler, C.; Ariga, A.; Ariga, T.; Bonomi, G.; Bräunig, P.; Bremer, J.; Brusa, R. S.; Cabaret, L.; Caccia, M.; Campbell, M.; Caravita, R.; Castelli, F.; Cerchiari, G.; Chlouba, K.; Cialdi, S.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Dudarev, A.; Ereditato, A.; Evans, C.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Haider, S.; Holmestad, H.; Huse, T.; Jordan, E.; Kellerbauer, A.; Kimura, M.; Krasnický, D.; Lagomarsino, V.; Lansonneur, P.; Lawler, G.; Lebrun, P.; Llopart, X.; Malbrunot, C.; Mariazzi, S.; Marx, L.; Matveev, V.; Mazzotta, Z.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pagano, D.; Penasa, L.; Petracek, V.; Pistillo, C.; Prelz, F.; Prevedelli, M.; Ravelli, L.; Resch, L.; Røhne, O. M.; Rotondi, A.; Sacerdoti, M.; Sandaker, H.; Santoro, R.; Scampoli, P.; Smestad, L.; Sorrentino, F.; Spacek, M.; Storey, J.; Strojek, I. M.; Testera, G.; Tietje, I.; Tlustos, L.; Widmann, E.; Yzombard, P.; Zavatarelli, S.; Zmeskal, J.; Zurlo, N.

    2016-09-01

    We present here the first results obtained employing the Timepix3 for the detection and tagging of annihilations of low energy antiprotons. The Timepix3 is a recently developed hybrid pixel detector with advanced Time-of-Arrival and Time-over-Threshold capabilities and has the potential of allowing precise kinetic energy measurements of low energy charged particles from their time of flight. The tagging of the characteristic antiproton annihilation signature, already studied by our group, is enabled by the high spatial and energy resolution of this detector. In this study we have used a new, dedicated, energy selection beamline (GRACE). The line is symbiotic to the AEgIS experiment at the CERN Antiproton Decelerator and is dedicated to detector tests and possibly antiproton physics experiments. We show how the high resolution of the Timepix3 on the Time-of-Arrival and Time-over-Threshold information allows for a precise 3D reconstruction of the annihilation prongs. The presented results point at the potential use of the Timepix3 in antimatter-research experiments where a precise and unambiguous tagging of antiproton annihilations is required.

  4. Feasibility of an antiproton-catalyzed fission-fragment rocket. Master's thesis

    SciTech Connect

    Hidinger, D.S.

    1992-03-01

    The purpose of this project was to investigate the feasibility of an antiproton catalyzed fission fragment rocket (FFR). The FFR is characterized by the extraction of fission fragments from the fuel, and the utilization of their kinetic energy for thrust generation. A significant drawback to previous FFR designs was the required critical nuclear pile as the fission fragment source. The author examined the possibility of replacing the critical pile with a sub-critical pile driven by antiprotons. Recent experiments have revealed that antiprotons stimulate highly energetic fissions in {sup 238}U, with a neutron multiplicity of 13.7 neutrons per fissions. This interaction was used as a throttled neutron source. The pile consisted of layers of fissile coated fibers which are designed to allow fission fragments to escape them, where the fragments collide with a fluid. The heated fluid is then ejected from the rocket to provide thrust. The calculations performed indicate that each antiproton injected into the pile can stimulate 8 or more fissions while maintaining a neutron multiplication of less than 0.4. Based on the results, the specific design presented was inadequate. Despite this, the concept of using the antiproton-U interaction as a source of thrust warrants further study.

  5. Recent observations of cosmic ray antiprotons and a critical assessment of the theories of their origin

    NASA Technical Reports Server (NTRS)

    Stephens, S. A.; Golden, R. L.

    1988-01-01

    The models proposed to explain the observed spectrum of cosmic ray antiprotons are reexamined in light of recent results from balloon-borne experiments. It is found that the prediction of modified closed galaxy model fits the observed data very well. Models in which secondary antiprotons are produced in the sources, could be made consistent with the data provided the secondary particles do not suffer considerable adiabatic deceleration. It has been shown that there cannot be any significant contribution to the observed antiprotons, from the evaporation of mini black holes or from the annihilation of dark matter like photinos. The role of extragalactic cosmic rays has been examined critically in the context of the recent data, and they are not the source of cosmic ray antiprotons. However, determination of the energy spectrum of antiprotons at least up to a few tens of GeV would be valuable to provide information on the possible existence of supersymmetric particles and on the modulation of extragalactic cosmic rays while entering the Galaxy.

  6. Possibility to achieve an antiproton polarizer by scattering off polarized positrons

    SciTech Connect

    Aulenbacher, K.; Arenhoevel, H.; Barday, R.; Jankowiak, A.; Walcher, Th.

    2008-02-06

    The theoretical prediction for the polarizing cross section when scattering antiprotons off polarized e-vector{sup +} amounts to 2.10{sup 13} barn at 1.7 keV hadron energy in the e-vector{sup +} rest frame. Under this conditions polarizing stored antiprotons in a cooler-like arrangement becomes feasible. Compact e-vector{sup +} sources of sufficient intensity can be provided with present day technology in order to achieve a polarization of P{sub p} = 0.17 for 10{sup 10} stored antiprotons within one hour. Positron storage ring based designs offer an enormous increase in intensity, making an efficient polarizer feasible, even if the cross sections are many orders of magnitude smaller than presently predicted.

  7. Solar Modulation of Low-Energy Antiproton and Proton Spectra Measured by BESS

    NASA Technical Reports Server (NTRS)

    Mitchell, John W.; Abe, Ko; Fuke, Hideyuki; Haino, Sadakazu; Hams, Thomas; Horikoshi, Atsushi; Kim, Ki-Chun; Lee, MooHyun; Makida, Yashuhiro; Matsuda, Shinya; Moiseev, Alexander; Nishimura, Jun; Nozaki, Mitsuaki

    2007-01-01

    The spectra of low-energy cosmic-ray protons and antiprotons have been measured by BESS in nine high-latitude balloon flights between 1993 and 2004. These measurements span a range of solar activity from the previous solar minimum through solar ma>:im%am and the onset of the present solar minimum, as well as a solar magnetic field reversal from positive to negative in 2000. Because protons and antiprotons differ only in charge sign, these simultaneous measurements provide a sensitive probe of charge dependent solar modulation. The antiproton to proton ratio measured by BESS is consistent with simple spherically symmetric models of solar modulation during the Sun's positive polarity phase, but favor charge-sign-dependent drift models during the negative phase. The BESS measurements will be presented and compared to various models of solar modulation.

  8. Classification of high-energy antiprotons on electrons background based on calorimeter data in PAMELA experiment

    NASA Astrophysics Data System (ADS)

    Dunaeva, O. A.; Alekseev, V. V.; Bogomolov, Yu V.; Lukyanov, A. D.; Malakhov, V. V.; Mayorov, A. G.; Rodenko, S. A.

    2017-01-01

    In modern experimental physics a heterogeneous coordinate-sensitive calorimeters are widely used due to their good characteristics and possibilities to obtain a three-dimensional information of particles interactions. Especially it is important at high-energies when electromagnetic or hadron showers are arise. We propose a quit efficient method to identify antiprotons (positrons) with energies more than 10 GeV on electron (proton) background by calorimeter of such kind. We construct the AdaBoost classifier and SVM to separate particles into two classes, different combinations of energy release along reconstructed particle trajectory were used as feature vector. We test a preliminary version of the method on a calorimeter of the PAMELA magnetic spectrometer. For high-energy particles we got a good quality of classification: it lost about 5 · 10‑2 of antiprotons, and less than 4 · 10‑4 of electrons were classified to antiproton class.

  9. Potential for a near-term very-low-energy antiproton source at Brookhaven Bational Laboratory. Special report

    SciTech Connect

    Nordley, G.D.

    1989-04-01

    The resolution of key issues in the use of antimatter for applications ranging from aerospace-materials analysis in the near term and propulsion energy storage in the far term requires experiments with low-energy, relatively slow-moving, or thermal, antiprotons. There is no United States source of antiprotons at that energy; therefore, a task was initiated with Brookhaven National Laboratory to determine what would be required in time, equipment, and money to create a source producing antiprotons at a rate (approx 10{sup 14}/yr) sufficient to support applications experiments. The estimate eventually derived from this first-order analysis was approximately $8.6M for an initial source of 20 KeV antiprotons plus another roughly estimated $5M for cooling to increase the production rate to 10{sup 14} - 10{sup 15} antiprotons per year.

  10. A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices.

    PubMed

    Pilan, N; Antoni, V; De Lorenzi, A; Chitarin, G; Veltri, P; Sartori, E

    2016-02-01

    A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF6 instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

  11. A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

    SciTech Connect

    Pilan, N. Antoni, V.; De Lorenzi, A.; Chitarin, G.; Veltri, P.; Sartori, E.

    2016-02-15

    A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF{sub 6} instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

  12. Evaluation of the dosimetric impact of applying flattening filter-free beams in intensity-modulated radiotherapy for early-stage upper thoracic carcinoma of oesophagus

    SciTech Connect

    Zhang, Wuzhe; Lin, Zhixiong; Yang, Zhining; Fang, Weisheng; Lai, Peibo; Lu, Jiayang; Wu, Vincent WC

    2015-06-15

    Flattening filter-free (FFF) radiation beams have recently become clinically available on modern linear accelerators in radiation therapy. This study aimed to evaluate the dosimetric impact of using FFF beams in intensity-modulated radiotherapy (IMRT) for early-stage upper thoracic oesophageal cancer. Eleven patients with primary stage upper thoracic oesophageal cancer were recruited. For each patient, two IMRT plans were computed using conventional beams (Con-P) and FFF beams (FFF-P), respectively. Both plans employed a five-beam arrangement and were prescribed with 64 Gy to (planning target volume) PTV1 and 54 Gy to PTV2 in 32 fractions using 6 MV photons. The dose parameters of the target volumes and organs at risks (OARs), and treatment parameters including the monitor units (MU) and treatment time (TT) for Con-P and FFF-P were recorded and compared. The mean D{sub 5} of PTV1 and PTV2 were higher in FFF-P than Con-P by 0.4 Gy and 0.3 Gy, respectively. For the OARs, all the dose parameters did not show significant difference between the two plans except the mean V{sub 5} and V{sub 10} of the lung in which the FFF-P was lower (46.7% vs. 47.3% and 39.1% vs. 39.6%, respectively). FFF-P required 54% more MU but 18.4% less irradiation time when compared to Con-P. The target volume and OARs dose distributions between the two plans were comparable. However, FFF-P was more effective in sparing the lung from low dose and reduced the mean TT compared with Con-P. Long-term clinical studies are suggested to evaluate the radiobiological effects of FFF beams.

  13. High-power Ti:sapphire lasers for spectroscopy of antiprotonic atoms and radioactive ions

    NASA Astrophysics Data System (ADS)

    Hori, M.; Dax, A.; Soter, A.

    2012-12-01

    The ASACUSA collaboration has developed injection-seeded Ti:sapphire lasers of linewidth Γpl ˜ 6 MHz, pulse energy 50-100 mJ, and output wavelength λ = 726-941 nm. They are being used in two-photon spectroscopy experiments of antiprotonic helium atoms at the Antiproton Decelerator (AD) of CERN. Ti:sapphire lasers of larger linewidth Γpl ˜ 100 MHz but more robust design will also be used in collinear resonance ionization spectroscopy (CRIS) experiments of neutron-deficient francium ions at the ISOLDE facility.

  14. High-power Ti:sapphire lasers for spectroscopy of antiprotonic atoms and radioactive ions

    NASA Astrophysics Data System (ADS)

    Hori, M.; Dax, A.; Soter, A.

    The ASACUSA collaboration has developed injection-seeded Ti:sapphire lasers of linewidth Γpl ˜ 6 MHz, pulse energy 50-100 mJ, and output wavelength λ = 726-941 nm. They are being used in two-photon spectroscopy experiments of antiprotonic helium atoms at the Antiproton Decelerator (AD) of CERN. Ti:sapphire lasers of larger linewidth Γpl ˜ 100 MHz but more robust design will also be used in collinear resonance ionization spectroscopy (CRIS) experiments of neutron-deficient francium ions at the ISOLDE facility.

  15. Pion, Kaon, Proton and Antiproton Production in Proton-Proton Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Blattnig, Steve R.

    2008-01-01

    Inclusive pion, kaon, proton, and antiproton production from proton-proton collisions is studied at a variety of proton energies. Various available parameterizations of Lorentz-invariant differential cross sections as a function of transverse momentum and rapidity are compared with experimental data. The Badhwar and Alper parameterizations are moderately satisfactory for charged pion production. The Badhwar parameterization provides the best fit for charged kaon production. For proton production, the Alper parameterization is best, and for antiproton production the Carey parameterization works best. However, no parameterization is able to fully account for all the data.

  16. PARTICLE BEAM TRACKING CIRCUIT

    DOEpatents

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  17. Relativistic-beam Pickup Test Facility

    SciTech Connect

    Kramer, S.L.; Simpson, J.; Konecny, R.; Suddeth, D.

    1983-01-01

    The electrical response of pickups and cavities to charged particle beams has been an area of considerable activity and concern for accelerator systems. With the advent of stochastic beam cooling, the position and frequency response of beam pickups has become a crucial parameter in determining the performance of these systems. The most frequently used method for measuring and calibrating beam pickups has been the use of current carrying wires to simulate relativistic beams. This method has sometimes led to incorrect predictions of the pickup response to particle beams. The reasons for the differences are not always obvious but could arise from: (1) wires are incapable of exciting or permitting many of the modes that beams excite or (2) the interaction of the wire with large arrays of pickups produce results which are not easily predicted. At Argonne these deficiencies are resolved by calibrating pickups with a relativistic electron beam. This facility is being used extensively by several groups to measure beam pickup devices and is the primary calibration facility for pickups to be used in the FNAL TEV-I Antiproton Source.

  18. Technical design report for the overline{P}ANDA (Anti Proton Annihilations at Darmstadt) Straw Tube Tracker. Strong interaction studies with antiprotons

    NASA Astrophysics Data System (ADS)

    Erni, W.; Keshelashvili, I.; Krusche, B.; Steinacher, M.; Heng, Y.; Liu, Z.; Liu, H.; Shen, X.; Wang, Q.; Xu, H.; Aab, A.; Albrecht, M.; Becker, J.; Csapó, A.; Feldbauer, F.; Fink, M.; Friedel, P.; Heinsius, F. H.; Held, T.; Klask, L.; Koch, H.; Kopf, B.; Leiber, S.; Leyhe, M.; Motzko, C.; Pelizäus, M.; Pychy, J.; Roth, B.; Schröder, T.; Schulze, J.; Sowa, C.; Steinke, M.; Trifterer, T.; Wiedner, U.; Zhong, J.; Beck, R.; Bianco, S.; Brinkmann, K. T.; Hammann, C.; Hinterberger, F.; Kaiser, D.; Kliemt, R.; Kube, M.; Pitka, A.; Quagli, T.; Schmidt, C.; Schmitz, R.; Schnell, R.; Thoma, U.; Vlasov, P.; Walther, D.; Wendel, C.; Würschig, T.; Zaunick, H. G.; Bianconi, A.; Bragadireanu, M.; Caprini, M.; Pantea, D.; Pantelica, D.; Pietreanu, D.; Serbina, L.; Tarta, P. D.; Kaplan, D.; Fiutowski, T.; Idzik, M.; Mindur, B.; Przyborowski, D.; Swientek, K.; Czech, B.; Kistryn, M.; Kliczewski, S.; Kozela, A.; Kulessa, P.; Lebiedowicz, P.; Pysz, K.; Schäfer, W.; Siudak, R.; Szczurek, A.; Jowzaee, S.; Kajetanowicz, M.; Kamys, B.; Kistryn, S.; Korcyl, G.; Korcyl, K.; Krzemien, W.; Magiera, A.; Moskal, P.; Palka, M.; Rudy, Z.; Salabura, P.; Smyrski, J.; Wrońska, A.; Augustin, I.; Lehmann, I.; Nimorus, D.; Schepers, G.; Al-Turany, M.; Arora, R.; Deppe, H.; Flemming, H.; Gerhardt, A.; Götzen, K.; Jordi, A. F.; Kalicy, G.; Karabowicz, R.; Lehmann, D.; Lewandowski, B.; Lühning, J.; Maas, F.; Orth, H.; Patsyuk, M.; Peters, K.; Saito, T.; Schepers, G.; Schmidt, C. J.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Voss, B.; Wieczorek, P.; Wilms, A.; Zühlsdorf, M.; Abazov, V. M.; Alexeev, G.; Arefiev, A.; Astakhov, V. I.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Yu. I.; Dodokhov, V. Kh.; Efremov, A. A.; Fedunov, A. G.; Festchenko, A. A.; Galoyan, A. S.; Grigoryan, S.; Karmokov, A.; Koshurnikov, E. K.; Lobanov, V. I.; Lobanov, Yu. Yu.; Makarov, A. F.; Malinina, L. V.; Malyshev, V. L.; Mustafaev, G. A.; Olshevskiy, A.; Pasyuk, M. A.; Perevalova, E. A.; Piskun, A. A.; Pocheptsov, T. A.; Pontecorvo, G.; Rodionov, V. K.; Rogov, Yu. N.; Salmin, R. A.; Samartsev, A. G.; Sapozhnikov, M. G.; Shabratova, G. S.; Skachkova, A. N.; Skachkov, N. B.; Strokovsky, E. A.; Suleimanov, M. K.; Teshev, R. Sh.; Tokmenin, V. V.; Uzhinsky, V. V.; Vodopyanov, A. S.; Zaporozhets, S. A.; Zhuravlev, N. I.; Zorin, A. G.; Branford, D.; Glazier, D.; Watts, D.; Woods, P.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Dobbs, S.; Metreveli, Z.; Seth, K.; Tomaradze, A.; Xiao, T.; Bettoni, D.; Carassiti, V.; Cotta Ramusino, A.; Dalpiaz, P.; Drago, A.; Fioravanti, E.; Garzia, I.; Savriè, M.; Stancari, G.; Bianchi, N.; Gianotti, P.; Guaraldo, C.; Lucherini, V.; Orecchini, D.; Pace, E.; Bersani, A.; Bracco, G.; Macri, M.; Parodi, R. F.; Bremer, D.; Dormenev, V.; Drexler, P.; Düren, M.; Eissner, T.; Föhl, K.; Galuska, M.; Gessler, T.; Hayrapetyan, A.; Hu, J.; Koch, P.; Kröck, B.; Kühn, W.; Lange, S.; Liang, Y.; Merle, O.; Metag, V.; Moritz, M.; Münchow, D.; Nanova, M.; Novotny, R.; Spruck, B.; Stenzel, H.; Ullrich, T.; Werner, M.; Xu, H.; Euan, C.; Hoek, M.; Ireland, D.; Keri, T.; Montgomery, R.; Protopopescu, D.; Rosner, G.; Seitz, B.; Babai, M.; Glazenborg-Kluttig, A.; Kavatsyuk, M.; Lemmens, P.; Lindemulder, M.; Löhner, H.; Messchendorp, J.; Moeini, H.; Schakel, P.; Schreuder, F.; Smit, H.; Tambave, G.; van der Weele, J. C.; Veenstra, R.; Sohlbach, H.; Büscher, M.; Deermann, D.; Dosdall, R.; Esch, S.; Gillitzer, A.; Goldenbaum, F.; Grunwald, D.; Henssler, S.; Herten, A.; Hu, Q.; Kemmerling, G.; Kleines, H.; Kozlov, V.; Lehrach, A.; Maier, R.; Mertens, M.; Ohm, H.; Orfanitski, S.; Prasuhn, D.; Randriamalala, T.; Ritman, J.; Röder, M.; Schadmand, S.; Serdyuk, V.; Sterzenbach, G.; Stockmanns, T.; Wintz, P.; Wüstner, P.; Xu, H.; Kisiel, J.; Li, S.; Li, Z.; Sun, Z.; Xu, H.; Rigato, V.; Fissum, S.; Hansen, K.; Isaksson, L.; Lundin, M.; Schröder, B.; Achenbach, P.; Bleser, S.; Cahit, U.; Cardinali, M.; Denig, A.; Distler, M.; Fritsch, M.; Jasinski, P.; Kangh, D.; Karavdina, A.; Lauth, W.; Merkel, H.; Michel, M.; Mora Espi, M. C.; Müller, U.; Pochodzalla, J.; Sanchez, S.; Sanchez-Lorente, A.; Schlimme, S.; Sfienti, C.; Thiel, M.; Weber, T.; Dormenev, V. I.; Fedorov, A. A.; Korzhik, M. V.; Missevitch, O. V.; Balanutsa, V.; Chernetsky, V.; Demekhin, A.; Dolgolenko, A.; Fedorets, P.; Gerasimov, A.; Goryachev, V.; Varentsov, V.; Boukharov, A.; Malyshev, O.; Marishev, I.; Semenov, A.; Böhmer, F.; Dørheim, S.; Ketzer, B.; Paul, S.; Hergemöller, A. K.; Khoukaz, A.; Köhler, E.; Täschner, A.; Wessels, J.; Varma, R.; Chaterjee, A.; Jha, V.; Kailas, S.; Roy, B. J.; Yan, Y.; Chinorat, K.; Khanchai, K.; Ayut, L.; Pomrad, S.; Baldin, E.; Kotov, K.; Peleganchuk, S.; Tikhonov, Yu.; Boucher, J.; Chambert, V.; Dbeyssi, A.; Gumberidze, M.; Hennino, T.; Imre, M.

    2013-02-01

    This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the overline{P}ANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole overline{P}ANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.

  19. Do Unpolarized Electrons Affect the Polarization of a Stored Beam?

    SciTech Connect

    Rathmann, Frank

    2009-08-04

    We present a short overview of the PAX physics case for polarized antiprotons. In order to progress towards a stored polarized antiproton beam, it is crucial to understand the interaction of polarized protons with unpolarized electrons. Therefore investigations that address in particular the contributions of electrons to the polarization buildup of a stored proton beam are presented here in more detail. The measurement of the depolarizing p-vectore cross section settled a long-standing controversy about the role of electrons in the polarization buildup of a stored beam by spin-filtering. Instead of studying the buildup of polarization in an initially unpolarized beam, here the inverse situation was investigated by observation of the depolarization of an initially polarized beam. For the first time, electrons in the electron cooler have been used as a target to study their depolarizing effect on a 49.3 MeV proton beam orbiting in COSY. The foreseen spin-filtering experiments at COSY-Juelich and at the AD of CERN are briefly discussed as well.

  20. APPA at FAIR: From fundamental to applied research

    NASA Astrophysics Data System (ADS)

    Stöhlker, Th.; Bagnoud, V.; Blaum, K.; Blazevic, A.; Bräuning-Demian, A.; Durante, M.; Herfurth, F.; Lestinsky, M.; Litvinov, Y.; Neff, S.; Pleskac, R.; Schuch, R.; Schippers, S.; Severin, D.; Tauschwitz, A.; Trautmann, C.; Varentsov, D.; Widmann, E.

    2015-12-01

    FAIR with its intense beams of ions and antiprotons provides outstanding and worldwide unique experimental conditions for extreme matter research in atomic and plasma physics and for application oriented research in biophysics, medical physics and materials science. The associated research programs comprise interaction of matter with highest electromagnetic fields, properties of plasmas and of solid matter under extreme pressure, density, and temperature conditions, simulation of galactic cosmic radiation, research in nanoscience and charged particle radiotherapy. A broad variety of APPA-dedicated facilities including experimental stations, storage rings, and traps, equipped with most sophisticated instrumentation will allow the APPA community to tackle new challenges. The worldwide most intense source of slow antiprotons will expand the scope of APPA related research to the exciting field of antimatter.

  1. Buffer-gas cooling of antiprotonic helium to 1.5 to 1.7 K, and antiproton-to-electron mass ratio.

    PubMed

    Hori, Masaki; Aghai-Khozani, Hossein; Sótér, Anna; Barna, Daniel; Dax, Andreas; Hayano, Ryugo; Kobayashi, Takumi; Murakami, Yohei; Todoroki, Koichi; Yamada, Hiroyuki; Horváth, Dezső; Venturelli, Luca

    2016-11-04

    Charge, parity, and time reversal (CPT) symmetry implies that a particle and its antiparticle have the same mass. The antiproton-to-electron mass ratio [Formula: see text] can be precisely determined from the single-photon transition frequencies of antiprotonic helium. We measured 13 such frequencies with laser spectroscopy to a fractional precision of 2.5 × 10(-9) to 16 × 10(-9) About 2 × 10(9) antiprotonic helium atoms were cooled to temperatures between 1.5 and 1.7 kelvin by using buffer-gas cooling in cryogenic low-pressure helium gas; the narrow thermal distribution led to the observation of sharp spectral lines of small thermal Doppler width. The deviation between the experimental frequencies and the results of three-body quantum electrodynamics calculations was reduced by a factor of 1.4 to 10 compared with previous single-photon experiments. From this, [Formula: see text] was determined as 1836.1526734(15), which agrees with a recent proton-to-electron experimental value within 8 × 10(-10).

  2. BEAM-BEAM 2003 SUMMARY.

    SciTech Connect

    FISCHER,W.SEN,T.

    2003-05-19

    This paper summarizes the presentations and discussions of the Beam-Beam'03 workshop, held in Montauk, Long Island, from May 19 to 23, 2003. Presentations and discussions focused on halo generation from beam-beam interactions; beam-beam limits, especially coherent limits and their effects on existing and future hadron colliders; beam-beam compensation techniques, particularly for long-range interactions; and beam-beam study tools in theory, simulation, and experiment.

  3. Perspective study of exotics and flavour baryons in antiproton-proton annihilation and proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Barabanov, Mikhail; Vodopyanov, Alexander

    2016-07-01

    Abstract. The spectroscopy of exotic states with hidden charm is discussed. Together with charmonium, these provide a good tool for testing theories of the strong interactions including both perturbative and non-perturbative QCD, lattice QCD, potential and other phenomenological models. An elaborated analysis of exotics spectrum is given, and attempts to interpret recent experimentally observed states with masses above the DD̅ threshold region are considered. Experimental results from different collaborations (BES, BaBar, Belle, LHCb) are analyzed with special attention given to recently discovered hidden charm states. Some of these states can be interpreted as higher-lying charmonium states and others as tetraquarks with hidden charm. It has been shown that charged/neutral tetraquarks must have their neutral/charge partners with mass values differ by at most a few MeV/c2, hypotheses that tend to coincide with those proposed by Maiani and Polosa. However, measurements of different decay modes are needed before firm conclusions can be made. These data can be derived directly from the experiments using ahigh quality antiproton beam with momentum up to 15 GeV/c and proton-proton collisions with momentum up to 26 GeV/c. DD

  4. Experimental determination of the lateral dose response functions of detectors to be applied in the measurement of narrow photon-beam dose profiles

    NASA Astrophysics Data System (ADS)

    Poppinga, D.; Meyners, J.; Delfs, B.; Muru, A.; Harder, D.; Poppe, B.; Looe, HK

    2015-12-01

    This study aims at the experimental determination of the detector-specific 1D lateral dose response function K(x) and of its associated rotational symmetric counterpart K(r) for a set of high-resolution detectors presently used in narrow-beam photon dosimetry. A combination of slit-beam, radiochromic film, and deconvolution techniques served to accomplish this task for four detectors with diameters of their sensitive volumes ranging from 1 to 2.2 mm. The particular aim of the experiment was to examine the existence of significant negative portions of some of these response functions predicted by a recent Monte-Carlo-simulation (Looe et al 2015 Phys. Med. Biol. 60 6585-607). In a 6 MV photon slit beam formed by the Siemens Artiste collimation system and a 0.5 mm wide slit between 10 cm thick lead blocks serving as the tertiary collimator, the true cross-beam dose profile D(x) at 3 cm depth in a large water phantom was measured with radiochromic film EBT3, and the detector-affected cross-beam signal profiles M(x) were recorded with a silicon diode, a synthetic diamond detector, a miniaturized scintillation detector, and a small ionization chamber. For each detector, the deconvolution of the convolution integral M(x)  =  K(x)  ∗  D(x) served to obtain its specific 1D lateral dose response function K(x), and K(r) was calculated from it. Fourier transformations and back transformations were performed using function approximations by weighted sums of Gaussian functions and their analytical transformation. The 1D lateral dose response functions K(x) of the four types of detectors and their associated rotational symmetric counterparts K(r) were obtained. Significant negative curve portions of K(x) and K(r) were observed in the case of the silicon diode and the diamond detector, confirming the Monte-Carlo-based prediction (Looe et al 2015 Phys. Med. Biol. 60 6585-607). They are typical for the perturbation of the secondary electron field by a detector with

  5. Closing in on mass-degenerate dark matter scenarios with antiprotons and direct detection

    SciTech Connect

    Garny, Mathias; Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan E-mail: ibarra@tum.de E-mail: stefan.vogl@tum.de

    2012-11-01

    Over the last years both cosmic-ray antiproton measurements and direct dark matter searches have proved particularly effective in constraining the nature of dark matter candidates. The present work focusses on these two types of constraints in a minimal framework which features a Majorana fermion as the dark matter particle and a scalar that mediates the coupling to quarks. Considering a wide range of coupling schemes, we derive antiproton and direct detection constraints using the latest data and paying close attention to astrophysical and nuclear uncertainties. Both signals are strongly enhanced in the presence of degenerate dark matter and scalar masses, but we show that the effect is especially dramatic in direct detection. Accordingly, the latest direct detection limits take the lead over antiprotons. We find that antiproton and direct detection data set stringent lower limits on the mass splitting, reaching 19% at a 300 GeV dark matter mass for a unity coupling. Interestingly, these limits are orthogonal to ongoing collider searches at the Large Hadron Collider, making it feasible to close in on degenerate dark matter scenarios within the next years.

  6. RAND Workshop on Antiproton Science and Technology, Annotated Executive Summary. (October 6-9, 1987)

    DTIC Science & Technology

    1988-10-01

    payload/gross weight ratios by clever use of antimatter to amplify the spccific impulse of standard engine cycles. Of course, advanced propulsion ...External Particle Fluxes H. Mayer (RAND Corporation) 4. Propulsion Test Facility - Antiproton Stopping and Annihilation in various Antimatter Engine Types...Needed Experimental Information D. Morgan (Livermore Laboratory) et al. (contributions) 5. Antimatter Spacecraft Propulsion Experiments on Energy

  7. Long-lived states of antiprotonic lithium pLi {sup +} produced in p+ Li collisions

    SciTech Connect

    Sakimoto, Kazuhiro

    2011-09-15

    Antiproton capture by lithium atoms (p+Li{yields}pLi{sup +}+e) is investigated at collision energies from 0.01 to 10 eV by using a semiclassical (also know as quantum-classical hybrid) method, in which the radial distance between the antiproton and the Li{sup +} ion is treated as a classical variable, and the other degrees of freedom are described by quantum mechanics. Analyzing the wave packet of the emitted electrons and making use of the energy conservation rule enable us to calculate the state distribution of the produced antiprotonic lithium pLi{sup +} atoms and also to distinguish between the capture and ionization ({yields}p+Li{sup +}+e) channels at collisional energies above the ionization threshold. This method is tested for the capture of negative muons by hydrogen atoms, which was rigorously investigated in previous quantum mechanical studies. Most of the pLi{sup +} atoms produced in p+Li are found to be sufficiently stable against Auger decays and are experimentally observable as long-lived states. The present system bears close similarities to the system of p+He(2S). It is therefore expected that long-lived antiprotonic helium pHe{sup +} atoms can be efficiently produced in the p capture by metastable He(2 {sup 3}S) atoms.

  8. Antiproton signatures from astrophysical and dark matter sources at the galactic center

    SciTech Connect

    Cembranos, J.A.R.; Gammaldi, V.; Maroto, A.L. E-mail: vivigamm@ucm.es

    2015-03-01

    The center of our Galaxy is a complex region characterized by extreme phenomena. The presence of the supermassive Sagittarius A* black hole, a high dark matter density and an even higher baryonic density are able to produce very energetic processes. Indeed, high energetic gamma-rays have been observed by different telescopes, although their origin is not clear. In this work, we estimate the possible antiproton flux component associated with this signal. The expected secondary astrophysical antiproton background already saturates the observed data. It implies that any other important astrophysical source leads to an inconsistent excess. We estimate the sensitivity of PAMELA to this new primary antiproton source, which depends on the diffusion model and its spectral features. In particular, we consider antiproton spectra described by a power-law, a monochromatic signal and a Standard Model particle-antiparticle channel production. This latter spectrum is typical in the production from annihilating or decaying dark matter. We pay particular attention to the case of a heavy dark matter candidate, which could be associated with the High Energy Stereoscopic System (HESS) data observed from the J1745-290 source.

  9. FAIR - An International Accelerator Facility for Research with Ions and Antiprotons

    SciTech Connect

    Henning, Walter

    2005-06-08

    An overview is given on the international Facility for Antiproton and Ion Research (FAIR) at GSI, its science motivation and goals, the facility lay-out and characteristics, the accelerator design challenges, the schedule for construction, and the international interest/participation in the project.

  10. Anti-proton tune measurements for the Fall 1995 accelerator studies

    SciTech Connect

    Marriner, john; /Fermilab

    1996-04-01

    A system to measure the tunes of a single antiproton (or proton) bunch was built and has been commissioned. The system achieved high sensitivity with a novel closed-orbit suppression system. The use of high bandwidth directional pickpus and kickers in conjunction with precise timing gates enabled the measurement of the tune of a single bunch.

  11. Transversity in Drell-Yan Process of Polarized Protons and Antiprotons in Pax Experiment

    NASA Astrophysics Data System (ADS)

    Efremov, A. V.; Goeke, K.; Schweitzer, P.

    2005-08-01

    Estimates are given for the double-spin asymmetry in lepton-pair production from collisions of transversely polarized protons and antiprotons for the kinematics of the recently proposed PAX experiment at GSI, on the basis of predictions for the transversity distribution from the chiral quark soliton model.

  12. Simple numerical models for antiproton-hydrogen scattering

    SciTech Connect

    Morgan Jr., D. L., LLNL

    1996-08-23

    A diode-side-pumped discrete-optic E{sup 3+}:YAG laser employs pump-light coupling through a sapphire plate diffusion-bonded to the laser slab, giving reduced thermal lensing and exceptional beam quality (M{sup 2} {approx} 1.3.) The novel architecture is also applicable to other side-pumped lasers.

  13. TECHNICAL NOTE: An unsupervised statistical damage detection method for structural health monitoring (applied to detection of delamination of a composite beam)

    NASA Astrophysics Data System (ADS)

    Iwasaki, Atsushi; Todoroki, Akira; Shimamura, Yoshinobu; Kobayashi, Hideo

    2004-10-01

    The present paper proposes a new damage diagnosis method for structural health monitoring that does not require data on damaged-state structures. Structural health monitoring is an essential technology for aged civil structures and advanced composite structures. For damage diagnostic methods, most current structural health monitoring systems adopt parametric methods based on modeling, or non-parametric methods such as artificial neural networks. The conventional methods require FEM modeling of structure or data for training the damaged-state structure. These processes require judgment by a human, resulting in high cost. The present paper proposes a new automatic damage diagnostic method for structural health monitoring that does not require these processes by using a system identification and statistical similarity test of the identified systems using an F-test. As an example of damage diagnosis using the new method, the present study describes delamination detection of a CFRP beam. System identification among the strain data measured on the surface of a composite beam is used for damage diagnosis. The results show that the new statistical damage diagnostic method successfully diagnoses damage without the use of modeling and without learning data for damaged structures.

  14. Beam-beam simulations for separated beams

    SciTech Connect

    Furman, Miguel A.

    2000-04-10

    We present beam-beam simulation results from a strong-strong gaussian code for separated beams for the LHC and RHIC. The frequency spectrum produced by the beam-beam collisions is readily obtained and offers a good opportunity for experimental comparisons. Although our results for the emittance blowup are preliminary, we conclude that, for nominal parameter values, there is no significant difference between separated beams and center-on-center collisions.

  15. The BESS investigation of the origin of cosmic-ray antiprotons and search for cosmological antimatter

    NASA Astrophysics Data System (ADS)

    Mitchell, John

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) collaboration has made precise measurements of the spectra of cosmic ray antiprotons and light nuclei and conducted a sensitive search for antinuclei. Ten BESS high-latitude flights, eight from Canada and two from Antarctica, span more than a Solar cycle between 1993 and 2007/2008. BESS measurements of low-energy antiprotons constrain candidate models for dark matter including the possible signature of primordial black hole evaporation. The stringent BESS antihelium upper limit helps define the limits of cosmological antimatter. BESS measurements of antiprotons and the elemental and isotopic spectra of H and He provide strong constraints on models of cosmic-ray transport in the Galaxy and Solar System. BESS has also reported the first antideuterium upper limit. BESS employs a superconducting magnetic-rigidity spectrometer with time-of-flight and aerogel Cherenkov detectors to identify incident particles by charge, charge sign, mass, and energy. The BESS-Polar long-duration instrument has a reduced lower energy limit of 100 MeV (top of the atmosphere) to increase its sensitivity to possible primary antiproton sources. BESS-Polar I was flown for 8.5 days from Antarctica in December 2004, recording 900 million events. BESS-Polar II was rebuilt with extended magnet lifetime, improved detector and electronic performance, and greater data storage capacity. It was flown from Antarctica December 2007 - January 2008, recording about 4.6 billion events during 24.5 days at float altitude with the magnet on. During the flight the influence of a high-speed stream in the Solar wind was observed. Details of the BESS-Polar II instrument and flight performance are reported elsewhere at this conference. The successful BESS-Polar II flight at Solar minimum is especially important. Most cosmic-ray antiprotons are secondary products of nuclear interactions of primary cosmic-ray nuclei with the interstellar gas

  16. The Bess Investigation of the Origin of Cosmic-ray Antiprotons and Search for Cosmological Antimatter

    NASA Technical Reports Server (NTRS)

    Mitchell, John; Yamamoto, Akira; Yoshimura, Koji; Makida, Yasuhiro; Matsuda, Shinya; Hasegawa, Masaya; Horikoshi, Atsushi; Tanaka,Ken-ichi; Suzuki, Junichi; Nishimura, Jun; Sakai, Ken-ichi; Shinoda, Ryoko; Orito, Rei; Matsukawa, Yosuke; Kusumoto, Akira; Fuke, Hideyuki; Mitchell, John W.; Streitmatter, Robert E.; Hams, Thomas; Sasaki, Makoto; Seo, Eun-suj; Lee, Moo-hyon; Kim, Ki-chun; Thakur, Neeharika; Ormes, Jonathan F.

    2008-01-01

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) collaboration has made precise measurements of the spectra of cosmic ray antiprotons and light nuclei and conducted a sensitive search for antinuclei. Ten BESS high-latitude flights, eight from Canada and two from Antarctica, span more than a Solar cycle between 1993 and 2007/2008. BESS measurements of low-energy antiprotons constrain candidate models for dark matter including the possible signature of primordial black hole evaporation. The stringent BESS measurements of antiprotons and the elemental and isotopic spectra of H and He provide strong constraints on models of cosmic-ray transport in the Galaxy and Solar System. BESS has also reported the first antideuterium upper limit. BESS employs a superconducting magnetic-rigity spectrometer with time-of-flight and aerogel Cherenkov detectors to identify incident particles by charge, charge sign, mass, and energy. The BESS-Polar long-duration instrument has reduced lower energy limit of 100 MeV (top of the atmosphere) to increase its sensitivity to possible primary antiproton sources. BESS-Polar II was rebuilt with extended magnet lifetime, improved detector and electronic performance, and greater data storage capacity. It was flown fro Antarctica December 2007-January 2008, recording about 4.6 bission events during 24.5 days at float altitude with the magnet on. During the flight the influence of a high-speed stream in the Solar wind was observed. Details of the BESS-Polar II instrument and flight performance are reported elsewhere at this conference. The successful BESS-Polar II flight at Solar minimum is especially important. Most cosmic-ray antiprotons are secondary products of nuclear interactions of primary cosmic-ray nuclei with the interstellar gas, giving a spectrum that peaks at about 2 GeV and falls rapidly to higher and lower energies. However, BESS data taken in the previous Solar minimum show a small excess over secondary

  17. Scintillating screens sensitivity and resolution studies for low energy, low intensity beam diagnostics

    SciTech Connect

    Harasimowicz, Janusz; Welsch, Carsten P.; Cosentino, Luigi; Finocchiaro, Paolo; Pappalardo, Alfio

    2010-10-15

    In order to investigate the limits of scintillating screens for beam profile monitoring in the ultra-low energy, ultra-low intensity regime, CsI:Tl, YAG:Ce, and a Tb glass-based scintillating fiber optic plate (SFOP) were tested. The screens response to 200 and 50 keV proton beams with intensities ranging from a few picoampere down to the subfemtoampere region was examined. In the following paper, the sensitivity and resolution studies are presented in detail for CsI:Tl and the SFOP, the two most sensitive screens. In addition, a possible use of scintillators for ultra-low energy antiproton beam monitoring is discussed.

  18. A program to study antiprotons in the cosmic rays: Arizona collaboration

    NASA Technical Reports Server (NTRS)

    Bowen, Theodore

    1987-01-01

    The Low Energy AntiProton (LEAP) experiment was designed to measure the primary antiproton flux in the 200 MeV to 1 GeV kinetic energy range. A superconducting magnetic spectrometer, a time-of-flight (TOF) detector, and a Cherenkov counter are the main components of LEAP. An additional scintillation detector was designed and constructed to detect the passage of particles through the bottom of the Cherenkov counter. The LEAP package was launched on August 22, 1987, and enjoyed a 27 hour flight, with 23 hours of data at high altitude. Preliminary plans for data analysis include using the Micro-Vax at the University of Arizona for data reduction of the Cherenkov and S2 signals.

  19. a Precision Comparison of the Proton-Antiproton Charge-To Ratio

    NASA Astrophysics Data System (ADS)

    Phillips, David Forrest

    A new comparison of the antiproton-proton charge -to-mass ratios has been completed. The measured ratio of charge-to-mass ratios for the antiproton and proton is 1.000 000 001 5 +/- 0.000 000 001 1. Comparing the cyclotron frequencies of a single p and p in a Penning tray improves upon the accuracy of earlier techniques by a factor of 45,000. This comparison is the most accurate mass spectroscopy of particles of opposite charge in a Penning trap and the most accurate test of the CPT theorem with baryons. Because of the high precision of the measurement, relativistic shifts in the cyclotron frequency provide a clean demonstration of the "relativistic" mass shift for typical cyclotron energies of 10-100 eV.

  20. Exploring the nuclear potential of antihyperons with antiprotons at {overline{P}}{ANDA}

    NASA Astrophysics Data System (ADS)

    Pochodzalla, Josef

    2009-11-01

    A schematic Monte Carlo simulation is used to examine the potential of the {overlineP} ANDA experiment to extract information on the interaction of antihyperons in nuclei by exclusive hyperon-antihyperon pair production close to threshold in antiproton nucleus interactions. Due to energy and momentum conservation event-by-event transverse momentum correlations of the produced hyperon and antihyperons contain information on the difference between their potentials. It is demonstrated that for {{Λ}{overline{Λ}}} and {{{Ξ}}{{overline{Ξ}}}} pairs produced at antiproton momenta of 1.66 GeV/ c and 2.9 GeV/ c, respectively, the asymmetry is sufficiently sensitive even if the density as well as the momentum dependencies of the potentials are considered.

  1. Cosmic-ray antiprotons, positrons, and gamma rays from halo dark matter annihilation

    NASA Technical Reports Server (NTRS)

    Rudaz, S.; Stecker, F. W.

    1988-01-01

    The subject of cosmic ray antiproton production is reexamined by considering other choices for the nature of the Majorana fermion chi other than the photino considered in a previous article. The calculations are extended to include cosmic-ray positrons and cosmic gamma rays as annihilation products. Taking chi to be a generic higgsino or simply a heavy Majorana neutrino with standard couplings to the Z-zero boson allows the previous interpretation of the cosmic antiproton data to be maintained. In this case also, the annihilation cross section can be calculated independently of unknown particle physics parameters. Whereas the relic density of photinos with the choice of parameters in the previous paper turned out to be only a few percent of the closure density, the corresponding value for Omega in the generic higgsino or Majorana case is about 0.2, in excellent agreement with the value associated with galaxies and one which is sufficient to give the halo mass.

  2. An applied light-beam induced current study of dye-sensitised solar cells: Photocurrent uniformity mapping and true photoactive area evaluation

    SciTech Connect

    Jones, Timothy W. Anderson, Kenrick F.; Duck, Benjamin C.; Wilson, Gregory J.; Feron, Krishna

    2014-07-28

    The conditions for light-beam induced current (LBIC) measurement were experimentally optimised for dye-sensitised solar cells. The impacts of too fast a laser diode modulation frequency (f) and too short a dwell time (t{sub 0}) were investigated for their distortions, artefacts, and noise on the overall photocurrent map image. Optimised mapping conditions for fastest measurement were obtained at a f = 15 Hz and t{sub 0} = 900 ms. Whole device maps (nominal area 4 × 4 mm{sup 2}) were obtained on devices in which fabrication defects were intentionally induced. The defects were readily resolved with the LBIC setup and conditions. The inclusion of defects had the effect of broadening the photocurrent distribution and producing a sub-optimal tail to photocurrent histograms. Photoactive areas were derived from LBIC maps and were larger than those predicted by the projected screen printing pattern by up to 25%, which has obvious implications for efficiency measurements made on nominal projected active area.

  3. Multiplicity Distributions from Antiproton-Proton Collisions at 1.8 Tev Center of Mass Energy

    NASA Astrophysics Data System (ADS)

    Wang, Chi-Ho.

    Charged-particle multiplicity distributions from antiproton-proton collisions at 1800 GeV center of mass energy, obtained with the E735 detector multiplicity hodoscope, are presented and discussed. A simple iteration method is used for conversion from number of observed hodoscope hits to true charged-particle multiplicity. The first four moments of the distribution are compared with distributions from lower energies. The distributions are also fit to KNO-G and negative binomial functions.

  4. Proceedings of the Antiproton Technology Workshop Held in Upton, New York on 10 May 1989

    DTIC Science & Technology

    1989-05-01

    Edwards Air Force Base, California 93523-5000 mm~mmmmmmmml mmIl.• ml l iJ m NOTICE When U.S. Government drawings, specifications, or other data are...before at these meetings, ASTER, named after the wildflower . Since I am limited to about ten minutes, I will keep my talk simple. Here is the outline...CALLAS JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY PASADENA, CA PRESENTED AT THE ANTIPROTON TECHNOLOGY WORKSHOP HELD AT BROOKHAVEN

  5. Observed antiprotons and energy dependent confinement of cosmic rays: A conflict?

    NASA Technical Reports Server (NTRS)

    Stephens, S. A.

    1985-01-01

    In the frame work of energy dependent confinement for cosmic rays, the energy spectrum inside the source is flatter than that observed. Antiproton observation suggests large amount of matter is being traversed by cosmic rays in some sources. As a result, secondary particles are produced in abundance. Their spectra was calculated and it is shown that the energy dependent confinement model is in conflict with some observations.

  6. Progress towards antihydrogen production by the reaction of cold antiprotons with positronium atoms

    SciTech Connect

    Charlton, M.; Laricchia, G.; Deutch, B.I.

    1995-03-01

    An experiment aimed at producing antihydrogen atoms by the reaction of cold antiprotons stored in a Penning trap with injected ground state positronium atoms is described. The apparatus developed in an attempt to observe the charge conjugate reaction using proton projectiles is discussed. Technically feasible upgrades to this apparatus are identified which may allow, in conjunction with the PS200 trap, antihydrogen production at LEAR.

  7. BEAMS3D Neutral Beam Injection Model

    SciTech Connect

    Lazerson, Samuel

    2014-04-14

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  8. Analysis of experimental data on interstellar antiprotons in the light of measurements of high-energy electrons and He-3 nuclei

    NASA Technical Reports Server (NTRS)

    Tan, L. C.

    1985-01-01

    The interstellar antiproton calculations were reexamined in view of the recent progress in measurements of interstellar electrons and He(3) nuclei. It was found that the divergence between the predicted antiproton flux and the existing datum at very low energies is increased. The proposed nonuniform galactic disk (NUGD) model qualitatively explains the unexpectedly large flux of interstellar antiprotons. Some ambiguities existed in the prototype of the model. It was unclear what fraction of observed antiprotons is of local origin. Previously the value of cosmic ray escape pathlength was suggested with quite a large arbitrariness.

  9. PAMELA results on the cosmic-ray antiproton flux from 60 MeV to 180 GeV in kinetic energy.

    PubMed

    Adriani, O; Barbarino, G C; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bonechi, L; Bongi, M; Bonvicini, V; Borisov, S; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carbone, R; Carlson, P; Casolino, M; Castellini, G; Consiglio, L; De Pascale, M P; De Santis, C; De Simone, N; Di Felice, V; Galper, A M; Gillard, W; Grishantseva, L; Hofverberg, P; Jerse, G; Karelin, A V; Koldashov, S V; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malvezzi, V; Marcelli, L; Mayorov, A G; Menn, W; Mikhailov, V V; Mocchiutti, E; Monaco, A; Mori, N; Nikonov, N; Osteria, G; Papini, P; Pearce, M; Picozza, P; Pizzolotto, C; Ricci, M; Ricciarini, S B; Rossetto, L; Simon, M; Sparvoli, R; Spillantini, P; Stozhkov, Y I; Vacchi, A; Vannuccini, E; Vasilyev, G; Voronov, S A; Wu, J; Yurkin, Y T; Zampa, G; Zampa, N; Zverev, V G

    2010-09-17

    The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray antiproton flux and the antiproton-to-proton flux ratio which extends previously published measurements down to 60 MeV and up to 180 GeV in kinetic energy. During 850 days of data acquisition approximately 1500 antiprotons were observed. The measurements are consistent with purely secondary production of antiprotons in the Galaxy. More precise secondary production models are required for a complete interpretation of the results.

  10. Galactic antiproton spectrum at high energies: Background expectation versus exotic contributions

    SciTech Connect

    Bringmann, Torsten; Salati, Pierre

    2007-04-15

    A new generation of upcoming space-based experiments will soon start to probe the spectrum of cosmic-ray antiparticles with an unprecedented accuracy and, in particular, will open up a window to energies much higher than those accessible so far. It is thus timely to carefully investigate the expected antiparticle fluxes at high energies. Here, we perform such an analysis for the case of antiprotons. We consider both standard sources as the collision of other cosmic rays with interstellar matter, as well as exotic contributions from dark matter annihilations in the galactic halo. Up to energies well above 100 GeV, we find that the background flux in antiprotons is almost uniquely determined by the existing low-energy data on various cosmic-ray species; for even higher energies, however, the uncertainties in the parameters of the underlying propagation model eventually become significant. We also show that if the dark matter is composed of particles with masses at the TeV scale, which is naturally expected in extra-dimensional models as well as in certain parameter regions of supersymmetric models, the annihilation flux can become comparable to--or even dominate--the antiproton background at the high energies considered here.

  11. Polarized χc2-charmonium production in antiproton-nucleus interactions

    NASA Astrophysics Data System (ADS)

    Larionov, A. B.; Strikman, M.; Bleicher, M.

    2014-01-01

    Starting from the Feynman diagram representation of multiple scattering we consider the polarized χc(1P)-charmonia production in antiproton-nucleus reactions close to the threshold (plab=5-7 GeV/c). The rescattering and absorption of the incoming antiproton and outgoing charmonium on nucleons are taken into account, including the possibility of the elastic and nondiagonal (flavor-conserving) scattering χcJN →χcJ' N, J, J'=0,1,2. The elementary amplitudes of the latter processes are evaluated by expanding the physical χc states in the Clebsch-Gordan series of the cc ¯ states with fixed values of internal orbital angular momentum (Lz) and spin projections on the χc momentum axis. The total interaction cross sections of these cc ¯ states with nucleons have been calculated in previous works using the QCD factorization theorem and the nonrelativistic quarkonium model, and turned out to be strongly Lz dependent due to the transverse size difference. This directly leads to finite values of the χc-nucleon nondiagonal scattering amplitudes. We show that the χc0N →χc2N transitions significantly influence the χc2 production with helicity zero at small transverse momenta. This can serve as a signal in future experimental tests of the quark structure of χc states by the PANDA Collaboration at the Facility for Antiproton and Ion Research (FAIR).

  12. Bayesian analysis of spatial-dependent cosmic-ray propagation: Astrophysical background of antiprotons and positrons

    NASA Astrophysics Data System (ADS)

    Feng, Jie; Tomassetti, Nicola; Oliva, Alberto

    2016-12-01

    The AMS-02 experiment has reported a new measurement of the antiproton/proton ratio in Galactic cosmic rays (CRs). In the energy range E ˜60 - 450 GeV , this ratio is found to be remarkably constant. Using recent data on CR proton, helium, and carbon fluxes, 10Be/9Be and B/C ratios, we have performed a global Bayesian analysis based on a Markov chain Monte Carlo sampling algorithm under a "two halo model" of CR propagation. In this model, CRs are allowed to experience a different type of diffusion when they propagate in the region close to the Galactic disk. We found that the vertical extent of this region is about 900 pc above and below the disk, and the corresponding diffusion coefficient scales with energy as D ∝E0.15 , describing well the observations on primary CR spectra, secondary/primary ratios, and anisotropy. Under this model, we have carried out improved calculations of antiparticle spectra arising from secondary CR production and their corresponding uncertainties. We made use of Monte Carlo generators and accelerator data to assess the antiproton production cross sections and their uncertainties. While the positron excess requires the contribution of additional unknown sources, we found that the new AMS-02 antiproton data are consistent, within the estimated uncertainties, with our calculations based on secondary production.

  13. Uniform longitudinal beam profiles in the Fermilab Recycler using adaptive rf correction

    SciTech Connect

    Hu, Martin; Broemmelsiek, Daniel Robert; Chase, Brian; Crisp, James L.; Eddy, Nathan; Joireman, Paul W.; Ng, King Yuen; /Fermilab

    2007-06-01

    The Fermilab Recycler Ring is a permanent magnet based 8 GeV anti-proton storage ring. A wideband RF system, driven with ARB's (ARBitrary waveform generators), allows the system to produce programmable barrier waveforms. Beam current profile distortion was observed, its origin verified both experimentally and theoretically, and an FPGA-based correction system was designed, tested and implemented to level the bunch profile.

  14. Transition Radiation Detector in the D0 colliding beam experiment at Fermilab

    SciTech Connect

    Piekarz, H.

    1995-04-01

    The construction, operation and response of the Transition Radiation Detector (TRD) at DO colliding beam experiment at Fermilab are presented. The use of the TRD signal to enhance electron identification and hadronic rejection in the multiparticle background characteristic for the antiproton-proton interactions at the center-of-mass energy of 1.8 TeV is also described and results are discussed.

  15. Subjet multiplicity of quark and gluon jets reconstructed with the relative transverse momenta algorithm in proton- antiproton collisions

    NASA Astrophysics Data System (ADS)

    Snihur, Robert Michael

    2000-12-01

    This thesis presents some of the first experimental results of the k⊥ jet algorithm at a hadron collider. Gluon jets dominate the final state of proton-antiproton (pp¯) collisions at high center-of- mass energies ( s = 1800 GeV). Quark jets make up a significant fraction of the jet cross section only at high jet transverse momentum pT or low s . For fixed pT, we compare jets at s = 1800 GeV to s = 630 GeV, and interpret differences in terms of differing contributions from gluon and quark jets. We define jets with a successive combination algorithm based on relative transverse momenta ( k⊥ ). To study jet structure, the k⊥ algorithm is then applied within the jet to resolve subjets. We measure the number of subjets within mixed quark and gluon jet samples at s = 1800 and 630 GeV. A simple method is used to extract measurements of pure quark and gluon jet samples separately. The method requires knowledge of the relative mix of quarks and gluons in the two s samples, which we derive from Monte Carlo and a detailed detector simulation. The number of subjets emitted in gluon jets is measured to be approximately twice that in quark jets.

  16. Shielding experiments by the JASMIN Collaboration at Fermilab (II) - radioactivity measurement induced by secondary particles from the anti-proton production target

    SciTech Connect

    Hiroshi, Yashima; Norihiro, Matsuda; Yoshimi, Kasugai; Hiroshi, Nakashima; Yukio, Sakamoto; Hiroshi, Matsumura; Hiroshi, Iwase; Norikazu, Kinoshita; David, Boehnlein; Gary, Lautenschlager; Anthony, Leveling; Nikolai, Mokhov; Kamran, Vaziri; Koji, Oishi

    2011-08-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting of an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 1012 protons per second. The samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured by studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.

  17. Shielding experiments by the JASMIN collaboration at Fermilab (II) - Radioactivity measurement induced by secondary particles from the anti-proton production target

    SciTech Connect

    Yashima, Hiroshi; Matsuda, Norihiro; Kasugai, Yoshimi; Matsumura, Hiroshi; Iwase, Hiroshi; Kinoshita, Norikazu; Boehnlein, David; Lauten, Gary; Leveling, Anthony; Mokhov, Nikolai; Vaziri, Kamran; /Fermilab /Shimizu, Tokyo /JAEA, Ibaraki

    2011-01-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 10{sub 12} protons per second. Samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured by studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.

  18. Shielding experiments by the JASMIN Collaboration at Fermilab (II) - radioactivity measurement induced by secondary particles from the anti-proton production target

    DOE PAGES

    Hiroshi, Yashima; Norihiro, Matsuda; Yoshimi, Kasugai; ...

    2011-08-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting of an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 1012 protons per second. The samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured bymore » studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.« less

  19. Measurement of the Galactic Cosmic Ray Antiproton Flux from 0.25 GEV to 3.11 GEV with the Isotope Matter Antimatter Experiment (IMAX)

    NASA Astrophysics Data System (ADS)

    Labrador, Allan Wayne

    1997-07-01

    The galactic cosmic ray proton and antiproton abundances were measured with the Isotope Matter Antimatter Experiment (IMAX), a balloon-borne magnet spectrometer. IMAX flew from Lynn Lake, Manitoba, Canada on July 16, 1992. Particles detected by IMAX were identified via the Cherenkov-Rigidity and TOF-Rigidity techniques, with measured mass resolution <=0.2 amu for Z = 1 particles. Previous cosmic ray antiproton experiments reported more antiprotons than expected from high energy cosmic ray interactions with the interstellar medium. IMAX data analysis yielded 124405 protons and 3 antiprotons in the energy range 0.19-0.97 GeV at the instrument, 140617 protons and 8 antiprotons at 0.97-2.58 GeV, and 22524 protons and 5 antiprotons at 2.58-3.08 GeV. These measurements are a statistical improvement over previous measurements, and they demonstrate improved separation of antiprotons from protons, electrons, and other cosmic ray species. When corrected for instrumental and atmospheric background and losses, the ratios at the top of the atmosphere are p/p = 3.21 (+3.49, -1.97)× 10-5 in the energy range 0.25-1.00 GeV, p/p = 5.38 (+3.48, -2.45)× 10-5 at 1.00-2.61 GeV, and p/p = 2.05 (+1.79, -1.15)× 10-4 at 2.61-3.11 GeV. The corresponding antiproton intensities are 2.3 (+2.5, -1.4)× 10-2 (m2 s sr GeV)-1, 2.1 (+1.4, -1.0)× 10-2 (m2 s sr GeV)-1, and 4.3 (+3.7, -2.4)× 10-2 (m2 s sr GeV)-1. The IMAX antiproton fluxes and antiproton/proton ratios are compared with recent Standard Leaky Box Model (SLBM) calculations, in which cosmic ray antiprotons arise solely from high energy cosmic ray interactions with the interstellar medium. Solar modulation effects are also calculated, showing that the antiproton/proton ratio can vary by an order of magnitude over the solar cycle. The IMAX antiproton measurements are consistent with recent calculations of the SLBM and solar modulation. No evidence is found in the IMAX data for excess antiprotons arising from exotic sources. Furthermore

  20. Effect of secondary ions on the electron beam optics in the Recycler Electron Cooler

    SciTech Connect

    Shemyakin, A.; Prost, L.; Saewert, G.; /Fermilab

    2010-05-01

    Antiprotons in Fermilab's Recycler ring are cooled by a 4.3 MeV, 0.1-0.5 A DC electron beam (as well as by a stochastic cooling system). The unique combination of the relativistic energy ({gamma} = 9.49), an Ampere-range DC beam, and a relatively weak focusing makes the cooling efficiency particularly sensitive to ion neutralization. A capability to clear ions was recently implemented by way of interrupting the electron beam for 1-30 {micro}s with a repetition rate of up to 40 Hz. The cooling properties of the electron beam were analyzed with drag rate measurements and showed that accumulated ions significantly affect the beam optics. For a beam current of 0.3 A, the longitudinal cooling rate was increased by factor of {approx}2 when ions were removed.

  1. Signal processing for longitudinal parameters of the Tevatron beam

    SciTech Connect

    Pordes, S.; Crisp, J.; Fellenz, B.; Flora, R.; Para, A.; Tollestrup, A.V.; /Fermilab

    2005-05-01

    We describe the system known as the Tevatron SBD [1] which is used to provide information on the longitudinal parameters of coalesced beam bunches in the Tevatron. The system has been upgraded over the past year with a new digitizer and improved software. The quantities provided for each proton and antiproton bunch include the intensity, the longitudinal bunch profile, the timing of the bunch with respect to the low-level RF, the momentum spread and the longitudinal emittance. The system is capable of 2 Hz operation and is run at 1 Hz.

  2. Error-induced beam degradation in Fermilab's accelerators

    NASA Astrophysics Data System (ADS)

    Yong, Sung-Yong Phil

    In Part I, three independent models of Fermilab's Booster synchrotron are presented. All three models are constructed to investigate and to explore the effects of unavoidable machine errors on a proton beam under the influence of space-charge effects. The first is a stochastic noise model. Electric current fluctuations arising from power supplies are ubiquitous and unavoidable and are a source of instabilities in accelerators of all types. A new noise module for generating the Ornstein-Uhlenbeck (O-U) stochastic noise is first created and incorporated into the existing Object-oriented Ring Beam Injection and Tracking (ORBIT-FNAL) package. After being convinced that the noise does matter to a beam with a preliminary model, we proceed to measure directly current ripples and common-mode voltages from all four Gradient Magnet Power Supplies (GMPS). Then, the current signals are Fourier-analyzed. Based upon the power spectra of current signals, we tune up the Ornstein-Uhlnbeck noise model. As a result, we are able to closely match the frequency spectra between current measurements and the modeled O-U stochastic noise. The stochastic noise modeled upon measurements is applied to the Booster beam in the presence of the full space-charge effects. This noise model, accompanied by a suite of beam diagnostic calculations, manifests that the stochastic noise, impinging upon the beam and coupled to the space-charge effects, can substantially enhance the beam degradation process throughout the injection period. The second model is a magnet misalignment model. It is the first time to utilize the latest beamline survey data for building a magnet-by-magnet misalignment model. Given as-found survey fiducial coordinates, we calculate all types of magnet alignment errors (station error, pitch, yaw, roll, twists, etc.) are implemented in the model. We then follow up with statistical analysis to understand how each type of alignment errors are currently distributed around the Booster

  3. Error-Induced Beam Degradation in Fermilab's Accelerators

    SciTech Connect

    Yoon, Sung-Young Phil

    2008-01-01

    In Part I, three independent models of Fermilab's Booster synchrotron are presented. All three models are constructed to investigate and explore the effects of unavoidable machine errors on a proton beam under the influence of space-charge effects. The first is a stochastic noise model. Electric current fluctuations arising from power supplies are ubiquitous and unavoidable and are a source of instabilities in accelerators of all types. A new noise module for generating the Ornstein-Uhlenbeck (O-U) stochastic noise is first created and incorporated into the existing Object-oriented Ring Beam Injection and Tracking (ORBIT-FNAL) package. After being convinced with a preliminary model that the noise, particularly non-white noise, does matter to beam quality, we proceeded to measure directly current ripples and common-mode voltages from all four Gradient Magnet Power Supplies (GMPS). Then, the current signals are Fourier-analyzed. Based upon the power spectra of current signals, we tune up the Ornstein-Uhlnbeck noise model. As a result, we are able to closely match the frequency spectra between current measurements and the modeled O-U stochastic noise. The stochastic noise modeled upon measurements is applied to the Booster beam in the presence of the full space-charge effects. This noise model, accompanied by a suite of beam diagnostic calculations, manifests that the stochastic noise, impinging upon the beam and coupled to the space-charge effects, can substantially enhance the beam degradation process throughout the injection period. The second model is a magnet misalignment model. It is the first time to utilize the latest beamline survey data for building a magnet-by-magnet misalignment model. Given as-found survey fiducial coordinates, we calculate all types of magnet alignment errors (station error, pitch, yaw, roll, twists, etc.) are implemented in the model. We then follow up with statistical analysis to understand how each type of alignment errors are

  4. High-precision comparison of the antiproton-to-proton charge-to-mass ratio.

    PubMed

    Ulmer, S; Smorra, C; Mooser, A; Franke, K; Nagahama, H; Schneider, G; Higuchi, T; Van Gorp, S; Blaum, K; Matsuda, Y; Quint, W; Walz, J; Yamazaki, Y

    2015-08-13

    Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H(-)) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q/m)p- to that for the proton (q/m)p and obtain (q/m)p-/(q/m)p − 1 =1(69) × 10(-12). The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of <720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of |α − 1| < 8.7 × 10(-7).

  5. High-precision comparison of the antiproton-to-proton charge-to-mass ratio

    NASA Astrophysics Data System (ADS)

    Ulmer, S.; Smorra, C.; Mooser, A.; Franke, K.; Nagahama, H.; Schneider, G.; Higuchi, T.; van Gorp, S.; Blaum, K.; Matsuda, Y.; Quint, W.; Walz, J.; Yamazaki, Y.

    2015-08-01

    Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H-) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton to that for the proton and obtain . The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of <720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of < 8.7 × 10-7.

  6. What does the PAMELA antiproton spectrum tell us about dark matter?

    SciTech Connect

    Hooper, Dan; Linden, Tim; Mertsch, Philipp E-mail: trlinden@uchicago.edu

    2015-03-01

    Measurements of the cosmic ray antiproton spectrum can be used to search for contributions from annihilating dark matter and to constrain the dark matter annihilation cross section. Depending on the assumptions made regarding cosmic ray propagation in the Galaxy, such constraints can be quite stringent. We revisit this topic, utilizing a set of propagation models fit to the cosmic ray boron, carbon, oxygen and beryllium data. We derive upper limits on the dark matter annihilation cross section and find that when the cosmic ray propagation parameters are treated as nuisance parameters (as we argue is appropriate), the resulting limits are significantly less stringent than have been previously reported. We also note (as have several previous groups) that simple GALPROP-like diffusion-reacceleration models predict a spectrum of cosmic ray antiprotons that is in good agreement with PAMELA's observations above ∼ 5 GeV, but that significantly underpredict the flux at lower energies. Although the complexity of modeling cosmic ray propagation at GeV-scale energies makes it difficult to determine the origin of this discrepancy, we consider the possibility that the excess antiprotons are the result of annihilating dark matter. Suggestively, we find that this excess is best fit for m{sub DM} ∼ 35 GeV and σ v ∼ 10{sup −26} cm{sup 3}/s (to b b-bar ), in good agreement with the mass and cross section previously shown to be required to generate the gamma-ray excess observed from the Galactic Center.

  7. The BESS Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter

    NASA Technical Reports Server (NTRS)

    Mitchell, John; Yamamoto, Akira

    2009-01-01

    The apex of the Balloon-borne Experiment with a Superconducting Spectrometer (BESS) program was reached with the Antarctic flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The US-Japan BESS Collaboration uses elementary particle measurements to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic sources, such as dark-matter candidates, and searches for heavier antinuclei that might reach Earth from antimatter domains formed during symmetry breaking processes in the early Universe. Since 1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of antideuterons and antihelium. The BESS-Polar II flight took place at Solar Minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The rich BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights and has 10-20 times the statistics of BESS data from the previous Solar Minimum. Here, we summarize the scientific results of BESS program, focusing on the results obtained using data from the long-duration flights of BESS-Polar I (2004) and BESS-Polar II.

  8. What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?

    SciTech Connect

    Hooper, Dan; Linden, Tim; Mertsch, Philipp

    2015-03-11

    Measurements of the cosmic ray antiproton spectrum can be used to search for contributions from annihilating dark matter and to constrain the dark matter annihilation cross section. Depending on the assumptions made regarding cosmic ray propagation in the Galaxy, such constraints can be quite stringent. We revisit this topic, utilizing a set of propagation models fit to the cosmic ray boron, carbon, oxygen and beryllium data. We derive upper limits on the dark matter annihilation cross section and find that when the cosmic ray propagation parameters are treated as nuisance parameters (as we argue is appropriate), the resulting limits are significantly less stringent than have been previously reported. We also note (as have several previous groups) that simple GALPROP-like diffusion-reacceleration models predict a spectrum of cosmic ray antiprotons that is in good agreement with PAMELA's observations above ~ 5 GeV, but that significantly underpredict the flux at lower energies. Although the complexity of modeling cosmic ray propagation at GeV-scale energies makes it difficult to determine the origin of this discrepancy, we consider the possibility that the excess antiprotons are the result of annihilating dark matter. Suggestively, we find that this excess is best fit for mDM ~ 35 GeV and σ v ~ 10$-$26 cm3/s (to $b\\bar{_b}$), in good agreement with the mass and cross section previously shown to be required to generate the gamma-ray excess observed from the Galactic Center.

  9. Search for Cosmic-ray Antiproton Origins and for Cosmological Antimatter with BESS

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akira; Abe, . W. Mitchellz K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Lee, M. H.; Makida, Y.; Matsuda, S.; Matsukawa, Y.; Matsumoto, K.; Moiseev, A. A.; Myers, Z.; Nishimura, J.; Nozaki, M.; Orito, R.; Ormes, J. F.; Sakai, K.; Sasaki, M.; Seo, E. S.; Shikaze, Y.; Shinoda, R.; Streitmatter, R. E.; Suzuki, J.; Takasugi, Y.; Takeuchi, K.; Tanaka, K.; Thakur, N.; Yamagami, T.; Yoshida, T.; Yoshimura, K.

    The BESS Collaboration performs elementary particle measurements in cosmic rays to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS has advanced measurement of the cosmic-ray antiproton spectra to inves-tigate signatures of possible exotic sources, such as evaporation of primordial black holes and dark-matter candidates, and searches for heavier antinuclei that might reach Earth from anti-matter domains formed during symmetry breaking processes in the early Universe. Since1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of antideuterons and antihelium. The apex of the Balloon-borne Experiment with a Superconducting Spectrom-eter (BESS) program was reached with the Antarctic balloon flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The BESS-Polar II flight took place at the expected `solar minimum', when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights, and has 10-20 times the statistics of BESS data from the previous Solar minimum in 1995-1997. Here, we summarize the scientific results of BESS program, focusing on the results obtained from the long-duration flights of BESS.

  10. Anti-proton annihilation in nuclei as a probe of QCD

    SciTech Connect

    Brodsky, S.J.

    1990-09-01

    Anti-proton annihilation in a nuclear target can test many novel aspects of quantum chromodynamics. In this talk I discuss a number of interesting features of such processes, including the formation of nuclear-bound quarkonium, tests of color transparency in hard, quasi-elastic nuclear reactions, higher-twist, coherent, and formation zone effects in hard inclusive nuclear reactions, reduced amplitude predictions for exclusive nuclear amplitudes, and color filter effects inclusive open and hidden charm production in nuclei. 43 refs., 6 figs., 2 tabs.

  11. Curve Generation for the RF Systems of the Antiproton Source Console Program Specification and Implementation

    SciTech Connect

    MacLachlan, J.A.

    1984-11-01

    The RF curves program is a PDP-11 console application to calculate the time dependence of amplitude, frequency, and phase for the RF systems of the Antiproton Source. The results of the calculation are formatted and scaled for the curve generator hardware. The user interface of the program is highly flexible with respect to the choice of parameters used to specify the desired curve. It consists of file management, plotting, editing, and hardware loading phases which are implemented as separate pages on the console display. This document provides the functional specification of the program and a discussion of the status of its implementation.

  12. AMS-02 antiprotons, at last! Secondary astrophysical component and immediate implications for Dark Matter

    NASA Astrophysics Data System (ADS)

    Giesen, Gaëlle; Boudaud, Mathieu; Génolini, Yoann; Poulin, Vivian; Cirelli, Marco; Salati, Pierre; Serpico, Pasquale D.

    2015-09-01

    Using the updated proton and helium fluxes just released by the AMS-02 experiment we reevaluate the secondary astrophysical antiproton to proton ratio and its uncertainties, and compare it with the ratio preliminarly reported by AMS-02. We find no unambiguous evidence for a significant excess with respect to expectations. Yet, some preference for a flatter energy dependence of the diffusion coefficient (with respect to the MED benchmark often used in the literature) starts to emerge. Also, we provide a first assessment of the room left for exotic components such as Galactic Dark Matter annihilation or decay, deriving new stringent constraints.

  13. Beam Purification by Photodetachment

    SciTech Connect

    Liu, Yuan; Beene, James R; Havener, Charles C; Galindo-Uribarri, Alfredo {nmn}; Andersson, P.; Lindahl, A. O.; Hanstorp, D.; Forstner, Dr. Oliver; Gottwald, T.; Wendt, K.

    2012-01-01

    Ion beam purity is of crucial importance to many basic and applied studies. Selective photodetachment has been proposed to suppress unwanted species in negative ion beams while preserving the intensity of the species of interest. A highly efficient technique based on photodetachment in a gas-filled radio frequency quadrupole ion cooler has been demonstrated. In off-line experiments with stable ions, up to 104 times suppression of the isobar contaminants in a number of interesting radioactive negative ion beams has been demonstrated. For selected species, this technique promises experimental possibilities in studies on exotic nuclei, accelerator mass spectrometry, and fundamental properties of negative atomic and molecular ions.

  14. Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter with BESS

    NASA Technical Reports Server (NTRS)

    Yamamoto, A.; Mitchell, J. W.; Yoshimura, K.; Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.; Lee, M. H.; Makida, M.; Matsuda, S.; Matsukawa, Y.; Matsumoto, K.; Moiseev, A. A.; Myers, Z.; Nishimura, J.; Nozaki, M.; Orito, R.; Sasaki, M.; Streitmatter, R. E.

    2011-01-01

    The balloon-borne experiment with a superconducting spectrometer (BESS) has performed cosmic-ray observations as a US-Japan cooperative space science program, and has provided fundamental data on cosmic rays to study elementary particle phenomena in the early Universe. The BESS experiment has measured the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic origins such as dark matter candidates or primordial black holes. and searched for heavier antinuclei that might reach Earth from antimatter domains formed in the early Universe. The apex of the BESS program was reached with the Antarctic flight of BESS-Polar II, during the 2007- 2008 Austral Summer, that obtained over 4.7 billion cosmic-ray events from 24.5 days of observation. The flight took place at the expected solar minimum, when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. Here, we report the scientific restults, focusing on the long-duration flights of BESS-Polar I (2004) and BESS-Polar II (2007-2008).

  15. Ion Storage with the High Performance Antiproton Trap (HiPAT)

    NASA Technical Reports Server (NTRS)

    Martin, James; Lewis, Raymond; Chakrabarti, Suman; Pearson, Boise

    2002-01-01

    The matter antimatter reaction represents the densest form of energy storage/release known to modern physics: as such it offers one of the most compact sources of power for future deep space exploration. To take the first steps along this path, NASA-Marshall Space Flight Center is developing a storage system referred to as the High Performance Antiproton Trap (HiPAT) with a goal of maintaining 10(exp 12) particles for up to 18 days. Experiments have been performed with this hardware using normal matter (positive hydrogen ions) to assess the device's ability to hold charged particles. These ions are currently created using an electron gun method to ionize background gas; however, this technique is limited by the quantity that can be captured. To circumvent this issue, an ion source is currently being commissioned which will greatly increase the number of ions captured and more closely simulate actual operations expected at an antiproton production facility. Ions have been produced, stored for various time intervals, and then extracted against detectors to measure species, quantity and energy. Radio frequency stabilization has been tested as a method to prolong ion lifetime: results show an increase in the baseline 1/e lifetime of trapped particles from hours to days. Impurities in the residual background gas (typically carbon-containing species CH4, CO, CO2, etc.) present a continuing problem by reducing the trapped hydrogen population through the mechanism of ion charge exchange.

  16. Ion Beam Propulsion Study

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Ion Beam Propulsion Study was a joint high-level study between the Applied Physics Laboratory operated by NASA and ASRC Aerospace at Kennedy Space Center, Florida, and Berkeley Scientific, Berkeley, California. The results were promising and suggested that work should continue if future funding becomes available. The application of ion thrusters for spacecraft propulsion is limited to quite modest ion sources with similarly modest ion beam parameters because of the mass penalty associated with the ion source and its power supply system. Also, the ion source technology has not been able to provide very high-power ion beams. Small ion beam propulsion systems were used with considerable success. Ion propulsion systems brought into practice use an onboard ion source to form an energetic ion beam, typically Xe+ ions, as the propellant. Such systems were used for steering and correction of telecommunication satellites and as the main thruster for the Deep Space 1 demonstration mission. In recent years, "giant" ion sources were developed for the controlled-fusion research effort worldwide, with beam parameters many orders of magnitude greater than the tiny ones of conventional space thruster application. The advent of such huge ion beam sources and the need for advanced propulsion systems for exploration of the solar system suggest a fresh look at ion beam propulsion, now with the giant fusion sources in mind.

  17. Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    NASA Astrophysics Data System (ADS)

    Aguilar, M.; Ali Cavasonza, L.; Alpat, B.; Ambrosi, G.; Arruda, L.; Attig, N.; Aupetit, S.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Başeǧmez-du Pree, S.; Battarbee, M.; Battiston, R.; Bazo, J.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bindi, V.; Boella, G.; de Boer, W.; Bollweg, K.; Bonnivard, V.; Borgia, B.; Boschini, M. J.; Bourquin, M.; Bueno, E. F.; Burger, J.; Cadoux, F.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Castellini, G.; Cernuda, I.; Cervelli, F.; Chae, M. J.; Chang, Y. H.; Chen, A. I.; Chen, G. M.; Chen, H. S.; Cheng, L.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Coste, B.; Creus, W.; Crispoltoni, M.; Cui, Z.; Dai, Y. M.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Dong, F.; Donnini, F.; Duranti, M.; D'Urso, D.; Egorov, A.; Eline, A.; Eronen, T.; Feng, J.; Fiandrini, E.; Finch, E.; Fisher, P.; Formato, V.; Galaktionov, Y.; Gallucci, G.; García, B.; García-López, R. J.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; Giovacchini, F.; Goglov, P.; Gómez-Coral, D. M.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guerri, I.; Guo, K. H.; Habiby, M.; Haino, S.; Han, K. C.; He, Z. H.; Heil, M.; Hoffman, J.; Hsieh, T. H.; Huang, H.; Huang, Z. C.; Huh, C.; Incagli, M.; Ionica, M.; Jang, W. Y.; Jinchi, H.; Kang, S. C.; Kanishev, K.; Kim, G. N.; Kim, K. S.; Kirn, Th.; Konak, C.; Kounina, O.; Kounine, A.; Koutsenko, V.; Krafczyk, M. S.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. S.; Li, J. Q.; Li, J. Q.; Li, Q.; Li, T. X.; Li, W.; Li, Z. H.; Li, Z. Y.; Lim, S.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, Hu; Lu, S. Q.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lv, S. S.; Majka, R.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mo, D. C.; Morescalchi, L.; Mott, P.; Nelson, T.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Nunes, P.; Oliva, A.; Orcinha, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Pauluzzi, M.; Pensotti, S.; Pereira, R.; Picot-Clemente, N.; Pilo, F.; Pizzolotto, C.; Plyaskin, V.; Pohl, M.; Poireau, V.; Putze, A.; Quadrani, L.; Qi, X. M.; Qin, X.; Qu, Z. Y.; Räihä, T.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rodríguez, I.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Sandweiss, J.; Saouter, P.; Schael, S.; Schmidt, S. M.; Schulz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Siedenburg, T.; Son, D.; Song, J. W.; Sun, W. H.; Tacconi, M.; Tang, X. W.; Tang, Z. C.; Tao, L.; Tescaro, D.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Türkoǧlu, C.; Urban, T.; Vagelli, V.; Valente, E.; Vannini, C.; Valtonen, E.; Vázquez Acosta, M.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Vitale, V.; Vitillo, S.; Wang, L. Q.; Wang, N. H.; Wang, Q. L.; Wang, X.; Wang, X. Q.; Wang, Z. X.; Wei, C. C.; Weng, Z. L.; Whitman, K.; Wienkenhöver, J.; Willenbrock, M.; Wu, H.; Wu, X.; Xia, X.; Xiong, R. Q.; Xu, W.; Yan, Q.; Yang, J.; Yang, M.; Yang, Y.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zeissler, S.; Zhang, C.; Zhang, J.; Zhang, J. H.; Zhang, S. D.; Zhang, S. W.; Zhang, Z.; Zheng, Z. M.; Zhu, Z. Q.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.; AMS Collaboration

    2016-08-01

    A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 ×1 05 antiproton events and 2.42 ×1 09 proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ˜60 to ˜500 GV , the antiproton p ¯, proton p , and positron e+ fluxes are found to have nearly identical rigidity dependence and the electron e- flux exhibits a different rigidity dependence. Below 60 GV, the (p ¯/p ), (p ¯/e+), and (p /e+) flux ratios each reaches a maximum. From ˜60 to ˜500 GV , the (p ¯/p ), (p ¯/e+), and (p /e+) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

  18. Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station.

    PubMed

    Aguilar, M; Ali Cavasonza, L; Alpat, B; Ambrosi, G; Arruda, L; Attig, N; Aupetit, S; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Başeǧmez-du Pree, S; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bindi, V; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Boschini, M J; Bourquin, M; Bueno, E F; Burger, J; Cadoux, F; Cai, X D; Capell, M; Caroff, S; Casaus, J; Castellini, G; Cernuda, I; Cervelli, F; Chae, M J; Chang, Y H; Chen, A I; Chen, G M; Chen, H S; Cheng, L; Chou, H Y; Choumilov, E; Choutko, V; Chung, C H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Creus, W; Crispoltoni, M; Cui, Z; Dai, Y M; Delgado, C; Della Torre, S; Demirköz, M B; Derome, L; Di Falco, S; Dimiccoli, F; Díaz, C; von Doetinchem, P; Dong, F; Donnini, F; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eronen, T; Feng, J; Fiandrini, E; Finch, E; Fisher, P; Formato, V; Galaktionov, Y; Gallucci, G; García, B; García-López, R J; Gargiulo, C; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Giovacchini, F; Goglov, P; Gómez-Coral, D M; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guerri, I; Guo, K H; Habiby, M; Haino, S; Han, K C; He, Z H; Heil, M; Hoffman, J; Hsieh, T H; Huang, H; Huang, Z C; Huh, C; Incagli, M; Ionica, M; Jang, W Y; Jinchi, H; Kang, S C; Kanishev, K; Kim, G N; Kim, K S; Kirn, Th; Konak, C; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H T; Lee, S C; Leluc, C; Li, H S; Li, J Q; Li, J Q; Li, Q; Li, T X; Li, W; Li, Z H; Li, Z Y; Lim, S; Lin, C H; Lipari, P; Lippert, T; Liu, D; Liu, Hu; Lu, S Q; Lu, Y S; Luebelsmeyer, K; Luo, F; Luo, J Z; Lv, S S; Majka, R; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D C; Morescalchi, L; Mott, P; Nelson, T; Ni, J Q; Nikonov, N; Nozzoli, F; Nunes, P; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Pauluzzi, M; Pensotti, S; Pereira, R; Picot-Clemente, N; Pilo, F; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Putze, A; Quadrani, L; Qi, X M; Qin, X; Qu, Z Y; Räihä, T; Rancoita, P G; Rapin, D; Ricol, J S; Rodríguez, I; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Sandweiss, J; Saouter, P; Schael, S; Schmidt, S M; Schulz von Dratzig, A; Schwering, G; Seo, E S; Shan, B S; Shi, J Y; Siedenburg, T; Son, D; Song, J W; Sun, W H; Tacconi, M; Tang, X W; Tang, Z C; Tao, L; Tescaro, D; Ting, Samuel C C; Ting, S M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vázquez Acosta, M; Vecchi, M; Velasco, M; Vialle, J P; Vitale, V; Vitillo, S; Wang, L Q; Wang, N H; Wang, Q L; Wang, X; Wang, X Q; Wang, Z X; Wei, C C; Weng, Z L; Whitman, K; Wienkenhöver, J; Willenbrock, M; Wu, H; Wu, X; Xia, X; Xiong, R Q; Xu, W; Yan, Q; Yang, J; Yang, M; Yang, Y; Yi, H; Yu, Y J; Yu, Z Q; Zeissler, S; Zhang, C; Zhang, J; Zhang, J H; Zhang, S D; Zhang, S W; Zhang, Z; Zheng, Z M; Zhu, Z Q; Zhuang, H L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P

    2016-08-26

    A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500  GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500  GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

  19. Measurement of Event Shapes in Proton-Antiproton Collisions at Center-of-Mass Energy 1.96 TeV

    SciTech Connect

    Aaltonen, T.; Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; /Purdue U. /Waseda U. /Dubna, JINR

    2011-03-01

    A study of event shape observables in proton-antiproton collisions at {radical}s = 1.96 TeV is presented. The data for this analysis were recorded by the CDF II detector at the Tevatron collider. The variables studied are the transverse thrust and thrust minor, both defined in the plane perpendicular to the beam direction. The observables are measured using energies from unclustered calorimeter cells. In addition to studies of the differential distributions, we present the dependence of event shape mean values on the leading jet transverse energy. Data are compared with pythia Tune A and to resummed parton level predictions that were matched to fixed order results at NLO accuracy (NLO+NLL). Predictions from pythia Tune A agree fairly well with the data. However, the underlying event contributes significantly to these observables, making it difficult to make direct comparisons to the NLO+NLL predictions, which do not account for the underlying event. To overcome this difficulty, we introduce a new observable, a weighted difference of the mean values of the thrust and thrust minor, which is less sensitive to the underlying event, allowing for a comparison with NLO+NLL. Both pythia Tune A and the NLO+NLL calculations agree well within the 20% theoretical uncertainty with the data for this observable, indicating that perturbative QCD successfully describes shapes of the hadronic final states.

  20. Simulation study of elliptic flow of charged hadrons produced in Au + Au collisions at energies available at the Facility for Antiproton and Ion Research

    NASA Astrophysics Data System (ADS)

    Sarkar, S.; Mali, P.; Mukhopadhyay, A.

    2017-01-01

    Centrality and system geometry dependence of azimuthal anisotropy of charged hadrons measured in terms of the elliptic flow parameter are investigated using Au+Au event samples at incident beam energy 20 A and 40 A GeV generated by ultrarelativistic quantum molecular dynamics (UrQMD) and a multiphase transport (AMPT) models. The Monte Carlo-Glauber model is employed to estimate the eccentricity of the overlapping zone at an early stage of the collisions. Anisotropies present both in the particle multiplicity distribution and in the kinetic radial expansion are examined by using standard statistical and phenomenological methods. In the context of the upcoming Compressed Baryonic Matter experiment to be held at the Facility for Antiproton and Ion Research (FAIR), the present set of simulated results provide us not only with an opportunity to examine the expected collective behavior of hadronic matter at high baryon density and moderate temperature, but when compared with similar results obtained from Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) experiments, they also allow us to investigate how anisotropy of hadronic matter may differ or agree with its low-baryon-density and high-temperature counterpart.

  1. Neutral particle beam intensity controller

    DOEpatents

    Dagenhart, William K.

    1986-01-01

    A neutral beam intensity controller is provided for a neutral beam generator in which a neutral beam is established by accelerating ions from an ion source into a gas neutralizer. An amplitude modulated, rotating magnetic field is applied to the accelerated ion beam in the gas neutralizer to defocus the resultant neutral beam in a controlled manner to achieve intensity control of the neutral beam along the beam axis at constant beam energy. The rotating magnetic field alters the orbits of ions in the gas neutralizer before they are neutralized, thereby controlling the fraction of neutral particles transmitted out of the neutralizer along the central beam axis to a fusion device or the like. The altered path or defocused neutral particles are sprayed onto an actively cooled beam dump disposed perpendicular to the neutral beam axis and having a central open for passage of the focused beam at the central axis of the beamline. Virtually zero therough 100% intensity control is achieved by varying the magnetic field strength without altering the ion source beam intensity or its species yield.

  2. Refractive beam shapers for focused laser beams

    NASA Astrophysics Data System (ADS)

    Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

    2016-09-01

    Focusing of laser radiation is most often used approach in various industrial micromachining applications like scribing, PCB drilling, and is important in scientific researches like laser heating in geophysics experiments with diamond anvil cells (DAC). Control of intensity distribution in focal spot is important task since optimum intensity profiles are rather flat-top, doughnut or "inverse-Gauss" than typical for lasers Gaussian profile. Because of high intensity of modern CW and pulsed lasers it is advisable to use refractive beam shaping optics with smooth optical surfaces providing high radiation resistance. Workable optical solutions can be built on the base of diffraction theory conclusion that flat-top intensity profile in focal plane of a lens is created when input beam has Airy-disk intensity distribution. It is suggested to apply refractive beam shapers converting, with minimum wavefront deformation, Gaussian profile of TEM00 beam to a beam with Airy disk intensity distribution, thereby optimizing conditions of interference near the focal plane of a lens after the beam shaper and providing flat-top, doughnut, "inverse-Gauss" profiles. This approach allows operation with CW and ultra-short pulse lasers, using F-theta lenses and objectives, mirror scanners, provides extended depth of field similar to Rayleigh length of comparable TEM00 beam, easy integration in industrial equipment, simple adjustment procedure and switching between profiles, telescope and collimator implementations. There will be considered design basics of beam shapers, analysis of profile behaviour near focal plane, examples of implementations in micromachining systems and experimental DAC setups, results of profile measurements and material processing.

  3. Double Transverse-Spin Asymmetries in DRELL-YAN and J/Φ Production from PROTON-ANTIPROTON Collisions

    NASA Astrophysics Data System (ADS)

    Guzzi, M.; Barone, V.; Cafarella, A.; Corianò, C.; Ratcliffe, P. G.

    We perform a NLO numerical study of the double transverse-spin asymmetries in the J/Φ resonance region for proton-antiproton collisions. We analyze the large x kinematic region, relevant for the proposed PAX experiment at GSI, and discuss the implication of the results for the extraction of the transversity densities.

  4. Beam diagnostics

    SciTech Connect

    Bogaty, J.; Clifft, B.E.; Zinkann, G.P.; Pardo, R.C.

    1995-08-01

    The ECR-PII injector beam line is operated at a fixed ion velocity. The platform high voltage is chosen so that all ions have a velocity of 0.0085c at the PII entrance. If a previous tune configuration for the linac is to be used, the beam arrival time must be matched to the previous tune as well. A nondestructive beam-phase pickup detector was developed and installed at the entrance to the PII linac. This device provides continuous phase and beam current information and allows quick optimization of the beam injected into PII. Bunches traverse a short tubular electrode thereby inducing displacement currents. These currents are brought outside the vacuum interface where a lumped inductance resonates electrode capacitance at one of the bunching harmonic frequencies. This configuration yields a basic sensitivity of a few hundred millivolts signal per microampere of beam current. Beam-induced radiofrequency signals are summed against an offset frequency generated by our master oscillator. The resulting kilohertz difference frequency conveys beam intensity and bunch phase information which is sent to separate processing channels. One channel utilizes a phase locked loop which stabilizes phase readings if beam is unstable. The other channel uses a linear full wave active rectifier circuit which converts kilohertz sine wave signal amplitude to a D.C. voltage representing beam current. A prototype set of electronics is now in use with the detector and we began to use the system in operation to set the arrival beam phase. A permanent version of the electronics system for the phase detector is now under construction. Additional nondestructive beam intensity and phase monitors at the {open_quotes}Booster{close_quotes} and {open_quotes}ATLAS{close_quotes} linac sections are planned as well as on some of the high-energy beam lines. Such a monitor will be particularly useful for FMA experiments where the primary beam hits one of the electric deflector plates.

  5. The CMS barrel calorimeter response to particle beams from 2-GeV/c to 350-GeV/c

    SciTech Connect

    Abdullin, S.; Abramov, V.; Acharya, B.; Adam, N.; Adams, M.; Adzic, P.; Akchurin, N.; Akgun, U.; Albayrak, E.; Alemany-Fernandez, R.; Almeida, N.; /Lisbon, LIFEP /Democritos Nucl. Res. Ctr. /Virginia U. /Iowa State U.

    2009-01-01

    The response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/c has been measured. To our knowledge, this is the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a detailed discussion of the underlying phenomena are presented. We also show techniques that apply corrections to the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons. Above 5 GeV/c, these corrections improve the energy resolution of the combined system where the stochastic term equals 84.7 {+-} 1.6% and the constant term is 7.4 {+-} 0.8%. The corrected mean response remains constant within 1.3% rms.

  6. Role of pentaquark components in ϕ meson production proton-antiproton annihilation reactions

    NASA Astrophysics Data System (ADS)

    Srisuphaphon, S.; Kaewsnod, A.; Limphirat, A.; Khosonthongkee, K.; Yan, Y.

    2016-02-01

    The pentaquark component uuds s ¯ is included in the proton wave functions to study ϕ meson production proton-antiproton annihilation reactions. With all possible configurations of the uuds subsystem proposed for describing the strangeness spin and magnetic moment of the proton, we estimate the branching ratios of the annihilation reactions at rest p p ¯→ϕ X (X =π0,η ,ρ0,ω ) from atomic p p ¯ S - and P -wave states by using effective quark line diagrams incorporating the 3P0 model. The best agreement of theoretical prediction with the experimental data is found when the pentaquark configuration of the proton wave function takes the flavor-spin symmetry [4] FS[22] F[22] S .

  7. Theoretical motivation for gravitation experiments on ultra-low energy antiprotons and antihydrogen

    SciTech Connect

    Nieto, M.M.

    1995-12-31

    It is known that the generally accepted theories of gravity and quantum mechanics are fundamentally incompatible. Thus, when one tries to combine these theories, one must beware of physical pitfalls. Modern theories of quantum gravity are trying to overcome these problems. Any ideas must confront the present agreement with general relativity, but yet be free to wonder about not understood phenomena, such as the dark matter problem. This all has led some {open_quotes}intrepid{close_quotes} theorists to consider a new gravitational regime, that of antimatter. Even more {open_quotes}daring{close_quotes} experimentalists are attempting, or considering attempting, the measurement of the gravitational force on antimatter, including low-energy antiprotons and, perhaps most enticing, antihydrogen.

  8. Nuclear fragmentation induced by low-energy antiprotons within a microscopic transport approach

    NASA Astrophysics Data System (ADS)

    Feng, Zhao-Qing

    2016-12-01

    Within the framework of the Lanzhou quantum molecular-dynamics transport model, the nuclear fragmentation induced by low-energy antiprotons has been investigated thoroughly. A coalescence approach is developed for constructing the primary fragments in phase space. The secondary decay process of the fragments is described by a well-known statistical code. It is found that the localized energy released in antibaryon-baryon annihilation is deposited in a nucleus mainly via pion-nucleon collisions, which leads to the emissions of pre-equilibrium particles, fission, evaporation of nucleons, light fragments, etc. The strangeness exchange reactions dominate the hyperon production. The averaged mass loss increases with the mass number of target nucleus. A bump structure in the domain of intermediate mass for heavy targets appears owing to the contribution of fission fragments.

  9. Sixfold improved single particle measurement of the magnetic moment of the antiproton

    NASA Astrophysics Data System (ADS)

    Nagahama, H.; Smorra, C.; Sellner, S.; Harrington, J.; Higuchi, T.; Borchert, M. J.; Tanaka, T.; Besirli, M.; Mooser, A.; Schneider, G.; Blaum, K.; Matsuda, Y.; Ospelkaus, C.; Quint, W.; Walz, J.; Yamazaki, Y.; Ulmer, S.

    2017-01-01

    Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.

  10. Propagation and secondary production of low energy antiprotons in the atmosphere

    NASA Technical Reports Server (NTRS)

    Bowen, T.; Moats, A.

    1985-01-01

    Current theories, in which the observed antiproton component is attributed strictly to secondary production in high energy inelastic collisions of protons with the interstellar medium or the atmosphere, apparently fail to explain the relatively high p vertical intensities measured at mountain and balloon altitudes. Therefore, a more careful calculation of the theoretical secondary intensity spectra is required before more exotic sources for these excess p's can be explored. A one dimensional diffusion equation is used to calculate the expected vertical intensity of p's due only to secondary production in the atmosphere; any assumed primary p spectrum is also included. Two adjustable parameters, the inelasticity and charge exchange in nucleon-nucleus collisions, were included in the algorithm. In order to obtain an independent estimate of their values the proton vertical intensities in the atmosphere were calculated, adjusting the parameters until the curves fit the experimental proton data, and then assumed that these values were identical in antinucleon-nucleus collisions.

  11. RF Manipulation of Ions in the High Performance Antiproton Trap (HiPAT)

    NASA Technical Reports Server (NTRS)

    Pearson, J. Boise; Martin, James J.; Sims, William H.; Chakrabarti, Suman; Lewis, Raymond A.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    The annihilation of antimatter provides the highest mass specific energy of any other known reaction. Proper harnessing of this energy holds great promise for future space propulsion systems. Many different propulsion concepts have been proposed that take advantage of antimatter, either using matter-antimatter as the primary fuel, or as a 'spark plug' for fusion and fission systems. In order to begin to address these concepts experimentally, a method of storing and transporting antimatter must be developed. The High Performance Antiproton Trap (HiPAT) is a first-generation storage and transportation device designed to store and transport 10(exp 12) antiprotons with a storage half-life of 18 days. It uses a Penning-Malmberg ion trap with a 4T magnetic field and 20 kV potential. This will enable researchers much more flexibility in the design of antimatter experiments related to propulsion. Ions cannot be stored indefinitely in a real trap, as ion cloud instabilities develop from imperfections in manufacturing and misalignments in assembly. Previous work has been done at both the National Institute of Standards and University of California in San Diego in using RF (radio frequency) signals to both diagnose and confine the ion cloud. Two electrodes in the trap have been segmented to allow both reception and transmission of RF waves in the ion cloud. Experiments are underway to determine the number of ions and density in the cloud by "listening" to protons contained in the HiPAT. Currently we believe the density of ions stored in the trap is roughly 10(exp 15) m(exp -3). Development of non-destructive techniques is vital to the project goals, enabling continuous monitoring of the quantities stored in the system. Experimental work is also being done in identifying RF transmission frequencies that can manipulate the density of the cloud, by exchanging energy and momentum between the RF wave and the ions. Preliminary experiments have demonstrated this interaction.

  12. A fussy revisitation of antiprotons as a tool for Dark Matter searches

    NASA Astrophysics Data System (ADS)

    Boudaud, Mathieu; Cirelli, Marco; Giesen, Gaëlle; Salati, Pierre

    2015-05-01

    Antiprotons are regarded as a powerful probe for Dark Matter (DM) indirect detection and indeed current data from PAMELA have been shown to lead to stringent constraints. However, in order to exploit their constraining/discovery power properly and especially in anticipation of the exquisite accuracy of upcoming data from AMS-02, great attention must be put into effects (linked to their propagation in the Galaxy) which may be perceived as subleading but actually prove to be quite relevant. Using a semi-analytic code for rapidity, we revisit the computation of the astrophysical background and of the DM antiproton fluxes. Like in the fully numerical standard calculations, we include the effects of: diffusive reacceleration, energy losses including tertiary component and solar modulation (in a force field approximation). We show that their inclusion can somewhat modify the current bounds, even at large DM masses, and that a wrong interpretation of the data may arise if they are not taken into account. At the present level of accuracy of the data from PAMELA, the inclusion of the above effects amounts to changing the constraints, with respect to the case in which they are neglected, of up to about 40% at a DM mass of 1 TeV and 30% at 10 TeV . When the AMS-02 level of precision is reached, including them would strengthen (lessen) the bounds on the annihilation cross section by up to a factor of 15 below (above) a DM mass of 300 GeV. The numerical results for the astrophysical background are provided in terms of fit functions; the results for Dark Matter are incorporated in the new release of the PPPC4DMID.

  13. Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

    SciTech Connect

    Seletskiy, Sergei M.

    2005-01-01

    Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the ¯rst cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cool- ing. The Recycler Electron Cooler (REC) is the key component of the Teva- tron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV car- rying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 ¹rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible.

  14. Beam-energy inequality in the beam-beam interaction

    SciTech Connect

    Krishnagopal, S.; Siemann, R. )

    1990-03-01

    Conditions for energy transparency,'' unequal-energy beams having the same beam-beam behavior, are derived for round beams from a Hamiltonian model of the beam-beam interaction. These conditions are equal fractional betatron tunes, equal synchrotron tunes, equal beam-beam strength parameters, equal nominal sizes, equal {beta}{sup *}'s and equal bunch lengths. With these conditions the only way to compensate for unequal energies is with the number of particles per bunch.

  15. Plasma-beam traps and radiofrequency quadrupole beam coolers.

    PubMed

    Maggiore, M; Cavenago, M; Comunian, M; Chirulotto, F; Galatà, A; De Lazzari, M; Porcellato, A M; Roncolato, C; Stark, S; Caruso, A; Longhitano, A; Cavaliere, F; Maero, G; Paroli, B; Pozzoli, R; Romé, M

    2014-02-01

    Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented.

  16. Plasma-beam traps and radiofrequency quadrupole beam coolers

    SciTech Connect

    Maggiore, M. Cavenago, M.; Comunian, M.; Chirulotto, F.; Galatà, A.; De Lazzari, M.; Porcellato, A. M.; Roncolato, C.; Stark, S.; Caruso, A.; Longhitano, A.; Cavaliere, F.; Maero, G.; Paroli, B.; Pozzoli, R.; Romé, M.

    2014-02-15

    Two linear trap devices for particle beam manipulation (including emittance reduction, cooling, control of instabilities, dust dynamics, and non-neutral plasmas) are here presented, namely, a radiofrequency quadrupole (RFQ) beam cooler and a compact Penning trap with a dust injector. Both beam dynamics studies by means of dedicated codes including the interaction of the ions with a buffer gas (up to 3 Pa pressure), and the electromagnetic design of the RFQ beam cooler are reported. The compact multipurpose Penning trap is aimed to the study of multispecies charged particle samples, primarily electron beams interacting with a background gas and/or a micrometric dust contaminant. Using a 0.9 T solenoid and an electrode stack where both static and RF electric fields can be applied, both beam transport and confinement operations will be available. The design of the apparatus is presented.

  17. Scaling properties of proton and antiproton production in sqrt[s(NN)]=200 GeV Au+Au collisions.

    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; 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, G; 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, L 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; 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

    2003-10-24

    We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at sqrt[s(NN)]=200 GeV measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5antiprotons. They show a centrality-scaling behavior different from that of pions. The pmacr;/pi and p/pi ratios are enhanced compared to peripheral Au+Au, p+p, and e(+)e(-) collisions. This enhancement is limited to p(T)<5 GeV/c as deduced from the ratio of charged hadrons to pi(0) measured in the range 1.5

  18. Liquid helium-free cryostat and hermetically sealed cryogenic microwave cavity for hyperfine spectroscopy of antiprotonic helium.

    PubMed

    Massiczek, O; Friedreich, S; Juhász, B; Widmann, E; Zmeskal, J

    2011-12-11

    The design and properties of a new cryogenic set-up for laser-microwave-laser hyperfine structure spectroscopy of antiprotonic helium - an experiment performed at the CERN-Antiproton Decelerator (AD), Geneva, Switzerland - are described. Similar experiments for (4)He have been performed at the AD for several years. Due to the usage of a liquid helium operated cryostat and therefore necessary refilling of coolants, a loss of up to 10% beamtime occurred. The decision was made to change the cooling system to a closed-circuit cryocooler. New hermetically sealed target cells with minimised (3)He gas volume and different dimensions of the microwave resonator for measuring the (3)He transitions were needed. A new set-up has been designed and tested at Stefan Meyer Institute in Vienna before being used for the 2009 and 2010 beamtimes at the AD.

  19. Beam tuning

    SciTech Connect

    Pardo, R.C.; Zinkann, G.P.

    1995-08-01

    A program for configuring the linac, based on previously run configurations for any desired beam was used during the past year. This program uses only a small number of empirical tunes to scale resonator fields to properly accelerate a beam with a different charge-to-mass (q/A) ratio from the original tune configuration. The program worked very well for the PII linac section where we can easily match a new beam`s arrival phase and velocity to the tuned value. It was also fairly successful for the Booster and ATLAS sections of the linac, but not as successful as for the PII linac. Most of the problems are associated with setting the beam arrival time correctly for each major linac section. This problem is being addressed with the development of the capacitive pickup beam phase monitor discussed above. During the next year we expect to improve our ability to quickly configure the linac for new beams and reduce the time required for linac tuning. Already the time required for linac tuning as a percentage of research hours has decreased from 22% in FY 1993 to 15% in the first quarter of FY 1995.

  20. BEAMS3D Neutral Beam Injection Model

    NASA Astrophysics Data System (ADS)

    McMillan, Matthew; Lazerson, Samuel A.

    2014-09-01

    With the advent of applied 3D fields in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous slowing down, and pitch angle scattering are modeled with the ADAS atomic physics database. Elementary benchmark calculations are presented to verify the collisionless particle orbits, NBI model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields. Notice: this manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

  1. Measurement of the inclusive jet cross section in proton-antiproton collisions at the center-of-mass energy of 1.96 TeV

    SciTech Connect

    Voutilainen, Mikko Antero

    2008-07-01

    This thesis studies the high-energy collisions of protons and antiprotons. The data used in the measurement were collected during 2004-2005 with the D0 detector at the Tevatron Collider of the Fermi National Accelerator Laboratory and correspond to 0.7 fb-1 of integrated luminosity. High energy hadron collisions usually produce collimated sprays of particles called jets. The energy of the jets is measured using a liquid Argon-Uranium calorimeter and the production angle is determined with the help of silicon microstrip and scintillating fiber trackers. The inclusive jet cross section in proton-antiproton collisions is measured as a function of jet transverse momentum pT in six bins of jet rapidity at the center-of-mass energy √s = 1.96 TeV. The measurement covers jet transerve momenta from 50 GeV up to 600 GeV and jet rapidities up to |y| = 2.4. The data are collected using a set of seven single jet triggers. Event and jet cuts are applied to remove non-physical backgrounds and cosmic-ray interactions. The data are corrected for jet energy calibration, cut and trigger efficiencies and finite jet pT resolution. The corrections are determined from data and the methods are tested with Monte Carlo simulation. The main experimental challenges in the measurement are the calibration of jet energies and the determination of the jet pT resolution. New methods are developed for the jet energy calibration that take into account physical differences between the {gamma}+jet and dijet calibration samples arising from quark and gluon jet differences. The uncertainty correlations are studied and provided as a set of uncertainty sources. The production of particle jets in hadron collisions is described by the theory of quantum chromodynamics (QCD). When the transverse jet momentum is large, the contributions from long-distance physics processes are small and the production rates of jets can be predicted by perturbative QCD. The

  2. Excitations and Fractionation Following Atomic Coulomb Capture and Nuclear Absorption of Antiprotons in SAMARIUM-150, SAMARIUM-152 and LEAD-208

    NASA Astrophysics Data System (ADS)

    Nicholas, Michael

    The E2 Nuclear Resonance Effect was studied using ^{150}Sm and ^{152}Sm, the former being a resonant isotope and the latter being non-resonant. By measuring the attenuation of x-ray intensity in the resonant isotope compared to the non-resonant isotope, a measure of the induced width in the upper admixed level due to antiproton absorption from the lower admixed level was found. The results obtained showed that the level widths measured experimentally were, for the upper level, broader than one would expect from theoretical calculations, indicating that the strong interaction is greater than one might expect for this antiproton-nucleus system. However, direct measurements of the width of a transition between low lying states (i.e. those of low principle quantum number, n) indicate that the reverse is true for these states. Here the measured width was rather less than theoretical predictions, indicating less strong interaction effects for such states that probe further into the nucleus. By measuring x-rays and gamma-rays emitted from a lead target after antiproton irradiation over a period of time the species created by antiproton absorption were identified and their abundances were calculated. The distribution of residual nuclei had the same general shape as that obtained from theoretical calculations using an intra-nuclear cascade approach followed by an evaporation process. The maximum of the experimental curve was at a higher atomic mass than the theoretical curve, indicating the possibility that too great an energy transfer between the system of pions created in the annihilation process and the nucleons in the lead nucleus is used in the theoretical calculations. Much care was spent in looking for fission following the deposition of some 2 GeV in the lead nucleus from the annihilation process, but no evidence could be seen.

  3. A Measurement of Charged and Neutral Elementary Particles Emitted from Antiproton Annihilation at Rest in Heavy Nuclei

    DTIC Science & Technology

    1989-06-15

    1991 SUMMARY Yields and ,nergy spectra of nuclear fragments and mesons emitted from antiproton crnihilation at rest in carbon, bismuth and uranium...anti- proton annihilation at rest in nuclei (carbon and uranium). These particles include (charged) pions, kaons, protons, light nuclear fragments ...included in order to demonstrate as discussed in [10], and escape of excess neutral pions the effect of pion absorption in the nuclear environment , due to

  4. A New Time-Dependent Scattering Theory: Application to the Capture of Antiprotons by Hydrogen Atoms and Helium Atoms

    SciTech Connect

    Tong, X. M.; Hino, K.; Toshima, N.

    2008-08-08

    We present a theoretical method for Coulomb three-body rearrangement collisions solving a Chew-Goldberger-type integral equation directly. The scattering boundary condition is automatically satisfied by adiabatically switching on the interaction between the projectile and target. Hence the outgoing wave function is obtained without the tedious procedure of adjusting the total wave function in the asymptotic region. All the dynamical information can be derived from the scattering wave function obtained on pseudo-spectral grids numerically. Using this method, we obtained the state-specified capture cross sections when antiprotons collide with hydrogen atoms or helium atoms. Differing from the capture processes of antiprotons by hydrogen atoms, the anomalous bumpy structures are revealed in the total angular momentum dependent capture cross sections by helium atoms. Further analysis shows that the bumps arise from the partial channel closing due to the removal of the energy degeneracy in the antiprotonic helium atom. The ejected electron energy distributions are also provided for the comparison with future experiments.

  5. Spectral Intensities of Antiprotons and the Nested Leaky-box Model for Cosmic Rays in the Galaxy

    NASA Astrophysics Data System (ADS)

    Cowsik, R.; Madziwa-Nussinov, T.

    2016-08-01

    In this paper we note that the spectral intensities of antiprotons observed in Galactic cosmic rays in the energy range ˜1-300 GeV by BESS, PAMELA, and AMS instruments display nearly the same spectral shape as that generated by primary cosmic rays through their interaction with matter in the interstellar medium, without any significant modifications. More importantly, a constant residence time of ˜2.3 ± 0.7 million years in the Galactic volume, independent of the energy of cosmic rays, matches the observed intensities. A small additional component of secondary antiprotons in the energy range below 10 GeV, generated in cocoon-like regions surrounding the cosmic-ray sources, seems to be present. We discuss this result in the context of observations of other secondary components such as positrons and boron, and the bounds on anisotropy of cosmic rays. In the nested leaky-box model the spectral intensities of antiprotons and positrons can be interpreted as secondary products of cosmic-ray interactions.

  6. Tilted foil polarization of radioactive beam nuclei

    NASA Astrophysics Data System (ADS)

    Goldring, Gvirol

    1992-11-01

    Tilted foil polarization has up to now been mostly applied to nuclear reaction products recoiling out of a target traversed by a primary particle beam. Being a universal phenomenon it can be applied equally well to beams of particles, primary or secondary, radioactive or other. There are however some technical considerations arising from the nature of the beam particles. Radioactive beams are associated with ground state nuclei. They usually have low nuclear spin and as a consequence-as will be shown later-low polarization. Secondary beams are usually low in intensity and do not impose any constraints on the foils they traverse; unlike intense primary heavy ion beams which, if they traverse the foils, essentially limit the foil material to carbon. We review here briefly the tilted foil polarization process and then discuss an experiment with an isomer beam. Finally we review experiments with radioactive beams, past, present and planned for the future.

  7. Foldable beam

    NASA Technical Reports Server (NTRS)

    Hedgepeth, J. M.; Coyner, J. V.; Crawford, R. F.

    1981-01-01

    A foldable beam possessing superior qualities of light weight, compactness for transportation, quick deployment with minimum use of force, and high strength is described. These qualities are achieved through the use of a series of longitudinally rigid segments, hinged along one side and threaded by one or two cables along the opposite side. Tightening the cables holds the beam extended. Loosening the cables permits the segments to fold away from the threaded side. In one embodiment the segments are connected by canted hinges with the result that the beam may be folded in a helix-like configuration around a cylinder. In another embodiment the segments themselves may be hinged to fold flat laterally as the beam is folded, resulting in a configuration that may be helixed around a shorter cylinder.

  8. Synchrotron radiation based beam diagnostics at the Fermilab Tevatron

    DOE PAGES

    Thurman-Keup, R.; Cheung, H. W. K.; Hahn, A.; ...

    2011-09-16

    Synchrotron radiation has been used for many years as a beam diagnostic at electron accelerators. It is not normally associated with proton accelerators as the intensity of the radiation is too weak to make detection practical. Therefore, if one utilizes the radiation originating near the edge of a bending magnet, or from a short magnet, the rapidly changing magnetic field serves to enhance the wavelengths shorter than the cutoff wavelength, which for more recent high energy proton accelerators such as Fermilab's Tevatron, tends to be visible light. This paper discusses the implementation at the Tevatron of two devices. A transversemore » beam profile monitor images the synchrotron radiation coming from the proton and antiproton beams separately and provides profile data for each bunch. A second monitor measures the low-level intensity of beam in the abort gaps which poses a danger to both the accelerator's superconducting magnets and the silicon detectors of the high energy physics experiments. Comparisons of measurements from the profile monitor to measurements from the flying wire profile systems are presented as are a number of examples of the application of the profile and abort gap intensity measurements to the modelling of Tevatron beam dynamics.« less

  9. Synchrotron radiation based beam diagnostics at the Fermilab Tevatron

    SciTech Connect

    Thurman-Keup, R.; Cheung, H. W. K.; Hahn, A.; Hurh, P.; Lorman, E.; Lundberg, C.; Meyer, T.; Miller, D.; Pordes, S.; Valishev, A.

    2011-09-16

    Synchrotron radiation has been used for many years as a beam diagnostic at electron accelerators. It is not normally associated with proton accelerators as the intensity of the radiation is too weak to make detection practical. Therefore, if one utilizes the radiation originating near the edge of a bending magnet, or from a short magnet, the rapidly changing magnetic field serves to enhance the wavelengths shorter than the cutoff wavelength, which for more recent high energy proton accelerators such as Fermilab's Tevatron, tends to be visible light. This paper discusses the implementation at the Tevatron of two devices. A transverse beam profile monitor images the synchrotron radiation coming from the proton and antiproton beams separately and provides profile data for each bunch. A second monitor measures the low-level intensity of beam in the abort gaps which poses a danger to both the accelerator's superconducting magnets and the silicon detectors of the high energy physics experiments. Comparisons of measurements from the profile monitor to measurements from the flying wire profile systems are presented as are a number of examples of the application of the profile and abort gap intensity measurements to the modelling of Tevatron beam dynamics.

  10. Synchrotron radiation based beam diagnostics at the Fermilab Tevatron

    NASA Astrophysics Data System (ADS)

    Thurman-Keup, R.; Cheung, H. W. K.; Hahn, A.; Hurh, P.; Lorman, E.; Lundberg, C.; Meyer, T.; Miller, D.; Pordes, S.; Valishev, A.

    2011-09-01

    Synchrotron radiation has been used for many years as a beam diagnostic at electron accelerators. It is not normally associated with proton accelerators as the intensity of the radiation is too weak to make detection practical. However, if one utilizes the radiation originating near the edge of a bending magnet, or from a short magnet, the rapidly changing magnetic field serves to enhance the wavelengths shorter than the cutoff wavelength, which for more recent high energy proton accelerators such as Fermilab's Tevatron, tends to be visible light. This paper discusses the implementation at the Tevatron of two devices. A transverse beam profile monitor images the synchrotron radiation coming from the proton and antiproton beams separately and provides profile data for each bunch. A second monitor measures the low-level intensity of beam in the abort gaps which poses a danger to both the accelerator's superconducting magnets and the silicon detectors of the high energy physics experiments. Comparisons of measurements from the profile monitor to measurements from the flying wire profile systems are presented as are a number of examples of the application of the profile and abort gap intensity measurements to the modelling of Tevatron beam dynamics. Work supported by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.

  11. Beam-beam deflection and signature curves for elliptic beams

    SciTech Connect

    Ziemann, V.

    1990-10-22

    In this note we will present closed expressions for the beam-beam deflection angle for arbitrary elliptic beams including tilt. From these expressions signature curves, i.e., systematic deviations from the round beam deflection curve due to ellipticity or tilt are derived. In the course of the presentation we will prove that it is generally impossible to infer individual beam sizes from beam-beam deflection scans. 3 refs., 2 figs.

  12. Experimental investigation of ≈130 keV kinetic energy antiprotons annihilation on nuclei

    NASA Astrophysics Data System (ADS)

    Aghai-Khozani, H.; Barna, D.; Corradini, M.; Hayano, R.; Hori, M.; Kobayashi, T.; Leali, M.; Lodi-Rizzini, E.; Mascagna, V.; Prest, M.; Soter, A.; Todoroki, K.; Vallazza, E.; Venturelli, L.; Zurlo, N.

    2014-04-01

    The study of the antiproton ( bar {p}) annihilation cross section on nuclei at low energies (eV-MeV region) has implications for fundamental cosmology as well as for nuclear physics. Concerning the former, different models try to explain the matter/antimatter asymmetry in the universe assuming the existence of the so-called "islands" where antinucleon-nucleon annihilations occur in the border region (Cohen et al. Astrophys. J. 495, 539-549, 1998), while, from the nuclear physics point of view, the annihilation process is a valuable tool to evaluate the neutron/proton ratio in order to probe the external region of the nucleus (Gupta et al. Nucl. Phys. B 70(3), 414-424, 1974). The existing data of antinucleon-nucleon (or -nucleus) annihilation cross-sections are mainly confined to energies above ≈1 MeV, while the cross section measured at LEAR in the 80's-90's (mostly with light targets Agnello et al. Phys. Lett. B 256, 349-353, 1991; Bertin et al. Phys. Lett. B 369, 77-85, 1996; Bertin et al. Phys. Lett. B 414, 220-228, 1997; Zenoni et al. Phys. Lett. B 461, 405-412, 1999; Bianconi et al. Phys. Lett. B 481, 194-198, 2000; Bianconi et al. Phys. Lett. B 492, 254-258, 2000) showed an unexpected behaviour for energies below 1 MeV (Bianconi et al. Phys. Lett. B 483, 353-359, 2000; Bianconi et al. Phys. Rev. C 62, 014611-7, 2000; Batty et al. Nucl. Phys. A 689, 721-740, 2001). The results showed a saturation with the atomic mass number against the A 2/3 trend which is observed for higher energies (being A the target mass number). The ASACUSA collaboration at CERN recently measured antiproton annihilation cross section on different kinds of nuclei with a bar {p} kinetic energy of 5.3 MeV (Bianconi et al. Phys. Lett. B 704, 461-466, 2011; Corradini et al. Nucl. Instr. Methods A 711, 12-20, 2013). Such results proved compatibility with the black-disk model with the Coulomb correction. But till now experimental difficulties prevented the investigation at energies below ≈1

  13. Dark matter annihilations into two light fermions and one gauge boson: general analysis and antiproton constraints

    SciTech Connect

    Garny, Mathias; Ibarra, Alejandro; Vogl, Stefan E-mail: alejandro.ibarra@ph.tum.de

    2012-04-01

    We study in this paper the scenario where the dark matter is constituted by Majorana particles which couple to a light Standard Model fermion and an extra scalar via a Yukawa coupling. In this scenario, the annihilation rate into the light fermions with the mediation of the scalar particle is strongly suppressed by the mass of the fermion. Nevertheless, the helicity suppression is lifted by the associated emission of a gauge boson, yielding annihilation rates which could be large enough to allow the indirect detection of the dark matter particles. We perform a general analysis of this scenario, calculating the annihilation cross section of the processes χχ→f f-bar V when the dark matter particle is a SU(2){sub L} singlet or doublet, f is a lepton or a quark, and V is a photon, a weak gauge boson or a gluon. We point out that the annihilation rate is particularly enhanced when the dark matter particle is degenerate in mass to the intermediate scalar particle, which is a scenario barely constrained by collider searches of exotic charged or colored particles. Lastly, we derive upper limits on the relevant cross sections from the non-observation of an excess in the cosmic antiproton-to-proton ratio measured by PAMELA.

  14. Double and single ionization of He and H{sub 2} by slow protons and antiprotons

    SciTech Connect

    Kimura, Mineo |; Shimamura, Isao; Inokuti, Mitio

    1994-12-31

    Double and single ionization of He and H{sub 2} by proton (p) and antiproton ({bar p})impact in the energy region below 50 keV was studied theoretically by using the semiclassical molecular picture. As the energy decreased, the ratio of the double- to the single-ionization cross section increased for impact and decreased for p impact for both He and H{sub 2}. These trends are consistent with recent measurements for He. Ionization mechanisms differ distinctly for p impact and {bar p} impact. For p impact, the dominant mechanism for double ionization at the lower energies is sequential ladder climbing by the two electrons through various excited channels and finally into the continuum. For {bar p} impact, in contrast, the approaching negative charge distorts both the He and H{sub 2} electron clouds toward the other side of the nucleus and decreases the electron binding energies. These effects enhance electron-electron interactions, increasing double ionization. For the H{sub 2}, an effect of molecular orientation is an additional complication in determining the dynamics.

  15. Exclusive Central $\\pi^{+}\\pi^{-}$ Production in Proton Antiproton Collisions at the CDF

    SciTech Connect

    Zurek, Maria

    2015-01-01

    Exclusive $\\pi^{=}\\pi^{-}$ production in proton-antiproton collisions at $\\sqrt{s}$ = 0.9 and 1.96 TeV in the Collider Detector at Fermilab has been measured. We select events with two particles with opposite charge in pseudorapidity region -1.3 < $\\eta$ < 1.3 with no other particles detected in -5.9 < $\\eta$ < 5.9. Particles are assumed to be pions. The $\\pi^{+}\\pi^{-}$system is required to have rapidity -1.0 < $y$ < 1.0. The data are expected to be dominated by the double pomeron exchange mechanism. Therefore, the quantum numbers of the central state are constrained. The data extend up to dipion mass M($\\pi^{+}\\pi^{-}$) = 5000 MeV/$c^2$. Resonance structures consistent with $f_0$ and $f_2$(1270) mesons are visible. The results are valuable for light hadron spectroscopy and for providing information about the nature of the pomeron in a region between non-perturbative and perturbative quantum chromodynamics

  16. Sixfold improved single particle measurement of the magnetic moment of the antiproton

    PubMed Central

    Nagahama, H.; Smorra, C.; Sellner, S.; Harrington, J.; Higuchi, T.; Borchert, M. J.; Tanaka, T.; Besirli, M.; Mooser, A.; Schneider, G.; Blaum, K.; Matsuda, Y.; Ospelkaus, C.; Quint, W.; Walz, J.; Yamazaki, Y.; Ulmer, S.

    2017-01-01

    Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20. PMID:28098156

  17. Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis

    SciTech Connect

    Cirelli, Marco; Giesen, Gaëlle; Taoso, Marco; Gaggero, Daniele; Urbano, Alfredo E-mail: daniele.gaggero@sissa.it E-mail: marco.taoso@cea.fr

    2014-12-01

    A GeV gamma-ray excess has possibly been individuated in Fermi-LAT data from the Galactic Center and interpreted in terms of Dark Matter (DM) annihilations, either in hadronic (essentially b b-bar ) or leptonic channels. In order to test this tantalizing interpretation, we address two issues: (i) we improve the computation of secondary emission from DM (Inverse Compton and Bremsstrahlung) with respect to previous works, confirming it to be very relevant for determining the DM spectrum in the leptonic channels, so that any conclusion on the DM nature of the signal critically depends on this contribution; (ii) we consider the constraints from antiprotons on the DM hadronic channel, finding that the uncertainties on the propagation model, and in particular on the halo height, play a major role. Moreover, we discuss the role of solar modulation, taking into account possible charge dependent effects whose importance is estimated exploiting detailed numerical tools. The limits that we obtain severely constrain the DM interpretation of the excess in the hadronic channel, for standard assumptions on the Galactic propagation parameters and solar modulation. However, they considerably relax if more conservative choices are adopted.

  18. Digitral Down Conversion Technology for Tevatron Beam Line Tuner at FNAL

    SciTech Connect

    Schappert, W.; Lorman, E.; Scarpine, V.; Ross, M.C.; Sebek, J.; Straumann, T.; /Fermilab /SLAC

    2008-03-17

    Fermilab is presently in Run II collider operations and is developing instrumentation to improve luminosity. Improving the orbit matching between accelerator components using a Beam Line Tuner (BLT) can improve the luminosity. Digital Down Conversion (DDC) has been proposed as a method for making more accurate beam position measurements. Fermilab has implemented a BLT system using a DDC technique to measure orbit oscillations during injections from the Main Injector to the Tevatron. The output of a fast ADC is downconverted and filtered in software. The system measures the x and y positions, the intensity, and the time of arrival for each proton or antiproton bunch, on a turn-by-turn basis, during the first 1024 turns immediately following injection. We present results showing position, intensity, and time of arrival for both injected and coasting beam. Initial results indicate a position resolution of {approx}20 to 40 microns and a phase resolution of {approx}25 ps.

  19. Coherent beam-beam interaction with four colliding beams

    NASA Astrophysics Data System (ADS)

    Podobedov, B.; Siemann, R. H.

    1995-09-01

    The coherent beam-beam interaction in the absence of Landau damping is studied with a computer simulation of four space-charge-compensated colliding beams. Results are presented for the modes, phase space structures, widths, and growth rates of coherent beam-beam resonances. These results are compared with solutions of the Vlasov equation, and with measurements made at the Dispositif de Collisions dans l'Igloo (DCI) storage ring in Orsay, France, which operated with space-charge-compensated colliding beams.

  20. BEAM-BEAM SIMULATIONS FOR DOUBLE-GAUSSIAN BEAMS.

    SciTech Connect

    MONTAG, C.; MALITSKY, N.; BEN-ZVI, I.; LITVINENKO, V.

    2005-05-16

    Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-gaussian beams. Here we report the effect of low-frequency random tune modulations on diffusion in double-gaussian beams and compare the effects to those in beam-beam interactions with regular gaussian beams and identical tune shift parameters.

  1. Beam Beam Simulation Studies for NLC And SLC2000

    SciTech Connect

    Thompson, K.A.; Chen, P.; Irwin, J.; Zimmermann, F.; /SLAC

    2010-05-27

    We apply and modify the computer codes CAIN(P.Chen, G.Horton-Smith, T.Ohgaki, A.W.Weidemann, K.Yokoya, contributed to Workshop on Gamma-Gamma Colliders, Berkeley, CA, March 28-31, 1994; SLAC-PUB-6583.) and GUINEAPIG(D.Schulte (DESY), unpublished.) to make detailed studies of the beam-beam interaction in the SLAC design for a future linear collider (NLC), as well as to the proposed SLC2000 project. Using realistic beam distributions, we present simulations related to the tuning and optimization of luminosity in SLC2000 and NLC.

  2. Measurement of Emittance of Beam in the Debuncher During Stacking

    SciTech Connect

    Halling, Mike

    1991-12-11

    The emittance of antiprotons in the debuncher was measured using two methods during normal stacking conditions. With 2.3 seconds of cooling the vertical emittance was found to be 3.6 {pi} mm-mr using scraper D:TJ308, and 2.9 {pi} mm-mr using the profile on SEM806. With 6.9 seconds of cooling time time the measured horizontal emittance was 2.1 {pi} mm-mr using D:RJ306 v.s. 1.9 {pi} mm-mr using SEM806; but with 2.3 seconds of cooling the measured emittance in the debuncher was larger than in the DTOA line, 4.5 {pi} mm-mr v.s. 2.8 {pi} mm-mr. This suggests that some beam is being scraped on a horizontal aperture restriction someplace in the extraction process.

  3. Beam rotation and shear in a large electron beam diode

    SciTech Connect

    Mansfield, C.R.; Oona, H.; Shurter, R.P.

    1990-01-01

    The time averaged electron beam current distribution of one of the electron guns of the Large Aperture Module (LAM) of the Aurora laser was measured as part of a larger set of experiments designed to study the electron beam transport to and energy deposition in the LAM laser chamber. The LAM laser chamber has a 1-m {times} 1-m aperture and is pumped from two sides along a 2-m length. A 10 ga. stainless steel sheet was placed inside the laser chamber and served multiple purposes. First, it was used to convert high energy electrons into X-rays in order to make radiograms of the electron beam. Second, the sheet was used as a Faraday cup to measure the total beam current. Third, individual Faraday cups were mounted on the plate to sample the time history of the electron beam at various positions. Each of the LAM electron gun diodes produces a beam of 750 kV electrons with a total current of about 500 kA which is relatively uniform over the cathode area of 1 m {times} 2 m. An applied magnetic field of about 1300 Gauss is used to prevent pinch of the beam during beam transport.

  4. Understanding Laser Beam Quality Beyond M2

    NASA Astrophysics Data System (ADS)

    Soskind, Y. G.; Soskind, M. G.

    2016-09-01

    The laser beam M2 quality parameter is based on the second moments' theory, as defined by ISO standards, and provides a common approach for defining the propagation characteristics of laser beams as a whole. At the same time, the M2 parameter fails to quantitatively distinguish the quality of laser beams with different spatial characteristics. For example, several laser beams with very different spatial profiles may have the same M2 value. To overcome this ambiguity, a different beam quality criterion is introduced, allowing for a quantitative definition of both the structured laser beam shape and its propagation characteristics. This criterion, called the encircled power M2 (EPM2), bridges the gap between the M2 quality parameter and the structured laser beam shape. Based on several examples we demonstrate the utility of EPM2 as applied to characterization of several structured laser beam types.

  5. Buckling of composite beams (CDDF)

    NASA Technical Reports Server (NTRS)

    Thompson, P.

    1994-01-01

    Presented are the results of an investigation of the twisting/warping deformation occurring in open-section composite beams. A series of C and L channels were manufactured using both hand layup and the innovative 'hot-drape forming' techniques. A transverse tip load was applied at the free end of the cantilevered open-section beams. The test setup allowed the tip load to be applied at various locations along the plane of and at the beam's shear center. Charts are included in this report depicting various angles of ply layups, loads applied, and load application points. A major verification resulting from this study is that the shear center of an open section composite beam can be altered, if not completely controlled, through laminate layup. Also, it was observed that the choice of the material system does not have an effect on the amount of deformation, as expected, and the material affects the location of an unsymmetric open section composite beam's true shear center. The results from this study have provided a foundation for further investigation into the apparent shifting of the shear center location in open-section composite beams.

  6. Inclusive Production of Strange Particles at the CERN Proton-Antiproton Collider

    NASA Astrophysics Data System (ADS)

    Tan, Ching-Hua

    1994-01-01

    During the 1987 run of the CERN Proton-Antiproton Collider, at sqrt{s} = 630 GeV, the UA1 experiment collected about 2.4 times 10^6 (65 murm b^{-1}) events with a minimum bias trigger. An extensive study of the strange particle productions in this data set was performed. The measured masses of the strange particles are in very good agreement with the particle data group values and demonstrate the superb quality of the data. The production cross sections of K_sp{S}{0}, K^+/- , Lambda and |{Lambda} are measured. K_sp{S}{0 }, K^+/- production cross section measurements are in agreement with an available new NLO QCD prediction. The K_sp{S }{0} to the charged hadrons production ratio and that of Lambda + |{Lambda} to the charged hadrons as a function of multiplicity are measured. They are well explained by the quark model. We have also compared these features with those in heavy ion experiments. The strangeness suppression factor lambda is measured to be exactly the world average value. The average p_{t} of K _sp{S}{0}, K/ pi ratio and lambda are found to increase with sqrt{s}. The predictions for K/pi and lambda are made at the LHC energy 15 TeV pp collisions. The initial energy density that UA1 reached is given and the expectations at the LHC 6300 GeV/A Pb-Pb and RHIC Au-Au 200 GeV/A collisions are illustrated. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.).

  7. Measurement of Prompt Photon Production in 1.8-TeV Proton - Antiproton Collisions

    SciTech Connect

    Ino, Takashi

    1996-06-01

    The inclusive production cross section of prompt photons with transverse energies 27 < EtEt < 40 GeV and in pseudorapidity 1.32 < ηη < 2.22 has been measured in proton antiproton collisions at s√s = 1.8 TeV. Using the data recorded by the CDF detector during the 1988-1989 TEVATRON collider run, corresponding to an integrated lurminosity of 3.8 ± 0.1 pb-1 3995 prompt photon candidate events are selected in the endplug electromagnetic calorimeter. From differences in the longitudinal cascade shower profile between a single photon and multi-photons from π0π0 and ηη meson decays, the number of prompt photon events in the candidates is extracted to be 1972 ± 353.The differences in the shower shape are obtained by a GEANT3 based Monte Carlo detector simulation, which has been careful1y studied and found to wel1 reproduce the electromagnetic cascade of electrons at various energies as wel1 as incident angles. The inclusive production cross section has been obtained to be σσ = 1.44 ± 0.09(stat..) ± 0.27(syst.) nb. The measurement agrees with the next-to-leading order QCD calculation using recent parton distribution functions. The differential cross section with respect to pseudorapidity has also been measured and found to be in good agreement with the QCD calculation. The photon event fraction and its dependence on the photon isolation are studied. The isolation dependence of the photon event fraction shows a consistency with the QCD prediction. Future prospects of prompt photon measurernents in the endplug region for the new data, which has been col1ected during 1992 to 1995 correspondingto roughly 110 pb-1 are also discussed.

  8. Measurement of Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight in Antarctica

    NASA Technical Reports Server (NTRS)

    Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Kim, K. C.; Kusumoto, A.; Lee, M. H.; Makida, Y.; Matsuda, S.; Matsukawa, Y.; Mitchell, J. W.; Nishimura, J.; Nozaki, M.; Orito, R.; Ormes, J. F.; Sakai, K.; Sasaki, M.; Seo, E. S.; Shinoda, R.; Streitmatter, R. E.; Suzuki, J.; Tanaka, K.; Thakur, N.

    2011-01-01

    The energy spectrum of cosmic-ray antiprotons (p(raised bar)'s) collected by the BESS-Polar II instrument during a long-duration flight over Antarctica in the solar minimum period of December 2007 through January 2008. The p(raised bar) spectrum measured by BESS-Polar II shows good consistency with secondary p(raised bar) calculations. Cosmologically primary p(raised bar)'s have been searched for by comparing the observed and calculated p(raised bar) spectra. The BESSPolar II result shows no evidence of primary p(raised bar)'s originating from the evaporation of PBH.

  9. The GAPS Experiment: A Search for Dark Matter Using Low Energy Antiprotons and Antideuterons [University of Hawaii Co-I

    NASA Astrophysics Data System (ADS)

    von Doetinchem, Philip

    This is a Co-I proposal in support of the PI lead proposal entitled "The GAPS experiment: a search for dark matter using low energy antiprotons and antideuterons" submitted by Prof. Charles Hailey, Columbia University. Our proposed program would support the Umiversity of Hawaii at Manoa tasks on the GAPS experiment as detailed in our task statement. The primary focus of this work is the calibration and test of the Si(Li) detector modules, instrument simulation and support of the flight program and scientific analysis.

  10. The GAPS Experiement: A Search for Dark Matter Using Low Energy Antiprotons and Antideuterons [UCLA Co-I

    NASA Astrophysics Data System (ADS)

    Ong, Rene

    This is a Co-I proposal in support of the PI lead proposal entitled "The GAPS Experiment: A Search for Dark Matter Using Low Energy Antiprotons and Antideuterons" submitted by Prof. Charles Hailey, Columbia University. Our proposed program would support the UCLA tasks on the GAPS experiment as detailed in our task statement. The primary focus of this work is on the development, construction and testing of the time-of-flight (TOF) system, the master GAPS trigger and support of the simulation and analysis tasks.

  11. An experiment to measure the energy spectrum of cosmic ray antiprotons from 100 to 1000 MeV

    NASA Technical Reports Server (NTRS)

    Salamon, M. H.; Price, P. B.; Barwick, S. W.; Lowder, D. M.; Ahlen, S. P.

    1985-01-01

    Production models were developed and the confirmation of each one had significant astrophysical impact. These include radical modifications of propagation models, cosmic ray antiprotons injection from neighboring domains of antimatter, p production by evaporating primordial black holes, and cosmic ray p's as annihilation products of supersymmetry particles that might make up the dark dynamical mass of the Galaxy. It is that p's originating from supersymmetric parents might have distinct spectral features that would survive solar modulation; in one model, higgsino annihilation proceeds through the bb quark-antiquark channel, producing a spectral bump at approx. 0.3 GeV in the p spectrum.

  12. The W boson transverse momentum spectrum in proton-antiproton collisions at radical s = 1. 8 TeV

    SciTech Connect

    Winer, B.L.

    1991-02-01

    The Collider Detector at Fermilab (CDF) was used to measure the transverse momentum distribution of W boson produced in proton-antiproton collisions at the Tevatron collider. The W bosons were identified by the decay W {yields} e{nu}. The results are in good agreement with a next-to-leading order calculation. The cross section for W production with P{sub T} > 50 GeV/c is 423 {plus minus} 58 (stat.) {plus minus} 108 (sys.) pb. 58 refs., 53 figs., 16 tabs.

  13. Measurement of the Cosmic-Ray Antiproton Spectrum at Solar Minimum with a Long-Duration Balloon Flight over Antarctica

    NASA Technical Reports Server (NTRS)

    Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Kim, K. C.; Kusumoto, A.; Lee, M. H.; Makida, Y.; Matsuda, S.; Matsukawa, Y.; Mitchell, J. W.; Nishimura, J.; Nozaki, M.; Orito, R.; Ormes, J. F.; Sakai, K.; Sasaki, M.; Seo, E. S.; Shinoda, R.; Streitmatter, R. E.; Suzuki, J.; Tanaka, K.; Thakur, N.

    2012-01-01

    The energy spectrum of cosmic-ray antiprotons (p-bar's) from 0.17 to 3.5 GeV has been measured using 7886 p-bar's detected by BESS-Polar II during a long-duration flight over Antarctica near solar minimum in December 2007 and January 2008. This shows good consistency with secondary p-bar calculations. Cosmologically primary p-bar's have been investigated by comparing measured and calculated p-bar spectra. BESS-Polar II data.show no evidence of primary p-bar's from the evaporation of primordial black holes.

  14. Coherent beam-beam effects, theory & observations

    SciTech Connect

    Yuri I Alexahin

    2003-07-16

    Current theoretical understanding of the coherent beam-beam effect as well as its experimental observations are discussed: conditions under which the coherent beambeam modes may appear, possibility of their resonant interaction (coherent resonances), stability of beam-beam oscillations in the presence of external impedances. A special attention is given to the coherent beam-beam modes of finite length bunches: the synchro-betatron coupling is shown to provide reduction in the coherent tuneshift and--at the synchrotron tune values smaller than the beam-beam parameter--Landau damping by overlapping synchrotron satellites.

  15. OTR Measurements and Modeling of the Electron Beam Optics at the E-Cooling Facility

    NASA Astrophysics Data System (ADS)

    Warner, A.; Burov, A.; Carlson, K.; Kazakevich, G.; Nagaitsev, S.; Prost, L.; Sutherland, M.; Tiunov, M.

    2006-03-01

    Optics of the electron beam accelerated in the Pelletron, intended for the electron cooling of 8.9 GeV antiprotons in the Fermilab recycler storage ring, has been studied. The beam profile parameters were measured under the accelerating section using Optical Transition Radiation (OTR) monitor. The monitor employs a highly-reflective 2 inch-diameter aluminum OTR-screen with a thickness of 5 μm and a digital CCD camera. The measurements were done in a pulse-signal mode in the beam current range of 0.03-0.8 A and at pulse durations ranging from 1 μs to 4 μs. Differential profiles measured in pulsed mode are compared with results obtained by modeling of the DC beam dynamics from the Pelletron cathode to the OTR monitor. The modeling was done with SAM, ULTRASAM and BEAM programs. An adjustment of the magnetic fields in the lenses of the accelerating section was done in the simulations. The simulated electron beam optics downstream of the accelerating section was in good agreement with the measurements made with pulsed beam.

  16. Transverse digital damper system for the Fermilab anti-proton recycler

    SciTech Connect

    Eddy, N.; Crisp, J.; /Fermilab

    2006-05-01

    A transverse damping system is used in the Recycler at Fermilab to damp beam instabilities which arise from large beam intensities with electron cooling. Initial tests of electron cooling demonstrated beam loss due to transverse beam motion when the beam was cooled past the beam density threshold. The transverse damper system consists of two horizontal and two vertical pickups whose signals are amplified and passed into an analog hybrid to generate a difference signal from each pickup. The difference signals are input to a custom digital damper board which digitizes the analog signals at 212mhz, performs digital processing of the signals inside a large Altera Stratix II FPGA, then provides analog output at 212mhz via digital to analog converters. The digital damper output is sent to amplifiers which drive one horizontal and one vertical kicker. An initial prototype digital damper board has been successfully used in the Recycler for over six months. Currently, work is underway to replace the prototype board with an upgraded VME version.

  17. Applied Stratigraphy

    NASA Astrophysics Data System (ADS)

    Lucas, Spencer G.

    Stratigraphy is a cornerstone of the Earth sciences. The study of layered rocks, especially their age determination and correlation, which are integral parts of stratigraphy, are key to fields as diverse as geoarchaeology and tectonics. In the Anglophile history of geology, in the early 1800s, the untutored English surveyor William Smith was the first practical stratigrapher, constructing a geological map of England based on his own applied stratigraphy. Smith has, thus, been seen as the first “industrial stratigrapher,” and practical applications of stratigraphy have since been essential to most of the extractive industries from mining to petroleum. Indeed, gasoline is in your automobile because of a tremendous use of applied stratigraphy in oil exploration, especially during the latter half of the twentieth century. Applied stratigraphy, thus, is a subject of broad interest to Earth scientists.

  18. Golden beam data for proton pencil-beam scanning.

    PubMed

    Clasie, Benjamin; Depauw, Nicolas; Fransen, Maurice; Gomà, Carles; Panahandeh, Hamid Reza; Seco, Joao; Flanz, Jacob B; Kooy, Hanne M

    2012-03-07

    Proton, as well as other ion, beams applied by electro-magnetic deflection in pencil-beam scanning (PBS) are minimally perturbed and thus can be quantified a priori by their fundamental interactions in a medium. This a priori quantification permits an optimal reduction of characterizing measurements on a particular PBS delivery system. The combination of a priori quantification and measurements will then suffice to fully describe the physical interactions necessary for treatment planning purposes. We consider, for proton beams, these interactions and derive a 'Golden' beam data set. The Golden beam data set quantifies the pristine Bragg peak depth-dose distribution in terms of primary, multiple Coulomb scatter, and secondary, nuclear scatter, components. The set reduces the required measurements on a PBS delivery system to the measurement of energy spread and initial phase space as a function of energy. The depth doses are described in absolute units of Gy(RBE) mm² Gp⁻¹, where Gp equals 10⁹ (giga) protons, thus providing a direct mapping from treatment planning parameters to integrated beam current. We used these Golden beam data on our PBS delivery systems and demonstrated that they yield absolute dosimetry well within clinical tolerance.

  19. Electrostatic Confinement of Charged Particle Beams

    NASA Astrophysics Data System (ADS)

    Pacheco, Jose; Weathers, Duncan; Ordonez, Carlos

    2009-04-01

    Many experiments rely on the confinement of charged particles. Examples of these experiments range from fusion studies to antiproton-positron studies for antihydrogen production. Researchers have already developed a variety of techniques for controlling and trapping charged particles. Examples of systems devised for such purposes include electrostatic traps in the form of a cavity [1],[2] or in the form of a storage ring like ELISA [3]. For this project, we are pursuing a different approach [4], which relies on a purely electrostatic environment for ion confinement. This system consists of a periodic electrode configuration of cylindrical symmetry that acts to confine an ion beam in the radial direction. In this manner, it is expected that long particle lifetimes inside the trap will be achieved, and that the system will have an inherent scalability to different ion energy. Results obtained from simulation of the proposed system will be presented and discussed along with a brief overview of the steps taken to develop a laboratory prototype. [1] M. Dahan et al., Rev. Sci. Instr. 69 (1998) 76. [2] H. F. Krause et al., American Institute of Physics. CAARI 16^th Int'l Conf. (2001). [3] S.P. Moller et al., Proc. of the 1997 Particle Accelerator Conference. vol 1. pp 1027-1029. Vancouver, Canada. May 1997. [4] J.R. Correa et al., Nucl. Instr. and Meth. In Phys. Res. B 241 (2005) 909-912.

  20. Effect of the coupling channel on the excitation of hydrogenic atoms by the impact of protons and antiprotons

    NASA Astrophysics Data System (ADS)

    Tantawi, Reda S.

    2014-02-01

    Excitation of hydrogenic atoms H, He+ and Li++ initially in the 2p excited state to the n = 3 states by impact of protons and antiprotons is studied using the single-center atomic orbital close-coupling formalism in its impact parameter approach. The calculations cover the incident energy range from 1 to 1000 keV, in which the straight-line trajectory description of nuclear motion is applicable and the inertial confinement plasma research is of main interest. The influences of couplings between the n = 2 states, as well as the back coupling to the 2p initial state, on the excitation processes are investigated. Including the back couplings is found to be more important in the case of proton scattering than in the case of antiproton, and neglecting couplings between the n = 2 states is found to increase the effect of the sign of the projectile's charge. The calculated cross sections for the H atom are compared with those obtained by previous theoretical calculations.

  1. Galactic cosmic-ray propagation in the light of AMS-02: Analysis of protons, helium, and antiprotons

    NASA Astrophysics Data System (ADS)

    Korsmeier, Michael; Cuoco, Alessandro

    2016-12-01

    We present novel constraints on cosmic-ray propagation in the Galaxy using the recent precise measurements of proton and helium spectra from AMS-02, together with preliminary AMS-02 data on the antiproton over proton ratio. To explore efficiently the large (up to 11-dimensional) parameter space we employ the nested-sampling algorithm as implemented in the MultiNest package, interfaced with the Galprop code to compute the model-predicted spectra. We use VOYAGER proton and helium data, sampling the local interstellar spectra, to constrain the solar modulation potential. We find that the turbulence of the Galactic magnetic field is well constrained, i.e., δ =0.3 0-0.02+0.03(stat )-0.04+0.10(sys ) , with uncertainties dominated by systematic effects. Systematic uncertainties are determined checking the robustness of the results to the minimum rigidity cut used to fit the data (from 1 GV to 5 GV), to the propagation scenario (convection vs no convection), and to the uncertainties in the knowledge of the antiproton production cross section. Convection and reacceleration are found to be degenerate and not well constrained singularly when using data above 5 GV. Using data above 1 GV reacceleration is required, vA=25 ±2 km /s , although this value might be significantly affected by the low-energy systematic uncertainty in the solar modulation. In a forthcoming companion paper, we investigate the constraints imposed by AMS-02 measurements on lithium, boron, and carbon.

  2. Applied oceanography

    SciTech Connect

    Bishop, J.M.

    1984-01-01

    This book combines oceanography principles and applications such as marine pollution, resources, and transportation. It is divided into two main parts treating the basic principles of physical oceanography, and presenting a unique systems framework showing how physical oceanography, marine ecology, economics, and government policy may be combined to define the newly developing field of applied oceanography.

  3. Applied Enzymology.

    ERIC Educational Resources Information Center

    Manoharan, Asha; Dreisbach, Joseph H.

    1988-01-01

    Describes some examples of chemical and industrial applications of enzymes. Includes a background, a discussion of structure and reactivity, enzymes as therapeutic agents, enzyme replacement, enzymes used in diagnosis, industrial applications of enzymes, and immobilizing enzymes. Concludes that applied enzymology is an important factor in…

  4. Tailored Positron Beams from Trapped Single-component Plasmas

    NASA Astrophysics Data System (ADS)

    Weber, T. R.

    2009-11-01

    There are a number of important uses of antiparticles (e.g., positrons and antiprotons) including the creation of antihydrogen, modeling astrophysical processes, and the characterization of materials and material surfaces. Much of this progress has been driven by the development of new plasma techniques to accumulate, manipulate and store antiparticles. This talk focuses on recent workfootnotetextT. R. Weber, J. R. Danielson and C. M. Surko, Phys. Plasmas 15, 012106 (2008).^,footnotetextT. R. Weber, J. R. Danielson and C. M. Surko, Phys. Plasmas 16, 057105 (2009). to create specially tailored positron beams with small transverse spatial extent ρb, narrow energy spreads δE, and high brightness by pulsed extraction from plasmas in a Penning-Malmberg trap. Experiments are presented using electron plasmas for increased data rate. By briefly lowering the exit-gate potential, beam pulses (δt < 10 μsec) from near the plasma center are created with ρb= 2 λD (HW 1/e) and δE T, where λD is the plasma Debye length, and T is the plasma temperature. Specifically, by tailoring the plasma temperature to T 25 meV and density to n0 10^10 cm-3, beams are created with δE < 35 meV and ρb< 50 μm. A nonlinear model for beam extraction is used to derive expressions for the beam amplitude Nb, transverse spatial profile σb(r), and single particle energy distribution as a function of the exit-gate potential VE, trap wall radius RW, and plasma parameters.^3 All predictions are verified for a wide range of plasmas. Protocols to optimize ρb and δE for various applications will be discussed. Prospects for cryogenic beams and pulsed extraction from the confining B field (to B = 0, for brightness enhancement and electrostatic focusing) will be discussed along with selected applications.

  5. Generation of electron Airy beams.

    PubMed

    Voloch-Bloch, Noa; Lereah, Yossi; Lilach, Yigal; Gover, Avraham; Arie, Ady

    2013-02-21

    Within the framework of quantum mechanics, a unique particle wave packet exists in the form of the Airy function. Its counterintuitive properties are revealed as it propagates in time or space: the quantum probability wave packet preserves its shape despite dispersion or diffraction and propagates along a parabolic caustic trajectory, even though no force is applied. This does not contradict Newton's laws of motion, because the wave packet centroid propagates along a straight line. Nearly 30 years later, this wave packet, known as an accelerating Airy beam, was realized in the optical domain; later it was generalized to an orthogonal and complete family of beams that propagate along parabolic trajectories, as well as to beams that propagate along arbitrary convex trajectories. Here we report the experimental generation and observation of the Airy beams of free electrons. These electron Airy beams were generated by diffraction of electrons through a nanoscale hologram, which imprinted on the electrons' wavefunction a cubic phase modulation in the transverse plane. The highest-intensity lobes of the generated beams indeed followed parabolic trajectories. We directly observed a non-spreading electron wavefunction that self-heals, restoring its original shape after passing an obstacle. This holographic generation of electron Airy beams opens up new avenues for steering electronic wave packets like their photonic counterparts, because the wave packets can be imprinted with arbitrary shapes or trajectories.

  6. Composite box beam analysis - Theory and experiments

    NASA Technical Reports Server (NTRS)

    Bauchau, O. A.; Coffenberry, B. S.; Rehfield, L. W.

    1987-01-01

    Beam theory is widely used as a first approximation in numerous structural applications. When applied to composite beams, the accuracy of beam theory becomes questionable because (1) the shearing and warping deformations become significant, as the shearing stiffness of composite laminates is often very low, and (2) several elastic couplings can occur that strongly influence the behavior of composite beams. The torsional behavior of thin-walled composite beams has important implications for aeronautical structures and is deeply modified by the above nonclassical effects. This paper presents two comprehensive analysis methodologies for composite beams and describes experimental results obtained from a thin-walled, rectangular cross-sectional beam. The theoretical predictions are found in good agreement with the observed twist and strain distributions. Out-of-plane torsional warping of the cross-section is found to be the key factor for an accurate modeling of the torsional behavior of such structures.

  7. Spiral laser beams in inhomogeneous media.

    PubMed

    Mahalov, Alex; Suazo, Erwin; Suslov, Sergei K

    2013-08-01

    Explicit solutions of the inhomogeneous paraxial wave equation in a linear and quadratic approximation are applied to wave fields with invariant features, such as oscillating laser beams in a parabolic waveguide and spiral light beams in varying media. A similar effect of superfocusing of particle beams in a thin monocrystal film, harmonic oscillations of cold trapped atoms, and motion in magnetic field are also mentioned.

  8. Beam geometry selection using sequential beam addition

    SciTech Connect

    Popple, Richard A. Brezovich, Ivan A.; Fiveash, John B.

    2014-05-15

    Purpose: The selection of optimal beam geometry has been of interest since the inception of conformal radiotherapy. The authors report on sequential beam addition, a simple beam geometry selection method, for intensity modulated radiation therapy. Methods: The sequential beam addition algorithm (SBA) requires definition of an objective function (score) and a set of candidate beam geometries (pool). In the first iteration, the optimal score is determined for each beam in the pool and the beam with the best score selected. In the next iteration, the optimal score is calculated for each beam remaining in the pool combined with the beam selected in the first iteration, and the best scoring beam is selected. The process is repeated until the desired number of beams is reached. The authors selected three treatment sites, breast, lung, and brain, and determined beam arrangements for up to 11 beams from a pool comprised of 25 equiangular transverse beams. For the brain, arrangements were additionally selected from a pool of 22 noncoplanar beams. Scores were determined for geometries comprised equiangular transverse beams (EQA), as well as two tangential beams for the breast case. Results: In all cases, SBA resulted in scores superior to EQA. The breast case had the strongest dependence on beam geometry, for which only the 7-beam EQA geometry had a score better than the two tangential beams, whereas all SBA geometries with more than two beams were superior. In the lung case, EQA and SBA scores monotonically improved with increasing number of beams; however, SBA required fewer beams to achieve scores equivalent to EQA. For the brain case, SBA with a coplanar pool was equivalent to EQA, while the noncoplanar pool resulted in slightly better scores; however, the dose-volume histograms demonstrated that the differences were not clinically significant. Conclusions: For situations in which beam geometry has a significant effect on the objective function, SBA can identify

  9. Search for Wh Production Using High-PT Isolated Like-Sign Dilepton Events in 1.96-TeV Proton-Antiproton Collisions

    SciTech Connect

    Wakisaka, Takayuki

    2009-04-01

    The thesis describes search for the neutral Higgs production associated with the W boson using high-PT isolated like-sign (LS) dilepton events in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV.

  10. Applied Nanotoxicology

    PubMed Central

    Hobson, David W.; Roberts, Stephen M.; Shvedova, Anna A.; Warheit, David B.; Hinkley, Georgia K.; Guy, Robin C.

    2016-01-01

    Nanomaterials, including nanoparticles and nanoobjects, are being incorporated into everyday products at an increasing rate. These products include consumer products of interest to toxicologists such as pharmaceuticals, cosmetics, food, food packaging, household products, and so on. The manufacturing of products containing or utilizing nanomaterials in their composition may also present potential toxicologic concerns in the workplace. The molecular complexity and composition of these nanomaterials are ever increasing, and the means and methods being applied to characterize and perform useful toxicologic assessments are rapidly advancing. This article includes presentations by experienced toxicologists in the nanotoxicology community who are focused on the applied aspect of the discipline toward supporting state of the art toxicologic assessments for food products and packaging, pharmaceuticals and medical devices, inhaled nanoparticle and gastrointestinal exposures, and addressing occupational safety and health issues and concerns. This symposium overview article summarizes 5 talks that were presented at the 35th Annual meeting of the American College of Toxicology on the subject of “Applied Nanotechnology.” PMID:26957538

  11. Electro-optic Waveguide Beam Deflector.

    DTIC Science & Technology

    beam deflection by variation in the electro - optic effect produced within the waveguide region in response to known or determinable magnitude variations in the electrical potential of an applied signal source.

  12. Applied geodesy

    SciTech Connect

    Turner, S.

    1987-01-01

    This volume is based on the proceedings of the CERN Accelerator School's course on Applied Geodesy for Particle Accelerators held in April 1986. The purpose was to record and disseminate the knowledge gained in recent years on the geodesy of accelerators and other large systems. The latest methods for positioning equipment to sub-millimetric accuracy in deep underground tunnels several tens of kilometers long are described, as well as such sophisticated techniques as the Navstar Global Positioning System and the Terrameter. Automation of better known instruments such as the gyroscope and Distinvar is also treated along with the highly evolved treatment of components in a modern accelerator. Use of the methods described can be of great benefit in many areas of research and industrial geodesy such as surveying, nautical and aeronautical engineering, astronomical radio-interferometry, metrology of large components, deformation studies, etc.

  13. Relativistic electron beam generator

    DOEpatents

    Mooney, L.J.; Hyatt, H.M.

    1975-11-11

    A relativistic electron beam generator for laser media excitation is described. The device employs a diode type relativistic electron beam source having a cathode shape which provides a rectangular output beam with uniform current density.

  14. Laser beam monitoring system

    DOEpatents

    Weil, Bradley S.; Wetherington, Jr., Grady R.

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  15. Signatures of a Two Million Year Old Supernova in the Spectra of Cosmic Ray Protons, Antiprotons, and Positrons.

    PubMed

    Kachelrieß, M; Neronov, A; Semikoz, D V

    2015-10-30

    The locally observed cosmic ray spectrum has several puzzling features, such as the excess of positrons and antiprotons above ~20  GeV and the discrepancy in the slopes of the spectra of cosmic ray protons and heavier nuclei in the TeV-PeV energy range. We show that these features are consistently explained by a nearby source which was active approximately two million years ago and has injected (2-3)×10^{50} erg in cosmic rays. The transient nature of the source and its overall energy budget point to the supernova origin of this local cosmic ray source. The age of the supernova suggests that the local cosmic ray injection was produced by the same supernova that has deposited ^{60}Fe isotopes in the deep ocean crust.

  16. Midrapidity antiproton-to-proton ratio from Au+Au collisions at sqrt [s(NN)]=130 GeV.

    PubMed

    Adler, C; Ahammed, Z; Allgower, C; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Bossingham, R; Boucham, A; Brandin, A; Caines, H; de la Barca Sánchez, M C; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chattopadhyay, S; Chen, M L; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Conin, L; Cormier, T M; Cramer, J G; Crawford, H J; DeMello, M; Deng, W S; Derevschikov, A A; Didenko, L; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Ferguson, M I; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Gagunashvili, N; Gans, J; Germain, M; Geurts, F; Ghazikhanian, V; Grabski, J; Grachov, O; Greiner, D; Grigoriev, V; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heffner, M; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Hümmler, H; Igo, G J; Ishihara, A; Ivanshin, Y I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Khodinov, A; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lamas-Valverde, J; Lamont, M A; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; LeCompte, T; Leontiev, V M; Leszczynski, P; LeVine, M J; Li, Q; Li, Q; Lindenbaum, S J; Lisa, M A; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lynn, D; Madansky, L; Majka, R; Maliszewski, A; Margetis, S; Martin, L; Marx, J; Matis, H S; Matulenko, Y A; McShane, T S; Melnick, Y; Meschanin, A; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moltz, D; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Nystrand, J; Odyniec, G; Ogawa, A; Ogilvie, C A; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Pinganaud, W; Platner, E; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Radomski, S; Rai, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Roy, C; Russ, D; Rykov, V; Sakrejda, I; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Seger, J; Seliverstov, D; Seyboth, P; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Stroebele, H; Struck, C; Suaide, A A; Sugarbaker, E; Suire, C; Symons, T J; Szanto de Toledo, A; Szarwas, P; Takahashi, J; Tang, A H; Thomas, J H; Tikhomirov, V; Trainor, T; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vanyashin, A; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Wells, R; Wenaus, T; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; 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; Zoulkarneev, R; Zubarev, A N

    2001-05-21

    We report results on the ratio of midrapidity antiproton-to-proton yields in Au+Au collisions at sqrt[s(NN)] = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of /y/<0.5 and 0.4

  17. Observation and study of bottom-meson decays to a charm meson, a proton-antiproton pair, and pions

    SciTech Connect

    Hong, Tae Min

    2010-04-27

    Bottom-meson decays with baryons show two unusual features—the branching fractions are enhanced for multibody decays and the baryon-antibaryon subsystem recoils against the other decay products—and their reasons are not yet well understood. Moreover, measurements using explicit reconstruction techniques constitute only about 1% out of about 8% of such decays. This Dissertation reports the study of ten bottom-meson decays (labeled 0– 9) to a proton-antiproton pair, a charm meson, and a system of up to two pions, using the BABAR Experiment’s 455×106 BB pairs produced with the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center.

  18. Phenomenological study of exclusive binary light particle production from antiproton-proton annihilation at FAIR/PANDA

    NASA Astrophysics Data System (ADS)

    Ying, Wang

    2016-08-01

    Exclusive binary annihilation reactions induced by antiprotons of momentum from 1.5 to 15 GeV/c can be extensively investigated at FAIR/PANDA [1]. We are especially interested in the channel of charged pion pairs. Whereas this very probable channel constitutes the major background for other processes of interest in the PANDA experiment, it carries unique physical information on the quark content of proton, allowing to test different models (quark counting rules, statistical models,..). To study the binary reactions of light meson formation, we are developing an effective Lagrangian model based on Feynman diagrams which takes into account the virtuality of the exchanged particles. Regge factors [2] and form factors are introduced with parameters which may be adjusted on the existing data. We present preliminary results of our formalism for different reactions of light meson production leading to reliable predictions of cross sections, energy and angular dependencies in the PANDA kinematical range.

  19. Erratum: Cosmic-Ray Antiproton Flux in the Energy Range from 200 to 600 MeV

    NASA Astrophysics Data System (ADS)

    Moiseev, A.; Yoshimura, K.; Ueda, I.; Anraku, K.; Golden, R.; Imori, M.; Inaba, S.; Kimbell, B.; Kimura, N.; Makida, Y.; Matsumoto, H.; Matsunaga, H.; Mitchell, J.; Motoki, M.; Nishimura, J.; Nozaki, M.; Orito, S.; Ormes, J.; Saeki, T.; Seo, E. S.; Stochaj, S.; Streitmatter, R.; Suzuki, J.; Tanaka, K.; Yajima, N.; Yamagami, T.; Yamamoto, A.; Yoshida, T.

    1997-06-01

    In the paper ``Cosmic-Ray Antiproton Flux in the Energy Range from 200 to 600 MeV'' by A. Moiseev, K. Yoshimura, I. Ueda, K. Anraku, R. Golden, M. Imori, S. Inaba, B. Kimbell, N. Kimura, Y. Makida, H. Matsumoto, H. Matsunaga, J. Mitchell, M. Motoki, J. Nishimura, M. Nozaki, S. Orito, J. Ormes, T. Saeki, E. S. Seo, S. Stochaj, R. Streitmatter, J. Suzuki, K. Tanaka, N. Yajima, T. Yamagami, A. Yamamoto, and T. Yoshida (BESS Collaboration) (ApJ, 474, 479 [1997]), there is an error in the horizontal axis labels of Figures 7a-7c. The labels should read ``Particle momentum, MeV/c,'' as given in the text.

  20. Properties of W + jet events in proton-antiproton collisions at 1.8 TeV

    SciTech Connect

    Drucker, Robert Brian

    1993-11-22

    W boson + QCD Jet events, produced in 1.8 TeV proton-antiproton collisions and measured by the Collider Detector at Fermilab (CDF), were used to measure the center-of-mass production angle of the W + jet system, and were also used to place limits on the production of excited quark states. The center-of-mass production angular distribution agrees well with leading order and next-to-leading order QCD predictions. Excited quark states were searched for in the reaction q + g → q* → q + W. Upper limits on the q* cross section, as a function of the q* mass, are shown. Comparison with a theoretical prediction for q* production excludes excited quark states with a mass in the range 150--530 GeV/c2, at 95% confidence.

  1. Search for new particles decaying into dijets in proton-antiproton collisions at s=1.96TeV

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Azzurri, P.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Bartsch, V.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Beringer, J.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R. E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bolla, G.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H. S.; Budd, S.; Burke, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S. H.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Choudalakis, G.; Chuang, S. H.; Chung, K.; Chung, W. H.; Chung, Y. S.; Chwalek, T.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M. E.; Conway, J.; Cordelli, M.; Cortiana, G.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Cully, J. C.; Dagenhart, D.; Datta, M.; Davies, T.; de Barbaro, P.; de Cecco, S.; Deisher, A.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Derwent, P. F.; di Giovanni, G. P.; Dionisi, C.; di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Donini, J.; Dorigo, T.; Dube, S.; Efron, J.; Elagin, A.; Erbacher, R.; Errede, D.; Errede, S.; Eusebi, R.; Fang, H. C.; Farrington, S.; Fedorko, W. T.; Feild, R. G.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J. E.; Garfinkel, A. F.; Genser, K.; Gerberich, H.; Gerdes, D.; Gessler, A.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Gimmell, J. L.; Ginsburg, C. M.; Giokaris, N.; Giordani, M.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Grundler, U.; Guimaraes da Costa, J.; Gunay-Unalan, Z.; Haber, C.; Hahn, K.; Hahn, S. R.; Halkiadakis, E.; Han, B.-Y.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harper, S.; Harr, R. F.; Harris, R. M.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heijboer, A.; Heinrich, J.; Henderson, C.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hidas, D.; Hill, C. S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.-C.; Huffman, B. T.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Jung, J. E.; Junk, T. R.; Kamon, T.; Kar, D.; Karchin, P. E.; Kato, Y.; Kephart, R.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Knuteson, B.; Ko, B. R.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kubo, T.; Kuhr, T.; Kulkarni, N. P.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lin, C.-S.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, T.; Lockyer, N. S.; Loginov, A.; Loreti, M.; Lovas, L.; Lucchesi, D.; Luci, C.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maki, T.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C. P.; Martin, A.; Martin, V.; Martínez, M.; Martínez-Ballarín, R.; Maruyama, T.; Mastrandrea, P.; Masubuchi, T.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Merkel, P.; Mesropian, C.; Miao, T.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mülmenstädt, J.; Mukherjee, A.; Muller, Th.; Mumford, R.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Nagano, A.; Naganoma, J.; Nakamura, K.; Nakano, I.; Napier, A.; Necula, V.; Nett, J.; Neu, C.; Neubauer, M. S.; Neubauer, S.; Nielsen, J.; Nodulman, L.; Norman, M.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Osterberg, K.; Pagan Griso, S.; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramonov, A. A.; Parks, B.; Pashapour, S.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Peiffer, T.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pinera, L.; Pitts, K.; Plager, C.; Pondrom, L.; Poukhov, O.; Pounder, N.; Prakoshyn, F.; Pronko, A.; Proudfoot, J.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rademacker, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Renz, M.; Rescigno, M.; Richter, S.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rossin, R.; Roy, P.; Ruiz, A.; Russ, J.; Rusu, V.; Saarikko, H.; Safonov, A.; Sakumoto, W. K.; Saltó, O.; Santi, L.; Sarkar, S.; Sartori, L.; Sato, K.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E. E.; Schmidt, M. A.; Schmidt, M. P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sexton-Kennedy, L.; Sforza, F.; Sfyrla, A.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shon, Y.; Shreyber, I.; Sidoti, A.; Sinervo, P.; Sisakyan, A.; Slaughter, A. J.; Slaunwhite, J.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Snihur, R.; Soha, A.; Somalwar, S.; Sorin, V.; Spalding, J.; Spreitzer, T.; Squillacioti, P.; Stanitzki, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G. L.; Stuart, D.; Suh, J. S.; Sukhanov, A.; Suslov, I.; Suzuki, T.; Taffard, A.; Takashima, R.; Takeuchi, Y.; Tanaka, R.; Tecchio, M.; Teng, P. K.; Terashi, K.; Thom, J.; Thompson, A. S.; Thompson, G. A.; Thomson, E.; Tipton, P.; Ttito-Guzmán, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Tourneur, S.; Trovato, M.; Tsai, S.-Y.; Tu, Y.; Turini, N.; Ukegawa, F.; Vallecorsa, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vidal, R.; Vila, I.; Vilar, R.; Vine, T.; Vogel, M.; Volobouev, I.; Volpi, G.; Wagner, P.; Wagner, R. G.; Wagner, R. L.; Wagner, W.; Wagner-Kuhr, J.; Wakisaka, T.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Weinberger, M.; Weinelt, J.; Wester, W. C., III; Whitehouse, B.; Whiteson, D.; Wicklund, A. B.; Wicklund, E.; Wilbur, S.; Williams, G.; Williams, H. H.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, C.; Wright, T.; Wu, X.; Würthwein, F.; Xie, S.; Yagil, A.; Yamamoto, K.; Yamaoka, J.; Yang, U. K.; Yang, Y. C.; Yao, W. M.; Yeh, G. P.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Yu, S. S.; Yun, J. C.; Zanello, L.; Zanetti, A.; Zhang, X.; Zheng, Y.; Zucchelli, S.

    2009-06-01

    We present a search for new particles which produce narrow two-jet (dijet) resonances using proton-antiproton collision data corresponding to an integrated luminosity of 1.13fb-1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude |y|<1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E6 diquark, color-octet techni-ρ, W', and Z'.

  2. Beam imaging sensor

    DOEpatents

    McAninch, Michael D.; Root, Jeffrey J.

    2016-07-05

    The present invention relates generally to the field of sensors for beam imaging and, in particular, to a new and useful beam imaging sensor for use in determining, for example, the power density distribution of a beam including, but not limited to, an electron beam or an ion beam. In one embodiment, the beam imaging sensor of the present invention comprises, among other items, a circumferential slit that is either circular, elliptical or polygonal in nature.

  3. Tunable beam displacer

    SciTech Connect

    Salazar-Serrano, Luis José; Valencia, Alejandra; Torres, Juan P.

    2015-03-15

    We report the implementation of a tunable beam displacer, composed of a polarizing beam splitter (PBS) and two mirrors, that divides an initially polarized beam into two parallel beams whose separation can be continuously tuned. The two output beams are linearly polarized with either vertical or horizontal polarization and no optical path difference is introduced between them. The wavelength dependence of the device as well as the maximum separation between the beams achievable is limited mainly by the PBS characteristics.

  4. BEAM INSTRUMENTATION FOR HIGH POWER HADRON BEAMS

    SciTech Connect

    Aleksandrov, Alexander V

    2013-01-01

    This presentation will describe developments in the beam diagnostics which support the understanding and operation of high power hadron accelerators. These include the measurement of large dynamic range transverse and longitudinal beam profiles, beam loss detection, and non-interceptive diagnostics.

  5. Propagation-invariant beams with quantum pendulum spectra: from Bessel beams to Gaussian beam-beams.

    PubMed

    Dennis, Mark R; Ring, James D

    2013-09-01

    We describe a new class of propagation-invariant light beams with Fourier transform given by an eigenfunction of the quantum mechanical pendulum. These beams, whose spectra (restricted to a circle) are doubly periodic Mathieu functions in azimuth, depend on a field strength parameter. When the parameter is zero, pendulum beams are Bessel beams, and as the parameter approaches infinity, they resemble transversely propagating one-dimensional Gaussian wave packets (Gaussian beam-beams). Pendulum beams are the eigenfunctions of an operator that interpolates between the squared angular momentum operator and the linear momentum operator. The analysis reveals connections with Mathieu beams, and insight into the paraxial approximation.

  6. Buckling of continuously supported hinged beams

    NASA Technical Reports Server (NTRS)

    Murthy, G. K. N.

    1975-01-01

    The effect on the buckling load of a hinge at the center of an infinite beam supported by a semiinfinite elastic continuum is analyzed using the complex Fourier transforms. An expression is obtained for the relationship between the surface deflection of the elastic continuum and the pressure distribution acting on the surface, and solutions are obtained for the assumed form of the pressure distribution below the beam. The analysis is applied to cases of uniform pressure over the width of the beam and a pressure distribution that occurs below a rigid stamp. The results show that the buckling loads for an infinite beam with a hinge at the center and supported by a semiinfinite elastic continuum are approximately one half of those for a beam without a hinge, and that this ratio is exactly one half for an infinite beam resting on a Winkler foundation.

  7. High-powered pulsed-ion-beam acceleration and transport

    SciTech Connect

    Humphries, S. Jr.; Lockner, T.R.

    1981-11-01

    The state of research on intense ion beam acceleration and transport is reviewed. The limitations imposed on ion beam transport by space charge effects and methods available for neutralization are summarized. The general problem of ion beam neutralization in regions free of applied electric fields is treated. The physics of acceleration gaps is described. Finally, experiments on multi-stage ion acceleration are summarized.

  8. Coupled-Beam and Coupled-Bunch Instabilities

    SciTech Connect

    Burov, Alexey

    2016-06-23

    A problem of coupled-beam instability is solved for two multibunch beams with slightly different revolution frequencies, as in the Fermilab Recycler Ring (RR). Sharing of the inter-bunch growth rates between the intra-bunch modes is described. The general analysis is applied to the RR; possibilities to stabilize the beams by means of chromaticity, feedback and Landau damping are considered.

  9. Beam quality measurements using digitized laser beam images

    SciTech Connect

    Duncan, M.D. ); Mahon, R. )

    1989-11-01

    A method is described for measuring various laser beam characteristics with modest experimental complexity by digital processing of the near and far field images. Gaussian spot sizes, peak intensities, and spatial distributions of the images are easily found. Far field beam focusability is determined by computationally applying apertures of circular of elliptical diameters to the digitized image. Visualization of the magnitude of phase and intensity distortions is accomplished by comparing the 2-D fast Fourier transform of both smoothed and unsmoothed near field data to the actual far field data. The digital processing may be performed on current personal computers to give the experimenter unprecedented capabilities for rapid beam characteriztion at relatively low cost.

  10. Antenna Beam Coverage Concepts

    NASA Technical Reports Server (NTRS)

    Estabrook, Polly; Motamedi, Masoud

    1990-01-01

    The strawman Personal Access Satellite System (PASS) design calls for the use of a CONUS beam for transmission between the supplier and the satellite and for fixed beams for transmission between the basic personal terminal and the satellite. The satellite uses a 3 m main reflector for transmission at 20 GHz and a 2 m main reflector for reception at 30 GHz. There are several types of spot beams under consideration for the PASS system besides fixed beams. The beam pattern of a CONUS coverage switched beam is shown along with that of a scanning beam. A switched beam refers to one in which the signal from the satellite is connected alternatively to various feed horns. Scanning beams are taken to mean beams whose footprints are moved between contiguous regions in the beam's coverage area. The advantages and disadvantages of switched and/or scanning beams relative to fixed beams. The consequences of using switched/scanning in lieu of fixed beams in the PASS design and attempts are made to evaluate the listed advantages and disadvantages. Two uses of switched/scanning beams are examined. To illustrate the implications of switched beams use on PASS system design, operation at two beam scan rates is explored.

  11. Dynamics of Charged Particles in an Adiabatic Thermal Beam Equilibrium

    NASA Astrophysics Data System (ADS)

    Chen, Chiping; Wei, Haofei

    2010-11-01

    Charged-particle motion is studied in the self-electric and self-magnetic fields of a well-matched, intense charged-particle beam and an applied periodic solenoidal magnetic focusing field. The beam is assumed to be in a state of adiabatic thermal equilibrium. The phase space is analyzed and compared with that of the well-known Kapchinskij-Vladimirskij (KV)-type beam equilibrium. It is found that the widths of nonlinear resonances in the adiabatic thermal beam equilibrium are narrower than those in the KV-type beam equilibrium. Numerical evidence is presented, indicating almost complete elimination of chaotic particle motion in the adiabatic thermal beam equilibrium.

  12. A symplectic coherent beam-beam model

    SciTech Connect

    Furman, M.A.

    1989-05-01

    We consider a simple one-dimensional model to study the effects of the beam-beam force on the coherent dynamics of colliding beams. The key ingredient is a linearized beam-beam kick. We study only the quadrupole modes, with the dynamical variables being the 2nd-order moments of the canonical variables q, p. Our model is self-consistent in the sense that no higher order moments are generated by the linearized beam-beam kicks, and that the only source of violation of symplecticity is the radiation. We discuss the round beam case only, in which vertical and horizontal quantities are assumed to be equal (though they may be different in the two beams). Depending on the values of the tune and beam intensity, we observe steady states in which otherwise identical bunches have sizes that are equal, or unequal, or periodic, or behave chaotically from turn to turn. Possible implications of luminosity saturation with increasing beam intensity are discussed. Finally, we present some preliminary applications to an asymmetric collider. 8 refs., 8 figs.

  13. Shaping nondiffracting beams with a differential operator approach

    NASA Astrophysics Data System (ADS)

    Lopez-Mago, Dorilian; Gutiérrez-Vega, Julio C.

    2016-09-01

    The commutation between the Helmholtz equation and the derivative operator allows us to generate novel nondiffracting beams. We apply a general differential operator to Bessel beams and study the resulting phase structure and orbital angular momentum (OAM). We find the parameters that preserve the OAM of the seed beam and show how to produce and control shape preserving vortex arrays. In analogy to the Poincaré sphere, our approach is used to develop an operator sphere connecting higher-order Bessel beams.

  14. Coherent beam amplification with a photorefractive liquid crystal.

    PubMed

    Khoo, I C; Guenther, B D; Wood, M V; Chen, P; Shih, M Y

    1997-08-15

    Coherent amplification of a signal beam by a strong pump beam is observed in thin films of fullerene-doped nematic liquid crystal. Exponential gain constants as high as 2890 cm(-1) with no phase cross talk are achieved at low applied dc bias voltage and pump beam intensity. The underlying mechanism is the electro-optically induced spatially reorientation of the liquid-crystal axis and the resultant phase-shifted index grating required for two-beam coupling.

  15. On Solutions for the Transient Response of Beams

    NASA Technical Reports Server (NTRS)

    Leonard, Robert W.

    1959-01-01

    Williams type modal solutions of the elementary and Timoshenko beam equations are presented for the response of several uniform beams to a general applied load. Example computations are shown for a free-free beam subject to various concentrated loads at its center. Discussion includes factors influencing the convergence of modal solutions and factors to be considered in a choice of beam theory. Results obtained by two numerical procedures, the traveling-wave method and Houbolt's method, are also presented and discussed.

  16. RHIC electron lens beam transport system design considerations

    SciTech Connect

    Luo, Y.; Heimerle, M.; Fischer, W.; Pikin, A.; Beebe, E.; Bruno, D.; Gassner, D.; Gu, X.; Gupta, R. C.; Hock, J.; Jain, A.; Lambiase, R.; Mapes, M.; Meng, W.; Montag, C.; Oerter, B.; Okamura, M.; Raparia, D.; Tan, Y.; Than, R.; Tuozzolo, J.; Zhang, W.

    2010-08-03

    To apply head-on beam-beam compensation for RHIC, two electron lenses are designed and will be installed at IP6 and IP8. Each electron lens has several sub-systems, including electron gun, electron collector, superconducting main solenoid (SM), diagnostics system and power supply system. In addition to these systems, beam transport system which can transport electron beam from electron gun side to collector side is also needed.

  17. Telecommunication using muon beams

    DOEpatents

    Arnold, Richard C.

    1976-01-01

    Telecommunication is effected by generating a beam of mu mesons or muons, varying a property of the beam at a modulating rate to generate a modulated beam of muons, and detecting the information in the modulated beam at a remote location.

  18. LANSCE beam current limiter

    SciTech Connect

    Gallegos, F.R.

    1996-06-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described.

  19. Classical-trajectory Monte Carlo calculations of the electronic stopping cross section for keV protons and antiprotons impinging on hydrogen atoms

    SciTech Connect

    Custidiano, Ernesto R.; Jakas, Mario M.

    2005-08-15

    Using the classical-trajectory Monte Carlo (CTMC) method, the electronic stopping cross sections of hydrogen atoms by protons and antiprotons impact are calculated. The results show that the CTMC method compares fairly well with previous quantum mechanics calculations of the stopping cross sections for the same colliding pairs. It turns out therefore that the CTMC method constitutes a reliable and, computationally speaking, convenient alternative to calculate the stopping of ions in matter. The present results also show that the stopping appears to be particularly sensitive to the angular momentum (L) of the electron orbit. In the case of protons, the highest sensitivity to L becomes evident around the energy of the maximum stopping. While for antiprotons the largest sensitivity of the stopping to L is observed down at low bombarding energies, i.e., below 10 keV.

  20. Probing the leading-twist transverse-momentum-dependent parton distribution function h1T⊥ via the polarized proton-antiproton Drell-Yan process

    NASA Astrophysics Data System (ADS)

    Zhu, Jiacai; Ma, Bo-Qiang

    2010-12-01

    We show that the polarized proton-antiproton Drell-Yan process is ideal to probe the pretzelosity distribution (h1T⊥), which is one of the new transverse-momentum-dependent parton distributions of the nucleon. We present predictions of the cos⁡(2ϕ+ϕa-ϕb) asymmetry in the transversely polarized proton-antiproton Drell-Yan process at PAX kinematics and find that the results are significantly larger compared with those of the sin⁡(3ϕh-ϕS) asymmetry in the semi-inclusive deep inelastic scattering process at HERMES, COMPASS, and JLab kinematics. We conclude that the cos⁡(2ϕ+ϕa-ϕb) asymmetry in the PAX experiment can probe the new physical quantity of the pretzelosity distribution.

  1. SUMMARY OF BEAM BEAM OBSERVATIONS DURING STORES IN RHIC.

    SciTech Connect

    FISCHER,W.

    2003-05-19

    During stores, the beam-beam interaction has a significant impact on the beam and luminosity lifetimes in RHIC. This was observed in heavy ion, and even more pronounced in proton collisions. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. In addition, RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. Coherent beam-beam modes were observed, and suppressed by tune changes. In this article we summarize the most important beam-beam observations made during stores so far.

  2. Automated beam builder

    NASA Technical Reports Server (NTRS)

    Muench, W. K.

    1980-01-01

    Requirements for the space fabrication of large space structures are considered with emphasis on the design, development, manufacture, and testing of a machine which automatically produces a basic building block aluminum beam. Particular problems discussed include those associated with beam cap forming; brace storage, dispensing, and transporting; beam component fastening; and beam cut-off. Various critical process tests conducted to develop technology for a machine to produce composite beams are also discussed.

  3. The GAPS Experiment: A Search for Dark Matter Using Low Energy Antiprotons and Antideuterons. Unversity of California, Berkeley Co-I

    NASA Astrophysics Data System (ADS)

    Boggs, Steven

    This is a Co-I proposal in support of the PI lead proposal entitled "The GAPS experiment: a search for dark matter using low energy antiprotons and antideuterons" submitted by Prof. Charles Hailey, Columbia University. Our proposed program would support the UC Berkeley tasks on the GAPS experiment as detailed in our task statement. The primary focus of this work in on the development and testing of the Si(Li) readout electronics and support of the flight program and scientific analysis.

  4. A Search for universal extra dimensions in the multi-lepton channel from proton anti-proton collisions at √s = 1.8 TeV

    SciTech Connect

    Lin, Chun

    2005-12-01

    In this thesis we present the results of a search for Universal Extra Dimensions (UED) with compactification radius near the TeV scale in the multi-lepton channel from proton-antiproton collisions at center-of-mass energy of 1.8 TeV at the Fermi National Accelerator Laboratory. This is the first UED search in the multi-lepton channel performed at the Tevatron.

  5. Viscoelastic Timoshenko beam theory

    NASA Astrophysics Data System (ADS)

    Hilton, Harry H.

    2009-03-01

    The concept of elastic Timoshenko shear coefficients is used as a guide for linear viscoelastic Euler-Bernoulli beams subjected to simultaneous bending and twisting. It is shown that the corresponding Timoshenko viscoelastic functions now depend not only on material properties and geometry as they do in elasticity, but also additionally on stresses and their time histories. Possible viscoelastic definitions are formulated and evaluated. In general, the viscoelastic relations are sufficiently complicated so that the elastic-viscoelastic correspondence principle (analogy) cannot be applied. This is particularly true for, but not limited to, elastic shear coefficients which are Poisson ratio dependent. Expressions for equivalent viscoelastic Timoshenko shear functions must, therefore, be derived de novo on a case by case basis, taking in to account specific relaxation moduli, stresses, temperatures and their time histories. Thus the elastic simplicity and generality is lost and hence rendering the use of viscoelastic Timoshenko shear functions as highly impractical. Consequently, it is necessary to directly solve the coupled viscoelastic beam governing relations for bending and twisting deflections by using appropriate solution protocols as discussed herein.

  6. Generation of plane shocks using intense heavy ion beams: Application to Richtmyer-Meshkov instability growth studies

    SciTech Connect

    Tahir, N. A.; Stoehlker, Th.; Shutov, A.; Zharkov, A. P.; Piriz, A. R.

    2011-03-15

    A design of a novel experiment that allows the generation of a well defined, steady, and strong plane shock wave employing an intense uranium ion beam that is incident on a wedge shaped compound target is presented. This technique will open up the possibility of carrying out unique high energy density physics experiments using these shock waves. One such experiment is to study the growth of Richtmyer-Meshkov instability in fluids as well as in solids, both in the linear and nonlinear regimes, as shown by detailed numerical simulations presented in this paper. The ion beam parameters used in this study correspond to those that will be available at the Facility for Antiprotons and Ion Research (FAIR) at Darmstadt.

  7. Highly sensitive superconducting circuits at ˜700 kHz with tunable quality factors for image-current detection of single trapped antiprotons

    NASA Astrophysics Data System (ADS)

    Nagahama, H.; Schneider, G.; Mooser, A.; Smorra, C.; Sellner, S.; Harrington, J.; Higuchi, T.; Borchert, M.; Tanaka, T.; Besirli, M.; Blaum, K.; Matsuda, Y.; Ospelkaus, C.; Quint, W.; Walz, J.; Yamazaki, Y.; Ulmer, S.

    2016-11-01

    We developed highly sensitive image-current detection systems based on superconducting toroidal coils and ultra-low noise amplifiers for non-destructive measurements of the axial frequencies (550-800 kHz) of single antiprotons stored in a cryogenic multi-Penning-trap system. The unloaded superconducting tuned circuits show quality factors of up to 500 000, which corresponds to a factor of 10 improvement compared to our previously used solenoidal designs. Connected to ultra-low noise amplifiers and the trap system, signal-to-noise-ratios of 30 dB at quality factors of >20 000 are achieved. In addition, we have developed a superconducting switch which allows continuous tuning of the detector's quality factor and to sensitively tune the particle-detector interaction. This allowed us to improve frequency resolution at constant averaging time, which is crucial for single antiproton spin-transition spectroscopy experiments, as well as improved measurements of the proton-to-antiproton charge-to-mass ratio.

  8. Measurement of long-range angular correlation and quadrupole anisotropy of pions and (anti)protons in central d+Au collisions at sNN=200 GeV

    DOE PAGES

    Adare, A.; Aidala, C.; Ajitanand, N. N.; ...

    2015-05-12

    In this study, we present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and aluminum bias p+p collisions at √sNN = 200 GeV. The charged hadron is measured at midrapidity lηl < 0.35, and the energy us measured at large rapidity (–3.7 < η < –3.1, Au-going direction). An enhanced near-side angular correlation across lΔηl > 2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v₂ for inclusive charged hadrons at midrapidity up to pT = 4.5 GeV/c. We alsomore » present the measurement of v₂ for identified π± and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at √sNN = 5.02 TeV. The magnitude of the mass-ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.« less

  9. Polarization of stored beam by spin-filtering at COSY

    NASA Astrophysics Data System (ADS)

    Ciullo, G.

    2014-01-01

    In the challenging aim to achieve polarized antiproton, the PAX collaboration performed dedicated measurements of the spin-dependent polarizing cross section for p- p scattering at COSY. The result, under a very nice control of the process, agrees with the theoretical previsions, and confirms the pursuability of the spin-filtering for polarizing antiprotons.

  10. RHIC electron lens beam transport system design considerations

    SciTech Connect

    Gu, X.; Pikin, A.; Okamura, M.; Fischer, W.; Luo, Y.; Gupta, R.; Hock, J.; Jain, A.; Raparia, D.

    2010-10-01

    To apply head-on beam-beam compensation for RHIC, two electron lenses are designed and will be installed at IP10. Electron beam transport system is one of important subsystem, which is used to transport electron beam from electron gun side to collector side. This system should be able to change beam size inside superconducting magnet and control beam position with 5 mm in horizontal and vertical plane. Some other design considerations for this beam transport system are also reported in this paper. The head-on beam-beam effect is one of important nonlinear source in storage ring and linear colliders, which have limited the luminosity improvement of many colliders, such as SppS, Tevatron and RHIC. In order to enhance the performance of colliders, beam-beam effects can be compensated with direct space charge compensation, indirect space charge compensation or betatron phase cancellation scheme. Like other colliders, indirect space charge compensation scheme (Electron Lens) was also proposed for Relativistic Heavy Ion Collider (RHIC) beam-beam compensation at Brookhaven National Laboratory. The two similar electron lenses are located in IR10 between the DX magnets. One RHIC electron lens consists of one DC electron gun, one superconducting magnet, one electron collector and beam transport system.

  11. Angular-momentum-dominated electron beams and flat-beam generation

    SciTech Connect

    Sun, Yin-e

    2005-06-01

    In the absence of external forces, if the dynamics within an electron beam is dominated by its angular momentum rather than other effects such as random thermal motion or self Coulomb-repulsive force (i.e., space-charge force), the beam is said to be angular-momentum-dominated. Such a beam can be directly applied to the field of electron-cooling of heavy ions; or it can be manipulated into an electron beam with large transverse emittance ratio, i.e., a flat beam. A flat beam is of interest for high-energy electron-positron colliders or accelerator-based light sources. An angular-momentum-dominated beam is generated at the Fermilab/NICADD photoinjector Laboratory (FNPL) and is accelerated to an energy of 16 MeV. The properties of such a beam is investigated systematically in experiment. The experimental results are in very good agreement with analytical expectations and simulation results. This lays a good foundation for the transformation of an angular-momentum-dominated beam into a flat beam. The round-to-flat beam transformer is composed of three skew quadrupoles. Based on a good knowledge of the angular-momentum-dominated beam, the quadrupoles are set to the proper strengths in order to apply a total torque which removes the angular momentum, resulting in a flat beam. For bunch charge around 0.5 nC, an emittance ratio of 100 ± 5 was measured, with the smaller normalized root-mean-square emittance around 0.4 mm-mrad. Effects limiting the flat-beam emittance ratio are investigated, such as the chromatic effects in the round-to-flat beam transformer, asymmetry in the initial angular-momentum-dominated beam, and space-charge effects. The most important limiting factor turns out to be the uncorrelated emittance growth caused by space charge when the beam energy is low, for example, in the rf gun area. As a result of such emittance growth prior to the round-to-flat beam transformer, the emittance ratio achievable in simulation decreases from orders of thousands to

  12. A method for the dynamic range extension of a pixelated Silicon detector beam profilometer based on the incomplete reset mechanism

    NASA Astrophysics Data System (ADS)

    Caccia, M.; Santoro, R.; Antonello, M.

    2017-03-01

    The SUCIMA collaboration, within a project supported by the European Commission in the Fifth Framework Program, developed a sensor for non-disruptive real-time beam profilometry for hadron therapy centres. The sensor, named MIMOTERA, has been used at different European facilities, imaging beams by direct impact on the sensor and by the detection of secondary electrons emitted by thin targets. In 2015, the detector has been thinned to 50 μm, integrated in a high vacuum and cryogenic temperature compliant assembly and successfully commissioned as antiproton beam monitor for the AEbar gIS experiment at CERN. The detector contributed to the optimisation of the experiment functionality providing the shape and position of the beam on a spill-by-spill basis. However, it failed in measuring the fluctuations of the beam intensity because the deposited energy exceeded the full well capacity and saturated the output signal. In order to recover this information, a method was developed based on the persistence of the signal in a series of frames that follows the one corresponding to the beam impact, due to the incomplete sensor reset. A laboratory test that makes use of a laser with tuneable intensity was designed and the method was qualified. This paper reports the description of the procedure and the main outcomes.

  13. Microwave accelerator E-beam pumped laser

    DOEpatents

    Brau, Charles A.; Stein, William E.; Rockwood, Stephen D.

    1980-01-01

    A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

  14. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    NASA Astrophysics Data System (ADS)

    Jang, Hyojae; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok

    2016-02-01

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  15. Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

    SciTech Connect

    Jang, Hyojae Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok

    2016-02-15

    A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

  16. Beam position monitor

    DOEpatents

    Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf

    2003-07-22

    An apparatus for determining the position of an x-ray beam relative to a desired beam axis. Where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in an a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.

  17. LANSCE beam current limiter

    SciTech Connect

    Gallegos, F.R.

    1997-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the beam current limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beamline below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described. {copyright} {ital 1997 American Institute of Physics.}

  18. Beam position monitor

    SciTech Connect

    Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf

    2000-09-21

    An apparatus for determining the position of an x-ray beam relative to a desired beam axis where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.

  19. Pyramid beam splitter

    DOEpatents

    McKeown, Mark H.; Beason, Steven C.; Fairer, George

    1992-01-01

    The apparatus of the present invention provides means for obtaining accurate, dependable, measurement of bearings and directions for geologic mapping in subterranean shafts, such as, for example, nuclear waste storage investigations. In operation, a laser beam is projected along a reference bearing. A pyramid is mounted such that the laser beam is parallel to the pyramid axis and can impinge on the apex of the pyramid thus splitting the beam several ways into several beams at right angles to each other and at right angles to the reference beam. The pyramid is also translatable and rotatable in a plane perpendicular to the reference beam.

  20. Electron beam depolarization in a damping ring

    SciTech Connect

    Minty, M.

    1993-04-01

    Depolarization of a polarized electron beam injected into a damping ring is analyzed by extending calculations conventionally applied to proton synchrotrons. Synchrotron radiation in an electron ring gives rise to both polarizing and depolarizing effects. In a damping ring, the beam is stored for a time much less than the time for self polarization. Spin flip radiation may therefore be neglected. Synchrotron radiation without spin flips, however, must be considered as the resonance strength depends on the vertical betatron oscillation amplitude which changes as the electron beam is radiation damped. An expression for the beam polarization at extraction is derived which takes into account radiation damping. The results are applied to the electron ring at the Stanford Linear Collider and are compared with numerical matrix formalisms.

  1. Coulomb blur advantage of a multi-shaped beam lithography approach

    NASA Astrophysics Data System (ADS)

    Slodowski, Matthias; Doering, Hans-Joachim; Elster, Thomas; Stolberg, Ines A.

    2009-03-01

    This paper describes a new multi beam approach in electron beam lithography called Multi Shaped Beam (MSB). Based on the well known Variable Shaped Beam (VSB) principle, the single shaped beam arrangement is extended and complemented by an array of individually controlled shaped beams. The positive effect of the MSB approach on resolution limiting stochastic beam blur due to Coulomb interactions will be highlighted applying detailed electron-optical Monte-Carlo simulations. To verify the feasibility of the above-mentioned new approach, there is also depicted a proof-of-lithography test stand based on a complete e-beam-lithography system containing MSB-specific hardware and software components.

  2. Measurement of Beam Tunes in the Tevatron Using the BBQ System

    SciTech Connect

    Edstrom, Dean R.; /Indiana U.

    2009-04-01

    Measuring the betatron tunes in any synchrotron is of critical importance to ensuring the stability of beam in the synchrotron. The Base Band Tune, or BBQ, measurement system was developed by Marek Gasior of CERN and has been installed at Brookhaven and Fermilab as a part of the LHC Accelerator Research Program, or LARP. The BBQ was installed in the Tevatron to evaluate its effectiveness at reading proton and antiproton tunes at its flattop energy of 980 GeV. The primary objectives of this thesis are to examine the methods used to measure the tune using the BBQ tune measurement system, to incorporate the system into the Fermilab accelerator controls system, ACNET, and to compare the BBQ to existing tune measurement systems in the Tevatron.

  3. Beam-beam issues in asymmetric colliders

    SciTech Connect

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e{sup +}- e{sup -} colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II).

  4. Transverse beam emittance measurement using quadrupole variation at KIRAMS-430

    NASA Astrophysics Data System (ADS)

    An, Dong Hyun; Hahn, Garam; Park, Chawon

    2015-02-01

    In order to produce a 430 MeV/u carbon ion (12 C 6+) beam for medical therapy, the Korea Institute of Radiological & Medical Sciences (KIRAMS) has carried out the development of a superconducting isochronous cyclotron, the KIRAMS-430. At the extraction of the cyclotron, an Energy Selection System (ESS) is located to modulate the fixed beam energy and to drive the ion beam through High Energy Beam Transport (HEBT) into the treatment room. The beam emittance at the ion beamline is to be measured to provide information on designing a beam with high quality. The well-known quadrupole variation method was used to determine the feasibility of measuring the transverse beam emittance. The beam size measured at the beam profile monitor (BPM) is to be utilized and the transformation of beam by transfer matrix is to be applied being taken under various transport condition of varying quadrupole magnetic strength. Two different methods where beam optics are based on the linear matrix formalism and particle tracking with a 3-D magnetic field distribution obtained by using OPERA3D TOSCA, are applied to transport the beam. The fittings for the transformation parameters are used to estimate the transverse emittance and the twiss parameters at the entrance of the quadrupole in the ESS. Including several systematic studies, we conclude that within the uncertainty the estimated emittances are consistent with the ones calculated by using Monte Carlo simulations.

  5. Ion-beam nitriding of steels

    NASA Technical Reports Server (NTRS)

    Salik, J.

    1984-01-01

    The application of the ion beam technique to the nitriding of steels is described. It is indicated that the technique can be successfully applied to nitriding. Some of the structural changes obtained by this technique are similar to those obtained by ion nitriding. The main difference is the absence of the iron nitride diffraction lines. It is found that the dependence of the resultant microhardness on beam voltage for super nitralloy is different from that of 304 stainless steel.

  6. Radioactive-ion-beam research at Livermore

    NASA Astrophysics Data System (ADS)

    Haight, R. C.; Mathews, G. J.; Ward, R. A.; Woosley, S. E.

    1983-06-01

    The ability to produce secondary radioactive heavy ion beams which can be isolated, focused, and transported to a secondary target can enable reaction studies and other research with the approximately more than 1300 nuclei with decay lifetimes approximately more than 1 microsec. Current research in secondary beam production and future applications in astrophysics, nuclear structure, heavy ion physics, and radiotherapy are examined as well as associated spin off and technology transfer in applied physics.

  7. Ion-beam nitriding of steels

    NASA Technical Reports Server (NTRS)

    Salik, J.

    1985-01-01

    The application of the ion beam technique to the nitriding of steels is described. It is indicated that the technique can be successfully applied to nitriding. Some of the structural changes obtained by this technique are similar to those obtained by ion nitriding. The main difference is the absence of the iron nitride diffraction lines. It is found that the dependence of the resultant microhardness on beam voltage for super nitralloy is different from that of 304 stainless steel.

  8. Successful Beam-Beam Tuneshift Compensation

    SciTech Connect

    Bishofberger, Kip Aaron

    2005-01-01

    The performance of synchrotron colliders has been limited by the beam-beam limit, a maximum tuneshift that colliding bunches could sustain. Due to bunch-to-bunch tune variation and intra-bunch tune spread, larger tuneshifts produce severe emittance growth. Breaking through this constraint has been viewed as impossible for several decades. This dissertation introduces the physics of ultra-relativistic synchrotrons and low-energy electron beams, with emphasis placed on the limits of the Tevatron and the needs of a tuneshift-compensation device. A detailed analysis of the Tevatron Electron Lens (TEL) is given, comparing theoretical models to experimental data whenever possible. Finally, results of Tevatron operations with inclusion of the TEL are presented and analyzed. It is shown that the TEL provides a way to shatter the previously inescapable beam-beam limit.

  9. Beam Control for Ion Induction Accelerators

    SciTech Connect

    Sangster, T.C.; Ahle, L.

    2000-02-17

    Coordinated bending and acceleration of an intense space-charge-dominated ion beam has been achieved for the first time. This required the development of a variable waveform, precision, bi-polar high voltage pulser and a precision, high repetition rate induction core modulator. Waveforms applied to the induction cores accelerate the beam as the bi-polar high voltage pulser delivers a voltage ramp to electrostatic dipoles which bend the beam through a 90 degree permanent magnet quadrupole lattice. Further work on emittance minimization is also reported.

  10. Automated beam steering using optimal control

    SciTech Connect

    Allen, C. K.

    2004-01-01

    We present a steering algorithm which, with the aid of a model, allows the user to specify beam behavior throughout a beamline, rather than just at specified beam position monitor (BPM) locations. The model is used primarily to compute the values of the beam phase vectors from BPM measurements, and to define cost functions that describe the steering objectives. The steering problem is formulated as constrained optimization problem; however, by applying optimal control theory we can reduce it to an unconstrained optimization whose dimension is the number of control signals.

  11. Bessel-Gauss beams as rigorous solutions of the Helmholtz equation.

    PubMed

    April, Alexandre

    2011-10-01

    The study of the nonparaxial propagation of optical beams has received considerable attention. In particular, the so-called complex-source/sink model can be used to describe strongly focused beams near the beam waist, but this method has not yet been applied to the Bessel-Gauss (BG) beam. In this paper, the complex-source/sink solution for the nonparaxial BG beam is expressed as a superposition of nonparaxial elegant Laguerre-Gaussian beams. This provides a direct way to write the explicit expression for a tightly focused BG beam that is an exact solution of the Helmholtz equation. It reduces correctly to the paraxial BG beam, the nonparaxial Gaussian beam, and the Bessel beam in the appropriate limits. The analytical expression can be used to calculate the field of a BG beam near its waist, and it may be useful in investigating the features of BG beams under tight focusing conditions.

  12. Search for Electroweak Single Top Quark Production in 1.96 TeV Proton-Antiproton Collisions

    SciTech Connect

    Stelzer, Bernd

    2005-01-01

    This thesis describes the first search for electroweak single top quark production in proton-antiproton collisions at a center of mass energy of 1.96 TeV. The data sample used for this analysis corresponds to 162 pb-1 recorded by the upgraded Collider Detector at Fermilab. The search is performed by doing a classic maximum likelihood fit to the HT distribution in data. The kinematic variable HT is the scalar sum of transverse energies of all final state particles in the event. This variable has the advantage that its distribution looks very similar for both contributing (s-channel and t-channel) single top processes, but is different for background processes. The combination of both channels to one signal improves the sensitivity of the search. No significant evidence for electroweak single top quark production is found and we set an upper limit at the 95% confidence level on the combined single top quark production cross section of 17.8 pb.

  13. Thermalization of dense hadronic matter in Au + Au collisions at energies available at the Facility for Antiproton and Ion Research

    NASA Astrophysics Data System (ADS)

    De, Somnath; De, Sudipan; Chattopadhyay, Subhasis

    2016-11-01

    The conditions of local thermodynamic equilibrium of baryons (nonstrange, strange) and mesons (strange) are presented for central Au + Au collisions at Facility for Antiproton and Ion Research (FAIR) energies using the microscopic transport model UrQMD. The net particle density, longitudinal-to-transverse pressure anisotropy, and inverse slope parameters of the energy spectra of nonstrange and strange hadrons are calculated inside a cell in the central region within rapidity window |y |<1.0 at different time steps after the collisions. We observed that the strangeness content is dominated by baryons at all energies; however, contributions from mesons become significant at higher energies. The time scale obtained from local pressure (momentum) isotropization and thermalization of energy spectra are nearly equal and found to decrease with increase in laboratory energy. The equilibrium thermodynamic properties of the system are obtained with a statistical thermal model. The time evolution of the entropy densities at FAIR energies are found to be very similar to the ideal hydrodynamic behavior at top Relativistic Heavy Ion Collider (RHIC) energy.

  14. Electron Beam Freeform Fabrication

    NASA Video Gallery

    Electron Beam Freeform Fabrication (EBF3) is a process by which NASA hopes to build metal parts in zero gravity environments. It's a layer-additive process that uses an electron beam and a solid wi...

  15. High energy beam lines

    NASA Astrophysics Data System (ADS)

    Marchetto, M.; Laxdal, R. E.

    2014-01-01

    The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.

  16. Profiling structured beams using injected aerosols

    NASA Astrophysics Data System (ADS)

    Loh, N. D.; Starodub, Dmitri; Lomb, Lukas; Hampton, Christina Y.; Martin, Andrew V.; Sierra, Raymond G.; Barty, Anton; Aquila, Andrew; Schulz, Joachim; Steinbrener, Jan; Shoeman, Robert L.; Kassemeyer, Stephan; Bostedt, Christoph; Bozek, John; Epp, Sascha W.; Erk, Benjamin; Hartmann, Robert; Rolles, Daniel; Rudenko, Artem; Rudek, Benedikt; Foucar, Lutz; Kimmel, Nils; Weidenspointner, Georg; Hauser, Günther; Holl, Peter; Pedersoli, Emanuele; Liang, MengNing; Hunter, Mark S.; Gumprecht, Lars; Coppola, Nicola; Wunderer, Cornelia; Graafsman, Heinz; Maia, Filipe R. N. C.; Ekeberg, Tomas; Hantke, Max; Fleckenstein, Holger; Hirsemann, Helmut; Nass, Karol; White, Thomas A.; Tobias, Herbert J.; Farquar, George R.; Benner, W. Henry; Hau-Riege, Stefan; Reich, Christian; Hartmann, Andreas; Soltau, Heike; Marchesini, Stefano; Bajt, Sasa; Barthelmess, Miriam; Strueder, Lothar; Ullrich, Joachim; Bucksbaum, Philip; Hodgson, Keith O.; Frank, Mathias; Schlichting, Ilme; Chapman, Henry N.; Bogan, Michael J.

    2012-10-01

    Profiling structured beams produced by X-ray free-electron lasers (FELs) is crucial to both maximizing signal intensity for weakly scattering targets and interpreting their scattering patterns. Earlier ablative imprint studies describe how to infer the X-ray beam profile from the damage that an attenuated beam inflicts on a substrate. However, the beams in-situ profile is not directly accessible with imprint studies because the damage profile could be different from the actual beam profile. On the other hand, although a Shack-Hartmann sensor is capable of in-situ profiling, its lenses may be quickly damaged at the intense focus of hard X-ray FEL beams. We describe a new approach that probes the in-situ morphology of the intense FEL focus. By studying the translations in diffraction patterns from an ensemble of randomly injected sub-micron latex spheres, we were able to determine the non-Gaussian nature of the intense FEL beam at the Linac Coherent Light Source (SLAC National Laboratory) near the FEL focus. We discuss an experimental application of such a beam-profiling technique, and the limitations we need to overcome before it can be widely applied.

  17. Vortex-based line beam optical tweezers

    NASA Astrophysics Data System (ADS)

    Cheng, Shubo; Tao, Shaohua

    2016-10-01

    A vortex-based line beam, which has a straight-line shape of intensity and possesses phase gradient along the line trajectory is developed and applied for optical manipulation in this paper. The intensity and phase distributions of the beam in the imaging plane of the Fourier transform are analytically studied. Simulation results show that the length of the line and phase gradient possessed by a vortex-based line beam are dependent on the topological charge and the azimuthal proportional constant. A superposition of multiple phase-only holograms with elliptical azimuthal phases can be used to generate an array of vortex-based line beams. Optical trapping with the vortex-based line beams has been implemented. Furthermore, the automatic transportation of microparticles along the line trajectory perpendicular to the optical axis is realized with an array of the beams. The generation method for the vortex-based line beam is simple. The beam would have potential applications in fields such as optical trapping, laser machining, and so on.

  18. Intense non-relativistic cesium ion beam

    SciTech Connect

    Lampel, M.C.

    1984-02-01

    The Heavy Ion Fusion group at Lawrence Berkeley Laboratory has constructed the One Ampere Cesium Injector as a proof of principle source to supply an induction linac with a high charge density and high brightness ion beam. This is studied here. An electron beam probe was developed as the major diagnostic tool for characterizing ion beam space charge. Electron beam probe data inversion is accomplished with the EBEAM code and a parametrically adjusted model radial charge distribution. The longitudinal charge distribution was not derived, although it is possible to do so. The radial charge distribution that is derived reveals an unexpected halo of trapped electrons surrounding the ion beam. A charge fluid theory of the effect of finite electron temperature on the focusing of neutralized ion beams (Nucl. Fus. 21, 529 (1981)) is applied to the problem of the Cesium beam final focus at the end of the injector. It is shown that the theory's predictions and assumptions are consistent with the experimental data, and that it accounts for the observed ion beam radius of approx. 5 cm, and the electron halo, including the determination of an electron Debye length of approx. 10 cm.

  19. Beam Dynamics for ARIA

    SciTech Connect

    Ekdahl, Carl August Jr.

    2014-10-14

    Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

  20. Study of beam-beam effects in eRHIC

    SciTech Connect

    Hao, Y.; Litvinenko, V.; Ptitsyn, V.

    2010-05-23

    Beam-beam effects in eRHIC have a number of unique features, which distinguish them from both hadron and lepton colliders. Due to beam-beam interaction, both electron and hadron beams would suffer quality degradation or beam loss from without proper treatments. Those features need novel study and dedicate countermeasures. We study the beam dynamics and resulting luminosity of the characteristics, including mismatch, disruption and pinch effects on electron beam, in additional to their consequences on the opposing beam as a wake field and other incoherent effects of hadron beam. We also carry out countermeasures to prevent beam quality degrade and coherent instability.