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Sample records for proton kicker extraction

  1. NuMI proton kicker extraction system

    SciTech Connect

    Jensen, C.C.; Krafczyk, G.A.; /Fermilab

    2005-05-01

    This system extracts up to 9.6 {micro}s of 120 GeV beam every 1.87 seconds for the NuMI beamline neutrino experiments. A pulse forming network consisting of two continuous wound coils and 68 capacitors was designed and built to drive three kicker magnets. The field stability requirement is better than {+-} 1% with a field rise time of 1.52 {micro}s. New kicker magnets were built based on the successful traveling wave magnets built for the Main Injector. Two of these magnets are in series which places a serious constraint on the rise time of the pulser. A forced cooling system using Fluorinert{reg_sign} was designed for the magnet termination resistors to maintain the field flatness and amplitude stability.

  2. CONSTRUCTION AND POWER TEST OF THE EXTRACTION KICKER MAGNET FOR SNS ACCUMULATOR RING.

    SciTech Connect

    PAI, C.; HAHN, H.; HSEUH, H.; LEE, Y.; MENG, W.; MI,J.; SANDBERG, J.; TODD, R.; ET AL.

    2005-05-16

    Two extraction kicker magnet assemblies that contain seven individual pulsed magnet modules each will kick the proton beam vertically out of the SNS accumulator ring into the aperture of the extraction Lambertson septum magnet. The proton beam then travels to the 1.4 MW SNS target assembly. The 14 kicker magnets and major components of the kicker assembly have been fabricated in BNL. The inner surfaces of the kicker magnets were coated with TiN to reduce the secondary electron yield. All 14 PFN power supplies have been built, tested and delivered to OWL. Before final installation, a partial assembly of the kicker system with three kicker magnets was assembled to test the functions of each critical component in the system. In this paper we report the progress of the construction of the kicker components, the TIN coating of the magnets, the installation procedure of the magnets and the full power test of the kicker with the PFN power supply.

  3. 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].

  4. Design Considerations of Fast Kicker Systems for High Intensity Proton Accelerators

    SciTech Connect

    Zhang, W; Sandberg, J; Parson, W M; Walstrom, P; Murray, M M; Cook, E; Hartouni, E

    2001-06-12

    In this paper, we discuss the specific issues related to the design of the Fast Kicker Systems for high intensity proton accelerators. To address these issues in the preliminary design stage can be critical since the fast kicker systems affect the machine lattice structure and overall design parameters. Main topics include system architecture, design strategy, beam current coupling, grounding, end user cost vs. system cost, reliability, redundancy and flexibility. Operating experience with the Alternating Gradient Synchrotron injection and extraction kicker systems at Brookhaven National Laboratory and their future upgrade is presented. Additionally, new conceptual designs of the extraction kicker for the Spallation Neutron Source at Oak Ridge and the Advanced Hydrotest Facility at Los Alamos are discussed.

  5. SNS EXTRACTION FAST KICKER SYSTEM DEVELOPMENT.

    SciTech Connect

    ZHANG,W.; SANDBERG,J.; LAMBIASE,R.; LEE,Y.Y.; LOCKEY,R.; MI,J.; NEHRING,T.; PAI,C.; TSOUPAS,N.; TUOZZOLO,J.; WARBURTON,D.; WEI,J.; RUST,K.; CUTLER,R.

    2003-06-15

    The SNS Extraction Fast Kicker System is a very high power, high repetition rate pulsed power system. It was design and developed at Brookhaven National Laboratory. This system will consist of fourteen identical high voltage, high current modulators, and their auxiliary control and charging systems. The modulators will drive fourteen extraction magnet sections located inside of the SNS accumulator ring. The required kicker field rise time is 200 ns, a pulse flattop of 700 ns, a pulse repetition rate of 60 pulse-per-second. A 2500 Ampere per modulator output is required to reach the extraction kicker magnetic field strength. This design features a Blumlein Pulse-Forming-Network based topology, a low beam impedance termination, a fast current switching thyratron, and low inductance capacitor banks. It has a maximum charging voltage of 50kV, an open circuit output of 100kV, and a designed maximum pulsed current output of 4kA per modulator. The overall system output will be multiple GVA with 60 Pulse-per-second repetition rate. A prototype modulator has been successfully built and tested well above the SNS requirement. The modulator system production is in progress.

  6. REDUCING BEAM COUPLING IMPEDANCES IN SNS RING EXTRACTION KICKERS

    SciTech Connect

    S.S. KURENNOY; D. DAVINO; Y. LEE

    2001-06-01

    The Spallation Neutron Source (SNS) Accumulator ring extraction system [1] includes 14 modules of window-frame ferrite pulsing kicker magnets with the rise time of about 200 ns. Their contribution to the beam coupling impedances is a serious concern. The kicker impedances, as well as its deflecting magnetic field versus time, are studied using detailed 3-D MAFIA modeling. Various design options, external circuit resistances, and a range of ferrite permeabilities are explored. A kicker module with wide conductor windings around the ferrite behind the kicker current sheet suggests a significant reduction of the kicker transverse and longitudinal coupling impedances. This design provides a good extraction field performance, as demonstrated by electromagnetic simulations. Results of measurements for a small model are also presented.

  7. REDUCING BEAM COUPLING IMPEDANCES IN SNS RING EXTRACTION KICKERS

    SciTech Connect

    Kurennoy, S.; Davino, D.; Lee, Y. Y.

    2001-01-01

    The Spallation Neutron Source (SNS) Accumulator ring extraction system includes 14 modules of windowframe ferrite pulsing kicker magnets with the rise time of about 200 ns. Their contribution to the beam coupling impedances is a serious concern. The kicker impedances, as well as its deflecting magnetic field versus time, are studied using detailed 3-D MAFIA modeling. Various design options, external circuit resistances, and a range of ferrite permeabilities are explored. A kicker module with wide conductor windings around the ferrite behind the kicker current sheet suggests a significant reduction of the kicker transverse and longitudinal coupling impedances. This design provides a good extraction field performance, as demonstrated by electromagnetic simulations. Results of measurements for a small model are also presented.

  8. Stripline design for the extraction kicker of Compact Linear Collider damping rings

    NASA Astrophysics Data System (ADS)

    Belver-Aguilar, C.; Faus-Golfe, A.; Toral, F.; Barnes, M. J.

    2014-07-01

    In the framework of the design study of future linear colliders, the Compact Linear Collider (CLIC) aims for electron-positron collisions with high luminosity at a nominal center-of-mass energy of 3 TeV. To achieve the luminosity requirements, predamping rings (PDRs) and damping rings (DRs) are required: they reduce the beam emittance before the beam is accelerated in the main linac. Several kicker systems are needed to inject and extract the beam from the PDRs and DRs. In order to achieve both low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. In this paper, we present the complete design of the striplines for the DR extraction kicker, since it is the most challenging from the field homogeneity point of view. The excellent field homogeneity required, as well as a good transmission of the high voltage pulse through the electrodes, has been achieved by choosing a novel electrode shape. With this new geometry, it has been possible to benefit from all the advantages that the most common shapes introduce separately. Furthermore, a detailed study of the different operating modes of a stripline kicker allowed the beam coupling impedance to be reduced at low frequencies: this cannot be achieved by tapering the electrodes. The optimum design of the striplines and their components has been based on studies of impedance matching, field homogeneity, power transmission, beam coupling impedance, and manufacturing tolerances. Finally, new ideas for further improvement of the performance of future striplines are reported.

  9. Development of a Fast High-Power Pulser and ILC DR Injection/Extraction Kicker

    SciTech Connect

    Krasnykh, A.; /SLAC

    2007-10-16

    Kicker is an efficient HOM power extractor. Peak HOM voltage and average power at the feeder may be sufficient to act on the kicker pulser. Feeder imperfections (real cable, feedthroughs, kicker electrodes, loads) is one source of residual energy between bunches. HOM spectrum is broad.

  10. BEAM EXTRACTION FROM THE SNS RING AND DESIGN OF EXTRACTION KICKERS.

    SciTech Connect

    TSOUPAS, N.; BLASKIEWICZ, M.; LEE, Y.Y.; MI, J.L.; SOUKAS, A.; WANG, J.G.; WEI, J.; ZHANG, S.Y.

    2000-06-30

    The accumulator ring of the Spallation Neutron Source (SNS) [1] will accumulate a proton beam, injected from a LINAC, into a single bunch containing {approximately} 2.1 x 10{sup 14} protons at a maximum energy of 1.3 GeV. The single bunch with length {approximately}650 nsec and a gap of {approximately}290 nsec will circulate into the accumulator ring for {approximately}1.0 msec before it is extracted into the RTBT transfer line. The accumulation, extraction frequency is set at 60 Hz. This paper discusses the extraction process and the requirements of the fast beam extraction system.

  11. MI Gap Clearing Kicker Magnet Design Review

    SciTech Connect

    Jensen, Chris; /Fermilab

    2008-10-01

    The kicker system requirements were originally conceived for the NOvA project. NOvA is a neutrino experiment located in Minnesota. To achieve the desired neutrino flux several upgrades are required to the accelerator complex. The Recycler will be used as a proton pre-injector for the Main Injector (MI). As the Recycler is the same size as the MI, it is possible to do a single turn fill ({approx}11 {micro}sec), minimizing the proton injection time in the MI cycle and maximizing the protons on target. The Recycler can then be filled with beam while the MI is ramping to extract beam to the target. To do this requires two new transfer lines. The existing Recycler injection line was designed for 10{pi} pbar beams, not the 20{pi} proton beams we anticipate from the Booster. The existing Recycler extraction line allows for proton injection through the MI, while we want direct injection from the Booster. These two lines will be decommissioned. The new injection line from the MI8 line into the Recycler will start at 848 and end with injection kickers at RR104. The new extraction line in the RR30 straight section will start with a new extraction kicker at RR232 and end with new MI injection kickers at MI308. Finally, to reduce beam loss activation in the enclosure, a new gap clearing kicker will be used to extract uncaptured beam created during the slip stack injection process down the existing dump line. It was suggested that the MI could benefit from this type of system immediately. This led to the early installation of the gap clearing system in the MI, followed by moving the system to Recycler during NOvA. The specifications also changed during this process. Initially the rise and fall time requirements were 38 ns and the field stability was {+-}1%. The 38 ns is based on having a gap of 2 RF buckets between injections. (There are 84 RF buckets that can be filled from the Booster for each injection, but 82 would be filled with beam. MI and Recycler contain 588 RF buckets

  12. RHIC ABORT KICKER WITH REDUCED COUPLING IMPEDANCE.

    SciTech Connect

    HAHN,H.; DAVINO,D.

    2002-06-02

    Kicker magnets typically represent the most important contributors to the transverse impedance budget of accelerators and storage rings. Methods of reducing the impedance value of the SNS extraction kicker presently under construction and, in view of a future performance upgrade, that of the RHIC abort kicker have been thoroughly studied at this laboratory. In this paper, the investigation of a potential improvement from using ferrite different from the BNL standard CMD5005 is reported. Permeability measurements of several ferrite types have been performed. Measurements on two kicker magnets using CMD5005 and C2050 suggest that the impedance of a magnet without external resistive damping, such as the RHIC abort kicker, would benefit.

  13. The Booster to AGS beam transfer fast kicker systems

    SciTech Connect

    Zhang, W.; Bunicci, J.; Soukas, A.V.; Zhang, S.Y.

    1992-08-01

    The Brookhaven AGS Booster has a very successful commissioning period in June 1991. The third phase of that commissioning was a beam extraction test. The Booster extraction fast kicker (F3) deflected a 1.2 GeV proton beam from the Booster circulating orbit into the extraction septum aperture, partially down the extraction line to a temporary beam stop. Now, the Booster is committed to the AGS operations program for both heavy ion and proton beams. Thus, the Booster extraction and the corresponding AGS injection systems must operate routinely up to a pulse repetition frequency of 7.5 Hertz, and up to a beam energy of 1.5 Gev. The injection fast kicker is located in the A5 section of the AGS ring and is used to deflect the proton or heavy ion beam into its final AGS closed orbit. A distinctive feature of the AGS injection fast kicker modulators is the tail-bitting function required for proton beam injection. This enables the system to produce a fast current fall time to go along with the high current pulse amplitude with a fast rise time. The AGS injection fast kicker system has three pulse modulators, and each modulator consists of two thyratrons. The main PFN thyratrons switch on the current, and the tail bitting thyratrons are used to force the magnet current to decrease rapidly. Two digital pulse delay generators are used to align the main thyratrons and the tail bitting thyratrons respectively. The system has been tested and installed. The final commissioning of the Booster to AGS beam transfer line and injection is currently being undertaken. In this article, the system design, realization techniques and performance data will be presented.

  14. Comparison of the Window-Frame RHIC-abort kicker with C-type Kicker

    SciTech Connect

    Tsoupas, N.; Hahn, H.; Meng, W.; Severance, Michael; McMahan, Brandon

    2014-08-26

    The high intensity proton bunches (~2.5x1011 p/bunch ) circulating in RHIC increase the temperature of the ferrite-made RHIC-abort-kickers above the Curie point; as a result, the kickers cannot provide the required field to abort the beam at the beam dump. A team of experts in the CAD department worked on modifying the design of the window-frame RHIC-abort kicker to minimize the hysteresis losses responsible for the increase of the ferrite’s temperature. In this technical note we report some results from the study of two possible modifications of the window-frame RHIC-abort kicker, and we compare these results with those of a propose C-type RHIC-abort kicker. We also include an Appendix where we describe a method which may further reduce the hysteresis losses of the window-frame kicker.

  15. SPEAR 3 INJECTION KICKER

    SciTech Connect

    Armett, Donald W.

    2002-08-20

    The design of the SPEAR 3 injection kicker system is presented. This system will include three kicker magnets and their associated pulsers. The magnet design is based on the DELTA kicker magnets, which present a low RF impedance to the beam, and are relatively straight-forward to construct. The pulsers use cascaded IGBT stages that are based on the modulator pulsers developed by a SLAC/LLNL collaboration for the NLC. Design considerations and the results of prototype tests will be discussed.

  16. Stripline kicker for integrable optics test accelerator

    SciTech Connect

    Antipov, Sergey A.; Didenko, Alexander; Lebedev, Valeri; Valishev, Alexander

    2016-06-30

    We present a design of a stripline kicker for Integrable Optics Test Accelerator (IOTA). For its experimental program IOTA needs two full-aperture kickers, capable to create an arbitrary controllable kick in 2D. For that reason their strengths are variable in a wide range of amplitudes up to 16 mrad, and the pulse length 100 ns is less than a revolution period for electrons. In addition, the kicker should have a physical aperture of 40 mm for a proposed operation with proton beam, and an outer size of 70 mm to fit inside existing quadrupole magnets to save space in the ring. Computer simulations using CST Microwave Studio show high field uniformity and wave impedance close to 50 {\\Omega}.

  17. Very fast kicker for accelerator applications

    SciTech Connect

    Grishanov, B.I.; Podgorny, F.V.; Ruemmler, J.; Shiltsev, V.D.

    1996-11-01

    We describe a very fast counter traveling wave kicker with a full pulse width of about 7 ns. Successful test experiment has been done with hi-tech semiconductor technology FET pulse generator with a MHz- range repetition rates and maximum kick strength of the order of 3 G{center_dot}m. Further. increase of the strength seems to be quite possible with the FET pursers, that makes the kicker to be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications.

  18. Reducing the extraction loss via laser notching the H- beam at the Booster injection revolution frequency

    SciTech Connect

    Yang, Xi; Ankenbrandt, Charles M.; /Fermilab

    2005-05-01

    With the requirement for more protons per hour from Booster, the radiation is a limiting factor. Laser notching the H{sup -} beam at the Booster injection revolution frequency and properly aligning those notches on top of each other at the injection and relative to the trigger of firing extraction kickers can remove most of the extraction loss caused by the slow rise time of the kicker field.

  19. Recycler short kicker beam impedance

    SciTech Connect

    Crisp, Jim; Fellenz, Brian; /Fermilab

    2009-07-01

    Measured longitudinal and calculated transverse beam impedance is presented for the short kicker magnets being installed in the Fermilab Recycler. Fermi drawing number ME-457159. The longitudinal impedance was measured with a stretched wire and the Panofsky equation was used to estimate the transverse impedance. The impedance of 3319 meters (the Recycler circumference) of stainless vacuum pipe is provided for comparison. Although measurements where done to 3GHz, impedance was negligible above 30MHz. The beam power lost to the kicker impedance is shown for a range of bunch lengths. The measurements are for one kicker assuming a rotation frequency of 90KHz. Seven of these kickers are being installed.

  20. The RHIC Injection Kicker

    NASA Astrophysics Data System (ADS)

    Hahn, H.; Tuozzolo, J. E.; Tsoupas, N.

    1997-05-01

    Beam transfer from the AGS to RHIC is performed in single-bunch mode. Close spacing of the bunches in the collider requires an injection kicker with a rise time of <95 nsec, suggesting adoption of a travelling wave solution. The required vertical kick of 0.186 T.m is provided by 4 units, each 1.12 m long with a 48.4× 48.4 mm aperture and operated at 1.6 kA. The kicker is constructed as a ``C'' cross section magnet, in which ferrite and high-permittivity ( ~ 100) dielectric sections alternate. The dielectric blocks provide the capacity necessary for the nominally 25 Ohm characteristic impedance of the travelling wave structure, but impose the practical limit on the peak voltage, and thus current, achievable. Computer studies to minimize local electric field enhancements resulted in a configuration capable of holding >50 kV, with adequate safety margin over the nominal 40 kV. Tests indicated the possibility of lowering the nominal voltage by operating mismatched into 20 Ohm terminations without degrading the pulse shape. In this paper, the experience gained in the fabrication of the four kicker units for the ``Sextant Test'' and the results from various single-unit tests and operation in beam are reported.

  1. The RHIC injection kicker

    SciTech Connect

    Hahn, H.; Tsoupas, N.; Tuozzolo, J.E.

    1997-07-01

    Beam transfer from the AGS to RHIC is performed in single-bunch mode. Close spacing of the bunches in the collider requires an injection kicker with a rise time of <90 nsec, suggesting adoption of a travelling wave structure. The required vertical kick of 0.186 t{center_dot}m is provided by 4 magnets, each 1.12 m long with a 48.4 x 48.4 mm aperture and operated at 1.6 kA. The kicker is constructed as a {open_quotes}C{close_quotes} cross section magnet, in which ferrite and high-permittivity dielectric sections alternate. The dielectric blocks provide the capacity necessary for the nominally 25 {Omega} characteristic impedance of the travelling wave structure, but impose the practical limit on the peak voltage, and thus current, achievable. Computer studies to minimize local electric field enhancements resulted in a configuration capable of holding {approximately} 50 kV, with adequate safety margin over the nominal 40 kV. Equivalent circuit analysis indicated the possibility of lowering the nominal voltage by operating mismatched into 20 {Omega} terminations without degrading the pulse shape. In this paper, the experience gained in the fabrication of the production units and the results from various single-unit tests and operation of four kickers with beam in the {open_quotes}Sextant Test{close_quotes} are reported.

  2. Design of fast kickers for the ISABELLE beam abort system

    SciTech Connect

    Nawrocky, R.J.; Montemurro, P.A.; Baron, J.

    1981-01-01

    The ISA beam abort (extraction) system must be highly efficient, in the sense of producing minimum beam loss, and reliable to prevent serious damage to accelerator components by the circulating high-energy beams. Since the stored beams will be debunched, the low-loss requirement can be met only with ultra-thin extraction septa and/or fast-acting kickers. This paper examines the design of the ISA extraction kickers subject to a set of extraction channel constraints and a given maximum working voltage. Expressions are derived for determining system parameters for both a lumped parameter magnet and a delay-line magnet. Using these relationships, design parameters are worked out for several possible system configurations. The paper also describes the construction of a full-scale prototype module of the kicker and summarizes the preliminary test results obtained with the module.

  3. THE RHIC BEAM ABORT KICKER SYSTEM.

    SciTech Connect

    HAHN,H.

    1999-03-29

    THE ENERGY STORED IN THE RHIC BEAM IS ABOUT 200 KJ PER RING AT DESIGN ENERGY AND INTENSITY. TO PREVENT QUENCHING OF THE SUPERCONDUCTING MAGNETS OR MATERIAL DAMAGE, THE BEAM WILL BE SAFELY DISPOSED OF BY AN INTERNAL BEAM ABORT SYSTEM, WHICH INCLUDES THE KICKER MAGNETS, THE PULSED POWER SUPPLIES, AND THE DUMP ABSORBER. DISPOSAL OF HEAVY IONS, SUCH AS GOLD, IMPOSES DESIGN CONSTRAINTS MORE SEVERE THAN THOSE FOR PROTON BEAMS OF EQUAL INTENSITY. IN ORDER TO MINIMIZE THE THERMAL SHOCK IN THE CARBON-FIBER DUMP BLOCK, THE BUNCHES MUST BE LATERALLY DISPERSED.

  4. RF Modeling of a Helical Kicker for Fast Chopping

    SciTech Connect

    Awida, Mohamed; Chen, Alex; Khabiboulline, Timergali; Saewert, Gregory; Yakovlev, Vyacheslav

    2015-06-01

    High intensity proton particle accelerators that supports several simultaneous physics experiments requires sharing the beam. A bunch by bunch beam chopper system located after the Radio Frequency Quadrupole (RFQ) is required in this case to structure the beam in the proper bunch format required by the several experiments. The unused beam will need to be kicked out of the beam path and is disposed in a beam dumb. In this paper, we report on the RF modeling results of a proposed helical kicker. Two beam kickers constitutes the proposed chopper. The beam sequence is formed by kicking in or out the beam bunches from the streamline. The chopper was developed for Project X Injection Experiment (PXIE).

  5. RHIC Abort Kicker Prefire Report

    SciTech Connect

    Tan, Y.; Perlstein, S.

    2014-07-07

    In an attempt to discover any pattern to prefire events, abort prefire kicker data from 2007 to the present day have been recorded. With the 2014 operations concluding, this comprises 8 years of prefire data. Any activities that the Pulsed Power Group did to decrease prefire occurrences were recorded as well, but some information may be missing. The following information is a compilation of the research to date.

  6. Kicker thyratron experience from SLC

    SciTech Connect

    Donaldson, A.R.; Cassel, R.L.; Mattison, T.S. ); Reginato, L.L. )

    1991-05-01

    The SLAC Linear Collider has five fast kickers for the damping ring injectors, extractors, and the electron extractor for the positron target that use multi-gap Deuterium-filled thyratrons. The thyratrons operate with 30 to 70 kV anode voltages and 1 to 5 kA currents, to deliver pulses to kicker magnets with {approx} 30 ns rise times, up to {approx} 150 ns pulse widths, at 120 Hz. Operating and lifetime experience with several types of thyratrons and support electronics are discussed. Floating driver and power supply electronics were replaced by a ferrite choke isolator to allow grounding of the cathode support electronics with a commensurate increase in operating reliability. The construction of a 100 ns Blumlein enabled detailed measurements of the switching times for all SLC thyratrons under similar conditions. In the final focus area, the kickers dump the SLC beams after the e{sup +} e{sup {minus}} collisions. These thyratrons function with 15 kV anode voltages and up to 2 kA currents to produce 1/2 sine pulses with {approx} 300 ns rise times, {approx} 550 ns FWHM, at 120 Hz. Operating experience with these thyratrons will also be presented. 7 refs., 1 fig., 3 tabs.

  7. LHC Kicker Beam-Impedance Calculation

    SciTech Connect

    Lambertson, G.R.

    1998-10-01

    Longitudinal and transverse beam impedances are calculated for the injection kickers designed for use in the CERN large hadron col- Iider. These combine the contributions of a ceramic beam tube with conducting stripes and a traveling-wave kicker magnet. The results show peak impedances of 1300 ohm longitudinal and 8 Mfl/m trans- verse for four units per ring.

  8. Proton Collimator for Fusion Energy Extraction

    NASA Astrophysics Data System (ADS)

    Momota, Hiromu; Miley, George

    2001-10-01

    A proton collimator concept is under study for use with various fusion devices such as an inertial confinement fusion (IEC) reactor. G. H. Miley, et al., IEEE Trans. on Plasma Science, 25 (1997), 733. It consists essentially of a pair of coils anti-parallel to an external magnetic channel. Spacing of the coils is equal to the coil radius, forming a "Helmholtz Coil". To eliminate the attractive force between pair coils, a stabilization coil is installed anti-parallel to pair coils. The resulting magnetic configuration is cylindrically symmetric. Currents on each coil are chosen to chancel the magnetic field at the center, forming a hexa-pole magnetic configuration. With the zero-field region near the plasma center, an inertial confinement fusion (ICF) reactor or the IEC could be operated without interference. Isotropic fusion protons, as well as leaking fuel components, from D-D or D-He3 fusion will be collimated by the outer magnetic field. This stream can then be lead to a traveling wave direct energy converter, TWDEC, H. Momota, et al., Fusion Technology, 21 (1992), 2307-2323. or to a thruster for space propulsion. H. Momota, et al., AIAA Joint Propulsion Conf., Huntsville Al. Bombardment of particles on structural devices can largely be avoided by optimizing current ratios on the pair and stabilization coils. Another property of this design is that it scatters charged particles into random directions near the center, providing a separation of low-energy leaking unburned fuel components from energetic fusion products. Such separation is essential for use with a TWDEC or for a space thruster to avoid unwanted waste of costly fuel components. A quantitative discussion of these features will be presented.

  9. Beam transport experiment with a new kicker control system on the HIRFL

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Yu; Zhou, De-Tai; Luo, Jin-Fu; Zhang, Jian-Chuan; Zhou, Wen-Xiong; Ni, Fa-Fu; Yin, Jun; Yin, Jia; Yuan, You-Jin; Shang-Guan, Jing-Bin

    2016-04-01

    A kicker control system is used for beam extraction and injection between two cooling storage rings (CSRs) at the Heavy Ion Research Facility in Lanzhou (HIRFL). To meet the requirements of special physics experiments, the kicker controller has been upgraded, with a new controller designed based on ARM+DSP+FPGA technology and monolithic circuit architecture, which can achieve a precision time delay of 2.5 ns. In September 2014, the new kicker control system was installed in the kicker field, and the test experiment using the system was completed. In addition, a pre-trigger signal was provided by the controller, which was designed to synchronize the beam diagnostic system and physics experiments. Experimental results indicate that the phenomena of “missed kick” and “inefficient kick” were not observed, and the multichannel trigger signal delay could be adjusted individually for kick power supplies in digitization; thus, the beam transport efficiency was improved compared with that of the original system. The fast extraction and injection experiment was successfully completed based on the new kicker control systems for HIRFL. Supported by National Natural Science Foundation of China (U1232123)

  10. Proton extraction by laser ablation of transition metals

    NASA Astrophysics Data System (ADS)

    Velardi, L.; Delle Side, D.; Krása, J.; Nassisi, V.

    2014-07-01

    A study on the proton beams extraction from a plasma generated by pulsed laser ablation by targets containing transition metals is presented. The targets used were pure disks of titanium and tantalum and disks of TiH2, obtained by compression of TiH2 powder. The plasma was produced by means of a nanosecond excimer KrF laser operating at low irradiance (109-1010 W/cm2). The proton and ions emission was analyzed by the time-of-flight technique using a Faraday cup as ion collector. Studies on the produced protons and ions at different laser irradiances from 2 to 15 GW/cm2 were performed. The characterization showed that it is possible to obtain good proton fluxes from these targets, up to 1011 proton/pulse. The results obtained are very interesting if compared with those available in literature where proton fluxes per pulse ranging from 108 to 109 by hydride targets were obtained, at the same laser irradiances.

  11. Resonant Kicker System Development at SLAC

    SciTech Connect

    Beukers, Tony; Krzaszczak, John; Larrus, Marc; Lira, Antonio de; /SLAC

    2009-04-27

    The design and installation of the Linear Coherent Light Source [1] at SLAC National Accelerator Laboratory has included the development of a kicker system for selective beam bunch dumping. The kicker is based on an LC resonant topology formed by the 50 uF energy storage capacitor and the 64 uH air core magnet load which has a sinusoidal pulse period of 400us. The maximum magnet current is 500 A. The circuit is weakly damped, allowing most of the magnet energy to be recovered in the energy storage capacitor. The kicker runs at a repetition rate of 120Hz. A PLC-based control system provides remote control and monitoring of the kicker via EPICS protocol. Fast timing and interlock signals are converted by discrete peak-detect and sample-hold circuits into DC signals that can be processed by the PLC. The design and experimental characterization of the system are presented.

  12. Some calculations for the RHIC kicker

    SciTech Connect

    Claus, J.

    1996-12-01

    This paper starts with a brief discussion of the design of the RHIC injection kicker magnets which calls for longitudinal and capacitive sections of the same order as the aperture, not much larger nor much smaller. This makes accurate analytical prediction of their behavior very difficult. In order to gain at least some qualitative insight of that behavior, the author preformed calculations which are based on the actual dimensions of the kickers but which neglect the end effects of the individual sections. The effects of the sectionalization are therefore exaggerated relative to reality in the results.

  13. Extracting the Proton Backward Spin Polarizability using Compton Scattering

    NASA Astrophysics Data System (ADS)

    Lefcochilos-Fogelquist, Heraclitos

    2016-09-01

    The proton spin-polarizabilities (SPs) are properties that quantify the response of the proton spin to electromagnetic waves. The SPs can be expressed in a linear combination called the backward spin polarizability (γπ) which arises in the cross-section of a Compton scattering event in which the incident photon is scattered at 180 degrees. As the cross-section at this angle cannot be experimentally determined, measurements of γπ are fitted using data with scattering angles close to 180 degrees. However, as the scattering angle is reduced the cross-section rapidly becomes determined by the values of the individual SPs, not γπ . This project investigated the viability of using cross-section data from different energy and angle bins to extract the γπ in order to optimize future experiments for γπ extraction. A Dispersion Relation was used to generate theory points based on randomly specified values of γπ and SPs for data sets of different energy and scattering angle. This was repeated 2000 times and the χ2 of each iteration was measured to determine if fits to a data set were dependent on the individual SPs values or γπ . This material is based upon work supported by the National Science Foundation under Grant No. IIA-1358175.

  14. Spiral kicker for the beam abort system

    SciTech Connect

    Martin, R.L.

    1983-01-01

    A brief study was carried out to determine the feasibility of a special kicker to produce a damped spiral beam at the beam dump for the beam abort system. There appears to be no problem with realizing this concept at a reasonably low cost.

  15. Precision fast kickers for kiloampere electron beams

    SciTech Connect

    Caporaso, G.J.; Chen, Y.J.; Weir, J.T.

    1999-10-06

    These kickers will be used to make fast dipoles and quadrupoles which are driven by sharp risetime pulsers to provide precision beam manipulations for high current kA electron beams. This technology will be used on the 2nd axis of the DARHT linac at LANL. It will be used to provide 4 micropulses of pulse width 20 to 120 nsec. selected from a 2 {micro}sec., 2kA, 20MeV macropulse. The fast pulsers will have amplitude modulation capability to compensate for beam-induced steering effects and other slow beam centroid motion to within the bandwidth of the kicker system. Scaling laws derived from theory will be presented along with extensive experimental data obtained on the test bed ETA-II.

  16. The PEP-II abort kicker system

    SciTech Connect

    Lamare, J de; Donaldson, A.; Kulikov, A. Lipari, J.

    1997-07-01

    The PEP-II project has two storage rings. The HER (High Energy Ring) has up to 1.48 A of electron beam at 9 GeV, and the LER (Low Energy Ring) has up to 2.14 A of positron beam at 3.1 GeV. To protect the HER and LER beam lines in the event of a ring component failure, each ring has an abort kicker system which directs the beam into a dump when a failure is detected. Due to the high current of the beams, the beam kick is tapered from 100% to 80% in 7.33 uS (the beam transit time around the time). This taper distributes the energy evenly across the window which separates the ring from the beam dump such that the window is not damaged. The abort kicker trigger is synchronized with the ion clearing gap of the beam allowing for the kicker field to rise from 0-80% in 370 nS. This report discusses the design of the system controls, interlocks, power supplies, and modulator.

  17. An Examination of Proton Charge Radius Extractions from e–p Scattering Data

    SciTech Connect

    Arrington, John

    2015-09-15

    A detailed examination of issues associated with proton radius extractions from elastic electron–proton scattering experiments is presented. Sources of systematic uncertainty and model dependence in the extractions are discussed, with an emphasis on how these may impact the proton charge and magnetic radii. A comparison of recent Mainz data to previous world data is presented, highlighting the difference in treatment of systematic uncertainties as well as tension between different data sets. We find several issues that suggest that larger uncertainties than previously quoted may be appropriate, but do not find any corrections which would resolve the proton radius puzzle.

  18. Equivalent circuit analysis of the RHIC injection kicker

    SciTech Connect

    Hahn, H.; Ratti, A.

    1997-07-01

    The RHIC injection kicker is built as a traveling wave structure in order to assure the required 95 nsec risetime in the deflection strength. The kicker is constructed from 14 cells, each 7.5 cm long, with alternating ferrite and high-permittivity dielectric sections. The cell structure permits an analysis of the electrical properties of the kicker using lumped L, C, and R circuit elements. Their values are obtained directly from impedance measurements of the full-length kicker, the inductance and shunt capacitance values by measuring the input impedance at 1 MHz with the output shorted and open, respectively. A lossy series resonance circuit in each cell is found to reproduce the measured input impedance of the terminated kicker up to {approximately}100 MHz. The validity of the equivalent circuit was confirmed by comparing the measured output current pulse shape time with that computed by the P-Spice program.

  19. Design and Testing of a Fast, 50 kV Solid-State Kicker Pulser

    SciTech Connect

    Cook, E G; Hickman, B C; Lee, B S; Hawkins, S A; Gower, E J; Allen, F V; Walstrom, P L

    2002-06-24

    The ability to extract particle beam bunches from a ring accelerator in arbitrary order can greatly extend an accelerator's capabilities and applications. A prototype solid-state kicker pulser capable of generating asynchronous bursts of 50 kV pulses has been designed and tested into a 50{Omega} load. The pulser features fast rise and fall times and is capable of generating an arbitrary pattern of pulses with a maximum burst frequency exceeding 5 MHz If required, the pulse-width of each pulse in the burst is independently adjustable. This kicker modulator uses multiple solid-state modules stacked in an inductive-adder configuration where the energy is switched into each section of the adder by a parallel array of MOSFETs. Test data, capabilities, and limitations of the prototype pulser are described.

  20. Longitudinal and transverse feedback kickers for the ALS

    SciTech Connect

    Corlett, J.N.; Johnson, J.; Lambertson, G.; Voelker, F.

    1994-06-01

    We describe the development of electromagnetic kickers for coupled-bunch feedback systems at the ALS. Transverse kickers are of a stripline design with one kicker per plane, operating in the baseband, 10 kHz to 250 MHz. Longitudinal lockers are of a coaxial design with electrodes paired in series operating over the band 1.00 to 1.25 GHz. Operating-band measurements and parasitic impedance measurements are presented. Power levels from beam induced signals are presented. Fabrication techniques are discussed.

  1. Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron

    NASA Astrophysics Data System (ADS)

    Zou, Ye; Tang, Jingyu; Yang, Zheng; Jing, Hantao

    2014-02-01

    This paper proposes a novel method to extract extremely weak beam from a high-intensity proton rapid cycling synchrotron (RCS) in the parasitic mode, while maintaining the normal fast extraction. The usual slow extraction method from a synchrotron by employing third-order resonance cannot be applied in a high-intensity RCS due to a very short flat-top at the extraction energy and the strict control on beam loss. The proposed parasitic slow extraction method moves the beam to scrape a scattering foil prior to the fast beam extraction by employing either a local orbit bump or momentum deviation or their combination, so that the halo part of the beam will be scattered. A part of the scattered particles will be extracted from the RCS and guided to the experimental area. The slow extraction process can last about a few milliseconds before the beam is extracted by the fast extraction system. The method has been applied to the RCS of China Spallation Neutron Source. With 1.6 GeV in the extraction energy, 62.5 μA in the average current and 25 Hz in the repetition rate for the RCS, the proton intensity by the slow extraction method can be up to 2×104 protons per cycle or 5×105 protons per second. The extracted beam has also a good time structure of approximately uniform in a spill which is required for many applications such as detector tests. Detailed studies including the scattering effect in the foil, the local orbit bump by the bump magnets and dispersive orbit bump by modifying the RF pattern, the multi-particle simulations by ORBIT and TURTLE codes, and some technical features for the extraction magnets are presented.

  2. Accelerator Fast Kicker R&D with Ultra Compact 50MVA Nano-Second FID Pulse Generator

    DTIC Science & Technology

    2013-06-01

    overall length of magnet or deflector . This demands a faster kicker system. To inject a 24 GeV beam into RHIC, the rise time of the kicker...kicker magnet or deflector length. In order to maintaining the same overall strength, six kicker modules, instead of four, will be used with shorter...individual kicker magnets or deflector length. This reduces the electrical pulse rise time constraint. The main parameters of injection kicker

  3. Status of the SLC damping ring kicker systems

    SciTech Connect

    Mattison, T.; Cassel, R.; Donaldson, A.; Gough, D.; Gross, G.; Harvey, A.; Hutchinson, D.; Nguyen, M.

    1991-05-01

    The damping ring kickers for the SLAC Linear Collider must meet extreme requirements on rise and fall time, flatness, time and amplitude jitter and drift, voltage, repetition rate, and reliability. After several generations of improvements to the pulsers, magnets, and controls, and evolution in the understanding of the requirements, the kicker systems are no longer a serious constraint on SLC performance. Implications for future linear colliders are discussed. 14 refs.

  4. Design of kicker magnet and power supply unit for synchrotron beam injection

    SciTech Connect

    Wang, Ju

    1991-03-01

    To inject beams from the positron accumulator ring (PAR) into the synchrotron, a pulsed kicker magnet is used. The specifications of this kicker magnet and the power supply unit are listed and discussed in this report.

  5. Development of an Adder-Topology ILC Damping Ring Kicker Modulator

    SciTech Connect

    Tang, Tao; Burkhart, Craig; /SLAC

    2009-05-08

    The ILC damping ring injection and extraction kickers will require high availability modulators that can deliver {+-}5 kV pulses into 50 {Omega} with a 2 ns flattop ({approx}1 ns rise and fall time) at up to 6 MHz. An effort is underway at SLAC National Accelerator Laboratory to meet these requirements using a transmission line adder topology to combine the output of an array of {approx}1 kV modules. The modules employ an ultra-fast hybrid MOSFET/driver that can switch 33 A in 1.2 ns. Experimental results for a scale adder structure are presented.

  6. Analysis of human muscle extracts by proton NMR

    SciTech Connect

    Venkatasubramanian, P.N.; Barany, M.; Arus, C.

    1986-03-01

    Perchloric acid extracts were prepared from pooled human muscle biopsies from patients diagnosed with scoliosis (SCOL) and cerebral palsy (CP). After neutralization with KOH and removal of perchlorate, the extracts were concentrated by freeze drying and dissolved in /sup 2/H/sub 2/O to contain 120 O.D. units at 280 nm per 0.5 ml. /sup 1/H NMR spectroscopy was performed with the 5 mm probe of a Varian XL300 instrument. Creatine, lactate, carnosine, and choline were the major resonances in the one-dimensional spectra of both extracts. With creatine as reference, 2.5-fold more lactate was found in SCOL than in CP, and a much smaller difference was also found in their carnosine content. Two-dimensional COSY comparison revealed several differences between the two extracts. Taurine, N-acetyl glutamate, glycerophosphoryl choline (or phosphoryl choline) and an unidentified spot were present only in the extract from SCOL but not in that from CP. On the other hand, aspartate, hydroxy-proline, carnitine and glycerophosphoryl ethanolamine were only present in CP but absent in SCOL. Alanine, cysteine, lysine and arginine appeared in both extracts without an apparent intensity difference.

  7. Control System for the LLNL Kicker Pulse Generator

    SciTech Connect

    Watson, J A; Anaya, R M; Cook, E G; Lee, B S; Hawkins, S A

    2002-06-18

    A solid-state high voltage pulse generator with multi-pulse burst capability, very fast rise and fall times, pulse width agility, and amplitude modulation capability for use with high speed electron beam kickers has been designed and tested at LLNL. A control system calculates a desired waveform to be applied to the kicker based on measured electron beam displacement then adjusts the pulse generators to provide the desired waveform. This paper presents the design of the control system and measure performance data from operation on the ETA-11 accelerator at LLNL.

  8. Analysis of beam loss induced abort kicker instability

    SciTech Connect

    Zhang W.; Sandberg, J.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Pai, C.; Tan, Y.

    2012-05-20

    Through more than a decade of operation, we have noticed the phenomena of beam loss induced kicker instability in the RHIC beam abort systems. In this study, we analyze the short term beam loss before abort kicker pre-fire events and operation conditions before capacitor failures. Beam loss has caused capacitor failures and elevated radiation level concentrated at failed end of capacitor has been observed. We are interested in beam loss induced radiation and heat dissipation in large oil filled capacitors and beam triggered thyratron conduction. We hope the analysis result would lead to better protection of the abort systems and improved stability of the RHIC operation.

  9. INJECTION ACCELERATION AND EXTRACTION OF HIGH INTENSITY PROTON BEAM FOR THE NEUTRINO FACILITY PROJECT AT BNL.

    SciTech Connect

    Tsoupas, N; Barton, D; Ganetis, G; Jain, A; Lee, Y; Marneris, I; Meng, W; Raparia, D; Roser, T; Ruggiero, A; Tuozzolo, J; Wanderer, P; Weng, W

    2003-05-12

    The proposed ''neutrino-production'' project [1.2] to be built at the Brookhaven National Laboratory (BNL) requires that the neutrino-production target be bombarded by a high intensity proton beam-pulse of {approx} 90 x 10{sup 12} protons of 28 GeV in energy and at a rate of 2.5 Hz, resulting in a 1 MW power of proton beam deposited on the target for the production of the neutrinos. In this paper we investigate the possibility of producing this high intensity proton beam, using as the main accelerator the Alternating Gradient Synchrotron (AGS) at the Brookhaven National Laboratory (BNL). The following aspects of the project are reported in this paper: (a) The beam injection into the AGS synchrotron of 1.2 GeV H{sup -} beam produced by a super-conducting LINAC[3]; (b) The effect of the eddy currents induced on the vacuum chamber of the circulating beam during the ''ramping'' of the main magnets of the AGS; (c) The method of the beam extraction from the AGS and the optics of the 28 GeV beam extracted from the AGS.

  10. Characterization of filter extractables by proton NMR spectroscopy: studies on intact filters with process buffers.

    PubMed

    Kao, Y H; Bender, J; Hagewiesche, A; Wong, P; Huang, Y; Vanderlaan, M

    2001-01-01

    Studies were conducted to characterize potential extractables from sterilizing grade filters. The focus of this report is the 0.22 micron Durapore (hydrophilic modified PVDF) filter which is used throughout our recovery processes. The objectives of this study are (1) to identify potential filter extractables from the hydrophilic PVDF filters; (2) to show that NMR spectroscopy may be used to detect filter extractables in the presence of product and excipients; and (3) to establish levels of filter extractables obtained by extraction with a variety of buffers. The data show that the primary source of filter extractables is the hydrophilic modification of the PVDF membrane surface. Extractables from the modified hydrophilic PVDF filter include propylene glycol (PG) and soluble oligomers of the hydroxypropyl acrylate and cross-linker. Propylene glycol, arising from the hydrolysis of the hydroxypropyl acrylate, appears to be the primary extractable in buffers above pH 11. Since the 1H-NMR method can easily detect the methyl proton signals of PG, an NMR assay was developed to detect PG in the presence of buffer excipients and final product. Propylene glycol can be used as a marker for the extractables from Durapore hydrophilic PVDF filters. Although numerous buffers were used to generate extractables from the PVDF filter, significant extractables (PG and soluble oligomers) were found only in high pH extraction buffers. As a result of this finding, only a limited number of new buffers or new PVDF filters will require testing for future validation studies. Process validation studies have shown that neither PG nor soluble oligomers are at levels that impact the quality or safety of the product.

  11. Solid-State Kicker Pulser for DARHT-2

    SciTech Connect

    Cook, E G; Lee, B S; Hawkins, S A; Allen, F V; Hickman, B C; Sullivan, J S; Brooksby, C A

    2001-06-07

    To replace a hard tube design, a solid-state kicker pulser for the Dual-Axis Radiographic Hydrodynamic Test facility (DARHT-2) has been designed and tested. This kicker modulator uses multiple solid-state modules stacked in an inductive-adder configuration where the energy is switched into each section of the adder by a parallel array of MOSFETs. The modulator features very fast rise and fall times, pulse width agility and a high pulse-repetition rate in burst mode. The modulator can drive a 50{Omega} load with voltages up to 20 kV and can be easily configured for either positive or negative polarity. The presentation will include test and operational data.

  12. Dynamic devices: A primer on pickups and kickers

    SciTech Connect

    Goldberg, D.A.; Lambertson, G.R.

    1991-11-01

    A charged-particle beam generates electromagnetic fields which in turn interact with the beam's surroundings. These interactions can produce fields which act back on the beam itself, or, if the surroundings'' are of suitably designed form (e.g., sensing electrodes with electrical connection to the outside world''), can provide information on various properties of the beam; such electrodes are generally known as pickups. Similarly, charged- particle beams respond to the presence of externally imposed electromagnetic fields; devices used to generate such fields are generally known as kickers. As we shall show, the behavior of an electrode system when it functions as a pickup is intimately related to its behavior as a kicker. A number of papers on pickup behavior have appeared in recent years in most of which the primary emphasis has been on beam instrumentation; there have also been several workshops on the subject. There have been several papers which have treated both pickup and kicker behavior of a particular electrode system, but this has been done in the context of discussing a specialized application, such as a stochastic cooling system. The approach in the present paper is similar to that of earlier works by one of the authors, which is to provide a unified treatment of pickup and kicker behavior, and, it is hoped, to give the reader an understanding which is both general and fundamental enough to make the above references easily accessible to him. As implied by the revised title, we have done the re-writing with the non-expert in mind. We have made the introduction both lengthier and more detailed, and done the same with much of the explanatory material and discussion.

  13. Dynamic devices: A primer on pickups and kickers

    SciTech Connect

    Goldberg, D.A.; Lambertson, G.R.

    1991-11-01

    A charged-particle beam generates electromagnetic fields which in turn interact with the beam`s surroundings. These interactions can produce fields which act back on the beam itself, or, if the ``surroundings`` are of suitably designed form (e.g., sensing electrodes with electrical connection to the ``outside world``), can provide information on various properties of the beam; such electrodes are generally known as pickups. Similarly, charged- particle beams respond to the presence of externally imposed electromagnetic fields; devices used to generate such fields are generally known as kickers. As we shall show, the behavior of an electrode system when it functions as a pickup is intimately related to its behavior as a kicker. A number of papers on pickup behavior have appeared in recent years in most of which the primary emphasis has been on beam instrumentation; there have also been several workshops on the subject. There have been several papers which have treated both pickup and kicker behavior of a particular electrode system, but this has been done in the context of discussing a specialized application, such as a stochastic cooling system. The approach in the present paper is similar to that of earlier works by one of the authors, which is to provide a unified treatment of pickup and kicker behavior, and, it is hoped, to give the reader an understanding which is both general and fundamental enough to make the above references easily accessible to him. As implied by the revised title, we have done the re-writing with the non-expert in mind. We have made the introduction both lengthier and more detailed, and done the same with much of the explanatory material and discussion.

  14. Some fast beam kicker magnet systems at SLAC

    SciTech Connect

    Bulos, F.; Cassel, R.L.; Donaldson, A.R.; Genova, L.F.; Grant, J.A.; Mihalka, A.M.; Sukiennick, B.A.; Tomlin, W.T.; Veldhuizen, F.T.; Walz, D.R.

    1987-01-01

    The Stanford Linear Collider requires very fast rise and fall times from its kicker magnets. The damping rings and positron source need either one or two bunches deflected from two or three that are separated in time by about 59 ns. The final focus region kicker magnets need a rise time of less than 700 ns and each one deflects only one bunch. This paper discusses the design and characteristics of a thyratron-switched, castor-oil-filled, coaxial, Blumlein line used for one bunch kicking. It discharges a 118 ns (at the base), 50 kV, 3 kA pulse into a 33 cm long, ferrite-loaded, kicker magnet of rectangular coaxial-line geometry, which in turn is terminated by a matched load. Reference is made to a Fermilab (FNAL) designed magnet and a dual-thyratron pulsar that will deflect two serial bunches in or out of the electron ring. Also, a brief description of the final focus magnet is given. Work is continuing on the various subsystem components to decrease the pulse rise and fall time, flattop ripple and jitter and to reduce some of the sources of noise and hv breakdown.

  15. Application of a continuous distribution model for proton binding by humic acids extracted from acidic lake sediments

    SciTech Connect

    Rhea, J.R.; Young, T.C. )

    1987-01-01

    The proton binding characteristics of humic acids extracted from the sediments of Cranberry Pond, an acidic water body located in the Adirondack Mountain region of New York State, were explored by the application of a nultiligand distribution model. The model characterizes a class of proton binding sites by mean log K values and the standard deviations of log K values and the mean. Mean log K values and their relative abundances were determined directly from experimental titration data. The model accurately predicts the binding of protons by the humic acids for pH values in the range 3.5 to 10.0.

  16. Application of a continuous distribution model for proton binding by humic acids extracted from acidic lake sediments

    NASA Astrophysics Data System (ADS)

    Rhea, James R.; Young, Thomas C.

    1987-10-01

    The proton binding characteristics of humic acids extracted from the sediments of Cranberry Pond, an acidic water body located in the Adirondack Mountain region of New York State, were explored by the application of a multiligand distribution model. The model characterizes a class of proton binding sites by mean log K values and the standard deviations of log K values about the mean. Mean log K values and their relative abundances were determined directly from experimental titration data. The model accurately predicts the binding of protons by the humic acids for pH values in the range 3.5 to 10.0.

  17. Overview of high voltage dielectric material for traveling wave kicker magnet application

    NASA Astrophysics Data System (ADS)

    Zhang,; Sandberg,; Tuozzolo,; Cassel,

    2002-06-01

    Pulsed high power fast kickers are being used to change beam trajectories in particle accelerators. The fast rise and fall time of pulse waveform demands a transmission line structure for the kicker deflector design. The ideal design will be parallel metal plates. However, it uses very long straight sections to achieve the required deflection. In accelerators with constrained straight sections, high permeability materials such as ferrite have to be used to gain deflection efficiency. The transmission line kicker magnet is also referred as traveling wave kicker magnet. Its construction is based on distributed 1-C cells along the longitudinal direction. The magnetic cells and capacitive cells are interleaved to simulate the characteristic impedance of a transmission line to minimize pulse reflection, and provide adequate frequency bandwidth to transmit the kicker pulse with fast rise and fall time. The magnetic cells are usually made of ferrite ceramics, but the capacitive cells have been made with different materials. For traveling wave kickers with higher impedance, the parallel plate vacuum capacitor has been used in CERN and KEK design. Others have used ceramic capacitors, printed circuit boards, and high permittivity ceramics as the capacitive cell. The high dielectric material has the advantage of compactness for low impedance kicker magnet construction. It continues to be very attractive for future kicker magnet applications. The high voltage phenomena associated with high dielectric ceramic materials have been widely reported in many industrial application areas.

  18. Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source

    SciTech Connect

    Roychowdhury, P. Mishra, L.; Kewlani, H.; Mittal, K. C.; Patil, D. S.

    2014-03-15

    A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20–40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, −2 to −4 kV, and 0 kV, respectively. The total ion beam current of 30–40 mA is recorded on Faraday cup at 40 keV of beam energy at 600–1000 W of microwave power, 800–1000 G axial magnetic field and (1.2–3.9) × 10{sup −3} mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source.

  19. Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source.

    PubMed

    Roychowdhury, P; Mishra, L; Kewlani, H; Patil, D S; Mittal, K C

    2014-03-01

    A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20-40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, -2 to -4 kV, and 0 kV, respectively. The total ion beam current of 30-40 mA is recorded on Faraday cup at 40 keV of beam energy at 600-1000 W of microwave power, 800-1000 G axial magnetic field and (1.2-3.9) × 10(-3) mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source.

  20. GAS DISCHARGE SWITCH EVALUATION FOR RHIC BEAM ABORT KICKER APPLICATION.

    SciTech Connect

    ZHANG,W.; SANDBERG,J.; SHELDRAKE,R.; PIRRIE,C.

    2002-06-30

    A gas discharge switch EEV HX3002 is being evaluated at Brookhaven National Laboratory as a possible candidate of RHIC Beam Abort Kicker modulator main switch. At higher beam energy and higher beam intensity, the switch stability becomes very crucial. The hollow anode thyratron used in the existing system is not rated for long reverse current conduction. The reverse voltage arcing caused thyratron hold-off voltage de-rating has been the main limitation of the system operation. To improve the system reliability, a new type of gas discharge switch has been suggested by Marconi Applied Technology for its reverse conducting capability.

  1. Design and test of the RHIC CMD10 abort kicker

    SciTech Connect

    Hahn, H.; Blaskiewicz, M.; Drees, A.; Fischer, W.; Mi, J.; Meng, W.; Montag, C.; Pai, C.; Sandberg, J.; Tsoupas, N.; Tuozzolo, J. E.; Zhang, W.

    2015-05-03

    In recent RHIC operational runs, planned and unplanned pre-fire triggered beam aborts have been observed that resulted in quenches of SC main ring magnets, indicating a weakened magnet kick strength due to beam-induced ferrite heating. An improvement program was initiated to reduce the longitudinal coupling impedance with changes to the ferrite material and the eddy-current strip geometry. Results of the impedance measurements and of magnet heating tests with CMD10 ferrite up to 190°C are reported. All 10 abort kickers in the tunnel have been modified and were provided with a cooling system for the RUN 15.

  2. Operational experience with SLC damping ring kicker magnets

    SciTech Connect

    Mattison, T.; Cassel, R.; Donaldson, A.; Gross, G.; Harvey, A.

    1991-05-01

    The damping ring kickers for the SLAC Linear Collider must provide 7 mrad kicks to 1.2 GeV beams with 60 nsec rise and fall times and fit in a 50 cm length around a 21 mm diameter ceramic beam pipe. This requires that they operate at up to 40 KV. The construction and operation of two types of quasi-coaxial ferrite magnet potted with RTV silicone rubber is discussed. Production yield has been improved by changes in RTV degassing, transfer, and cure. Operation lifetime is dominated by voltage, radiation, and thermal cycling. 4 refs., 2 figs.

  3. Measurement and simulation of the RHIC abort kicker longitudinal impedence

    SciTech Connect

    Abreu,N.P.; Hahn,H.; Choi, E.

    2009-09-01

    In face of the new upgrades for RHIC the longitudinal impedance of the machine plays an important role in setting the threshold for instabilities and the efficacy of some systems. In this paper we describe the measurement of the longitudinal impedance of the abort kicker for RHIC as well as computer simulations of the structure. The impedance measurement was done by the S{sub 21} wire method covering the frequency range from 9 kHz to 2.5 GHz. We observed a sharp resonance peak around 10 MHz and a broader peak around 20 MHz in both, the real and imaginary part, of the Z/n. These two peaks account for a maximum imaginary longitudinal impedance of j15 {Omega}, a value an order of magnitude larger than the estimated value of j0.2 {Omega}, which indicates that the kicker is one of the main sources of longitudinal impedance in the machine. A computer model was constructed for simulations in the CST MWS program. Results for the magnet input and the also the beam impedance are compared to the measurements. A more detail study of the system properties and possible changes to reduce the coupling impedance are presented.

  4. Research and development of RHIC injection kicker upgrade with nano second FID pulse generator

    SciTech Connect

    Zhang W.; Sandberg, J.; Hahn, H.; Fischer, W.; Liaw, C.J.; Pai, C.; Tuozzolo, J.

    2012-05-20

    Our recent effort to test a 50 kV, 1 kA, 50 ns pulse width, 10 ns pulse rise time FID pulse generator with a 250 ft transmission cable, resistive load, and existing RHIC injection kicker magnet has produced unparalleled results. This is the very first attempt to drive a high strength fast kicker magnet with a nano second high pulsed power (50 MVA) generator for large accelerator and colliders. The technology is impressive. We report here the result and future plan of RHIC Injection kicker upgrade.

  5. 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.

  6. Los Alamos high-current proton storage ring

    NASA Astrophysics Data System (ADS)

    Lawrence, G. P.; Hardekopf, R. A.; Jason, A. J.; Clout, P. N.; Sawyer, G. A.

    1985-05-01

    The Proton Storage Ring (PSR), whose installation was recently completed at Los Alamos, is a fast-cycling high-current accumulator designed to produce intense 800 MeV proton pulses for driving a spallation neutron source. The ring converts long beam pulses from the LAMPF linear accelerator into short bunches well matched to requirements of a high-resolution neutron-scattering materials science program. The initial performance goal for this program is to provide 100-(MU)A average current at the neutron production target within a 12-Hz pulse rate. Operation at 20 (MU)A is scheduled for September 1985, with full intensity within the next year. The storage ring was originally designed to function in a second mode in which six 1-ns bunches are accumulated and separately extracted every LAMPF macropulse. Implementation of this mode, which would serve a fast-neutron nuclear-physics program, was deferred in favor of initial concentration on the neutron-scattering program. The PSR design and status is summarized. Unique machine features include high peak current, two-step charge-stripping injection, a low-impedance buncher amplifier to counter beam-loading, and a high-repetition-rate strip-line extraction kicker.

  7. A waveguide overloaded cavity kicker for the HLS II longitudinal feedback system

    NASA Astrophysics Data System (ADS)

    Li, Wu-Bin; Zhou, Ze-Ran; Sun, Bao-Gen; Wu, Fang-Fang; Xu, Wei; Lu, Ping; Yang, Yong-Liang

    2014-03-01

    In the upgrade project of Hefei Light Source (HLS II), a new digital longitudinal bunch-by-bunch feedback system will be developed to suppress the coupled bunch instabilities in the storage ring effectively. We design a new waveguide overloaded cavity longitudinal feedback kicker as the feedback actuator. The beam pipe of the kicker is a racetrack shape so as to avoid a transition part to the octagonal vacuum chamber. The central frequency and the bandwidth of the kicker have been simulated and optimized to achieve design goals by the HFSS code. A higher shunt impedance can be obtained by using a nose cone to reduce the feedback power requirement. Before the kicker cavity was installed in the storage ring, a variety of measurements were carried out to check its performance. All these results of simulation and measurement are presented.

  8. An overview of high voltage dielectric material for traveling wave kicker magnet application

    SciTech Connect

    Wu Zhang et al.

    2002-08-19

    Pulsed high power fast kickers are being used to change beam trajectories in particle accelerators. The fast rise and fall time of pulse waveform demands a transmission line structure for the kicker deflector design. The ideal design will be parallel metal plates. However, it uses very long straight sections to achieve the required deflection. In accelerators with constrained straight sections, high permeability materials such as ferrite have to be used to gain deflection efficiency. The transmission line kicker magnet is also referred as traveling wave kicker magnet. Its construction is based on distributed L-C cells along the longitudinal direction. The magnetic cells and capacitive cells are interleaved to simulate the characteristic impedance of a transmission line to minimize pulse reflection, and provide adequate frequency bandwidth to transmit the kicker pulse with fast rise and fall time. The magnetic cells are usually made of ferrite ceramics, but the capacitive cells have been made with different materials. For traveling wave kickers with higher impedance, the parallel plate vacuum capacitor has been used in CERN and KEK design. Others have used ceramic capacitors, printed circuit boards, and high permittivity ceramics as the capacitive cell. The high dielectric material has the advantage of compactness for low impedance kicker magnet construction. It continues to be very attractive for future kicker magnet applications. The high voltage phenomena associated with high dielectric ceramic materials have been widely reported in many industrial application areas. Their implication in the traveling wave magnet application has to be well understood. In this presentation, the areas requiring further quantitative study will be outlined.

  9. AN OVERVIEW OF HIGH VOLTAGE DIELECTRIC MATERIAL FOR TRAVELING WAVE KICKER MAGNET APPLICATION.

    SciTech Connect

    ZHANG,W.; SANDBERG,J.; TUOZZOLO,J.; CASSEL,R.; DUCIMETIERE,L.; JENSEN,C.; BARNES,M.; WAIT,G.; WANG,J.

    2002-06-30

    Pulsed high power fast kickers are being used to change beam trajectories in particle accelerators. The fast rise and fall time of pulse waveform demands a transmission line structure for the kicker deflector design. The ideal design will be parallel metal plates. However, it uses very long straight sections to achieve the required deflection. In accelerators with constrained straight sections, high permeability materials such as ferrite have to be used to gain deflection efficiency. The transmission line kicker magnet is also referred as traveling wave kicker magnet. Its construction is based on distributed 1-C cells along the longitudinal direction. The magnetic cells and capacitive cells are interleaved to simulate the characteristic impedance of a transmission line to minimize pulse reflection, and provide adequate frequency bandwidth to transmit the kicker pulse with fast rise and fall time. The magnetic cells are usually made of ferrite ceramics, but the capacitive cells have been made with different materials. For traveling wave kickers with higher impedance, the parallel plate vacuum capacitor has been used in CERN and KEK design. Others have used ceramic capacitors, printed circuit boards, and high permittivity ceramics as the capacitive cell. The high dielectric material has the advantage of compactness for low impedance kicker magnet construction. It continues to be very attractive for future kicker magnet applications. The high voltage phenomena associated with high dielectric ceramic materials have been widely reported in many industrial application areas. Their implication in the traveling wave magnet application has to be well understood. In this presentation, the areas requiring further quantitative study will be outlined.

  10. LBNE lattice & optics for proton extraction at MI-10 and transport to a target above grade

    SciTech Connect

    Johnstone, John A.; /Fermilab

    2011-09-01

    For the Long Baseline Neutrino Experiment (LBNE) at Fermilab 120 GeV/c protons will be transported from the Main Injector (MI) to an on-site production target. The lattice design and optics discussed here has the beam extracted vertically upwards from MI-10 and the keeps the majority of the line at an elevation above the glacial till/rock interface and terminates on a target at 10 ft above grade. The LBNE beamline discussed here is a modular optics design comprised of 3 distinct lattice configurations, including the specialized MI {yields} LBNE matching section and Final Focus. The remainder of the line is defined by six FODO cells, in which the length and phase advance are chosen specifically such that beam size does not exceed that of the MI while also making the most efficient use of space for achromatic insertions. Dispersion generated by variations in the beam trajectory are corrected locally and can not bleed out to corrupt the optics elsewhere in the line. Aperture studies indicate that the line should be able to transport the worst quality beam that the Main Injector might provide. New IDS dipole correctors located at every focusing center provide high-quality orbit control and further ensure that LBNE meets the stringent requirements for environmental protection.

  11. In situ baking method for degassing of a kicker magnet in accelerator beam line

    SciTech Connect

    Kamiya, Junichiro Ogiwara, Norio; Yanagibashi, Toru; Kinsho, Michikazu; Yasuda, Yuichi

    2016-03-15

    In this study, the authors propose a new in situ degassing method by which only kicker magnets in the accelerator beam line are baked out without raising the temperature of the vacuum chamber to prevent unwanted thermal expansion of the chamber. By simply installing the heater and thermal radiation shield plates between the kicker magnet and the chamber wall, most of the heat flux from the heater directs toward the kicker magnet. The result of the verification test showed that each part of the kicker magnet was heated to above the target temperature with a small rise in the vacuum chamber temperature. A graphite heater was selected in this application to bake-out the kicker magnet in the beam line to ensure reliability and easy maintainability of the heater. The vacuum characteristics of graphite were suitable for heater operation in the beam line. A preliminary heat-up test conducted in the accelerator beam line also showed that each part of the kicker magnet was successfully heated and that thermal expansion of the chamber was negligibly small.

  12. Fast and reliable kicker magnets for the SLC damping rings

    SciTech Connect

    Mattison, T.S.; Cassel, R.L.; Donaldson, A.R.; Gross, G.

    1995-06-01

    The design, construction, and operation of a kicker magnet with superior electromagnetic performance and greatly improved radiation tolerance is described. A short flux return of high mu ferrite improves the field strength and linearity with current, and novel metallic field-confining structures minimize the inductance. An 8-cell structure with capacitance integrated into each cell makes the magnet a nearly perfect transmission line. The capacitor dielectric is 1 cm thick alumina-loaded epoxy, processed to eliminate air voids, and cast in a multiple step procedure developed to circumvent epoxy shrinkage. The magnet operates with pulses of up to 40 kV and 3.2 kA at 120 Hz, with magnet transit times of less than 35 nsec and field rise and fall times of less than 60 nsec.

  13. ADVANCEMENT OF THE RHIC BEAM ABORT KICKER SYSTEM.

    SciTech Connect

    ZHANG,W.AHRENS,L.MI,J.OERTER,B.SANDBERG,J.WARBURTON,D.

    2003-05-12

    As one of the most critical system for RHIC operation, the beam abort kicker system has to be highly available, reliable, and stable for the entire operating range. Along with the RHIC commission and operation, consistent efforts have been spend to cope with immediate issues as well as inherited design issues. Major design changes have been implemented to achieve the higher operating voltage, longer high voltage hold-off time, fast retriggering and redundant triggering, and improved system protection, etc. Recent system test has demonstrated for the first time that both blue ring and yellow ring beam abort systems have achieved more than 24 hours hold off time at desired operating voltage. In this paper, we report break down, thyratron reverse arcing, and to build a fast re-trigger system to reduce beam spreading in event of premature discharge.

  14. AN ENGINEERING SOLUTION TO THE RHIC BEAM ABORT KICKER UPGRADE.

    SciTech Connect

    ZHANG,W.ROSER,T.SANDBERG,J.TAN,Y.ET AL.

    2004-05-23

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory is the world largest superconducting accelerator for nuclear energy research. Particle beams traveling in opposite directions in two accelerator rings, Blue and Yellow, collide at six interaction regions to create phenomena of the early universe. There are more than 1700 superconducting magnets and very sophisticate and delicate large detectors inside the RHIC tunnel. With high beam intensity and ultra high beam energy, an inadvertent loss of beam can result severe damage to the superconducting magnets and detectors. Beam abort kickers are used to remove beam safely from the ring. The large inductive load, high current capability, short beam gap, and high reliability are the challenging issues of this system design. With high intensity and high momentum beam operation, it is desirable to have all high voltage modulators located outside of RHIC tunnel. However, to generate 22 kA output current per modulator with fast rise time, a conventional low impedance PFN and matched transmission cable design can push the operation voltage easily into 100 kV range. The large quantity of high voltage pulse transmission cables required by conventional design is another difficult issue. Therefore, the existing system has all ten high voltage modulators located inside RHIC tunnel. More than a hundred plastic packaged mineral oil filled high voltage capacitors raise serious concerns of fire and smoking threats. Other issues, such as kicker misfire, device availability in the future, and inaccessibility during operation, also demand an engineering solution for the future upgrade. In this paper, we investigate an unconventional approach to meet the technical challenges of RHIC beam abort system. The proposed design has all modulators outside of the RHIC tunnel. It will transmit output pulse through high voltage cables. The modulators will utilize solid-state switches, and operate at a maximum voltage in 30 to

  15. Multi-pulse extraction from Los Alamos Proton Storage Ring for radiographic applications

    SciTech Connect

    Thiessen, H.A.; Neri, F.; Rust, K.; Redd, D.B.

    1997-08-01

    In Proton Radiography, one of the goals is a motion picture of a rapidly moving object. The Los Alamos Proton Storage Ring (PSR) in its normal operating mode, delivers a single pulse approximately 120 ns wide (fwhm). In development runs at the PSR, the authors successfully demonstrated operation of a technique to deliver two pulses, each 40 nsec wide, with adjustable spacing.

  16. A pinger system for the Los Alamos Proton Storage Ring

    SciTech Connect

    Hardek, T.W.; Thiessen, H.A.

    1991-01-01

    Developers at the Proton Storage Ring have long desired a modulator and electrode combination capable of kicking the 800-MeV proton beam enough to conduct tune measurements with full intensity beams. At present this has been accomplished by reducing the voltage on one extraction kicker modulator and turning the other off. This method requires that all of the accumulated beam be lost on the walls of the vacuum chamber. In addition to tune measurements a more recent desire is to sweep out beam that may have leaked into the area between bunches. A four-meter electrode has been designed and constructed for the purpose. The design is flexible in that the electrode may be split in the center and rotated in order to provide vertical and horizontal electrodes each 2 meters long. In addition two solid-state pulse modulators that can provide 10kV in burst mode at up to 700 KHz have been purchased. This hardware and its intended use are described. 3 refs., 2 figs., 1 tab.

  17. 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.

  18. Kicker field simulation and measurement for the muon g-2 experiment at FNAL

    NASA Astrophysics Data System (ADS)

    Chang, Seung Pyo; Kim, Young Im; Choi, Jihoon; Semertzidis, Yannis; muon g-2 experiment Collaboration

    2017-01-01

    In the Muon g-2 experiment, muon beam is injected to the storage ring in a slightly tilted orbit whose center is 77 mm away from the center of the ring. The kicker is needed to send the muon beam to the central orbit. The magnetic kicker is designed for the experiment and about 0.1 Tm field integral is needed. The peak current pulse is 4200 A to make this field integral. This strong kicker pulse could make unwanted eddy current occur. This eddy current could spoil the main magnetic field of the storage ring. This could be a critical threat to the precision of experiment. The kicker field simulation has done using OPERA to estimate the effects. Also the kicker field should be measured based on Faraday effect. The measurement has tested in the lab before install the experiment area. In this presentation, the simulation and measurement results will be discussed. This work was supported by IBS-R017-D1-2016-a00.

  19. Eliminating the Spot Dilution Due to Kicker Switching in DARHT-II

    SciTech Connect

    Chen, Y-J; Chambers, F W; Paul, A C; Watson, A; Weir, J T

    2003-05-06

    To produce four short x-ray pulses for radiography, the second-axis of the Dual Axis Radiographic Hydrodynamic Test facility (DARHT-II) will use a fast kicker to select current pulses out of the 2-ms duration beam provided by the accelerator. Beam motion during the kicker voltage switching could lead to dilution of the time integrated beam spot and make the spot elliptical. A large elliptical x-ray source produced by those beams would degrade the resolution and make radiographic analysis difficult. We have developed a tuning strategy to eliminate the spot size dilution, and tested the strategy successfully on ETA-II with the DARHT-II kicker hardware.

  20. BEAM DYNAMICS ANALYSIS FOR THE ULTRA-FAST KICKER IN CIRCULAR COOLER RING OF JLEIC

    SciTech Connect

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.; Wang, Shaoheng

    2016-05-01

    An ultra-fast kicker system consisting of four quarter wavelength resonator based deflecting cavities was developed that simultaneously resonates at 10 subharmonic modes of the 476.3MHz bunch repetition frequency. Thus every 10th bunch in the bunch train will experience a transverse kick while all the other bunches are undisturbed. This fast kicker is being developed for the Energy Recovery Linac (ERL) based electron Circular Cooler Ring (CCR) in the proposed Jefferson Lab Electron Ion Collider (JLEIC, previously MEIC). The electron bunches can be reused 10-30 turns thus the beam current in the ERL can be reduced to 1/10 - 1/30 (150mA - 50mA) of the cooling bunch current (1.5A). In this paper, several methods to synthesize such a kicker waveform and the comparison made by the beam dynamics tracking in Elegant will be discussed.

  1. MARS Tracking Simulations for the Mu2e Slow Extracted Proton Beam

    SciTech Connect

    Nagaslaev, Vladimir; Rakhno, Igor

    2015-06-01

    Particle tracking taking into account interactions with fields and materials is necessary for proper evaluation of the resonant extraction losses and geometry optimization for the extraction beam line. This paper describes the tracking simulations for the Mu2e Resonant Extraction and discusses the geometry choices made based on these simulations.

  2. BEAM EXTRACTION FROM THE RECYCLER RING TO P1 LINE AT FERMILAB

    SciTech Connect

    Xiao, M.; Capista, D.; Adams, P.; Morris, D.; Yang, M. J.; Hazewood, K.

    2016-10-03

    The transfer line for beam extraction from the Recycler ring to P1 line provides a way to deliver 8 GeV kinetic energy protons from the Booster to the Delivery ring, via the Recycler, using existing beam transport lines, and without the need for new civil construction. It was designed in 2012. The kicker magnets at RR520 and the lambertson magnet at RR522 in the RR were installed in 2014 Summer Shutdown, the elements of RR to P1 Stub (permanent quads, trim quads, correctors, BPMs, the toroid at 703 and vertical bending dipole at V703 (ADCW) were installed in 2015 Summer Shutdown. On Tuesday, June 21, 2016, beam line from the Recycler Ring to P1 line was commissioned. The detailed results will be presented in this report.

  3. Experimental optimization of beam quality extracted from a duoplasmatron proton ion source

    SciTech Connect

    Batygin, Y. K.; Draganic, I. N.; Fortgang, C. M.

    2014-10-01

    The LANSCE accelerator facility operates with two independent ion injectors for H⁺ and H⁻ particle beams. The H⁺ ion beam is formed using a duoplasmatron source followed by a 750 keV Cockroft-Walton accelerating column. Formation of an optimal plasma meniscus is an important feature for minimizing beam emittance, and maximizing beam brightness. A series of experiments were performed to find the optimal combination of extraction voltage and extracted current for the H⁺ beam. Measurements yielded the best ratio of beam perveance to Child–Langmuir perveance of 0.52 for maximizing beam brightness.

  4. Stochastic cooling of 200 MeV protons

    NASA Astrophysics Data System (ADS)

    Lambertson, G.; Bisognano, J.; Flood, W.; Laslett, L. J.; Leemann, C.; Leskovar, B.; Lo, C. C.; Main, R.; Smith, L.; Staples, J.

    1980-07-01

    Vertical and longitudinal cooling was achieved at the FNAL 200 MeV cooling ring. Initial longitudinal cooling times of 20 seconds for 1.5 x 1 million circulating protons are in approximate 20 seconds for 1.5 x 1 million circulating protons are in approximate agreement with calculations based on measured system parameters. The cooling systems have an electronic bandwidth of approxmately 300 MHz, traveling wave pickups and kickers, and a notch filter using flexible cable. The traveling wave structures provide a good signal-to-noise ratio and reduce output power requirements.

  5. Modeling of an inductive adder kicker pulser for DARHT-II

    SciTech Connect

    Wang, L; Caporaso, G J; Cook, E G

    2000-09-25

    An all solid-state kicker pulser for a high current induction accelerator (the Dual-Axis Radiographic Hydrodynamic Test facility DARHT-2) has been designed and fabricated. This kicker pulser uses multiple solid state modulators stacked in an inductive-adder configuration. Each modulator is comprised of multiple metal-oxide-semiconductor field-effect transistors (MOSFETs) which quickly switch the energy storage capacitors across a magnetic induction core. Metglas is used as the core material to minimize loss. Voltage from each modulator is inductively added by a voltage summing stalk and delivered to a 50 ohm output cable. A lumped element circuit model of the inductive adder has been developed to optimize the performance of the pulser. Results for several stalk geometries will be compared with experimental data.

  6. Measurement of the coupling impedances of the kickers in the SIS and ESR at GSI.

    NASA Astrophysics Data System (ADS)

    Blell, U.

    1997-05-01

    At high particle intensities coherent transverse beam oscillations may be excited due to the coupling of the beam to individual accelerators structures. The characteristic values to describe these beam instabilities are the longitudinal- and transverse coupling impedances. One reason for this beam instability is the inductive interaction between the beam and the kicker magnets. The type of the magnet, e.g. window-frame magnet or C-magnet, and its external electrical network are the most important quantities to identify the coupling impedances below the cut-off frequency of the beam pipe. For the kicker modules in the SIS and ESR accelerators at GSI the mathematical basis, theory and measured results will be presented.

  7. Mechanical design of ceramic beam tube braze joints for NOvA kicker magnets

    SciTech Connect

    Ader, C.R.; Reilly, R.E.; Wilson, J.H.; /Fermilab

    2010-05-01

    The NO?A Experiment will construct a detector optimized for electron neutrino detection in the existing NuMI neutrino beam. The NuMI beam line is capable of operating at 400 kW of primary beam power and the upgrade will allow up to 700 kW. Ceramic beam tubes are utilized in numerous kicker magnets in different accelerator rings at Fermi National Accelerator Laboratory. Kovar flanges are brazed onto each beam tube end, since kovar and high alumina ceramic have similar expansion curves. The tube, kovar flange, end piece, and braze foil alloy brazing material are stacked in the furnace and then brazed. The most challenging aspect of fabricating kicker magnets in recent years have been making hermetic vacuum seals on the braze joints between the ceramic and flange. Numerous process variables can influence the robustness of conventional metal/ceramic brazing processes. The ceramic-filler metal interface is normally the weak layer when failure does not occur within the ceramic. Differences between active brazing filler metal and the moly-manganese process will be discussed along with the applicable results of these techniques used for Fermilab production kicker tubes.

  8. Design and optimization of a longitudinal feedback kicker cavity for the HLS-II storage ring

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Z. Wu, W.; He, Duo-Hui; K. Wu, Y.

    2013-03-01

    In the Hefei Light Source (HLS) storage ring, multibunch operation is used to obtain a high luminosity. Multibunch instabilities can severely limit light source performance with a variety of negative impacts, including beam loss, low injection efficiency, and overall degradation of the beam quality. Instabilities of a multibunch beam can be mitigated using certain techniques including increasing natural damping (operating at a higher energy), lowering the beam current, and increasing Landau damping. However, these methods are not adequate to stabilize a multibunch electron beam at a low energy and with a high current. In order to combat beam instabilities in the HLS storage ring, active feedback systems including a longitudinal feedback system (LFB) and a transverse feedback system (TFB) will be developed as part of the HLS upgrade project, the HLS- II storage ring project. As a key component of the longitudinal bunch-by-bunch feedback system, an LFB kicker cavity with a wide bandwidth and high shunt impedance is required. In this paper we report our work on the design of the LFB kicker cavity for the HLS- II storage ring and present the new tuning and optimization techniques developed in designing this high performance LFB kicker.

  9. Development of an abort gap monitor for high-energy proton rings

    SciTech Connect

    Beche, Jean-Francois; Byrd, John; De Santis, Stefano; Denes, Peter; Placidi, Massimo; Turner, William; Zolotorev, Max

    2004-05-03

    The fill pattern in proton synchrotrons usually features an empty gap, longer than the abort kicker raise time, for machine protection. This gap is referred to as the ''abort gap'' and any particles, which may accumulate in it due to injection errors and diffusion between RF buckets, would be lost inside the ring, rather than in the beam dump, during the kicker firing. In large proton rings, due to the high energies involved, it is vital to monitor the build up of charges in the abort gap with a high sensitivity. We present a study of an abort gap monitor based on a photomultiplier with a gated microchannel plate, which would allow for detecting low charge densities by monitoring the synchrotron radiation emitted. We show results of beam test experiments at the Advanced Light Source using a Hamamatsu 5916U MCP-PMT and compare them to the specifications for the Large Hadron Collider

  10. Investigation of the skin depth effect of a metallic coating on a ceramic beampipe inside a kicker

    SciTech Connect

    Ng, K.Y.

    1985-07-01

    Inside a kicker magnet, metallic beampipe cannot be used because it will screen off the rapid rising of the kicker's magnetic field. When a ceramic beampipe is used, one usually coats the inside with a thin layer of metal so as to carry at least part of the beam's image current and to prevent static charge buildup. The purpose of this article is to investigate whether such a coating will alter the risetime constant of the magnetic field significantly, whether such a coating can withstand the strong transient current induced by the fast rising magnetic field, and whether the back magnetic field generated by this transient current is strong enough to upset the designed risetime of the kicker.

  11. Design of the 0.5 - 1 GHz Planar Recycler Pickup and Kicker Antennas

    SciTech Connect

    Deibele, C.; /Fermilab

    1999-01-01

    The stochastic cooling system in the Recycler ring at Fermilab required the addition of a 0.5-1 GHz cooling system. This requirement dictated the design of a new antenna for this band of the system. The design problem is defined, method of design is illustrated, and the measurement data are reported. The Recycler is a storage ring comprised of mostly permanent magnets located in the tunnel of the Main Injector at Fermilab. The goal for the construction of the Recycler is to collect and store unused antiprotons from collisions in the Tevatron for use in future collisions in the Tevatron. It will both stochastically and electron cool these unused antiprotons before another collision experiment is possible in the Tevatron. By reusing the antiprotons the luminosity of the experiment can be increased faster. The Recycler will use three bands for its stochastic cooling system. It will reuse the existing designs from the Antiproton Source for the 1-2 GHz and 2-4 GHz systems, and it requires a new design for an additional lower frequency band for the 0.5-1 GHz system. Since the existing designs were fabricated using a microstrip topology it was desired that the new design use a similar topology so that the vacuum tank designs and supporting hardware be identical for all three bands. A primary difference between the design of the pickups/kickers of the Antiproton Source and the Recycler is a different aperture in the machine itself. The Recycler has a bigger aperture and consequently reusing the designs for the existing Antiproton Source pickups/kickers is not electrically optimal but is cost efficient. Measurements will be shown later in this paper for the design of the 0.5-1 GHz system showing the effect of the aperture on the antenna performance. A mockup of the Recycler tank was manufactured for designing and testing the 0.5-1 GHz pickups/kickers. The design procedure was an iterative process and required both a constant dialogue and also a strong relationship with a

  12. AGS new fast extraction system and the single bunch extraction test

    SciTech Connect

    Weng, W.T.

    1983-01-01

    For the neutrino physics program and for the CBA injection, a new fast extraction system has been implemented to improve the extraction efficiency and the quality of the extracted beam. Central to the new system is a new fast kicker, placed at the H5 straight section, capable of rising between bunches, t/sub r/ < 170 nsec, and staying constant for 2.6 ..mu..sec with flat top ripple less than +-1.5%. So far, the system has been operated for longer than 3000 hours and routinely extracts 10/sup 13/ ppp at 99% efficiency. Experiment 745 on QCD test requires a single AGS bunch of 40 nsec. For this purpose another fast kicker was placed at the E5 straight section and powered by a new pulser to produce a half sinusoidal pulse with both a rise and fall time of 200 nsec. A single AGS bunch was extracted through the slow beam channel at 22 GeV/c leaving the remaining 11 bunches undisturbed which continued to be accelerated to 29.4 GeV/c and extracted by the H5 kicker through the fast beam channel. Because the ring circumference ratio of CBA to the AGS is 4-3/4, some of the injected beam from the AGS has to contain 11 bunches instead of 12; consequently, this single bunch extraction mode will also be used for CBA injection.

  13. Harmonic Resonant Kicker Design for the MEIC Electron Circular Cooler Ring

    SciTech Connect

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.

    2015-09-01

    Bunched-beam electron cooling of the high-energy ion beam emittance may be a crucial technology for the proposed Medium energy Electron Ion Collider (MEIC) to achieve its design luminosity. A critical component is a fast kicker system in the Circular Ring (CR) that periodically switches electron bunches in and out of the ring from and to the driver Energy Recovery Linac (ERL). Compared to a conventional strip-line type kicker, a quarter-wave resonator (QWR)-based deflecting structure has a much higher shunt impedance and so requires much less RF power. The cavity has been designed to resonate simultaneously at many harmonic modes that are integer multiples of the fundamental mode. In this way the resulting waveform will kick only a subset of the circulating bunches. In this paper, analytical shunt impedance optimization, the electromagnetic simulations of this type of cavity, as well as tuner and coupler concept designs to produce 5 odd and 5 even harmonics of 47.63MHz will be presented, in order to kick every 10th bunch in a 476.3 MHz bunch train.

  14. Extraction of jet properties from two particle azimuthal correlations in proton-proton and gold+gold collisions at center of mass energy = 200 GeV

    NASA Astrophysics Data System (ADS)

    Constantin, Paul

    Two particle azimuthal correlation functions measured in pp and AuAu collisions at sNN = 200 GeV at midrapidity with the central arms of the PHENIX detector are analyzed in order to extract the properties of hadronic jets produced in QCD vacuum and highly excited QCD media, like the jet shape parameters jT and kT, the jet conditional yields (number of associated hadrons per high pT trigger hadron) and the jet fragmentation function. The analysis of pp data starts with the measurement of the vacuum fragmentation function from which the pT dependence of the mean fragmentation momentum fraction is extracted. We obtain a constant value of = 0.74 +/- 0.02 for pT above 3 GeV/c. Soft (non-perturbative) parton fragmentation becomes significant below 3 GeV/c and the slope of the fragmentation function is pT dependent in this region. Gaussian fits to jet induced azimuthal correlations are employed to measure the mean jet fragmentation transverse momentum <| jTy|> = 359 +/- 11 (stat) +/- 6 (syst) MeV/c and the mean partonic transverse momentum <|k Ty|> = 964 +/- 49 (stat) +/- 16 (syst) MeV/c. The analysis of AuAu data is based on azimuthal correlation functions between charged hadrons in the 1.5--3 GeV/c and 3--5 GeV/c pT regions in five classes of collision centrality. The mean jet fragmentation transverse momentum <|jTy|> is centrality independent and consistent with the value in pp data mentioned above. A strong broadening with the centrality of the extracted mean partonic transverse momentum <|kTy|> (multiplied by ) is observed. This is an important finding because hadronic jet quenching through energy loss is expected to be accompanied by a broadening effect. Another important finding is that the jet conditional yields in both the near (Deltaφ ˜ 0) and away (Deltaφ ˜ pi) regions exhibit a slightly raising trend with centrality. This was also expected to accompany the jet quenching found at higher pT based on simple energy conservation considerations.

  15. Effects of providing advance cues during a soccer penalty kick on the kicker's rate of success.

    PubMed

    Núñez, F Javier; Oño, Antonio; Raya, Antonio; Bilbao, Alfonso

    2010-12-01

    The effect of explicitly providing goalkeeper's movement advanced cue to the kicker during a real penalty kick task was assessed. 32 expert soccer players (M age= 23.2 yr.), who were divided into four groups: an experimental group, a discovery group, a placebo group, and a control group, participated. Rate of success in the task was assessed, as well as goals, decision times, and ball flight times. Providing an advance cue significantly improved the players' rate of success relative to players without the advance cue; this difference was still present after 1 and 7 days without training. The experimental group adapted better to the time range within which the response could be effective, while the discovery group showed adaptations. Explicit instructions about the advance cues available from goalkeepers' actions before the dive during practice can improve penalty kick performance.

  16. A Pulsed Modulator Power Supply for the g-2 Muon Storage Ring Injection Kicker

    SciTech Connect

    Mi,J.; Lee, Y.Y.; Morse, W. M.; Pai, C.; Pappas, G.; Sanders, R.; Semertzidis, Y.

    1999-03-29

    This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the g-2 storage ring that has been built at Brookhaven. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95 kV. the damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. this paper discusses the modulator design, construction and operation.

  17. A PULSED MODULATOR POWER SUPPLY FOR THE G-2 MUON STORAGE RING INJECTION KICKER.

    SciTech Connect

    MI,J.LEE,Y.Y.MORSE,W.M.PAI,C.I.PAPPAS,G.C.SANDERS,Y.SEMERTIZIDIS,Y.,ET AL.

    2003-03-01

    This paper describes the pulse modulator power supplies used to drive the kicker magnets that inject the muon beam into the 8-2 storage ring that has been built at Brookhaven National Laboratory. Three modulators built into coaxial structures consisting of a series circuit of an energy storage capacitor, a damping resistor and a fast thyratron switch are used to energize three magnets that kick the beam into the proper orbit. A 100 kV charging power supply is used to charge the capacitor to 95kV. The damping resistor shapes the magnet current waveform to a 450 nanosecond half-sine to match the injection requirements. This paper discusses the modulator design, construction and operation.

  18. An IGBT Driven Slotted Beam Pipe Kicker for SPEAR III Injection

    SciTech Connect

    Cassel, Richard

    2002-08-21

    The SPEAR III injection kicker system is composed of three kicker magnets, K1, K2, and K3. These magnets, along with the power modulators to drive them constitute an injection system which will be used to deflect an incoming electron beam with an energy of 3.3 GeV by an angle of 2.5 mrad for K1 and K3, and 1 mrad for K2. The pulse shape of the magnetic field in the three magnets must be matched in order to preserve a closed orbit. The pulse duration is required to be less than 780 ns, with rise and fall times of less than 375 ns, and a pulse repetition frequency of 10 Hz. The aperture of all three magnets is 60 x 34 mm in an 8 inch vacuum vessel. The magnetic length is 1.2 m for K1 and K3, and 0.6 m for K2 [1]. The magnet design employs a slotted beam pipe which is shorted at one end. A solid state IGBT based, induction type of modulator drives the magnets. Modulators for K1 and K3 consist of eight 4.5 kV, 600 A IGBTs, and eight Finemet magnet cores with four 22.5 Ohm output cables to drive 2381 A into the magnets. The modulator for K2 uses four IGBTs and cores, and 8 output cables to produce a 2619 A pulse. Cables of length greater than one half the pulse width must be used in order to avoid reflections from the shorted magnet. The design charge voltage for the modulators is 20 kV for K1 and K3. This paper describes the magnet and modulator design, as and presents test data from a prototype system.

  19. A study of coal extraction with electron paramagnetic resonance (EPR) and proton nuclear magnetic resonance relaxation techniques. Quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Doetschman, D.C.; Mehlenbacher, R.C.; Ito, O.

    1993-09-01

    An electron spin and proton magnetic relaxation study is presented on the effects of the solvent extraction of coal on the macromoleculer network of the coal and on the mobile molecular species that are initially within the coal. The eight Argonne Premium coals were extracted at room temperature with a 1:1 (v/v) N-methylpyrrolidinone (NMP)-CS2 solvent mixture under an inert atmosphere. As much solvent as possible was removed from extract and residue by treatment in a vacuum. The mobilization of molecular free radicals by the solvent and the exposure of free radicals in the macromoleculer matrix to solvent or to species dissolved in the solvent, results in a preferential survival of residue radicals of types that depend on the particular coal and results in the apparently fairly uniform loss of all types of radicals in bituminous coal extracts. The surviving extract and residue free radicals are more predominantly of the odd- alternate hydrocarbon free radical type. The spin-lattice relaxation (SLR) of these coal free radicals has previously been inferred (Doetschman and Dwyer, Energy Fuels, 1992, 6, 783) to be from the modulation of the intramolecular electron-nuclear dipole-interactions of the CH groups in a magnetic field by rocldng motions of the radical in the coal matrix. Such a modulation would depend not only on the rocking amplitude and frequency but also upon the electron spin density at the CH groups in the radical. The observed SLR rates decrease with coal rank in agreement with the smaller spin densities and the lower rocidng amplitudes that are expected for the larger polycondensed ring systems in coals of higher rank. The SLR rates are found to be generally faster in the extracts (than residues) where the molecular species would be expected to have a smaller polycondensed ring system than in the macromoleculer matrix of the residue.

  20. High Current and High Power Fast Kicker System Conceptual Design and Technology Overview for DeeMe Experiment

    DTIC Science & Technology

    2013-06-01

    deflectors , instrumentation and controls, and a set of pulse transmission cables if generators were located outside beam enclosure such as...design by evaluating requirement and main parameters. There are several types of kicker deflectors , such as parallel plate strip-lines, parallel wires... deflector for higher deflection efficiency within limited longitudinal space. The real estate space at beam line is precious. Therefore, the design

  1. Apparatus for proton radiography

    DOEpatents

    Martin, Ronald L.

    1976-01-01

    An apparatus for effecting diagnostic proton radiography of patients in hospitals comprises a source of negative hydrogen ions, a synchrotron for accelerating the negative hydrogen ions to a predetermined energy, a plurality of stations for stripping extraction of a radiography beam of protons, means for sweeping the extracted beam to cover a target, and means for measuring the residual range, residual energy, or percentage transmission of protons that pass through the target. The combination of information identifying the position of the beam with information about particles traversing the subject and the back absorber is performed with the aid of a computer to provide a proton radiograph of the subject. In an alternate embodiment of the invention, a back absorber comprises a plurality of scintillators which are coupled to detectors.

  2. Recent experience in the fabrication and brazing of ceramic beam tubes for kicker magnets at FNAL

    SciTech Connect

    Ader, C.R.; Jensen, C.; Reilly, R.; Snee, D.; Wilson, J.H.; /Fermilab

    2008-06-01

    Ceramic beam tubes are utilized in numerous kicker magnets in different accelerator rings at Fermi National Accelerator Laboratory. Kovar flanges are brazed onto each beam tube end, since kovar and high alumina ceramic have similar expansion curves. The tube, kovar flange, end piece, and braze foil (titanium/incusil) alloy brazing material are stacked in the furnace and then brazed in the furnace at 1000 C. The ceramic specified is 99.8% Alumina, Al{sub 2}O{sub 3}, a strong recrystallized high-alumina fabricated by slip casting. Recent experience at Fermilab with the fabrication and brazing of these tubes has brought to light numerous problems including tube breakage and cracking and also the difficulty of brazing the tube to produce a leak-tight joint. These problems may be due to the ceramic quality, voids in the ceramic, thinness of the wall, and micro-cracks in the ends which make it difficult to braze because it cannot fill tiny surface cracks which are caused by grain pullout during the cutting process. Solutions which are being investigated include lapping the ends of the tubes before brazing to eliminate the micro-cracks and also metallization of the tubes.

  3. Multiple harmonic frequencies resonant cavity design and half-scale prototype measurements for a fast kicker

    NASA Astrophysics Data System (ADS)

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.; Wang, Shaoheng; Guo, Jiquan

    2016-12-01

    Quarter wavelength resonator (QWR) based deflecting cavities with the capability of supporting multiple odd-harmonic modes have been developed for an ultrafast periodic kicker system in the proposed Jefferson Lab Electron Ion Collider (JLEIC, formerly MEIC). Previous work on the kicking pulse synthesis and the transverse beam dynamics tracking simulations show that a flat-top kicking pulse can be generated with minimal emittance growth during injection and circulation of the cooling electron bunches. This flat-top kicking pulse can be obtained when a DC component and 10 harmonic modes with appropriate amplitude and phase are combined together. To support 10 such harmonic modes, four QWR cavities are used with 5, 3, 1, and 1 modes, respectively. In the multiple-mode cavities, several slightly tapered segments of the inner conductor are introduced to tune the higher order deflecting modes to be harmonic, and stub tuners are used to fine tune each frequency to compensate for potential errors. In this paper, we summarize the electromagnetic design of the five-mode cavity, including the geometry optimization to get high transverse shunt impedance, the frequency tuning and sensitivity analysis, and the single loop coupler design for coupling to all of the harmonic modes. In particular we report on the design and fabrication of a half-scale copper prototype of this proof-of-principle five-odd-mode cavity, as well as the rf bench measurements. Finally, we demonstrate mode superposition in this cavity experimentally, which illustrates the kicking pulse generation concept.

  4. Position measurements for the isotope production facility and the switchyard kicker upgrade projects

    SciTech Connect

    Gilpatrick, J. D.; Barr, D. S.; O'Hara, J. F.; Shurter, R. B.; Stettler, M. W.; Martinez, D. G.

    2003-01-01

    The Los Alamos Neutron Science Center (LANSCE) is installing two beam lines to both improve operational tuning and provide new capabilities within the facility. The Isotope Production Facility (IPF) will provide isotopes for medical purposes by using the H' beam spur at 100 MeV and the Switchyard Kicker Upgrade (SYK) will allow the LANSCE 800-MeV H beam to be rapidly switched between various beam lines within the facility. The beam position measurements for both of these beam lines uses a standard micro-stripline beam position monitor (BPM) with both a 50-mm and 75-mm radius. The cable plant is unique in that it unambiguously provides a method of verifying the operation of the complete position measurement. The processing electronics module uses a log ratio technique with error corrections such that it has a dynamic range of -12 dBm to -85 dBm with errors less than 0.15 dB within this range. This paper will describe the primary components of these measurement systems and provide initial data of their operation.

  5. Design, analysis and measurement of very fast kicker magnets at SLAC

    SciTech Connect

    Weaver, J.N.; Bowden, G.B.; Bulos, F.; Cassel, R.L.; Donaldson, A.R.; Harvey, A.; Kulikov, A.V.; Nguyen, M.N.; Odian, A.; Price, V.G.

    1989-03-01

    Recent experience with SLC has shown that very fast, ferrite-loaded, transmission-line, beam-kicker magnets can cause significant and undesirable distortion of a 1.5-2.5 kA, 20-4- kV pulse as it travels through the magnet. In general, there is a net lengthening of the pulse, with increases in its rise and fall times, a decrease in amplitude, and an unsymmetrical rounding of the flattop. In this partially tutorial treatise, a number of practical design considerations are discussed in terms of equivalent circuits, magnet circuit dispersion and dissipation, undesired circuit shunting and coupling, high-voltage breakdown problems and high-order-mode losses that lead to beam tube heating. These effects are linked to the properties of the materials, the presence of radiation and realizable magnet topologies. Measurements and calculations of some of these characteristics for several magnet designs are reviewed. The results presented come from a truly eclectic effort. 8 refs., 1 fig.

  6. A fast "kicker" using a two-channel rectangular dielectric wakefield accelerator structure

    NASA Astrophysics Data System (ADS)

    Marshall, Thomas C.; Shchelkunov, Sergey V.; Sotnikov, Gennadij V.; Hirshfield, Jay L.

    2017-03-01

    A method is proposed to select and eject bunches of electrons or positrons from a high energy train of charged bunches, based on proven dielectric wakefield accelerator technology. The kicker structure, consisting of a pair of adjacent rectangular dielectric-lined waveguides, permits the coupling of the wakefield that is generated from a train of low-energy (˜6 MeV) "drive bunches" moving in one waveguide to the adjacent waveguide where a portion of a train of high energy "witness bunches" needs to be diverted. A very fast response time (˜1 ns) for bunch deflection is estimated, and a structure as short as 10-30 cm would suffice to impart to the diverted bunches a transverse kick of an interest to high-energy accelerator application, e.g. 150 keV/c. The witness bunch width must be less than 0.2 - 0.3 mm to have an emittance dilution that makes the deflected bunch suitable for e.g. FEL applications.

  7. Application of ion exchange and extraction chromatography to the separation of actinium from proton-irradiated thorium metal for analytical purposes.

    PubMed

    Radchenko, V; Engle, J W; Wilson, J J; Maassen, J R; Nortier, F M; Taylor, W A; Birnbaum, E R; Hudston, L A; John, K D; Fassbender, M E

    2015-02-06

    Actinium-225 (t1/2=9.92d) is an α-emitting radionuclide with nuclear properties well-suited for use in targeted alpha therapy (TAT), a powerful treatment method for malignant tumors. Actinium-225 can also be utilized as a generator for (213)Bi (t1/2 45.6 min), which is another valuable candidate for TAT. Actinium-225 can be produced via proton irradiation of thorium metal; however, long-lived (227)Ac (t1/2=21.8a, 99% β(-), 1% α) is co-produced during this process and will impact the quality of the final product. Thus, accurate assays are needed to determine the (225)Ac/(227)Ac ratio, which is dependent on beam energy, irradiation time and target design. Accurate actinium assays, in turn, require efficient separation of actinium isotopes from both the Th matrix and highly radioactive activation by-products, especially radiolanthanides formed from proton-induced fission. In this study, we introduce a novel, selective chromatographic technique for the recovery and purification of actinium isotopes from irradiated Th matrices. A two-step sequence of cation exchange and extraction chromatography was implemented. Radiolanthanides were quantitatively removed from Ac, and no non-Ac radionuclidic impurities were detected in the final Ac fraction. An (225)Ac spike added prior to separation was recovered at ≥ 98%, and Ac decontamination from Th was found to be ≥ 10(6). The purified actinium fraction allowed for highly accurate (227)Ac determination at analytical scales, i.e., at (227)Ac activities of 1-100 kBq (27 nCi to 2.7 μCi).

  8. A Single Pulse Sub-Nanosecond Proton RFQ

    SciTech Connect

    Hamm, R W; Pearce-Percy, H; Pearson, D; Rougieri, M; Weir, J; Zografos, A; Guethlein, G; Hawkins, S; Falabella, S; Poole, B; Blackfield, D

    2011-03-29

    A Radio Frequency Quadrupole (RFQ) linac system has been developed to provide a single pulse of 2 MeV protons with a beam pulse width of {approx}300 ps and a charge of 30 pC, either for injection into a pulsed Dielectric Wall Accelerator or for bombardment of a target to produce a fast neutron pulse. The 1.2 m long RFQ structure operates at 425 MHz and bunches and accelerates a single 2.35 ns beam pulse injected into it at 35 keV using a parallel plate deflector placed directly in front of the RFQ entrance. The input acceptance properties of the RFQ allow a simple dc bias voltage on the plates to block acceleration of the unwanted beam, with a short rf voltage pulse applied to null the deflection field for the ions within the 8 mm 'kicker' plate length. The use of the RFQ as the accelerating structure allows one to efficiently produce a large charge in a single sub-ns bunch. In addition, the kicker can also be used without the dc bias voltage to produce a 'notch' in the normal RFQ output beam for synchrotron injection.

  9. Exploring universality of transversity in proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Radici, Marco; Ricci, Alessandro M.; Bacchetta, Alessandro; Mukherjee, Asmita

    2016-08-01

    We consider the azimuthal correlations of charged hadron pairs with large total transverse momentum and small relative momentum, produced in proton-proton collisions with one transversely polarized proton. One of these correlations directly probes the chiral-odd transversity parton distribution in connection with a chiral-odd interference fragmentation function. We present predictions for this observable based on previous extractions of transversity (from charged pion pair production in semi-inclusive deep-inelastic scattering) and of the interference fragmentation function (from the production of back-to-back charged pion pairs in electron-positron annihilations). All analyses are performed in the framework of collinear factorization. We compare our predictions to the recent data on proton-proton collisions released by the STAR Collaboration at RHIC, and we find them reasonably compatible. This comparison confirms for the first time the predicted role of transversity in proton-proton collisions, and it allows us to test its universality.

  10. Proton Therapy

    MedlinePlus

    ... for e-updates Please leave this field empty Proton Therapy SHARE Home > Treatment and Care > Treatments Listen ... a nucleus, which holds two types of particles—protons and neutrons. The nucleus is surrounded by electrons. ...

  11. Enantioselective Protonation

    PubMed Central

    Mohr, Justin T.; Hong, Allen Y.; Stoltz, Brian M.

    2010-01-01

    Enantioselective protonation is a common process in biosynthetic sequences. The decarboxylase and esterase enzymes that effect this valuable transformation are able to control both the steric environment around the proton acceptor (typically an enolate) and the proton donor (typically a thiol). Recently, several chemical methods to achieve enantioselective protonation have been developed by exploiting various means of enantiocontrol in different mechanisms. These laboratory transformations have proven useful for the preparation of a number of valuable organic compounds. PMID:20428461

  12. Separation of (44)Ti from proton irradiated scandium by using solid-phase extraction chromatography and design of (44)Ti/(44)Sc generator system.

    PubMed

    Radchenko, V; Meyer, C A L; Engle, J W; Naranjo, C M; Unc, G A; Mastren, T; Brugh, M; Birnbaum, E R; John, K D; Nortier, F M; Fassbender, M E

    2016-12-16

    Scandium-44g (half-life 3.97h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, (18)F, due to its favorable decay parameters. One source of (44g)Sc is the long-lived parent nuclide (44)Ti (half-life 60.0 a). A (44)Ti/(44g)Sc generator would have the ability to provide radionuclidically pure (44g)Sc on a daily basis. The production of (44)Ti via the (45)Sc(p,2n) reaction requires high proton beam currents and long irradiation times. Recovery and purification of no-carrier added (nca) (44)Ti from scandium metal targets involves complex separation chemistry. In this study, separation systems based on solid phase extraction chromatography were investigated, including branched diglycolamide (BDGA) resin and hydroxamate based ZR resin. Results indicate that ZR resin in HCl media represents an effective (44)Ti/(44g)Sc separation system.

  13. RHIC polarized proton-proton operation at 100 GeV in Run 15

    SciTech Connect

    Schoefer, V.; Aschenauer, E. C.; Atoian, G.; Blaskiewicz, M.; Brown, K. A.; Bruno, D.; Connolly, R.; D Ottavio, T.; Drees, K. A.; Dutheil, Y.; Fischer, W.; Gardner, C.; Gu, X.; Hayes, T.; Huang, H.; Laster, J.; Liu, C.; Luo, Y.; Makdisi, Y.; Marr, G.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R.; Marusic, A.; Minty, M.; Montag, C.; Morris, J.; Narayan, G.; Nemesure, S.; Pile, P.; Poblaguev, A.; Ranjbar, V.; Robert-Demolaize, G.; Roser, T.; Schmidke, W. B.; Severino, F.; Shrey, T.; Smith, K.; Steski, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; White, S.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S. Y.

    2015-05-03

    The first part of RHIC Run 15 consisted of ten weeks of polarized proton on proton collisions at a beam energy of 100 GeV at two interaction points. In this paper we discuss several of the upgrades to the collider complex that allowed for improved performance. The largest effort consisted in commissioning of the electron lenses, one in each ring, which are designed to compensate one of the two beam-beam interactions experienced by the proton bunches. The e-lenses raise the per bunch intensity at which luminosity becomes beam-beam limited. A new lattice was designed to create the phase advances necessary for a beam-beam compensation with the e-lens, which also has an improved off-momentum dynamic aperture relative to previous runs. In order to take advantage of the new, higher intensity limit without suffering intensity driven emittance deterioration, other features were commissioned including a continuous transverse bunch-by-bunch damper in RHIC and a double harmonic RF cature scheme in the Booster. Other high intensity protections include improvements to the abort system and the installation of masks to intercept beam lost due to abort kicker pre-fires.

  14. Tomographic image of the proton

    NASA Astrophysics Data System (ADS)

    Dupré, R.; Guidal, M.; Vanderhaeghen, M.

    2017-01-01

    We have carried out a phenomenological analysis of the latest deep virtual Compton scattering experimental data based on the generalized parton distribution formalism. This allows us to extract the dependence of the spatial size of the proton on the quark's longitudinal momentum. This results in the first continuous two-dimensional momentum-space image and tomography of the proton based on experimental data.

  15. 1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS.

    SciTech Connect

    LAMBIASE,R.ENG,W.SANDBERG,J.DEWAN,S.HOLMES,R.RUST,K.ZENG,J.

    2004-03-10

    This paper describes simulation and experimental results for a 1400A, {+-} 900V peak rated, switch mode power supply for SNS Injection Kicker Magnets. For each magnet (13 m{Omega}, 160{micro}H), the power supply must supply controlled pulses at 60 Hz repetition rate. The pulse current must rise from zero to maximum in less than 1 millisec in a controlled manner, flat top for up to 2 millisec, and should fall in a controlled manner to less than 4A within 500{micro}s. The low current performance during fall time is the biggest challenge in this power supply. The simulation results show that to meet the controlled fall of the current and the current ripple requirements, voltage loop bandwidth of at least 10 kHz and switching frequency of at least 100 kHz are required. To achieve high power high frequency switching with IGBT switches, a series connected topology with three phase shifted (O{sup o}, 60{sup o} & 120{sup o}) converters each with 40 kHz switching frequency (IGBT at 20kHz), has been achieved. In this paper, the circuit topology, relevant system specifications and experimental results that meet the requirements of the power supply are described in detail. A unique six pulse SCR rectifier circuit with capacitor storage has been implemented to achieve minimum pulse width to meet required performance during current fall time below 50A due to the very narrow pulse width and non-linearity from IGBT turn-on/off times.

  16. Injection/Extraction Studies In The Non-scaling FFAG For The Neutrino Factory

    SciTech Connect

    Pasternak, J.; Berg, J. Scott; Kelliher, D. J.; Machida, S.

    2011-10-06

    The Neutrino Factory is under intensive study in the framework of the International Design Study for future precision neutrino oscillation physics. According to the current baseline the major part of muon acceleration is foreseen to take part in the non-scaling fixed field alternating gradient (NS-FFAG) ring. The NS-FFAG lattice design was recently modified to accommodate long straight sections necessary for the injection/extraction systems. The length of the long drift was optimized minimizing the necessary septum field, which according to present studies needs to be below 2 T. The injection/extraction schemes allowing to reuse the kickers for both signs of muons are presented. The design of the kicker system based on current technology is discussed. The preliminary design of a septum magnet focused on minimization of the stray field leakage is studied.

  17. Proton Transport

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    The transport of protons across membranes is an essential process for both bioenergetics of modern cells and the origins of cellular life. All living systems make use of proton gradients across cell walls to convert environmental energy into a high-energy chemical compound, adenosine triphosphate (ATP), synthesized from adenosine diphosphate. ATP, in turn, is used as a source of energy to drive many cellular reactions. The ubiquity of this process in biology suggests that even the earliest cellular systems were relying on proton gradient for harvesting environmental energy needed to support their survival and growth. In contemporary cells, proton transfer is assisted by large, complex proteins embedded in membranes. The issue addressed in this Study was: how the same process can be accomplished with the aid of similar but much simpler molecules that could have existed in the protobiological milieu? The model system used in the study contained a bilayer membrane made of phospholipid, dimyristoylphosphatidylcholine (DMPC) which is a good model of the biological membranes forming cellular boundaries. Both sides of the bilayer were surrounded by water which simulated the environment inside and outside the cell. Embedded in the membrane was a fragment of the Influenza-A M$_2$ protein and enough sodium counterions to maintain system neutrality. This protein has been shown to exhibit remarkably high rates of proton transport and, therefore, is an excellent model to study the formation of proton gradients across membranes. The Influenza M$_2$ protein is 97 amino acids in length, but a fragment 25 amino acids long. which contains a transmembrane domain of 19 amino acids flanked by three amino acids on each side. is sufficient to transport protons. Four identical protein fragments, each folded into a helix, aggregate to form small channels spanning the membrane. Protons are conducted through a narrow pore in the middle of the channel in response to applied voltage. This

  18. Uncertainty estimates for proton-proton fusion

    NASA Astrophysics Data System (ADS)

    Acharya, Bijaya

    2017-01-01

    We calculate the proton-proton fusion cross section using chiral effective field theory (χEFT) and perform a rigorous analysis of the associated uncertainties. The statistical errors in the low-energy constants, which are fitted too scattering and bound-state observables in the pion-nucleon, nucleon-nucleon, and few-nucleon sectors, are propagated to the calculated cross section. We also investigate the sensitivity of the fusion cross section to the high-momentum cutoff of the χEFT. We extract a value for the zero-energy S-factor using a polynomial extrapolant and analyze the errors associated with this procedure. Our result is compared to that of another χEFT calculation in which the wave functions were represented in a truncated Hilbert space with discrete basis states. Supported by the NSF under Grant Nos. PHY-1516077 and PHY- 1555030.

  19. A real time status monitor for transistor bank driver power limit resistor in boost injection kicker power supply

    SciTech Connect

    Mi, J.; Tan, Y.; Zhang, W.

    2011-03-28

    For years suffering of Booster Injection Kicker transistor bank driver regulator troubleshooting, a new real time monitor system has been developed. A simple and floating circuit has been designed and tested. This circuit monitor system can monitor the driver regulator power limit resistor status in real time and warn machine operator if the power limit resistor changes values. This paper will mainly introduce the power supply and the new designed monitoring system. This real time resistor monitor circuit shows a useful method to monitor some critical parts in the booster pulse power supply. After two years accelerator operation, it shows that this monitor works well. Previously, we spent a lot of time in booster machine trouble shooting. We will reinstall all 4 PCB into Euro Card Standard Chassis when the power supply system will be updated.

  20. Proton sponge-functionalized silica as high performance adsorbents for solid-phase extraction of trace perfluoroalkyl sulfonates in the environmental water samples and their direct analysis by MALDI-TOF-MS.

    PubMed

    Cao, Dong; Hu, Ming; Han, Chunguang; Yu, Jiyao; Cui, Lin; Liu, Yongxue; Wang, Hailin; Cai, Yaqi; Kang, Yuehui; Zhou, Yiqi

    2012-05-07

    1,8-Bis(dimethylamino)naphthalene (DMAN), a classical 'proton sponge', was functionalized on silica particles as a novel solid-phase extraction (SPE) adsorbent (DMAN@silica) for extracting perfluoroalkyl sulfonates (PFSs). High reproducibility and excellent extraction capability for PFSs were obtained in a wide pH range (3.0~8.5). The adsorbed PFSs on DMAN@silica sorbents could be efficiently eluted by 1,8-bis(tetramethylguanidino)naphthalene (TMGN) solution which is a proton sponge with higher proton affinity than DMAN. The elution could be directly analyzed by MALDI-TOF-MS using TMGN as matrix. Clear mass spectra for the PFSs were obtained due to no matrix ions interference observed. Furthermore, a novel strategy based on the DMAN@silica-SPE enrichment, followed by MALDI-TOF-MS analysis, was proposed and applied for PFSs quantification in environmental water samples. The calibration curves of each of the target analytes showed a wide linear dynamic range of response (0.1-10 ng L(-1) for perfluorooctane sulfonate (PFOS), perfluorohexyl sulfonate (PFHxS) and perfluorobutylsulfonate (PFBS)), which were over 2 orders of magnitude. The detection limits for PFOS, PFHxS, and PFBS were 0.021, 0.016, and 0.013 ng L(-1), respectively (S/N = 3). Recoveries of PFOS, PFHxS, and PFBS are in the ranges of 92-104%, 95-102%, and 98-109% for spiked river water samples. These results indicated that the prepared DMAN@silica adsorbents could efficiently enrich PFSs and that the proposed method is reliable.

  1. Proton Therapy

    MedlinePlus

    ... effects of the treatment. top of page What equipment is used? Proton beam therapy uses special machines, ... tumor cells. top of page Who operates the equipment? With backgrounds in mechanical, electrical, software, hardware and ...

  2. Proton Therapy

    MedlinePlus

    ... Liver Breast Esophagus Rectum Skull base sarcomas Pediatric brain tumors Head and neck - see the Head and Neck Cancer page Eye ... Intensity-Modulated Radiation Therapy (IMRT) Brain Tumor Treatment Brain Tumors Prostate Cancer Lung Cancer ... related to Proton Therapy Videos related ...

  3. Proton Radiobiology

    PubMed Central

    Tommasino, Francesco; Durante, Marco

    2015-01-01

    In addition to the physical advantages (Bragg peak), the use of charged particles in cancer therapy can be associated with distinct biological effects compared to X-rays. While heavy ions (densely ionizing radiation) are known to have an energy- and charge-dependent increased Relative Biological Effectiveness (RBE), protons should not be very different from sparsely ionizing photons. A slightly increased biological effectiveness is taken into account in proton treatment planning by assuming a fixed RBE of 1.1 for the whole radiation field. However, data emerging from recent studies suggest that, for several end points of clinical relevance, the biological response is differentially modulated by protons compared to photons. In parallel, research in the field of medical physics highlighted how variations in RBE that are currently neglected might actually result in deposition of significant doses in healthy organs. This seems to be relevant in particular for normal tissues in the entrance region and for organs at risk close behind the tumor. All these aspects will be considered and discussed in this review, highlighting how a re-discussion of the role of a variable RBE in proton therapy might be well-timed. PMID:25686476

  4. Evaluation of the Proton Charge Radius from Electron–Proton Scattering

    SciTech Connect

    Arrington, John; Sick, Ingo

    2015-09-15

    In light of the proton radius puzzle, the discrepancy between measurements of the proton charge radius from muonic hydrogen and those from electronic hydrogen and electron–proton (e–p) scattering measurements, we re-examine the charge radius extractions from electron scattering measurements. We provide a recommended value for the proton root-mean-square charge radius, r{sub E} = 0.879 ± 0.011 fm, based on a global examination of elastic e–p scattering data. The uncertainties include contributions to account for tension between different data sets and inconsistencies between radii using different extraction procedures.

  5. Proton maser

    NASA Astrophysics Data System (ADS)

    Ensley, D. L.

    1988-01-01

    New calculations are reported which confirm the ability of an a priori random, initial-phase proton beam to drive a simple, single-stage microwave cavity maser or transit-time oscillator (TTO) to saturation conversion efficiencies of about 11 percent. The required initial TE(011) mode field can be provided from beam ramp-up bandwidth of excitation to a low level from an external source. A saturation field of 45 tesla and output power of 0.2 TW are calculated using an electron insulation field of 10 tesla and a 3 MeV, 400 Ka/sq cm beam. Results are compared to those for an electron beam of the same energy and geometry, and it is shown that proton beams potentially can provide a three order of magnitude increase in overall microwave power production density over that obtainable from electron beam TTOs.

  6. Proton scaling

    SciTech Connect

    Canavan, Gregory H

    2009-01-01

    This note presents analytic estimates of the performance of proton beams in remote surveillance for nuclear materials. The analysis partitions the analysis into the eight steps used by a companion note: (1) Air scattering, (2) Neutron production in the ship and cargo, (3) Target detection probability, (4) Signal produced by target, (5) Attenuation of signal by ship and cargo, (6) Attenuation of signal by air, (7) Geometric dilution, and (8) Detector Efficiency. The above analyses indicate that the dominant air scattering and loss mechanisms for particle remote sensing are calculable with reliable and accepted tools. They make it clear that the conversion of proton beams into neutron sources rapidly goes to completion in all but thinnest targets, which means that proton interrogation is for all purposes executed by neutrons. Diffusion models and limiting approximations to them are simple and credible - apart from uncertainty over the cross sections to be used in them - and uncertainty over the structure of the vessels investigated. Multiplication is essentially unknown, in part because it depends on the details of the target and its shielding, which are unlikely to be known in advance. Attenuation of neutron fluxes on the way out are more complicated due to geometry, the spectrum of fission neutrons, and the details of their slowing down during egress. The attenuation by air is large but less uncertain. Detectors and technology are better known. The overall convolution of these effects lead to large but arguably tolerable levels of attenuation of input beams and output signals. That is particularly the case for small, mobile sensors, which can more than compensate for size with proximity to operate reliably while remaining below flux limits. Overall, the estimates used here appear to be of adequate accuracy for decisions. That assessment is strengthened by their agreement with companion calculations.

  7. CFD Study of the Hydrocarbon Boost Low-Pressure Inducer and Kicker in the Presence of a Circumferential Groove

    NASA Technical Reports Server (NTRS)

    Coker, Robert

    2011-01-01

    Results are presented of a computational fluid dynamics (CFD) study done in support of Marshall Space Flight Center's (MSFC) sub-scale water flow experiments of the Hydrocarbon Boost (HCB) Oxidizer Turbopump (OTP) being developed by the Air Force Research Laboratory (AFRL) and Aerojet. A circumferential groove may be added to the pump to reduce synchronous cavitation and subsequent bearing loads at a minimal performance cost. However, the energy may reappear as high order cavitation (HOC) that spans a relatively large frequency range. Thus, HOC may have implications for the full-scale OTP inducer in terms of reduced structural margin at higher mode frequencies. Simulations using the LOCI/Stream CFD program were conducted in order to explore the fluid dynamical impact of the groove on the low-pressure inducer and kicker. It was found that the circumferential groove has minimal head performance impact, but causes back-flowing high-swirl fluid to interact with the nearly-axial incoming fluid just above the inducer blades. The high-shear interface between the fluids is Kelvin-Helmholtz unstable, resulting in trains of low pressure regions or 'pearls' forming near the upstream edge of the groove. When the static pressure in these regions becomes low enough and they get cut by the blade leading edge, HOC is thought to occur. Although further work is required, the numerical models indicate that HOC will occur in the runbox of the AFRL/Aerojet HCB OTP. Comparisons to the ongoing water flow experiments will be discussed, as well as possible designs that may mitigate HOC while continuing to reduce synchronous cavitation. December 2011 MSS/LPS/SPS Joint Subcommittee Meeting ABSTRACT SUBMITTAL FORM

  8. Extraction of CP Properties of the H(125) Boson Discovered in Proton-Proton Collisions at√s = 7 and 8 TeV with the CMS Detector at the LHC

    SciTech Connect

    Chen, Yi

    2015-01-01

    In this thesis we build a novel analysis framework to perform the direct extraction ofall possible effective Higgs boson couplings to the neutral electroweak gauge bosonsin the H → ZZ (*) → 4 channel also referred to as the golden channel. We use analytic expressions of the full decay differential cross sections for the H → V V → 4process, and the dominant irreducible standard model q q → 4 background where¯4 = 2e2µ, 4e, 4µ. Detector effects are included through an explicit convolution ofthese analytic expressions with transfer functions that model the detector responsesas well as acceptance and efficiency effects. Using the full set of decay observables, weconstruct an unbinned 8-dimensional detector level likelihood function which is continuous in the effective couplings, and includes systematics. All potential anomalouscouplings of HV V where V = Z, γ are considered, allowing for general CP even/oddadmixtures and any possible phases. We measure the CP -odd mixing between thetree-level HZZ coupling and higher order CP -odd couplings to be compatible withzero, and in the range [-0.40, 0.43], and the mixing between HZZ tree-level couplingand higher order CP -even coupling to be in the ranges [-0.66, -0.57] U [-0.15, 1.00];namely compatible with a standard model Higgs. We discuss the expected precisionin determining the various HV V couplings in future LHC runs. A powerful and at first glance surprising prediction of the analysis is that with 100-400 fb-1 , the goldenchannel will be able to start probing the couplings of the Higgs boson to diphotons inthe 4 channel. We discuss the implications and further optimization of the methodsfor the next LHC runs.

  9. Proton radiography to improve proton therapy treatment

    NASA Astrophysics Data System (ADS)

    Takatsu, J.; van der Graaf, E. R.; Van Goethem, M.-J.; van Beuzekom, M.; Klaver, T.; Visser, J.; Brandenburg, S.; Biegun, A. K.

    2016-01-01

    The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT) images. This causes systematic uncertainties in the calculated proton range in a patient of typically 3-4%, but can become even 10% in bone regions [1,2,3,4,5,6,7,8]. This may lead to no dose in parts of the tumor and too high dose in healthy tissues [1]. A direct measurement of proton stopping powers with high-energy protons will allow reducing these uncertainties and will improve the quality of the treatment. Several studies have shown that a sufficiently accurate radiograph can be obtained by tracking individual protons traversing a phantom (patient) [4,6,10]. Our studies benefit from the gas-filled time projection chambers based on GridPix technology [2], developed at Nikhef, capable of tracking a single proton. A BaF2 crystal measuring the residual energy of protons was used. Proton radiographs of phantom consisting of different tissue-like materials were measured with a 30×30 mm2 150 MeV proton beam. Measurements were simulated with the Geant4 toolkit.First experimental and simulated energy radiographs are in very good agreement [3]. In this paper we focus on simulation studies of the proton scattering angle as it affects the position resolution of the proton energy loss radiograph. By selecting protons with a small scattering angle, the image quality can be improved significantly.

  10. Solid-phase extraction combined with dispersive liquid-liquid microextraction and chiral liquid chromatography-tandem mass spectrometry for the simultaneous enantioselective determination of representative proton-pump inhibitors in water samples.

    PubMed

    Zhao, Pengfei; Deng, Miaoduo; Huang, Peiting; Yu, Jia; Guo, Xingjie; Zhao, Longshan

    2016-09-01

    This report describes, for the first time, the simultaneous enantioselective determination of proton-pump inhibitors (PPIs-omeprazole, lansoprazole, pantoprazole, and rabeprazole) in environmental water matrices based on solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME) and chiral liquid chromatography-tandem mass spectrometry. The optimized results of SPE-DLLME were obtained with PEP-2 column using methanol-acetonitrile (1/1, v/v) as elution solvent, dichloroethane, and acetonitrile as extractant and disperser solvent, respectively. The separation and determination were performed using reversed-phase chromatography on a cellulose chiral stationary phase, a Chiralpak IC (250 mm × 4.6 mm, 5 μm) column, under isocratic conditions at 0.6 mL min(-1) flow rate. The analytes were detected in multiple reaction monitoring (MRM) mode by triple quadrupole mass spectrometry. Isotopically labeled internal standards were used to compensate matrix interferences. The method provided enrichment factors of around 500. Under optimal conditions, the mean recoveries for all eight enantiomers from the water samples were 89.3-107.3 % with 0.9-10.3 % intra-day RSD and 2.3-8.1 % inter-day RSD at 20 and 100 ng L(-1) levels. Correlation coefficients (r (2)) ≥ 0.999 were achieved for all enantiomers within the range of 2-500 μg L(-1). The method detection and quantification limits were at very low levels, within the range of 0.67-2.29 ng L(-1) and 2.54-8.68 ng L(-1), respectively. This method was successfully applied to the determination of the concentrations and enantiomeric fractions of the targeted analytes in wastewater and river water, making it applicable to the assessment of the enantiomeric fate of PPIs in the environment. Graphical Abstract Simultaneous enantioselective determination of representative proton-pump inhibitors in water samples.

  11. Proton-proton correlations in distinguishing the two-proton emission mechanism of 23Al and 22Mg

    NASA Astrophysics Data System (ADS)

    Fang, D. Q.; Ma, Y. G.; Sun, X. Y.; Zhou, P.; Togano, Y.; Aoi, N.; Baba, H.; Cai, X. Z.; Cao, X. G.; Chen, J. G.; Fu, Y.; Guo, W.; Hara, Y.; Honda, T.; Hu, Z. G.; Ieki, K.; Ishibashi, Y.; Ito, Y.; Iwasa, N.; Kanno, S.; Kawabata, T.; Kimura, H.; Kondo, Y.; Kurita, K.; Kurokawa, M.; Moriguchi, T.; Murakami, H.; Ooishi, H.; Okada, K.; Ota, S.; Ozawa, A.; Sakurai, H.; Shimoura, S.; Shioda, R.; Takeshita, E.; Takeuchi, S.; Tian, W. D.; Wang, H. W.; Wang, J. S.; Wang, M.; Yamada, K.; Yamada, Y.; Yasuda, Y.; Yoneda, K.; Zhang, G. Q.; Motobayashi, T.

    2016-10-01

    The proton-proton momentum correlation functions [Cp p(q ) ] for the kinematically complete decay channels 23Al→p +p +21Na and 22Mg→p +p +20Ne have been measured at the RIKEN RI Beam Factory. From the very different correlation strength of Cp p(q ) for 23Al and 22Mg, the source size and emission time information were extracted from the Cp p(q ) data by assuming a Gaussian source profile in the correlation function calculation code (crab). The results indicated that the mechanism of two-proton emission from 23Al was mainly sequential emission, while that of 22Mg was mainly three-body simultaneous emission. By combining our earlier results of the two-proton relative momentum and the opening angle, it is pointed out that the mechanism of two-proton emission could be distinguished clearly.

  12. R_transport_matrices of the Fast Extraction Beam (FEB) of the AGS, and Beam Parameters at the Starting point of the AtR Line

    SciTech Connect

    Tsoupas,N.; MacKay, W.W.; Satogata, T.; Glenn, W.; Ahrens, L.; Brown, K.; Gardner, C.; Tanaka, S.

    2008-01-01

    As part of the task to improve and further automate the 'AtR BPM Application' we provide the theoretically calculated R-transport-matrices for the following beam line sections, which are shown schematically in Figure 1: (a) the Fast Extraction Beam section (FEB) of the AGS synchrotron. The FEB section starts at the middle of the GlO-kicker and ends at the middle of the H1 0{_}septum. (b) the Drift Extraction Channel (DEC) section of the AGS synchrotron. The DEC section starts at the middle of the H10{_}septum, continues along the fringe field region of the H11,H12, and H13 AGS main magnets, and ends at the starting point of the AtR line. The knowledge of these R-transport-matrices are needed in order to calculate the beam parameters at the beginning of the AtR line, which in turn, are required to calculate the magnet settings of the U{_}line, that match the U{_}line into the W{_}line. Also by incorporating these R{_}matrices into the model of the AtR line, the G10 kicker and the H10 septum are included in the AtR model therefore one can investigate any 'jitter' of either the GlO{_}kicker or HlO{_}septum by looking at the trajectory of the beam in the AtR line.

  13. Synchrotron based proton drivers

    SciTech Connect

    Weiren Chou

    2002-09-19

    Proton drivers are the proton sources that produce intense short proton bunches. They have a wide range of applications. This paper discusses the proton drivers based on high-intensity proton synchrotrons. It gives a review of the high-intensity proton sources over the world and a brief report on recent developments in this field in the U.S. high-energy physics (HEP) community. The Fermilab Proton Driver is used as a case study for a number of challenging technical design issues.

  14. The proton (nuclear) microprobe

    NASA Astrophysics Data System (ADS)

    Legge, G. J. F.

    1989-04-01

    The scanning proton microprobe (SPMP) is closely related to the scanning electron microprobe (SEMP) or scanning electron microscope (SEM) with X-ray detector. Though the much greater elemental sensitivity of the SPMP is inherent in the physics, the generally inferior spatial resolution of the SPMP is not inherent and big improvements are possible, As its alternative name would imply, the SPMP is often used with heavier particle beams and with nuclear rather than atomic reactions. Its versatility and quantitative accuracy have justified greater instrumentation and computer power than that associated with other microprobes. It is fast becoming an industrially and commercially important instrument and there are few fields of scientific research in which it has not played a part. Notable contributions have been made in biology, medicine, agriculture, semiconductors, geology, mineralogy, extractive metallurgy, new materials, archaeology, forensic science, catalysis, industrial problems and reactor technology.

  15. Puzzling out the proton radius puzzle

    SciTech Connect

    Mihovilovič, M.; Merkel, H.; Weber, A.

    2016-01-22

    The discrepancy between the proton charge radius extracted from the muonic hydrogen Lamb shift measurement and the best present value obtained from the elastic scattering experiments, remains unexplained and represents a burning problem of today’s nuclear physics: after more than 50 years of research the radius of a basic constituent of matter is still not understood. This paper presents a summary of the best existing proton radius measurements, followed by an overview of the possible explanations for the observed inconsistency between the hydrogen and the muonic-hydrogen data. In the last part the upcoming experiments, dedicated to remeasuring the proton radius, are described.

  16. Puzzling out the proton radius puzzle

    NASA Astrophysics Data System (ADS)

    Mihovilovič, M.; Merkel, H.; Weber, A.

    2016-01-01

    The discrepancy between the proton charge radius extracted from the muonic hydrogen Lamb shift measurement and the best present value obtained from the elastic scattering experiments, remains unexplained and represents a burning problem of today's nuclear physics: after more than 50 years of research the radius of a basic constituent of matter is still not understood. This paper presents a summary of the best existing proton radius measurements, followed by an overview of the possible explanations for the observed inconsistency between the hydrogen and the muonic-hydrogen data. In the last part the upcoming experiments, dedicated to remeasuring the proton radius, are described.

  17. Proton Therapy - Accelerating Protons to Save Lives

    SciTech Connect

    Keppel, Cynthia

    2011-10-25

    In 1946, physicist Robert Wilson first suggested that protons could be used as a form of radiation therapy in the treatment of cancer because of the sharp drop-off that occurs on the distal edge of the radiation dose. Research soon confirmed that high-energy protons were particularly suitable for treating tumors near critical structures, such as the heart and spinal column. The precision with which protons can be delivered means that more radiation can be deposited into the tumor while the surrounding healthy tissue receives substantially less or, in some cases, no radiation. Since these times, particle accelerators have continuously been used in cancer therapy and today new facilities specifically designed for proton therapy are being built in many countries. Proton therapy has been hailed as a revolutionary cancer treatment, with higher cure rates and fewer side effects than traditional X-ray photon radiation therapy. Proton therapy is the modality of choice for treating certain small tumors of the eye, head or neck. Because it exposes less of the tissue surrounding a tumor to the dosage, proton therapy lowers the risk of secondary cancers later in life - especially important for young children. To date, over 80,000 patients worldwide have been treated with protons. Currently, there are nine proton radiation therapy facilities operating in the United States, one at the Hampton University Proton Therapy Institute. An overview of the treatment technology and this new center will be presented.

  18. Design and construction of a compact microwave proton source for a proton linac.

    PubMed

    Hong, I S; Park, B S; Jang, J H; Kwon, H J; Cho, Y S; Hwang, Y S

    2010-02-01

    A 100 MeV, 20 mA proton linear accelerator is being developed by the Proton Engineering Frontier Project at the Korea Atomic Energy Research Institute. 20 MeV acceleration system using radio frequency quadrupole and drift tube linac was already developed and has been tested. To operate this acceleration system with a long time, more reliable proton source is needed. A compact microwave proton source was proposed and has been designed and constructed as a prototype ion source for the 100 MeV proton linear accelerator. The design of microwave power injection system is based on the microwave proton injector at LANL and CEA. The wave power from a 2.45 GHz, 2 kW magnetron source is introduced into a compact plasma chamber with 7 cm diameter and 5 cm length through a standard tapered, double-ridged waveguide (WRD250) and a quartz window. The microwave power supply is installed on high voltage platform. Axial magnetic fields up to 1 kG can be provided with a water-cooled solenoid coil. A single-hole three electrode extraction system is designed for an extraction current up to 30 mA at a 50 kV extraction voltage. The design and initial operations of the proton source are presented.

  19. Design and construction of a compact microwave proton source for a proton linac

    SciTech Connect

    Hong, I. S.; Park, B. S.; Jang, J. H.; Kwon, H. J.; Cho, Y. S.; Hwang, Y. S.

    2010-02-15

    A 100 MeV, 20 mA proton linear accelerator is being developed by the Proton Engineering Frontier Project at the Korea Atomic Energy Research Institute. 20 MeV acceleration system using radio frequency quadrupole and drift tube linac was already developed and has been tested. To operate this acceleration system with a long time, more reliable proton source is needed. A compact microwave proton source was proposed and has been designed and constructed as a prototype ion source for the 100 MeV proton linear accelerator. The design of microwave power injection system is based on the microwave proton injector at LANL and CEA. The wave power from a 2.45 GHz, 2 kW magnetron source is introduced into a compact plasma chamber with 7 cm diameter and 5 cm length through a standard tapered, double-ridged waveguide (WRD250) and a quartz window. The microwave power supply is installed on high voltage platform. Axial magnetic fields up to 1 kG can be provided with a water-cooled solenoid coil. A single-hole three electrode extraction system is designed for an extraction current up to 30 mA at a 50 kV extraction voltage. The design and initial operations of the proton source are presented.

  20. Elastic proton-proton scattering at RHIC

    SciTech Connect

    Yip, K.

    2011-09-03

    Here we describe elastic proton+proton (p+p) scattering measurements at RHIC in p+p collisions with a special optics run of {beta}* {approx} 21 m at STAR, at the center-of-mass energy {radical}s = 200 GeV during the last week of the RHIC 2009 run. We present preliminary results of single and double spin asymmetries.

  1. Proton pump inhibitors

    MedlinePlus

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  2. What's In a Proton?

    ScienceCinema

    Brookhaven Lab

    2016-07-12

    Physicist Peter Steinberg explains that fundamental particles like protons are themselves made up of still smaller particles called quarks. He discusses how new particles are produced when quarks are liberated from protons...a process that can be observed

  3. What's In a Proton?

    SciTech Connect

    Brookhaven Lab

    2009-07-08

    Physicist Peter Steinberg explains that fundamental particles like protons are themselves made up of still smaller particles called quarks. He discusses how new particles are produced when quarks are liberated from protons...a process that can be observed

  4. Mechanism of proton entry into the cytoplasmic section of the proton-conducting channel of bacteriorhodopsin.

    PubMed

    Checover, S; Nachliel, E; Dencher, N A; Gutman, M

    1997-11-11

    Bacteriorhodopsin is the light-driven proton-pumping protein of Halobacterium salinarum that extracts protons from the well-buffered cytoplasmic space within the time limits set by the photocycle turnover. The specific mechanism of the proton uptake by the cytoplasmic surface of the protein was investigated in this study by the laser-induced proton pulse technique. The purple membrane preparations were labeled by fluorescein at two residues (36 or 38) of the cytoplasmic surface of the protein, sites that are close to the orifice of the proton-conducting channel. The membranes were pulsed by protons discharged from photoexcited pyranine [Nachliel, E., Gutman, M., Kiryati, S., and Dencher, N.A. (1996) Proc. Nat Acad. Sci. U.S.A. 93, 10747-10752). The reaction of the discharged protons with the pyranine anion and the fluorescein was measured with sub-microsecond resolution. The experimental signals were reconstructed through numeric integration of differential rate equations which quantitated the rates of all proton transfer reactions between all reactants present in the system. The interaction of protons with the orifice of the cytoplasmic channel is enhanced by the exposed carboxylates of the protein. A cluster of three carboxylates acts as a strong proton attractor site while one carboxylate, identified as D36, acts as a mediator that delivers the proton to the channel. The combination of these reactions render the surface of the protein with properties of a proton-collecting antenna. The size of the collecting area is less than that of the protein's surface.

  5. Probing the Spin Structure of the Proton Using Polarized Proton-Proton Collisionsand the Production of W Bosons

    SciTech Connect

    Beaumier, Michael J.

    2016-08-01

    This thesis discusses the process of extracting the longitudinal asymmetry, A$W±\\atop{L}$ describing W → μ production in forward kinematic regimes. This asymmetry is used to constrain our understanding of the polarized parton distribution functions characterizing $\\bar{u}$ and $\\bar{d}$ sea quarks in the proton. This asymmetry will be used to constrain the overall contribution of the sea-quarks to the total proton spin. The asymmetry is evaluated over the pseudorapidity range of the PHENIX Muon Arms, 2.1 < |η| 2.6, for longitudinally polarized proton-proton collisions at 510 GeV √s. In particular, I will discuss the statistical methods used to characterize real muonic W decays and the various background processes is presented, including a discussion of likelihood event selection and the Extended Unbinned Maximum Likelihood t. These statistical methods serve estimate the yields of W muonic decays, which are used to calculate the longitudinal asymmetry.

  6. Proton: the particle.

    PubMed

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

  7. Proton: The Particle

    SciTech Connect

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

  8. Operation of the TRIUMF Proton Therapy Facility.

    NASA Astrophysics Data System (ADS)

    Blackmore, E. W.; Evans, B.; Mouat, M.; Duzenli, C.; Ma, R.; Pickles, T.; Paton, K.

    1997-05-01

    The Proton Therapy Facility at TRIUMF is now in routine operation treating ocular tumours using 70 MeV protons extracted from the 500 MeV H^- cyclotron. This paper describes the proton beam line, treatment control, and dosimetry systems which are designed to provide accurate therapeutic dose delivery. The reproducibility of the shape and range of the unmodulated Bragg peak for various operating conditions of the cyclotron is discussed, along with the technique for producing a uniform modulated or spread-out Bragg peak. The patient positioning chair, which has six motorized degrees of freedom, the patient mask and bite-block, and the X-ray verification system ensure sub-millimeter positioning accuracy. Patient treatments are scheduled one week per month with the treatment dose of 50 proton-Gy delivered in four daily fractions.

  9. Study of proton radioactivities

    SciTech Connect

    Davids, C.N.; Back, B.B.; Henderson, D.J.

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  10. Toward a resolution of the proton size puzzle

    SciTech Connect

    Miller, G. A.; Thomas, A. W.; Carroll, J. D.; Rafelski, J.

    2011-08-15

    We show that off-mass-shell effects arising from the internal structure of the proton provide a new proton polarization mechanism in the Lamb shift, proportional to the lepton mass to the fourth power. This effect is capable of resolving the current puzzle regarding the difference in the proton radius extracted from muonic compared with electronic hydrogen experiments. These off-mass-shell effects could be probed in several other experiments. A significant ambiguity appearing in dispersion relation evaluations of the proton polarizability contribution to the Lamb shift is noted.

  11. High-Intensity Proton Accelerator

    SciTech Connect

    Jay L. Hirshfield

    2011-12-27

    Analysis is presented for an eight-cavity proton cyclotron accelerator that could have advantages as compared with other accelerators because of its potentially high acceleration gradient. The high gradient is possible since protons orbit in a sequence of TE111 rotating mode cavities of equally diminishing frequencies with path lengths during acceleration that greatly exceed the cavity lengths. As the cavities operate at sequential harmonics of a basic repetition frequency, phase synchronism can be maintained over a relatively wide injection phase window without undue beam emittance growth. It is shown that use of radial vanes can allow cavity designs with significantly smaller radii, as compared with simple cylindrical cavities. Preliminary beam transport studies show that acceptable extraction and focusing of a proton beam after cyclic motion in this accelerator should be possible. Progress is also reported on design and tests of a four-cavity electron counterpart accelerator for experiments to study effects on beam quality arising from variations injection phase window width. This device is powered by four 500-MW pulsed amplifiers at 1500, 1800, 2100, and 2400 MHz that provide phase synchronous outputs, since they are driven from a with harmonics derived from a phase-locked 300 MHz source.

  12. Proton conductivity in ampullae of Lorenzini jelly

    PubMed Central

    Josberger, Erik E.; Hassanzadeh, Pegah; Deng, Yingxin; Sohn, Joel; Rego, Michael J.; Amemiya, Chris T.; Rolandi, Marco

    2016-01-01

    In 1678, Stefano Lorenzini first described a network of organs of unknown function in the torpedo ray—the ampullae of Lorenzini (AoL). An individual ampulla consists of a pore on the skin that is open to the environment, a canal containing a jelly and leading to an alveolus with a series of electrosensing cells. The role of the AoL remained a mystery for almost 300 years until research demonstrated that skates, sharks, and rays detect very weak electric fields produced by a potential prey. The AoL jelly likely contributes to this electrosensing function, yet the exact details of this contribution remain unclear. We measure the proton conductivity of the AoL jelly extracted from skates and sharks. The room-temperature proton conductivity of the AoL jelly is very high at 2 ± 1 mS/cm. This conductivity is only 40-fold lower than the current state-of-the-art proton-conducting polymer Nafion, and it is the highest reported for a biological material so far. We suggest that keratan sulfate, identified previously in the AoL jelly and confirmed here, may contribute to the high proton conductivity of the AoL jelly with its sulfate groups—acid groups and proton donors. We hope that the observed high proton conductivity of the AoL jelly may contribute to future studies of the AoL function. PMID:27386543

  13. Applying Occam's Razor To The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas

    2016-09-01

    Over the past five decades, ever more complex mathematical functions have been used to extract the radius of the proton from electron scattering data. For example, in 1963 the proton radius was extracted with linear and quadratic fits of low Q2 data (< 3 fm-2) and by 2014 a non-linear regression of two tenth order power series functions with thirty-one normalization parameters and data out to 25 fm-2 was used. But for electron scattering, the radius of the proton is determined by extracting the slope of the charge form factor at a Q2 of zero. By using higher precision data than was available in 1963 and focusing on the low Q2 data from 1974 to today, we find extrapolating functions consistently produce a proton radius of around 0.84 fm. A result that is in agreement with modern Lamb shift measurements.

  14. RHIC Polarized proton operation

    SciTech Connect

    Huang, H.; Ahrens, L.; Alekseev, I.G.; Aschenauer, E.; Atoian, G.; Bai, M.; Bazilevsky, A.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; Dion, A.; D'Ottavio, T.; Drees, K.A.; Fischer, W.; Gardner, C.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Hulsart, R.L.; Laster, J.; Liu, C.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Marr, G.J.; Marusic, A.; Meot, F.; Mernick, K.; Michnoff, R,; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Poblaguev, A.; Ptitsyn, V.; Ranjibar, V.; Robert-Demolaize, G.; Roser, T.; J.; Severino, F.; Schmidke, B.; Schoefer, V.; Severino, F.; Smirnov, D.; Smith, K.; Steski, D.; Svirida, D.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J. Wang, G.; Wilinski, M.; Yip, K.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2011-03-28

    injection, the polarized hydrogen jet target runs for every fill with both beams. Based on the known analyzing power, there is very little polarization loss between injection and 100 GeV. An alternative way is to measure the asymmetry at 100 GeV followed by ramping up to 250 GeV and back down to 100 GeV and then to measure the asymmetry again at 100 GeV. If the asymmetry after the down ramp is similar to the measurement before the up ramp, polarization was also preserved during the ramp to 250 GeV. The analyzing power at storage energy can then be extracted from the asymmetries measured at 100 GeV and 250 GeV. The tune and orbit feedbacks are essential for the down ramp to be possible. The polarized proton operation is still going on. We will push bunch intensity higher until reaching the beam-beam limit. The even higher intensity will have to wait for the electron lenses to compensate the beam-beam effect. To understand the details of spin dynamics in RHIC with two snakes, spin simulation with the real magnet fields have been developed recently. The study will provide guidance for possible polarization loss schemes. Further polarization gain will requires a polarized source upgrade; more careful setup jump quads in the AGS to get full benefit; and control emittance in the whole accelerator chain.

  15. The AGS new fast extraction system for the g-2 experiment and RHIC injection

    SciTech Connect

    Tanaka, M.; Lee, Y.Y.

    1991-01-01

    The AGS requires a new fast extraction beam (NewFEB) system for the muon g-2 experiment and the Relativistic Heavy Ion Collider (RHIC). The proposed NewFEB system will consist of a new fast multi-pulsing kicker placed at straight section G10 and an ejector septum magnet at H10, together will local orbit bumps generated by powering backleg windings on the AGS main magnets. The new system is capable of performing single bunch multiple extraction as often as every 8 ms up to 12 times per AGS cycle, in addition to the standard single turn fast extraction. The conceptual design of the NewFEB system will be discussed. 3 refs., 3 figs., 1 tab.

  16. Electron-proton spectrometer

    NASA Technical Reports Server (NTRS)

    Winckler, J. R.

    1973-01-01

    An electron-proton spectrometer was designed to measure the geomagnetically trapped radiation in a geostationary orbit at 6.6 earth radii in the outer radiation belt. This instrument is to be flown on the Applications Technology Satellite-F (ATS-F). The electron-proton spectrometer consists of two permanent magnet surface barrier detector arrays and associated electronics capable of selecting and detecting electrons in three energy ranges: (1) 30-50 keV, (2) 150-200 keV, and (3) 500 keV and protons in three energy ranges. The electron-proton spectrometer has the capability of measuring the fluxes of electrons and protons in various directions with respect to the magnetic field lines running through the satellite. One magnet detector array system is implemented to scan between EME north and south through west, sampling the directional flux in 15 steps. The other magnet-detector array system is fixed looking toward EME east.

  17. Surface Protonics Promotes Catalysis

    NASA Astrophysics Data System (ADS)

    Manabe, R.; Okada, S.; Inagaki, R.; Oshima, K.; Ogo, S.; Sekine, Y.

    2016-12-01

    Catalytic steam reforming of methane for hydrogen production proceeds even at 473 K over 1 wt% Pd/CeO2 catalyst in an electric field, thanks to the surface protonics. Kinetic analyses demonstrated the synergetic effect between catalytic reaction and electric field, revealing strengthened water pressure dependence of the reaction rate when applying an electric field, with one-third the apparent activation energy at the lower reaction temperature range. Operando–IR measurements revealed that proton conduction via adsorbed water on the catalyst surface occurred during electric field application. Methane was activated by proton collision at the Pd–CeO2 interface, based on the inverse kinetic isotope effect. Proton conduction on the catalyst surface plays an important role in methane activation at low temperature. This report is the first describing promotion of the catalytic reaction by surface protonics.

  18. Surface Protonics Promotes Catalysis

    PubMed Central

    Manabe, R.; Okada, S.; Inagaki, R.; Oshima, K.; Ogo, S.; Sekine, Y.

    2016-01-01

    Catalytic steam reforming of methane for hydrogen production proceeds even at 473 K over 1 wt% Pd/CeO2 catalyst in an electric field, thanks to the surface protonics. Kinetic analyses demonstrated the synergetic effect between catalytic reaction and electric field, revealing strengthened water pressure dependence of the reaction rate when applying an electric field, with one-third the apparent activation energy at the lower reaction temperature range. Operando–IR measurements revealed that proton conduction via adsorbed water on the catalyst surface occurred during electric field application. Methane was activated by proton collision at the Pd–CeO2 interface, based on the inverse kinetic isotope effect. Proton conduction on the catalyst surface plays an important role in methane activation at low temperature. This report is the first describing promotion of the catalytic reaction by surface protonics. PMID:27905505

  19. Proton-proton colliding beam facility ISABELLE

    SciTech Connect

    Hahn, H

    1980-01-01

    This paper attempts to present the status of the ISABELLE construction project, which has the objective of building a 400 + 400 GeV proton colliding beam facility. The major technical features of the superconducting accelerators with their projected performance are described. Progress made so far, difficulties encountered, and the program until completion in 1986 is briefly reviewed.

  20. Proton therapy in Japan

    SciTech Connect

    Tsunemoto, H.; Morita, S.; Ishikawa, T.; Furukawa, S.; Kawachi, K.; Kanai, T.; Ohara, H.; Kitagawa, T.; Inada, T.

    1985-01-01

    There are two facilities for clinical trials with protons in Japan: the National Institute of Radiological Sciences (NIRS), Chiba, and the Particle Radiation Medical Science Center (PARMS), University of Tsukuba. At the National Institute of Radiological Sciences, patient treatment with the 70 MeV proton beam began in November 1979, and 29 patients were treated through December 1984. Of 11 patients who received protons only, 9 have had local control of the tumor. Two of the 9 patients, suffering from recurrent tumor after radical photon beam irradiation, developed complications after proton treatment. In the patients treated with photons or neutrons followed by proton boost, tumors were controlled in 12 of 18 patients (66.6%), and no complications were observed in this series. Malignant melanoma could not be controlled with the proton beam. A spot-beam-scanning system for protons has been effectively used in the clinical trials to minimize the dose to the normal tissues and to concentrate the dose in the target volume. At the Particle Radiation Medical Science Center, University of Tsukuba, treatment with a vertical 250 MeV proton beam was begun in April 1983, and 22 patients were treated through February 1984. Local control of the tumor was observed in 14 of 22 patients (63.6%), whereas there was no local control in the treatment of glioblastoma multiforme. There have been no severe complications in patients treated at PARMS. The results suggest that local control of tumors will be better with proton beams than with photon beams, whereas additional modalities are required to manage radioresistant tumors.

  1. The Proton launcher

    NASA Astrophysics Data System (ADS)

    Bond, A.; Parfitt, J.

    1985-08-01

    The capabilities, design features and missions for the Soviet Proton booster are described. The Proton, outfitted with six strap-on boosters, launched the Vega 1 and 2 Venus/Halley dual mission spacecraft. RD-253 engines burn N2O4 and UDMH fuels, possibly through a preburner before the combustion chamber. A vacuum thrust of 450,000 lb is projected for the engine. Analyses are presented to set the launch weight at 1,600,000 lb, implying that the vehicle is based on an ICBM design. It is suggested that the Proton has sufficiently high noise and vibration levels to prohibit it from being man-rated.

  2. Are protons nonidentical fermions?

    SciTech Connect

    Mart, T.

    2014-09-25

    We briefly review the progress of our investigation on the electric (charge) radius of the proton. In order to explain the recently measured proton radius, which is significantly smaller than the standard CODATA value, we assume that the real protons radii are not identical, they are randomly distributed in a certain range. To obtain the measured radius we average the radii and fit both the mean radius and the range. By using an averaged dipole form factor we obtain the charge radius r{sub E} = 0.8333 fm, in accordance with the recent measurement of the Lamb shift in muonic hydrogen.

  3. Feasibility study of proton-based quality assurance of proton range compensator

    NASA Astrophysics Data System (ADS)

    Park, S.; Jeong, C.; Min, B. J.; Kwak, J.; Lee, J.; Cho, S.; Shin, D.; Lim, Y. K.; Park, S. Y.; Lee, S. B.

    2013-06-01

    All patient specific range compensators (RCs) are customized for achieving distal dose conformity of target volume in passively scattered proton therapy. Compensators are milled precisely using a computerized machine. In proton therapy, precision of the compensator is critical and quality assurance (QA) is required to protect normal tissues and organs from radiation damage. This study aims to evaluate the precision of proton-based quality assurance of range compensator. First, the geometry information of two compensators was extracted from the DICOM Radiotherapy (RT) plan. Next, RCs were irradiated on the EBT film individually by proton beam which is modulated to have a photon-like percent depth dose (PDD). Step phantoms were also irradiated on the EBT film to generate calibration curve which indicates relationship between optical density of irradiated film and perpendicular depth of compensator. Comparisons were made using the mean absolute difference (MAD) between coordinate information from DICOM RT and converted depth information from the EBT film. MAD over the whole region was 1.7, and 2.0 mm. However, MAD over the relatively flat regions on each compensator selected for comparison was within 1 mm. These results shows that proton-based quality assurance of range compensator is feasible and it is expected to achieve MAD over the whole region less than 1 mm with further correction about scattering effect of proton imaging.

  4. The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Downie, E. J.

    2016-03-01

    The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle, the proposed solutions, and the new electron scattering and spectroscopy experiments planned and underway. We then introduce the MUSE experiment, which seeks to resolve the puzzle by simultaneously measuring elastic electron and muon scattering on the proton, in both charge states, thereby providing new information to the puzzle. MUSE addresses issues of two-photon effects, lepton universality and, possibly, new physics, while providing simultaneous form factor, and therefore radius, measurements with both muons and electrons.

  5. Proton channel models

    PubMed Central

    Pupo, Amaury; Baez-Nieto, David; Martínez, Agustín; Latorre, Ramón; González, Carlos

    2014-01-01

    Voltage-gated proton channels are integral membrane proteins with the capacity to permeate elementary particles in a voltage and pH dependent manner. These proteins have been found in several species and are involved in various physiological processes. Although their primary topology is known, lack of details regarding their structures in the open conformation has limited analyses toward a deeper understanding of the molecular determinants of their function and regulation. Consequently, the function-structure relationships have been inferred based on homology models. In the present work, we review the existing proton channel models, their assumptions, predictions and the experimental facts that support them. Modeling proton channels is not a trivial task due to the lack of a close homolog template. Hence, there are important differences between published models. This work attempts to critically review existing proton channel models toward the aim of contributing to a better understanding of the structural features of these proteins. PMID:24755912

  6. Proton beam therapy facility

    SciTech Connect

    Not Available

    1984-10-09

    It is proposed to build a regional outpatient medical clinic at the Fermi National Accelerator Laboratory (Fermilab), Batavia, Illinois, to exploit the unique therapeutic characteristics of high energy proton beams. The Fermilab location for a proton therapy facility (PTF) is being chosen for reasons ranging from lower total construction and operating costs and the availability of sophisticated technical support to a location with good access to patients from the Chicago area and from the entire nation. 9 refs., 4 figs., 26 tabs.

  7. The proton driver design study

    SciTech Connect

    Editors: W. Chou, C.M. Ankenbrandt and E.I. Malamud

    2001-03-08

    In a 1997 summer study, a team led by Steve Holmes formulated a development plan for the Fermilab proton source and described the results in TM-2021. Subsequently, at the end of 1998, a task group was formed to prepare a detailed design of a high intensity facility called the Proton Driver to replace the Fermilab Booster. In the past two years the design effort has attracted more than fifty participants, mostly from the Beams Division. Physicists and engineers from the Technical Division and FESS as well as other institutions, including the Illinois Institute of Technology (IIT), Stanford University, University of Hawaii, CERN in Switzerland, Rutherford Appleton Laboratory in England and the IHEP in Russia also contributed heavily. The results of that effort are summarized in this document describing the design of a 16 GeV synchrotron, two new beam transport lines (a 400 MeV injection line and a 12/16 GeV extraction line), and related improvements to the present negative ion source and the 400 MeV Linac. A construction cost estimate is presented in Appendix A.

  8. Tracking of proton flow during transition from anaerobiosis to steady state. 1. Response of matrix pH indicators.

    PubMed

    Luvisetto, S; Schmehl, I; Cola, C; Azzone, G F

    1991-11-15

    1. The kinetics of acidification and realkalinization of the matrix after addition of nigericin to respiring and non-respiring mitochondria, recorded by intramitochondrial pH indicators such as neutral red and 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF), is complementary to that recorded by extramitochondrial pH indicators. The extent of acidification decreases with the logarithm of the KCl concentration and is inhibited by Pi and ammonium ions. 2. Proton translocation during respiration has been compared with proton extraction from matrix bulk water. During oxygen pulses to EGTA-untreated mitochondria, BCECF records an extraction of protons from matrix bulk water of about 2-3 nmol H+/mg, reduced to 1-2 nmol H+/mg in EGTA-treated mitochondria. Since the amount of proton translocation required to achieve steady state is of the order of 6-7 nmol H+/mg, it appears that 75-90% of the protons are not extracted from matrix bulk water. Only a slight response is recorded by neutral red. 3. The effect of permeant cations and of uncouplers on the distribution of proton extraction between membrane and matrix bulk water has been studied in presteady state. During Sr2+ uptake, proton extrusion into cytosolic bulk water, as well as proton extraction from matrix bulk water, corresponds almost to 100% of the protons translocated by the redox proton pumps. In the absence of Sr2+, parallel to the disappearance of the proton extrusion in cytosolic bulk water, the proton extraction from matrix bulk water diminishes to about 20% of the proton translocation. 4. The mechanism by which divalent cation uptake and protonophoric uncouplers affect the distribution of proton extraction between matrix bulk water and membrane domains and the nature of the membrane domains are discussed.

  9. Proton dynamics in cancer

    PubMed Central

    2010-01-01

    Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth. Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC) in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology. PMID:20550689

  10. High Temperature Protonic Conductors

    NASA Technical Reports Server (NTRS)

    Dynys, Fred; Berger, Marie-Helen; Sayir, Ali

    2007-01-01

    High Temperature Protonic Conductors (HTPC) with the perovskite structure are envisioned for electrochemical membrane applications such as H2 separation, H2 sensors and fuel cells. Successive membrane commercialization is dependent upon addressing issues with H2 permeation rate and environmental stability with CO2 and H2O. HTPC membranes are conventionally fabricated by solid-state sintering. Grain boundaries and the presence of intergranular second phases reduce the proton mobility by orders of magnitude than the bulk crystalline grain. To enhanced protonic mobility, alternative processing routes were evaluated. A laser melt modulation (LMM) process was utilized to fabricate bulk samples, while pulsed laser deposition (PLD) was utilized to fabricate thin film membranes . Sr3Ca(1+x)Nb(2-x)O9 and SrCe(1-x)Y(x)O3 bulk samples were fabricated by LMM. Thin film BaCe(0.85)Y(0.15)O3 membranes were fabricated by PLD on porous substrates. Electron microscopy with chemical mapping was done to characterize the resultant microstructures. High temperature protonic conduction was measured by impedance spectroscopy in wet air or H2 environments. The results demonstrate the advantage of thin film membranes to thick membranes but also reveal the negative impact of defects or nanoscale domains on protonic conductivity.

  11. Protons and how they are transported by proton pumps.

    PubMed

    Buch-Pedersen, M J; Pedersen, B P; Veierskov, B; Nissen, P; Palmgren, M G

    2009-01-01

    The very high mobility of protons in aqueous solutions demands special features of membrane proton transporters to sustain efficient yet regulated proton transport across biological membranes. By the use of the chemical energy of ATP, plasma-membrane-embedded ATPases extrude protons from cells of plants and fungi to generate electrochemical proton gradients. The recently published crystal structure of a plasma membrane H(+)-ATPase contributes to our knowledge about the mechanism of these essential enzymes. Taking the biochemical and structural data together, we are now able to describe the basic molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological proton pumps emerge. Most notably, the minimal pumping apparatus of all pumps consists of a central proton acceptor/donor, a positively charged residue to control pK(a) changes of the proton acceptor/donor, and bound water molecules to facilitate rapid proton transport along proton wires.

  12. The physics of proton therapy.

    PubMed

    Newhauser, Wayne D; Zhang, Rui

    2015-04-21

    The physics of proton therapy has advanced considerably since it was proposed in 1946. Today analytical equations and numerical simulation methods are available to predict and characterize many aspects of proton therapy. This article reviews the basic aspects of the physics of proton therapy, including proton interaction mechanisms, proton transport calculations, the determination of dose from therapeutic and stray radiations, and shielding design. The article discusses underlying processes as well as selected practical experimental and theoretical methods. We conclude by briefly speculating on possible future areas of research of relevance to the physics of proton therapy.

  13. The physics of proton therapy

    PubMed Central

    Newhauser, Wayne D; Zhang, Rui

    2015-01-01

    The physics of proton therapy has advanced considerably since it was proposed in 1946. Today analytical equations and numerical simulation methods are available to predict and characterize many aspects of proton therapy. This article reviews the basic aspects of the physics of proton therapy, including proton interaction mechanisms, proton transport calculations, the determination of dose from therapeutic and stray radiations, and shielding design. The article discusses underlying processes as well as selected practical experimental and theoretical methods. We conclude by briefly speculating on possible future areas of research of relevance to the physics of proton therapy. PMID:25803097

  14. Proton irradiation and endometriosis

    SciTech Connect

    Wood, D.H.; Yochmowitz, M.G.; Salmon, Y.L.; Eason, R.L.; Boster, R.A.

    1983-08-01

    It was found that female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was determined to be 7 years after the proton exposure. The doses and energies of the radiation received by the experimental animals were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event. It is concluded that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crew members. 15 references.

  15. Proton-Proton Scattering at 105 Mev and 75 Mev

    DOE R&D Accomplishments Database

    Birge, R. W.; Kruse, U. E.; Ramsey, N. F.

    1951-01-31

    The scattering of protons by protons provides an important method for studying the nature of nuclear forces. Recent proton-proton scattering experiments at energies as high as thirty Mev{sup 1} have failed to show any appreciable contribution to the cross section from higher angular momentum states, but it is necessary to bring in tensor forces to explain the magnitude of the observed cross section.

  16. Relative Proton Affinities from Kinetic Energy Release Distributions for Dissociation of Proton-Bound Dimers

    SciTech Connect

    Hache, John J.; Laskin, Julia ); Futrell, Jean H. )

    2002-12-19

    Kinetic energy release distributions (KERDs) upon dissociation of proton-bound dimers are utilized along with Finite Heat Bath theory analysis to obtain relative proton affinities of monomeric species composing the dimer. The proposed approach allows accurate measurement of relative proton affinities based on KERD measurements for the compound with unknown thermochemical properties versus a single reference base. It also allows distinguishing the cases when dissociation of proton-bound dimers is associated with reverse activation barrier, for which both our approach and the kinetic method become inapplicable. Results are reported for the n-butanol-n-propanol dimer, for which there is no significant difference in entropy effects for two reactions and for the pyrrolidine-1,2-ethylenediamine dimer, which is characterized by a significant difference in entropy effects for the two competing reactions. Relative protonation affinities of -1.0?0.3 kcal/mol for the n-butanol-n-propanol pair and 0.27?0.10 kcal/mol for the pyrrolidine-1,2-ethylenediamine pair are in good agreement with literature values. Relative reaction entropies were extracted from the branching ratio and KERD measurements. Good correspondence was found between the relative reaction entropies for the n-butanol-n-propanol dimer (D(DS?)=-0.3?1.5 cal/mol K) and the relative protonation entropy for the two monomers (D(DSp)=0). However, the relative reaction entropy for the pyrrolidine-1,2-ethylenediamine dimer is higher than the difference in protonation entropies (D(DS?)=8.2?0.5 cal/mol K vs. D(DSp)=5 cal/mol K).

  17. The Search for Proton Decay.

    ERIC Educational Resources Information Center

    Marshak, Marvin L.

    1984-01-01

    Provides the rationale for and examples of experiments designed to test the stability of protons and bound neutrons. Also considers the unification question, cosmological implications, current and future detectors, and current status of knowledge on proton decay. (JN)

  18. Three new defined proton affinities for polybasic molecules in the gas-phase: Proton microaffinity, proton macroaffinity and proton overallaffinity

    NASA Astrophysics Data System (ADS)

    Salehzadeh, Sadegh; Bayat, Mehdi

    2006-08-01

    A theoretical study on complete protonation of a series of tetrabasic molecules with general formula N[(CH 2) nNH 2][(CH 2) mNH 2][(CH 2) pNH 2] (tren, pee, ppe, tpt, epb and ppb) is reported. For first time, three kinds of gas-phase proton affinities for each polybasic molecule are defined as: 'proton microaffinity (PA n, i)', 'proton macroaffinity (PA)' and 'proton overall affinity ( PA)'. The variations of calculated logPA in the series of these molecules is very similar to that of their measured log Kn. There is also a good correlation between the calculated gas-phase proton macroaffinities and proton overallaffinities with corresponding equilibrium macroconstants and overall protonation constants in solution.

  19. Proton therapy in clinical practice

    PubMed Central

    Liu, Hui; Chang, Joe Y.

    2011-01-01

    Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy. PMID:21527064

  20. Proton bunch compression strategies

    SciTech Connect

    Lebedev, Valeri; /Fermilab

    2009-10-01

    The paper discusses main limitations on the beam power and other machine parameters for a 4 MW proton driver for muon collider. The strongest limitation comes from a longitudinal microwave instability limiting the beam power to about 1 MW for an 8 GeV compressor ring.

  1. High Power Proton Facilities

    NASA Astrophysics Data System (ADS)

    Nagaitsev, Sergei

    2015-04-01

    This presentation will provide an overview of the capabilities and challenges of high intensity proton accelerators, such as J-PARC, Fermilab MI, SNS, ISIS, PSI, ESS (in the future) and others. The presentation will focus on lessons learned, new concepts, beam loss mechanisms and methods to mitigate them.

  2. Protons Trigger Mitochondrial Flashes.

    PubMed

    Wang, Xianhua; Zhang, Xing; Huang, Zhanglong; Wu, Di; Liu, Beibei; Zhang, Rufeng; Yin, Rongkang; Hou, Tingting; Jian, Chongshu; Xu, Jiejia; Zhao, Yan; Wang, Yanru; Gao, Feng; Cheng, Heping

    2016-07-26

    Emerging evidence indicates that mitochondrial flashes (mitoflashes) are highly conserved elemental mitochondrial signaling events. However, which signal controls their ignition and how they are integrated with other mitochondrial signals and functions remain elusive. In this study, we aimed to further delineate the signal components of the mitoflash and determine the mitoflash trigger mechanism. Using multiple biosensors and chemical probes as well as label-free autofluorescence, we found that the mitoflash reflects chemical and electrical excitation at the single-organelle level, comprising bursting superoxide production, oxidative redox shift, and matrix alkalinization as well as transient membrane depolarization. Both electroneutral H(+)/K(+) or H(+)/Na(+) antiport and matrix proton uncaging elicited immediate and robust mitoflash responses over a broad dynamic range in cardiomyocytes and HeLa cells. However, charge-uncompensated proton transport, which depolarizes mitochondria, caused the opposite effect, and steady matrix acidification mildly inhibited mitoflashes. Based on a numerical simulation, we estimated a mean proton lifetime of 1.42 ns and diffusion distance of 2.06 nm in the matrix. We conclude that nanodomain protons act as a novel, to our knowledge, trigger of mitoflashes in energized mitochondria. This finding suggests that mitoflash genesis is functionally and mechanistically integrated with mitochondrial energy metabolism.

  3. Intensity modulated proton therapy

    PubMed Central

    Grassberger, C

    2015-01-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed “pencil beams” of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak—the characteristic peak of dose at the end of range—combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radiotherapy or volumetric modulated arc therapy) with dose modulation along the beam axis as well as lateral, in-field, dose modulation. The clinical practice of IMPT further improves the healthy tissue vs target dose differential in comparison with X-rays and thus allows increased target dose with dose reduction elsewhere. In addition, heavy-charged-particle beams allow for the modulation of biological effects, which is of active interest in combination with dose “painting” within a target. The clinical utilization of IMPT is actively pursued but technical, physical and clinical questions remain. Technical questions pertain to control processes for manipulating pencil beams from the creation of the proton beam to delivery within the patient within the accuracy requirement. Physical questions pertain to the interplay between the proton penetration and variations between planned and actual patient anatomical representation and the intrinsic uncertainty in tissue stopping powers (the measure of energy loss per unit distance). Clinical questions remain concerning the impact and management of the technical and physical questions within the context of the daily treatment delivery, the clinical benefit of IMPT and the biological response differential compared with X-rays against which clinical benefit will be judged. It is expected that IMPT will replace other modes of proton field delivery. Proton radiotherapy, since its first practice 50 years ago, always required the

  4. Proton radiography for clinical applications

    NASA Astrophysics Data System (ADS)

    Talamonti, C.; Reggioli, V.; Bruzzi, M.; Bucciolini, M.; Civinini, C.; Marrazzo, L.; Menichelli, D.; Pallotta, S.; Randazzo, N.; Sipala, V.; Cirrone, G. A. P.; Petterson, M.; Blumenkrantz, N.; Feldt, J.; Heimann, J.; Lucia, D.; Seiden, A.; Williams, D. C.; Sadrozinski, H. F.-W.; Bashkirov, V.; Schulte, R.

    2010-01-01

    Proton imaging is not yet applied as a clinical routine, although its advantages have been demonstrated. In the context of quality assurance in proton therapy, proton images can be used to verify the correct positioning of the patient and to control the range of protons. Proton computed tomography (pCT) is a 3D imaging method appropriate for planning and verification of proton radiation treatments, because it allows evaluating the distributions of proton stopping power within the tissues and can be directly utilized when the patient is in the actual treatment position. The aim of the PRoton IMAging experiment, supported by INFN, and the PRIN 2006 project, supported by MIUR, is to realize a proton computed radiography (pCR) prototype for reconstruction of proton images from a single projection in order to validate the technique with pre-clinical studies and, eventually, to conceive the configuration of a complete pCT system. A preliminary experiment performed at the 250 MeV proton synchrotron of Loma Linda University Medical Center (LLUMC) allowed acquisition of experimental data before the completion of PRIMA project's prototype. In this paper, the results of the LLUMC experiment are reported and the reconstruction of proton images of two phantoms is discussed.

  5. Is the proton radius puzzle evidence of extra dimensions?

    NASA Astrophysics Data System (ADS)

    Dahia, F.; Lemos, A. S.

    2016-08-01

    The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between the 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.

  6. Qweak: First Direct Measurement of the Proton's Weak Charge

    NASA Astrophysics Data System (ADS)

    Androic, D.; Armstrong, D. S.; Asaturyan, A.; Averett, T.; Balewski, J.; Bartlett, K.; Beaufait, J.; Beminiwattha, R. S.; Benesch, J.; Benmokhtar, F.; Birchall, J.; Carlini, R. D.; Cates, G. D.; Cornejo, J. C.; Covrig, S.; Dalton, M. M.; Davis, C. A.; Deconinck, W.; Diefenbach, J.; Dowd, J. F.; Dunne, J. A.; Dutta, D.; Duvall, W. S.; Elaasar, M.; Falk, W. R.; Finn, J. M.; Forest, T.; Gal, C.; Gaskell, D.; Gericke, M. T. W.; Grames, J.; Gray, V. M.; Grimm, K.; Guo, F.; Hoskins, J. R.; Johnston, K.; Jones, D.; Jones, M.; Jones, R.; Kargiantoulakis, M.; King, P. M.; Korkmaz, E.; Kowalski, S.; Leacock, J.; Leckey, J.; Lee, A. R.; Lee, J. H.; Lee, L.; MacEwan, S.; Mack, D.; Magee, J. A.; Mahurin, R.; Mammei, J.; Martin, J. W.; McHugh, M. J.; Meekins, D.; Mei, J.; Michaels, R.; Micherdzinska, A.; Mkrtchyan, A.; Mkrtchyan, H.; Morgan, N.; Myers, K. E.; Narayan, A.; Ndukum, L. Z.; Nelyubin, V.; Nuhait, H.; Nuruzzaman; van Oers, W. T. H.; Opper, A. K.; Page, S. A.; Pan, J.; Paschke, K. D.; Phillips, S. K.; Pitt, M. L.; Poelker, M.; Rajotte, J. F.; Ramsay, W. D.; Roche, J.; Sawatzky, B.; Seva, T.; Shabestari, M. H.; Silwal, R.; Simicevic, N.; Smith, G. R.; Solvignon, P.; Spayde, D. T.; Subedi, A.; Subedi, R.; Suleiman, R.; Tadevosyan, V.; Tobias, W. A.; Tvaskis, V.; Waidyawansa, B.; Wang, P.; Wells, S. P.; Wood, S. A.; Yang, S.; Young, R. D.; Zang, P.; Zhamkochyan, S.

    2017-03-01

    The Qweak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q2 = 0.025 (GeV/c)2. The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. The results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis.

  7. Proton radiography and tomography with application to proton therapy.

    PubMed

    Poludniowski, G; Allinson, N M; Evans, P M

    2015-09-01

    Proton radiography and tomography have long promised benefit for proton therapy. Their first suggestion was in the early 1960s and the first published proton radiographs and CT images appeared in the late 1960s and 1970s, respectively. More than just providing anatomical images, proton transmission imaging provides the potential for the more accurate estimation of stopping-power ratio inside a patient and hence improved treatment planning and verification. With the recent explosion in growth of clinical proton therapy facilities, the time is perhaps ripe for the imaging modality to come to the fore. Yet many technical challenges remain to be solved before proton CT scanners become commonplace in the clinic. Research and development in this field is currently more active than at any time with several prototype designs emerging. This review introduces the principles of proton radiography and tomography, their historical developments, the raft of modern prototype systems and the primary design issues.

  8. Proton radiography and tomography with application to proton therapy

    PubMed Central

    Allinson, N M; Evans, P M

    2015-01-01

    Proton radiography and tomography have long promised benefit for proton therapy. Their first suggestion was in the early 1960s and the first published proton radiographs and CT images appeared in the late 1960s and 1970s, respectively. More than just providing anatomical images, proton transmission imaging provides the potential for the more accurate estimation of stopping-power ratio inside a patient and hence improved treatment planning and verification. With the recent explosion in growth of clinical proton therapy facilities, the time is perhaps ripe for the imaging modality to come to the fore. Yet many technical challenges remain to be solved before proton CT scanners become commonplace in the clinic. Research and development in this field is currently more active than at any time with several prototype designs emerging. This review introduces the principles of proton radiography and tomography, their historical developments, the raft of modern prototype systems and the primary design issues. PMID:26043157

  9. Measuring proton energies and fluxes using EIT (SOHO) CCD areas outside the solar disk images

    NASA Astrophysics Data System (ADS)

    Didkovsky, L. V.; Judge, D. L.; Jones, A. R.; Rhodes, E. J., Jr.; Gurman, J. B.

    2006-05-01

    An indirect proton flux measuring tool based on discrimination of the energy deposited by protons in 128×128 pixel EIT CCD areas outside the solar disk images is presented. Single pixel intensity events are converted into proton incident energy flux using modeled energy deposition curves for angles of incidence ± 60° in four EIT spatial areas with different proton stopping power. The extracted proton flux is corrected for both the loss of one-pixel events in the range of angles of incidence as well as for the contribution to the single pixel events resulting from scattered middle-energy protons (low-energy or high-energy particles are stopped by the EIT components or pass through them, accordingly). A simple geometrical approach was found and applied to correct for a non-unique relation between the proton-associated CCD output signal and the incident proton energy. With this geometrical approximation four unique proton incident energy ranges were determined as 45-49, 145-154, 297-335, and 390-440 MeV. The indirect proton flux measuring tool has been tested by comparing Solar Energetic Particles (SEP) flux temporal profiles extracted from the EIT CCD frames and downloaded from the GOES database for the Bastille Day (BD) of 2000 July 14 and the more recent 2005 January 20 events. The SEP flux temporal profiles and proton spectra extracted from the EIT in the relatively narrow energy ranges between 45 and 440 MeV reported here are consistent with the related GOES profiles. The four additional EIT extracted ranges provide higher energy resolution of the SEP data.

  10. Measurement of the Proton + Proton Going to Proton + Proton + Neutral Pion Cross-Section Near Threshold

    NASA Astrophysics Data System (ADS)

    Ross, M. Alan

    1991-02-01

    The first nuclear physics experiment at the IUCF Cooler is a measurement of the p+ptop+p+ pi^0 cross section near threshold. The Cooler, together with a thin internal H_2 gas jet target, allows for a precise cross section measurement by providing well-defined interaction energies and by eliminating background from p-nucleus pion production which has a much lower threshold. A cylindrically symmetric detector system has been installed in one of the straight sections of the ring and is used to detect the coincident protons in the exit channel with good energy and angular resolution. The mass of the unobserved is then deduced. Elastically scattered protons were detected at the same time and by the same detector as pion production events. Elastic scattering was used for normalization to obtain an absolute p+p top+p+pi^0 cross section.

  11. The HERA Proton

    NASA Astrophysics Data System (ADS)

    Habib, Shiraz

    2014-04-01

    The almost 1 fb-1 of ep data collected by the H1 and ZEUS collider experiments at HERA allows for a precise determination of the proton's parton distribution functions (PDFs). Measurements used to constrain the PDFs—inclusive and jet cross sections, charm contribution to the F2 proton structure function, F_2cbar c — are presented herein. The measurement process itself includes cataloguing the sensitivity of the cross sections to the various sources of correlated systematic uncertainties. In the jet measurement, correlations of a statistical nature are also quantified and catalogued. These correlations provide a basis to combine measurements of the same physical observable across different time periods, experiments and measurement methodology. The subsequent PDF fitting procedure also takes into account such correlations. The resulting HERAPDF1.5 set based on inclusive data as well as PDF sets derived from inclusive plus charm data are presented togeteher with their predictions for pp cross sections at the LHC.

  12. Proton therapy in the clinic.

    PubMed

    DeLaney, Thomas F

    2011-01-01

    The clinical advantage for proton radiotherapy over photon approaches is the marked reduction in integral dose to the patient, due to the absence of exit dose beyond the proton Bragg peak. The integral dose with protons is approximately 60% lower than that with any external beam photon technique. Pediatric patients, because of their developing normal tissues and anticipated length of remaining life, are likely to have the maximum clinical gain with the use of protons. Proton therapy may also allow treatment of some adult tumors to much more effective doses, because of normal tissue sparing distal to the tumor. Currently, the most commonly available proton treatment technology uses 3D conformal approaches based on (a) distal range modulation, (b) passive scattering of the proton beam in its x- and y-axes, and (c) lateral beam-shaping. It is anticipated that magnetic pencil beam scanning will become the dominant mode of proton delivery in the future, which will lower neutron scatter associated with passively scattered beam lines, reduce the need for expensive beam-shaping devices, and allow intensity-modulated proton radiotherapy. Proton treatment plans are more sensitive to variations in tumor size and normal tissue changes over the course of treatment than photon plans, and it is expected that adaptive radiation therapy will be increasingly important for proton therapy as well. While impressive treatment results have been reported with protons, their cost is higher than for photon IMRT. Hence, protons should ideally be employed for anatomic sites and tumors not well treated with photons. While protons appear cost-effective for pediatric tumors, their cost-effectiveness for treatment of some adult tumors, such as prostate cancer, is uncertain. Comparative studies have been proposed or are in progress to more rigorously assess their value for a variety of sites. The utility of proton therapy will be enhanced by technological developments that reduce its cost

  13. Proton conducting cerate ceramics

    SciTech Connect

    Coffey, G.W.; Pederson, L.R.; Armstrong, T.R.; Bates, J.L.; Weber, W.J.

    1995-08-01

    Cerate perovskites of the general formula AM{sub x}Ce{sub 1-x}O{sub 3-{delta}}, where A = Sr or Ba and where M = Gd, Nd, Y, Yb or other rare earth dopant, are known to conduct a protonic current. Such materials may be useful as the electrolyte in a solid oxide fuel cell operating at intermediate temperatures, as an electrochemical hydrogen separation membrane, or as a hydrogen sensor. Conduction mechanisms in these materials were evaluated using dc cyclic voltammetry and mass spectrometry, allowing currents and activation energies for proton, electron, and oxygen ion contributions to the total current to be determined. For SrYb{sub 0.05}Ce{sub 0.95}O{sub 3-{delta}}, one of the best and most environmentally stable compositions, proton conduction followed two different mechanisms: a low temperature process, characterized by an activation energy of 0.42{+-}0.04 eV, and a high temperature process, characterized by an activation energy of 1.38{+-}0.13 eV. It is believed that the low temperature process is dominated by grain boundary conduction while bulk conduction is responsible for the high temperature process. The activation energy for oxygen ion conduction (0.97{+-}0.10 eV) agrees well with other oxygen conductors, while that for electronic conduction, 0.90{+-}0.09 eV, is affected by a temperature-dependent electron carrier concentration. Evaluated by direct measurement of mass flux through a dense ceramic with an applied dc field, oxygen ions were determined to be the majority charge carrier except at the lowest temperatures, followed by electrons and then protons.

  14. Smashing Protons to Smithereens

    ScienceCinema

    Marc-André Pleier

    2016-07-12

    Pleier discusses the extraordinary research taking place at the Large Hadron Collider (LHC) — the world’s newest, biggest, and highest energy particle accelerator located at CERN. Pleier is one of hundreds of researchers from around the world working on ATLAS, a seven-story particle detector positioned at a point where the LHC’s oppositely circulating beams of protons slam into one another head-on.

  15. Proton computed tomography

    NASA Astrophysics Data System (ADS)

    Bucciantonio, Martina; Sauli, Fabio

    2015-05-01

    Proton computed tomography (pCT) is a diagnostic method capable of in situ imaging the three-dimensional density distribution in a patient before irradiation with charged particle beams. Proposed long time ago, this technology has been developed by several groups, and may become an essential tool for advanced quality assessment in hadrontherapy. We describe the basic principles of the method, its performance and limitations as well as provide a summary of experimental systems and of results achieved.

  16. 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.

  17. Polarized protons at RHIC

    SciTech Connect

    Makdisi, Y.

    1992-01-01

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 {times} 10{sup 32}/cm{sup 2}/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined.

  18. Polarized protons at RHIC

    SciTech Connect

    Makdisi, Y.

    1992-10-01

    The approval for construction of the Relativistic Heavy Ion Collider (RHIC) provides a potential opportunity to collide polarized proton beams at energies up to 500 GeV in the center of mass and high luminosities approaching 2 {times} 10{sup 32}/cm{sup 2}/sec. This capability is enhanced by the fact that the AGS has already accelerated polarized protons and relies on the newly completed Accumulator/Booster for providing the required polarized proton intensity and a system of spin rotators (Siberian snakes) to retain the polarization. The RHIC Spin Collaboration was formed and submitted a Letter of Intent to construct this polarized collider capability and utilize its physics opportunities. In this presentation, I will discuss the plans to upgrade the AGS, the proposed layout of the RHIC siberian snakes, and timetables. The physics focus is the measurement of the spin dependent parton distributions with such accessible probes including high p(t) jets, direct photons, and Drell Yan. The attainable sensitivities and the progress that has been reached in defining the detector requirements will be outlined.

  19. Proton-proton correlations observed in two-proton radioactivity of 94Ag.

    PubMed

    Mukha, Ivan; Roeckl, Ernst; Batist, Leonid; Blazhev, Andrey; Döring, Joachim; Grawe, Hubert; Grigorenko, Leonid; Huyse, Mark; Janas, Zenon; Kirchner, Reinhard; La Commara, Marco; Mazzocchi, Chiara; Tabor, Sam L; Van Duppen, Piet

    2006-01-19

    The stability and spontaneous decay of naturally occurring atomic nuclei have been much studied ever since Becquerel discovered natural radioactivity in 1896. In 1960, proton-rich nuclei with an odd or an even atomic number Z were predicted to decay through one- and two-proton radioactivity, respectively. The experimental observation of one-proton radioactivity was first reported in 1982, and two-proton radioactivity has now also been detected by experimentally studying the decay properties of 45Fe (refs 3, 4) and 54Zn (ref. 5). Here we report proton-proton correlations observed during the radioactive decay of a spinning long-lived state of the lightest known isotope of silver, 94Ag, which is known to undergo one-proton decay. We infer from these correlations that the long-lived state must also decay through simultaneous two-proton emission, making 94Ag the first nucleus to exhibit one- as well as two-proton radioactivity. We attribute the two-proton emission behaviour and the unexpectedly large probability for this decay mechanism to a very large deformation of the parent nucleus into a prolate (cigar-like) shape, which facilitates emission of protons either from the same or from opposite ends of the 'cigar'.

  20. Proton transfer in acetaldehyde and acetaldehyde-water clusters: Vacuum ultraviolet photoionization experiment and theoretical calculations

    NASA Astrophysics Data System (ADS)

    Kostko, Oleg; Troy, Tyler P.; Bandyopadhyay, Biswajit; Ahmed, Musahid

    2015-03-01

    Acetaldehyde, a probable human carcinogen and of environmental importance, upon solvation provides a test bed for understanding proton transfer pathways and catalytic mechanisms. In this study, we report on single photon vacuum ultraviolet photoionization of small acetaldehyde and acetaldehyde-water clusters. Appearance energies of protonated clusters are extracted from the experimental photoionization efficiency curves and compared to electronic structure calculations. The comparison of experimental data to computational results provides mechanistic insight into the fragmentation mechanisms of the observed mass spectra. Using deuterated water for isotopic tagging, we observe that proton transfer is mediated via acetaldehyde and not water in protonated acetaldehyde-water clusters.

  1. THE POLARIZATION PARAMETER IN ELASTIC PROTON-PROTON SCATTERING FROM .75 TO 2.84 GEV.

    DTIC Science & Technology

    PROTON SCATTERING, POLARIZATION), (*NUCLEAR SPINS, POLARIZATION), PROTON REACTIONS, ELASTIC SCATTERING, MEASUREMENT, PARTICLE ACCELERATOR TARGETS, LIQUEFIED GASES, HELIUM, CARBON, ANTIPARTICLES , PROTON CROSS SECTIONS

  2. Parasitic extraction of 900-GeV/c protons from the Tevatron using a bent silicon crystal and measurement of the $b \\bar{b}$ production cross-section at $\\sqrt{s}$ = 38.8-GeV

    SciTech Connect

    Ramachandran, Sathyadev

    1997-01-01

    This dissertation discusses results from an experiment demonstrating the feasibility of a novel extraction scheme using channeling in a bent crystal at future high-energy colliders for doing heavy avor physics in a xed target environment concurrently with collider experiments. In the second half of this dissertation we present the results from a measurement of the inclusive cross-section for b$\\bar{b}$ production at the center-of-mass energy of 38.8 GeV using the semileptonic decays of the beauty mesons.

  3. Differential Cross Sections for Proton-Proton Elastic Scattering

    NASA Technical Reports Server (NTRS)

    Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

    2009-01-01

    Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

  4. Proton structure functions at HERA

    NASA Astrophysics Data System (ADS)

    Abt, Iris

    2014-05-01

    The "proton structure" is a wide field. Discussed are predominantly the precision measurements of the proton structure functions at HERA and some of their implications for the LHC measurements. In addition, a discussion of what a proton structure function represents is provided. Finally, a connection to nuclear physics is attempted. This contribution is an updated reprint of a contribution to "Deep Inelastic Scattering 2012".1

  5. Release from ISOLDE molten metal targets under pulsed proton beam conditions

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Catherall, R.; Cyvoct, G.; Evensen, A. H. M.; Lindroos, M.; Jonsson, O. C.; Kugler, E.; Schindl, K.; Ravn, H.; Wildner, E.; Drumm, P.; Obert, J.; Putaux, J. C.; Sauvage, J.

    1996-04-01

    By moving the ISOLDE mass separators from the 600 MeV Synchrocyclotron (SC) to the 1 GeV Proton-Synchrotron-Booster (PS) the instantaneous energy density of the proton beam went up by 3 orders of magnitude. The developments of the molten metal target units and the optimization of the PS proton beam to cope with the effects of the thermal shocks induced by the proton beam are described. The energy density of the PS proton beam was reduced by spatial defocusing and time staggered extraction of the four PS-accelerators. The release from lanthanum, lead and tin targets is discussed for different settings of the proton beam and compared to the release observed at ISOLDE-SC. The yields of Hg isotopes are presented.

  6. Synchronous timing of multi-energy fast beam extraction during a single AGS cycle

    SciTech Connect

    Gabusi, J.; Naase, S.

    1985-01-01

    Synchronous triggering of fast beams is required because the field of Kicker Magnets must rise within the open space between one beam bunch and the next. Within the Brookhaven AGS, Fast Extracted Beam (FEB) triggering combines nominal timing, based on beam energy with bunch-to-bunch synchronization, based on the accelerating rf waveform. During beam acceleration, a single bunch is extracted at 22 GeV/c and within the same AGS cycle, the remaining eleven bunches are extracted at 28.4 GeV/c. When the single bunch is extracted, a ''hole'', which is left in the remaining circulating beam, can appear in random locations within the second extraction during successive AGS cycles. To overcome this problem, a synchronous rf/12 counting scheme and logic circuitry are used to keep track of the bunch positions relative to each other, and to place the ''hole'' in any desired location within the second extraction. The rf/12 signal is used also to synchronize experimenters triggers.

  7. Proton irradiation and endometriosis

    SciTech Connect

    Wood, D.H.; Yochmowitz, M.G.; Salmon, Y.L.; Eason, R.L.; Boster, R.A.

    1983-08-01

    Female rhesus monkeys given single total-body exposures of protons of varying energies developed endometriosis at a frequency significantly higher than that of nonirradiated animals of the same age. The minimum latency period was 7 years after exposure. The doses and energies of the radiation received were within the range that could be received by an aircrew member in near-earth orbit during a random solar flare event, leading to the conclusion that endometriosis should be a consideration in assessing the risk of delayed radiation effects in female crewmembers.

  8. Proton Size Anomaly

    SciTech Connect

    Barger, Vernon; Chiang, Cheng-Wei; Keung, Wai-Yee; Marfatia, Danny

    2011-04-15

    A measurement of the Lamb shift in muonic hydrogen yields a charge radius of the proton that is smaller than the CODATA value by about 5 standard deviations. We explore the possibility that new scalar, pseudoscalar, vector, and tensor flavor-conserving nonuniversal interactions may be responsible for the discrepancy. We consider exotic particles that, among leptons, couple preferentially to muons and mediate an attractive nucleon-muon interaction. We find that the many constraints from low energy data disfavor new spin-0, spin-1, and spin-2 particles as an explanation.

  9. Proton Upset Monte Carlo Simulation

    NASA Technical Reports Server (NTRS)

    O'Neill, Patrick M.; Kouba, Coy K.; Foster, Charles C.

    2009-01-01

    The Proton Upset Monte Carlo Simulation (PROPSET) program calculates the frequency of on-orbit upsets in computer chips (for given orbits such as Low Earth Orbit, Lunar Orbit, and the like) from proton bombardment based on the results of heavy ion testing alone. The software simulates the bombardment of modern microelectronic components (computer chips) with high-energy (.200 MeV) protons. The nuclear interaction of the proton with the silicon of the chip is modeled and nuclear fragments from this interaction are tracked using Monte Carlo techniques to produce statistically accurate predictions.

  10. Proton radius from electron scattering data

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; Meekins, David; Norum, Blaine; Sawatzky, Brad

    2016-05-01

    Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon, and Stanford. Methods: We make use of stepwise regression techniques using the F test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate error estimates. Results: Starting with the precision, low four-momentum transfer (Q2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q2 data on GE to select functions which extrapolate to high Q2, we find that a Padé (N =M =1 ) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, GE(Q2) =(1+Q2/0.66 GeV2) -2 . Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extremely-low-Q2 data or by use of the Padé approximant for extrapolation using a larger

  11. Proton radius from electron scattering data

    SciTech Connect

    Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; Meekins, David; Norum, Blaine; Sawatzky, Brad

    2016-05-01

    Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon, and Stanford. Methods: We make use of stepwise regression techniques using the F test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate error estimates. Results: Starting with the precision, low four-momentum transfer (Q2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q2 data on GE to select functions which extrapolate to high Q2, we find that a Padé (N=M=1) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, GE(Q2)=(1+Q2/0.66GeV2)−2. Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extremely-low-Q2 data or by use of the Padé approximant for extrapolation using a larger range of

  12. Design of a compact ring for proton radiation applications

    NASA Astrophysics Data System (ADS)

    Li, Guang-Rui; Zheng, Shu-Xin; Yao, Hong-Juan; Guan, Xia-Ling; Wang, Xue-Wu; Huang, Wen-Hui

    2017-01-01

    This paper presents the design of a compact proton synchrotron, including lattice structure, injection system and extraction system, for radiation applications. The lattice is based on a DBFO cell and shows good properties like small β max and decent kick arm. Radiation applications require relative strong and continuous beam, so we propose strip injection and resonance extraction for the design. A phase space painting scheme is designed and simulated by ORBIT. The scheme achieves good uniformity in phase space. The extraction system is designed and optimized by multi-particle tracking.

  13. Proton-air and proton-proton cross sections from air shower data

    NASA Technical Reports Server (NTRS)

    Linsley, J.

    1985-01-01

    Data on the fluctuations in depth of maximum development of cosmic ray air showers, corrected for the effects of mixed primary composition and shower development fluctuations, yield values of the inelastic proton-air cross section for laboratory energies in the range 10 to the 8th power to 10 to the 10th power GeV. From these values of proton-air cross section, corresponding values of the proton-proton total cross section are derived by means of Glauber theory and geometrical scaling. The resulting values of proton-proton cross section are inconsistent with a well known 1n(2)s extrapolation of ISR data which is consistent with SPS data; they indicate a less rapid rate of increase in the interval 540 sq root of s 100000 GeV.

  14. 30-kV proton injector for PIGMI

    SciTech Connect

    Hamm, R.W.; Mueller, D.W.; Sturgess, R.G.

    1981-01-01

    A 30-kV proton injector designed for matching a 31-mA proton beam into the radio-frequency quadrupole (RFQ) section of the PIGMI accelerator has been constructed and tested. This injector uses a small efficient duoplasmatron ion source and a single-gap extraction system for creating a convergent ion beam, and a three-element unipotential einzel lens for focusing the ion beam into the RFQ. A description of this prototype injector is presented, along with the experimental data obtained during the testing of this system.

  15. Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Peng, C.; Gao, H.

    2016-03-01

    The puzzle of proton charge radius was recently raised by the measurement of muonic hydrogen Lamb shift at Paul Scherrer Institute (PSI), whose results were seven standard deviations smaller than the CODATA recommended value. To investigate this discrepancy, the PRad experiment was proposed and approved at Thomas Jefferson National Accelerator Facility (JLab). The experiment will extract the proton charge radius with a sub-percent accuracy by measuring the cross-sections of unpolarized electronproton elastic scattering in an unprecedented low Q2 region (2×10-4 GeV2/c2).

  16. [Proton imaging applications for proton therapy: state of the art].

    PubMed

    Amblard, R; Floquet, V; Angellier, G; Hannoun-Lévi, J M; Hérault, J

    2015-04-01

    Proton therapy allows a highly precise tumour volume irradiation with a low dose delivered to the healthy tissues. The steep dose gradients observed and the high treatment conformity require a precise knowledge of the proton range in matter and the target volume position relative to the beam. Thus, proton imaging allows an improvement of the treatment accuracy, and thereby, in treatment quality. Initially suggested in 1963, radiographic imaging with proton is still not used in clinical routine. The principal difficulty is the lack of spatial resolution, induced by the multiple Coulomb scattering of protons with nuclei. Moreover, its realization for all clinical locations requires relatively high energies that are previously not considered for clinical routine. Abandoned for some time in favor of X-ray technologies, research into new imaging methods using protons is back in the news because of the increase of proton radiation therapy centers in the world. This article exhibits a non-exhaustive state of the art in proton imaging.

  17. Proton in SRF Niobium

    SciTech Connect

    Wallace, John Paul

    2011-03-31

    Hydrogen is a difficult impurity to physically deal with in superconducting radio frequency (SRF) niobium, therefore, its properties in the metals should be well understood to allow the metal's superconducting properties to be optimized for minimum loss in the construction of resonant accelerator cavities. It is known that hydrogen is a paramagnetic impurity in niobium from NMR studies. This paramagnetism and its effect on superconducting properties are important to understand. To that end analytical induction measurements aimed at isolating the magnetic properties of hydrogen in SRF niobium are introduced along with optical reflection spectroscopy which is also sensitive to the presence of hydrogen. From the variety, magnitude and rapid kinetics found in the optical and magnetic properties of niobium contaminated with hydrogen forced a search for an atomic model. This yielded quantum mechanical description that correctly generates the activation energy for diffusion of the proton and its isotopes not only in niobium but the remaining metals for which data is available. This interpretation provides a frame work for understanding the individual and collective behavior of protons in metals.

  18. Berkeley Proton Linear Accelerator

    DOE R&D Accomplishments Database

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  19. Proton in SRF Niobium

    NASA Astrophysics Data System (ADS)

    Wallace, John Paul

    2011-03-01

    Hydrogen is a difficult impurity to physically deal with in superconducting radio frequency (SRF) niobium, therefore, its properties in the metals should be well understood to allow the metal's superconducting properties to be optimized for minimum loss in the construction of resonant accelerator cavities. It is known that hydrogen is a paramagnetic impurity in niobium from NMR studies. This paramagnetism and its effect on superconducting properties are important to understand. To that end analytical induction measurements aimed at isolating the magnetic properties of hydrogen in SRF niobium are introduced along with optical reflection spectroscopy which is also sensitive to the presence of hydrogen. From the variety, magnitude and rapid kinetics found in the optical and magnetic properties of niobium contaminated with hydrogen forced a search for an atomic model. This yielded quantum mechanical description that correctly generates the activation energy for diffusion of the proton and its isotopes not only in niobium but the remaining metals for which data is available. This interpretation provides a frame work for understanding the individual and collective behavior of protons in metals.

  20. Emission of neutron-proton and proton-proton pairs in neutrino scattering

    NASA Astrophysics Data System (ADS)

    Ruiz Simo, I.; Amaro, J. E.; Barbaro, M. B.; De Pace, A.; Caballero, J. A.; Megias, G. D.; Donnelly, T. W.

    2016-11-01

    We use a recently developed model of relativistic meson-exchange currents to compute the neutron-proton and proton-proton yields in (νμ ,μ-) scattering from 12C in the 2p-2h channel. We compute the response functions and cross sections with the relativistic Fermi gas model for different kinematics from intermediate to high momentum transfers. We find a large contribution of neutron-proton configurations in the initial state, as compared to proton-proton pairs. In the case of charge-changing neutrino scattering the 2p-2h cross section of proton-proton emission (i.e., np in the initial state) is much larger than for neutron-proton emission (i.e., two neutrons in the initial state) by a (ω , q)-dependent factor. The different emission probabilities of distinct species of nucleon pairs are produced in our model only by meson-exchange currents, mainly by the Δ isobar current. We also analyze other effects including exchange contributions and the effect of the axial and vector currents.

  1. Analyzing Powers and Differential Cross Sections for Polarized Proton Neutron Going to Negative Pion Proton Proton

    NASA Astrophysics Data System (ADS)

    Duncan, Fraser Andrew

    There is considerable interest in the pn to pi^-pp reaction which can proceed by a nonresonant channel from the isospin 0 pn initial state (an NDelta intermediate state cannot be formed). This thesis describes a measurement of analyzing powers and triple differential cross sections for a subset of this reaction, pn to pi^-pp(^1S_0) by isolating the quasifree process in pd to pi^-ppp_{s}. The experimental arrangement selects the relative S-wave component of the outgoing "diproton". The experiment was done on TRIUMF beam line 1B using a LD_2 target; the pion was detected in a magnetic spectrometer, the two outgoing protons in a scintillator bar array. The spectator proton was undetected. Data were taken in August 1989 at 353, 403 and 440 MeV beam energies. Of these the 403 and 440 MeV data are analysed in this thesis and analyzing powers and triple differential cross sections as a function of pion scattering angle extracted at centre of mass kinetic energies, T_{CM}, of 55 and 70 MeV (corresponding to the 403 and 440 MeV beam energies respectively). Partial wave analysis of the data shows that, while the isospin 0 channel dominates the reaction, contributing approximately 75% of the cross section at the energies studied here, there are significant contributions from the s and d-wave pion, isospin 1 channels. Of particular importance is the contribution from the s-wave pion, isospin 1, channel whose interference with the isospin 0 channels produces the characteristic shapes of the cross sections and analyzing powers observed in the data. The d-wave pion, isospin 1 channels, are also required to fully explain the observed analyzing power distributions, and are essential for the T_{CM} = 70MeV data. Comparisons of the pion production data measured in this experiment with pion absorption measurements on ^3He, where the absorption process is pi^-pp(^1S_0) to pn, show a shift in the shape of the differential cross section which can be interpreted as due to differences in

  2. Development of Cogging at the Fermilab Booster

    SciTech Connect

    Seiya, K.; Chaurize, S.; Drennan, C.; Pellico, W.; Triplett, A. K.; Waller, A.

    2015-01-30

    The development of magnetic cogging is part of the Fermilab Booster upgrade within the Proton Improvement Plan (PIP). The Booster is going to send 2.25E17 protons/hour which is almost double the present flux, 1.4E17 protons/hour to the Main Injector (MI) and Recycler (RR). The extraction kicker gap has to synchronize to the MI and RR injection bucket in order to avoid a beam loss at the rising edge of the extraction and injection kickers. Magnetic cogging is able to control the revolution frequency and the position of the gap using the magnetic field from dipole correctors while radial position feedback keeps the beam at the central orbit. The new cogging is expected to reduce beam loss due to the orbit changes and reduce beam energy loss when the gap is created. The progress of the magnetic cogging system development is going to be discussed in this paper.

  3. Proton therapy - Present and future.

    PubMed

    Mohan, Radhe; Grosshans, David

    2017-01-15

    In principle, proton therapy offers a substantial clinical advantage over conventional photon therapy. This is because of the unique depth-dose characteristics of protons, which can be exploited to achieve significant reductions in normal tissue doses proximal and distal to the target volume. These may, in turn, allow escalation of tumor doses and greater sparing of normal tissues, thus potentially improving local control and survival while at the same time reducing toxicity and improving quality of life. Protons, accelerated to therapeutic energies ranging from 70 to 250MeV, typically with a cyclotron or a synchrotron, are transported to the treatment room where they enter the treatment head mounted on a rotating gantry. The initial thin beams of protons are spread laterally and longitudinally and shaped appropriately to deliver treatments. Spreading and shaping can be achieved by electro-mechanical means to treat the patients with "passively-scattered proton therapy" (PSPT) or using magnetic scanning of thin "beamlets" of protons of a sequence of initial energies. The latter technique can be used to treat patients with optimized intensity modulated proton therapy (IMPT), the most powerful proton modality. Despite the high potential of proton therapy, the clinical evidence supporting the broad use of protons is mixed. It is generally acknowledged that proton therapy is safe, effective and recommended for many types of pediatric cancers, ocular melanomas, chordomas and chondrosarcomas. Although promising results have been and continue to be reported for many other types of cancers, they are based on small studies. Considering the high cost of establishing and operating proton therapy centers, questions have been raised about their cost effectiveness. General consensus is that there is a need to conduct randomized trials and/or collect outcomes data in multi-institutional registries to unequivocally demonstrate the advantage of protons. Treatment planning and plan

  4. Ground-state proton decay of 69Br and implications for the 68Se astrophysical rapid proton-capture process waiting point.

    PubMed

    Rogers, A M; Famiano, M A; Lynch, W G; Wallace, M S; Amorini, F; Bazin, D; Charity, R J; Delaunay, F; de Souza, R T; Elson, J; Gade, A; Galaviz, D; van Goethem, M-J; Hudan, S; Lee, J; Lobastov, S; Lukyanov, S; Matoš, M; Mocko, M; Schatz, H; Shapira, D; Sobotka, L G; Tsang, M B; Verde, G

    2011-06-24

    We report on the first direct measurement of the proton separation energy for the proton-unbound nucleus (69)Br. Bypassing the (68)Se waiting point in the rp process is directly related to the 2p-capture rate through (69)Br, which depends exponentially on the proton separation energy. We find a proton separation energy for (69)Br of Sp((69)Br )= -785(-40)(+34) keV; this is less bound compared to previous predictions which have relied on uncertain theoretical calculations. The influence of the extracted proton separation energy on the rp process occurring in type I x-ray bursts is examined within the context of a one-zone burst model.

  5. Proton Collimators for Fusion Reactors

    NASA Technical Reports Server (NTRS)

    Miley, George H.; Momota, Hiromu

    2003-01-01

    Proton collimators have been proposed for incorporation into inertial-electrostatic-confinement (IEC) fusion reactors. Such reactors have been envisioned as thrusters and sources of electric power for spacecraft and as sources of energetic protons in commercial ion-beam applications.

  6. Proton radii of neutron-rich B isotopes and neutron surface thickness in 17B

    NASA Astrophysics Data System (ADS)

    Kanungo, Rituparna; Estrade, Alfredo; Horiuchi, Wataru

    2014-09-01

    As the neutron to proton asymmetry increases nuclei develop exotic structures such as neutron skin and halo. It is important to investigate how this asymmetry affects the proton distribution. The matter and proton radii have started unfolding a complete picture of the halo. For two-neutron halos the correlation between the halo neutrons and their distance from the core can be derived to define the average halo geometry. The proton radii are crucial information to extract the neutron skin thickness to constrain the equation of state of asymmetric nuclear matter. Very limited information is available on the proton radii of very neutron-rich nuclei. In this presentation, we will describe the new technique of extracting proton radii from charge changing cross sections using relativistic beams at GSI, Germany. The presentation will show first measurements of proton radii of the neutron-rich boron isotopes. The implications of the results in understanding the neutron surface thickness in the Borromean 17B and its possible halo structure will be discussed. As the neutron to proton asymmetry increases nuclei develop exotic structures such as neutron skin and halo. It is important to investigate how this asymmetry affects the proton distribution. The matter and proton radii have started unfolding a complete picture of the halo. For two-neutron halos the correlation between the halo neutrons and their distance from the core can be derived to define the average halo geometry. The proton radii are crucial information to extract the neutron skin thickness to constrain the equation of state of asymmetric nuclear matter. Very limited information is available on the proton radii of very neutron-rich nuclei. In this presentation, we will describe the new technique of extracting proton radii from charge changing cross sections using relativistic beams at GSI, Germany. The presentation will show first measurements of proton radii of the neutron-rich boron isotopes. The implications

  7. Polarized proton collider at RHIC

    NASA Astrophysics Data System (ADS)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S. Y.; Luccio, A.; MacKay, W. W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A. N.

    2003-03-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998 [2]), reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to s=500 GeV.

  8. Lepton Universality Test in the Photoproduction of e-e+ Versus μ-μ+ Pairs on a Proton Target

    NASA Astrophysics Data System (ADS)

    Pauk, Vladyslav; Vanderhaeghen, Marc

    2015-11-01

    In view of the significantly different proton charge radius extracted from muonic hydrogen Lamb shift measurements as compared to electronic hydrogen spectroscopy or electron-scattering experiments, we study in this Letter the photoproduction of a lepton pair on a proton target in the limit of very small momentum transfer as a way to provide a test of the lepton universality when extracting the proton charge form factor. By detecting the recoiling proton in the γ p →l-l+p reaction, we show that a measurement of a ratio of e-e++μ-μ+ over e-e+ cross sections with an absolute precision of 7 ×1 0-4 would allow for a test to distinguish, at the 3 σ level, between the two different proton charge radii currently extracted from muonic and electronic observables.

  9. Predicting Solar Protons: A Statistical Approach

    DTIC Science & Technology

    2009-03-01

    above the background flux of protons (Kahler and Vourlidas , 2005). These are known as solar energetic protons (SEP). Some of these groups of protons...tempsep,10, ’b+’); 79 Bibliography Aschwanden, M. Physics of the solar corona , Praxis Publishing Ltd. 2004 Balch, C. C. ―SEC proton...prediction of all models measured. 15. SUBJECT TERMS Solar Energetic Protons, Solar Flares, Protons, Solar Corona , Cosmic Radiation 16

  10. Proton decay, 1982

    NASA Astrophysics Data System (ADS)

    Marciano, W. J.

    1982-03-01

    Employing the current world average Lambda/sub MS/ = 0.160 GeV as input, the minimal Georgi-Glashow SU(5) model predicts sq sin theta/sub W/(m/sub W/) = 0.214, m/sub b/m/sub tau/ approximately 2.8 and tau/sub p approximately (0.4 approximately 12) x 10 approximately to the 29th power yr. The first two predictions are in excellent agreement with experiment; but the implied proton life time is already somewhat below the present experimental bound. In this status report, uncertainties in tau/sub p/ are described and effects of appendages to the SU(5) model (such as new fermion generations, scalars, supersymmetry, etc.) are examined.

  11. Dose perturbations by electromagnetic transponders in the proton environment.

    PubMed

    Dolney, Derek; McDonough, James; Vapiwala, Neha; Metz, James M

    2013-03-07

    Surgically implanted electromagnetic transponders have been used in external beam radiotherapy for target localization and position monitoring in real time. The effect of transponders on proton therapy dose distributions has not been reported. A Monte Carlo implementation of the transponder geometry is validated against film measurements in a proton SOBP and subsequently used to generate dose distributions for transponders at different positions and orientations in the proton SOBP. The maximum dose deficit is extracted in each case. Dose shadows of up to 60% occur for transponders positioned very near the end of range of the Bragg peak. However, if transponders are positioned further than 5 mm from the end of range, and are not oriented parallel to the beam direction, then the dose deficit can be kept below 10%.

  12. Proton Transfer Reactions Studied Using the VANDLE Neutron Detector Array

    NASA Astrophysics Data System (ADS)

    Thornsberry, C. R.; Burcher, S.; Gryzwacz, R.; Jones, K. L.; Paulauskas, S. V.; Smith, K.; Vostinar, M.; Allen, J.; Bardayan, D. W.; Blankstein, D.; Deboer, J.; Hall, M.; O'Malley, P. D.; Reingold, C.; Tan, W.; Cizewski, J. A.; Lepailleur, A.; Walter, D.; Febbraro, M.; Pain, S. D.; Marley, S. T.

    2016-09-01

    Proton transfer reactions, such as (d,n), are powerful tools for the study of single particle proton states of exotic nuclei. Measuring the outgoing neutron allows for the extraction of spectroscopic information from the recoil nucleus. With the development of new radioactive ion beam facilities, such as FRIB in the U.S., comes the need for new tools for the study of reactions involving radioactive nuclei. Neutron detectors, such as VANDLE, are sensitive to gamma rays in addition to neutrons. This results in high background rates for measurements with high external trigger rates. The use of discriminating recoil particle detectors, such as phoswich detectors, allow for the selection of a clean recoil tag by separating the recoil nucleus of interest from unreacted RIB components. Developments of low energy proton transfer measurements in inverse kinematics and recent (d,n) results will be presented. This work supported in part by the U.S. Department of Energy and the National Science Foundation.

  13. Electrochemical reactivity and proton transport mechanisms in nanostructured ceria

    NASA Astrophysics Data System (ADS)

    Ding, J.; Strelcov, E.; Kalinin, S. V.; Bassiri-Gharb, N.

    2016-08-01

    Electrochemical reactivity and ionic transport at the nanoscale are essential in many energy applications. In this study, time-resolved Kelvin probe force microscopy (tr-KPFM) is utilized for surface potential mapping of nanostructured ceria, in both space and time domains. The fundamental mechanisms of proton injection and transport are studied as a function of environmental conditions and the presence or absence of triple phase boundaries. Finite element modeling is used to extract physical parameters from the experimental data, allowing not only quantification of the observed processes, but also decoupling of their contributions to the measured signal. The constructed phase diagrams of the parameters demonstrate a thermally activated proton injection reaction at the triple phase boundary, and two transport processes that are responsible for the low-temperature proton conductivity of nanostructured ceria.

  14. High intensity electron cyclotron resonance proton source for low energy high intensity proton accelerator.

    PubMed

    Roychowdhury, P; Chakravarthy, D P

    2009-12-01

    Electron cyclotron resonance (ECR) proton source at 50 keV, 50 mA has been designed, developed, and commissioned for the low energy high intensity proton accelerator (LEHIPA). Plasma characterization of this source has been performed. ECR plasma was generated with 400-1100 W of microwave power at 2.45 GHz, with hydrogen as working gas. Microwave was fed in the plasma chamber through quartz window. Plasma density and temperature was studied under various operating conditions, such as microwave power and gas pressure. Langmuir probe was used for plasma characterization using current voltage variation. The typical hydrogen plasma density and electron temperature measured were 7x10(11) cm(-3) and 6 eV, respectively. The total ion beam current of 42 mA was extracted, with three-electrode extraction geometry, at 40 keV of beam energy. The extracted ion current was studied as a function of microwave power and gas pressure. Depending on source pressure and discharge power, more than 30% total gas efficiency was achieved. The optimization of the source is under progress to meet the requirement of long time operation. The source will be used as an injector for continuous wave radio frequency quadrupole, a part of 20 MeV LEHIPA. The required rms normalized emittance of this source is less than 0.2 pi mm mrad. The simulated value of normalized emittance is well within this limit and will be measured shortly. This paper presents the study of plasma parameters, first beam results, and the status of ECR proton source.

  15. High intensity electron cyclotron resonance proton source for low energy high intensity proton accelerator

    SciTech Connect

    Roychowdhury, P.; Chakravarthy, D. P.

    2009-12-15

    Electron cyclotron resonance (ECR) proton source at 50 keV, 50 mA has been designed, developed, and commissioned for the low energy high intensity proton accelerator (LEHIPA). Plasma characterization of this source has been performed. ECR plasma was generated with 400-1100 W of microwave power at 2.45 GHz, with hydrogen as working gas. Microwave was fed in the plasma chamber through quartz window. Plasma density and temperature was studied under various operating conditions, such as microwave power and gas pressure. Langmuir probe was used for plasma characterization using current voltage variation. The typical hydrogen plasma density and electron temperature measured were 7x10{sup 11} cm{sup -3} and 6 eV, respectively. The total ion beam current of 42 mA was extracted, with three-electrode extraction geometry, at 40 keV of beam energy. The extracted ion current was studied as a function of microwave power and gas pressure. Depending on source pressure and discharge power, more than 30% total gas efficiency was achieved. The optimization of the source is under progress to meet the requirement of long time operation. The source will be used as an injector for continuous wave radio frequency quadrupole, a part of 20 MeV LEHIPA. The required rms normalized emittance of this source is less than 0.2 {pi} mm mrad. The simulated value of normalized emittance is well within this limit and will be measured shortly. This paper presents the study of plasma parameters, first beam results, and the status of ECR proton source.

  16. Proton therapy for prostate cancer.

    PubMed

    Hoppe, Bradford; Henderson, Randal; Mendenhall, William M; Nichols, Romaine C; Li, Zuofeng; Mendenhall, Nancy P

    2011-06-01

    Proton therapy has been used in the treatment of cancer for over 50 years. Due to its unique dose distribution with its spread-out Bragg peak, proton therapy can deliver highly conformal radiation to cancers located adjacent to critical normal structures. One of the important applications of its use is in prostate cancer, since the prostate is located adjacent to the rectum and bladder. Over 30 years of data have been published on the use of proton therapy in prostate cancer; these data have demonstrated high rates of local and biochemical control as well as low rates of urinary and rectal toxicity. Although before 2000 proton therapy was available at only a couple of centers in the United States, several new proton centers have been built in the last decade. With the increased availability of proton therapy, research on its use for prostate cancer has accelerated rapidly. Current research includes explorations of dose escalation, hypofractionation, and patient-reported quality-of-life outcomes. Early results from these studies are promising and will likely help make proton therapy for the treatment of prostate cancer more cost-effective.

  17. Proton fragmentation functions considering finite-mass corrections

    NASA Astrophysics Data System (ADS)

    Moosavi Nejad, S. M.; Soleymaninia, M.; Maktoubian, A.

    2016-10-01

    We present new sets of proton fragmentation functions (FFs) describing the production of protons from the gluon and each of the quarks, obtained by the NLO QCD fits to all relevant data sets of single-inclusive electron-positron annihilation. Specifically, we determine their uncertainties using the Gaussian method for error estimation. Our analysis is in good agreement with the e + e - annihilation data. We also include finite-mass effects of the proton in our calculations, a topic to which very little attention is paid in the literature. Proton mass effects turn out to be appreciable for gluon and light quark FFs. The inclusion of finite-mass effects tends to improve the overall description of the data by reducing the minimized χ2 values significantly. As an application, we apply the extracted FFs to make predictions for the scaled-energy distribution of protons inclusively produced in top quark decays at next-to-leading order, relying on the universality and scaling violations of FFs.

  18. Eta Meson Production in Proton-Proton and Nuclear Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank

    2008-01-01

    Total cross sections for eta meson production in proton - proton collisions are calculated. The eta meson is mainly produced via decay of the excited nucleon resonance at 1535 MeV. A scalar quantum field theory is used to calculate cross sections, which also include resonance decay. Comparison between theory and experiment is problematic near threshold when resonance decay is not included. When the decay is included, the comparison between theory and experiment is much better.

  19. A coherent analysis of elastic electron-proton scattering data

    NASA Astrophysics Data System (ADS)

    Bernauer, Jan

    2016-09-01

    The extraction of form factors and radii from scattering data is a treacherous business, and it is easy to bias the result with the choice of an unsuitable fit function. In the first part of the talk, I will present our analysis of the Mainz and world data sets, and the checks we have made to ensure that the results are accurate and unbiased. Recently, several authors have reanalyzed the Mainz and world data sets on electron-proton scattering, with the aim to extract the proton charge radius. The results fall into two groups: radii around 0.88 fm and around 0.84 fm, respectively. We find that the latter group typically is affected by various problems, discussed in the second part of the talk.

  20. Precision Rosenbluth measurement of the proton elastic form factors

    SciTech Connect

    I. A. Qattan; J. Arrington; R. E. Segel; X. Zheng; K. Aniol; O. K. Baker; R. Beams; E. J. Brash; J. Calarco; A. Camsonne; J.-P. Chen; M. E. Christy; D. Dutta; R. Ent; S. Frullani; D. Gaskell; O. Gayou; R. Gilman; C. Glashausser; K. Hafidi; J.-O. Hansen; D. W. Higinbotham; W. Hinton; R. J. Holt; G. M. Huber; H. Ibrahim; L. Jisonna; M. K. Jones; C. E. Keppel; E. Kinney; G. J. Kumbartzki; A. Lung; D. J. Margaziotis; K. McCormick; D. Meekins; R. Michaels; P. Monaghan; P. Moussiegt; L. Pentchev; C. Perdrisat; V. Punjabi; R. Ransome; J. Reinhold; B. Reitz; A. Saha; A. Sarty; E. C. Schulte; K. Slifer; P. Solvignon; V. Sulkosky; K. Wijesooriya; B. Zeidman

    2004-10-01

    We report the results of a new Rosenbluth measurement of the proton form factors at Q{sup 2} values of 2.64, 3.20 and 4.10 GeV{sup 2}. Cross sections were determined by detecting the recoiling proton in contrast to previous measurements in which the scattered electron was detected. At each Q{sup 2}, relative cross sections were determined to better than 1%. The measurement focused on the extraction of G{sub E}/G{sub M} which was determined to 4-8% and found to approximate form factor scaling, i.e. {mu}{sub p}G{sub E} {approx} G{sub M}. These results are consistent with and much more precise than previous Rosenbluth extractions. However, they are inconsistent with recent polarization transfer measurements of comparable precision, implying a systematic difference between the two techniques.

  1. Kaon photoproduction off proton

    NASA Astrophysics Data System (ADS)

    Skoupil, Dalibor; Bydžovský, Petr

    2016-11-01

    We have recently constructed our version of the Regge-plus-resonance (RPR) model and two variants of an isobar model for photoproduction of kaons on the proton, utilizing new experimental data from CLAS, LEPS, and GRAAL collaborations for adjusting free parameters of the models. Higher-spin nucleon (3/2 and 5/2) and hyperon (3/2) resonances were included using the consistent formalism by Pascalutsa and found to play an important role in data description. The set of chosen nucleon resonances in our new isobar models agrees well with the set of the most probable contributing states determined in the Bayesian analysis with the RPR model whilst only 6 out of 10 N*'s selected in the RPR fit of ours overlap with the nucleon resonant states in the Bayesian analysis. Results of two versions of the isobar model are compared to the new version of the RPR model and experimental data in the third-resonance region and their properties are discussed. We place an emphasis on the choice of resonances, the predictions in the forward- and backward-angle region as well as the choice of the hadron form factor.

  2. Design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    NASA Astrophysics Data System (ADS)

    Huang, Liang-Sheng; Ji, Hong-Fei; Wang, Sheng

    2016-09-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized.

  3. Proton-Coupled Electron Transfer

    SciTech Connect

    Weinberg, Dave; Gagliardi, Christopher J.; Hull, Jonathan F; Murphy, Christine Fecenko; Kent, Caleb A.; Westlake, Brittany C.; Paul, Amit; Ess, Daniel H; McCafferty, Dewey Granville; Meyer, Thomas J

    2012-07-11

    Proton-Coupled Electron Transfer (PCET) describes reactions in which there is a change in both electron and proton content between reactants and products. It originates from the influence of changes in electron content on acid-base properties and provides a molecular-level basis for energy transduction between proton transfer and electron transfer. Coupled electron-proton transfer or EPT is defined as an elementary step in which electrons and protons transfer from different orbitals on the donor to different orbitals on the acceptor. There is (usually) a clear distinction between EPT and H-atom transfer (HAT) or hydride transfer, in which the transferring electrons and proton come from the same bond. Hybrid mechanisms exist in which the elementary steps are different for the reaction partners. EPT pathways such as PhO•/PhOH exchange have much in common with HAT pathways in that electronic coupling is significant, comparable to the reorganization energy with H{sub DA} ~ λ. Multiple-Site Electron-Proton Transfer (MS-EPT) is an elementary step in which an electron-proton donor transfers electrons and protons to different acceptors, or an electron-proton acceptor accepts electrons and protons from different donors. It exploits the long-range nature of electron transfer while providing for the short-range nature of proton transfer. A variety of EPT pathways exist, creating a taxonomy based on what is transferred, e.g., 1e-/2H+ MS-EPT. PCET achieves “redox potential leveling” between sequential couples and the buildup of multiple redox equivalents, which is of importance in multielectron catalysis. There are many examples of PCET and pH-dependent redox behavior in metal complexes, in organic and biological molecules, in excited states, and on surfaces. Changes in pH can be used to induce electron transfer through films and over long distances in molecules. Changes in pH, induced by local electron transfer, create pH gradients and a driving

  4. POLARIZED PROTON COLLISIONS AT RHIC.

    SciTech Connect

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

    2005-05-16

    The Relativistic Heavy Ion Collider provides not only collisions of ions but also collisions of polarized protons. In a circular accelerator, the polarization of polarized proton beam can be partially or fully lost when a spin depolarizing resonance is encountered. To preserve the beam polarization during acceleration, two full Siberian snakes were employed in RHIC. In 2002, polarized proton beams were first accelerated to 100 GeV and collided in RHIC. Beams were brought into collisions with longitudinal polarization at the experiments STAR and PHENIX by using spin rotators. Optimizing polarization transmission efficiency and improving luminosity performance are significant challenges. Currently, the luminosity lifetime in RHIC is limited by the beam-beam effect. The current state of RHIC polarized proton program, including its dedicated physics run in 2005 and efforts to optimize luminosity production in beam-beam limited conditions are reported.

  5. Spectrum of solar flare protons

    NASA Astrophysics Data System (ADS)

    Podgorny, I. M.; Balabin, Yu. V.; Podgorny, A. I.; Vashenyuk, E. V.

    2010-08-01

    Most of big solar flares are accompanied by relativistic protons. The prompt component of relativistic protons moves along the interplanetary magnetic field lines and arrives at the Earth's orbit when the flare favorably located in the western solar hemisphere. The neutron monitor measurements reveal an exponential law energy spectrum. Calculations of relativistic proton acceleration in the flare current sheet with magnetic and electric fields found from 3D MHD simulations also demonstrate an exponential law spectrum. A comparison of the measured and calculated spectra permits to estimate the rate of reconnection in the Bastille flare (14 July 2000) as ˜107cm/s. The delay component of relativistic protons exhibits a power law energy spectrum.

  6. Fluorine-proton correlation from isolated trifluoromethyl groups using unresolved J-couplings.

    PubMed

    Howe, Peter W A

    2012-10-01

    Fluorine-containing compounds are rare in biological systems, so fluorine NMR spectroscopy can selectively detect and quantify fluorinated xenobiotics in crude biological extracts. The high sensitivity of fluorine NMR allows the detection of compounds containing isolated trifluoromethyl groups at nanogramme levels. However, it only provides limited structural information about trifluoromethyl-containing compounds owing to the difficulty of interpreting fluorine chemical shifts and the low sensitivity of HOESY experiments used to correlate fluorine nuclei with protons in the same compound. This paper demonstrates that long-range fluorine-proton J-couplings can be used to correlate isolated trifluoromethyl groups with nearby protons with significantly higher sensitivity than HOESY. Fluorine-observe fluorine-proton HMQC can even give correlations when the fluorine-proton J-couplings are less than the observed fluorine resonance linewidth, so it provides a useful alternative source of structural information about fluorinated xenobiotics.

  7. PULSED POWER APPLICATIONS IN HIGH INTENSITY PROTON RINGS.

    SciTech Connect

    ZHANG, S.Y.; SANDBERG, J.; ET AL.

    2005-05-16

    Pulsed power technology has been applied in particle accelerators and storage rings for over four decades. It is most commonly used in injection, extraction, beam manipulation, source, and focusing systems. These systems belong to the class of repetitive pulsed power. In this presentation, we review and discuss the history, present status, and future challenge of pulsed power applications in high intensity proton accelerators and storage rings.

  8. Studying the Proton Spin Puzzle with PHENIX

    NASA Astrophysics Data System (ADS)

    Daugherity, Michael

    2012-03-01

    The proton spin puzzle remains one of the biggest mysteries in fundamental particle physics today. This talk will explore how the PHENIX Collaboration's forward W-boson program uses RHIC, the world's only polarized proton-proton collider, to probe the spin structure of the proton.

  9. Parametric Model for Astrophysical Proton-Proton Interactions and Applications

    SciTech Connect

    Karlsson, Niklas

    2007-01-01

    Observations of gamma-rays have been made from celestial sources such as active galaxies, gamma-ray bursts and supernova remnants as well as the Galactic ridge. The study of gamma rays can provide information about production mechanisms and cosmic-ray acceleration. In the high-energy regime, one of the dominant mechanisms for gamma-ray production is the decay of neutral pions produced in interactions of ultra-relativistic cosmic-ray nuclei and interstellar matter. Presented here is a parametric model for calculations of inclusive cross sections and transverse momentum distributions for secondary particles--gamma rays, e±, ve, $\\bar{v}$e, vμ and $\\bar{μ}$e--produced in proton-proton interactions. This parametric model is derived on the proton-proton interaction model proposed by Kamae et al.; it includes the diffraction dissociation process, Feynman-scaling violation and the logarithmically rising inelastic proton-proton cross section. To improve fidelity to experimental data for lower energies, two baryon resonance excitation processes were added; one representing the Δ(1232) and the other multiple resonances with masses around 1600 MeV/c2. The model predicts the power-law spectral index for all secondary particle to be about 0.05 lower in absolute value than that of the incident proton and their inclusive cross sections to be larger than those predicted by previous models based on the Feynman-scaling hypothesis. The applications of the presented model in astrophysics are plentiful. It has been implemented into the Galprop code to calculate the contribution due to pion decays in the Galactic plane. The model has also been used to estimate the cosmic-ray flux in the Large Magellanic Cloud based on HI, CO and gamma-ray observations. The transverse momentum distributions enable calculations when the proton distribution is anisotropic. It is shown that the gamma-ray spectrum and flux due to a

  10. Understanding the proton's spin structure

    SciTech Connect

    Fred Myhrer; Thomas, Anthony W.

    2010-02-01

    We discuss the tremendous progress that has been towards an understanding of how the spin of the proton is distributed on its quark and gluon constituents. This is a problem that began in earnest twenty years ago with the discovery of the proton "spin crisis" by the European Muon Collaboration. The discoveries prompted by that original work have given us unprecedented insight into the amount of spin carried by polarized gluons and the orbital angular momentum of the quarks.

  11. High intensity protons in RHIC

    SciTech Connect

    Montag, C.; Ahrens, L.; Blaskiewicz, M.; Brennan, J. M.; Drees, K. A.; Fischer, W.; Huang, H.; Minty, M.; Robert-Demolaize, G.; Thieberger, P.; Yip, K.

    2012-01-05

    During the 2012 summer shutdown a pair of electron lenses will be installed in RHIC, allowing the beam-beam parameter to be increased by roughly 50 percent. To realize the corresponding luminosity increase bunch intensities have to be increased by 50 percent, to 2.5 {center_dot} 10{sup 11} protons per bunch. We list the various RHIC subsystems that are most affected by this increase, and propose beam studies to ensure their readiness. The proton luminosity in RHIC is presently limited by the beam-beam effect. To overcome this limitation, electron lenses will be installed in IR10. With the help of these devices, the headon beam-beam kick experienced during proton-proton collisions will be partially compensated, allowing for a larger beam-beam tuneshift at these collision points, and therefore increasing the luminosity. This will be accomplished by increasing the proton bunch intensity from the presently achieved 1.65 {center_dot} 10{sup 11} protons per bunch in 109 bunches per beam to 2.5 {center_dot} 10{sup 11}, thus roughly doubling the luminosity. In a further upgrade we aim for bunch intensities up to 3 {center_dot} 10{sup 11} protons per bunch. With RHIC originally being designed for a bunch intensity of 1 {center_dot} 10{sup 11} protons per bunch in 56 bunches, this six-fold increase in the total beam intensity by far exceeds the design parameters of the machine, and therefore potentially of its subsystems. In this note, we present a list of major subsystems that are of potential concern regarding this intensity upgrade, show their demonstrated performance at present intensities, and propose measures and beam experiments to study their readiness for the projected future intensities.

  12. Inelastic proton-solid collisions

    NASA Astrophysics Data System (ADS)

    Echenique, P. M.; Flores, F.

    1987-05-01

    A first-principles calculation of charge states of moving protons in Al is presented. The many-body self-energy approach combined with ordinary atomic physics has been used. We find that at high velocities, V>2V0 or 3V0 (Bohr velocity), the processes are atomiclike, while at intermediate velocities, 0.7V0proton charges.

  13. Strangeness asymmetry in the proton

    NASA Astrophysics Data System (ADS)

    Alberg, Mary

    2015-04-01

    Strangeness asymmetry in the proton may arise from fluctuations of the proton into meson-baryon pairs. The leading contributions to proton strangeness are from the KΛ , KΣ , K* Λ and K* Σ states. We use a Fock state expansion of the proton in terms of these pairs to represent the strange meson cloud. We determine the strangeness distributions of the proton in a hybrid convolution model, in which the fluctuations are represented either by light-cone wave functions or meson-baryon splitting functions. For the parton distributions of the s(s) quarks in the bare baryons(mesons) of the Fock states, we use light cone wave functions or our statistical model, which expands the bare hadrons in terms of quark-gluon states. The momentum distributions of the s and s quarks in each Fock state differ because they are constituents of different hadrons. We present our results for proton strangeness asymmetry, and compare them to NuTeV and to global parton distributions. This research has been supported in part by NSF Award 1205686.

  14. Generation of proton aurora by magnetosonic waves.

    PubMed

    Xiao, Fuliang; Zong, Qiugang; Wang, Yongfu; He, Zhaoguo; Su, Zhenpeng; Yang, Chang; Zhou, Qinghua

    2014-06-05

    Earth's proton aurora occurs over a broad MLT region and is produced by the precipitation of low-energy (2-10 keV) plasmasheet protons. Proton precipitation can alter chemical compositions of the atmosphere, linking solar activity with global climate variability. Previous studies proposed that electromagnetic ion cyclotron waves can resonate with protons, producing proton scattering precipitation. A long-outstanding question still remains whether there is another mechanism responsible for the proton aurora. Here, by performing satellite data analysis and diffusion equation calculations, we show that fast magnetosonic waves can produce trapped proton scattering that yields proton aurora. This provides a new insight into the mechanism of proton aurora. Furthermore, a ray-tracing study demonstrates that magnetosonic wave propagates over a broad MLT region, consistent with the global distribution of proton aurora.

  15. Generation of proton aurora by magnetosonic waves

    PubMed Central

    Xiao, Fuliang; Zong, Qiugang; Wang, Yongfu; He, Zhaoguo; Su, Zhenpeng; Yang, Chang; Zhou, Qinghua

    2014-01-01

    Earth's proton aurora occurs over a broad MLT region and is produced by the precipitation of low-energy (2–10 keV) plasmasheet protons. Proton precipitation can alter chemical compositions of the atmosphere, linking solar activity with global climate variability. Previous studies proposed that electromagnetic ion cyclotron waves can resonate with protons, producing proton scattering precipitation. A long-outstanding question still remains whether there is another mechanism responsible for the proton aurora. Here, by performing satellite data analysis and diffusion equation calculations, we show that fast magnetosonic waves can produce trapped proton scattering that yields proton aurora. This provides a new insight into the mechanism of proton aurora. Furthermore, a ray-tracing study demonstrates that magnetosonic wave propagates over a broad MLT region, consistent with the global distribution of proton aurora. PMID:24898626

  16. Total pion-proton cross section from the new LHCf data on leading neutrons spectra

    NASA Astrophysics Data System (ADS)

    Ryutin, R. A.

    2017-02-01

    In the light of the latest data by the LHCf collaboration of the LHC on leading neutrons spectra it is possible to obtain total pion-proton cross sections in the TeV energy region. In this work the exact extraction procedure is shown. Final results for the pion-proton cross section are collected at several different values of the colliding energy and compared with some popular theoretical predictions. The errors of the results are estimated.

  17. Proton Pair Production Cross Sections at BESIII

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaorong

    Using data samples collected with the BESIII detector at the BEPCII collider, the Born cross section of e + e - to pbar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV is provided. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal. In addition, the ratio of electric to magnetic form factors are extracted for the data samples with larger statistics. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30%. The |GE/GM| ratios are close to unity and consistent with BaBar results in the same q2 region.

  18. Proton Spin Structure in the Resonance Region

    SciTech Connect

    F. R. Wesselmann; K. Slifer; S. Tajima; A. Aghalaryan; A. Ahmidouch; R. Asaturyan; F. Bloch; W. Boeglin; P. Bosted; C. Carasco; R. Carlini; J. Cha; J. P. Chen; M. E. Christy; L. Cole; L. Coman; D. Crabb; S. Danagoulian; D. Day; J. Dunne; M. Elaasar; R. Ent; H. Fenker; E. Frlez; L. Gan; D. Gaskell; J. Gomez; B. Hu; M. K. Jones; J. Jourdan; C. Keith; C. E. Keppel; M. Khandaker; A. Klein; L. Kramer; Y. Liang; J. Lichtenstadt; R. Lindgren; D. Mack; P. McKee; D. McNulty; D. Meekins; H. Mkrtchyan; R. Nasseripour; I. Niculescu; K. Normand; B. Norum; D. Pocanic; Y. Prok; B. Raue; J. Reinhold; J. Roche; D. Rohe; O. A. Rondon; N. Savvinov; B. Sawatzky; M. Seely; I. Sick; C. Smith; G. Smith; S. Stepanyan; L. Tang; G. Testa; W. Vulcan; K. Wang; G. Warren; S. Wood; C. Yan; L. Yuan; Junho Yun; Markus Zeier; Hong Guo Zhu

    2006-10-11

    The RSS collaboration has measured the spin structure functions g{sub 1} and g{sub 2} of the proton at Jefferson Lab using the lab's polarized electron beam, the Hall C HMS spectrometer and the UVa polarized solid target. The asymmetries A{sub parallel} and A{sub perp} were measured at the elastic peak and in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q{sup 2} = 1.3 GeV{sup 2}. The extracted spin structure functions and their kinematic dependence make a significant contribution in the study of higher-twist effects and polarized duality tests.

  19. Development of Proton Computed Tomography for Applications in Proton Therapy

    NASA Astrophysics Data System (ADS)

    Bashkirov, Vladimir; Schulte, Reinhard; Coutrakon, George; Erdelyi, Bela; Wong, Kent; Sadrozinski, Hartmut; Penfold, Scott; Rosenfeld, Anatoly; McAllister, Scott; Schubert, Keith

    2009-03-01

    Determination of the Bragg peak position in proton therapy requires accurate knowledge of the electron density and ratio of effective atomic number and mass (Z/A) of the body tissues traversed. While the Z/A ratio is fairly constant for human tissues, the density of tissues varies significantly. One possibility to obtain accurate electron density information of tissues is to use protons of sufficient energy to penetrate the patient and measure their energy loss. From these transmission measurements, it is possible to reconstruct a three-dimensional map of electron densities using algebraic techniques. The interest in proton computed tomography (pCT) has considerably increased in recent years due to the more common use of proton accelerators for cancer treatment world-wide and a modern design concept based on current high-energy physics technology has been suggested. This contribution gives a status update on the pCT project carried out by the pCT Collaboration, a group of institutions sharing interest and expertise in the development of pCT. We will present updated imaging data obtained with a small pCT prototype developed in collaboration with the Santa Cruz Institute of Particle Physics and installed on the proton research beam line at Loma Linda University Medical Center. We will discuss hardware decisions regarding the next-generation pCT scanner, which will permit scanning of head-sized objects. Progress has also been made in the formulation of the most likely path of protons through an object and parallelizable iterative reconstruction algorithms that can be implemented on general-purpose commodity graphics processing units. Finally, we will present simulation studies for utilizing pCT technology for on-line proton dose verification and tumor imaging with positron emission tomography (PET).

  20. Neutron-Proton Asymmetry Dependence of Spectroscopic Factors in Ar Isotopes

    SciTech Connect

    Lee, Jenny; Tsang, Betty; Shapira, Dan

    2010-01-01

    Spectroscopic factors have been extracted for proton-rich 34Ar and neutron-rich 46Ar using the (p, d) neutron transfer reaction. The experimental results show little reduction of the ground state neutron spectroscopic factor of the proton-rich nucleus 34Ar compared to that of 46Ar. The results suggest that correlations, which generally reduce such spectroscopic factors, do not depend strongly on the neutron-proton asymmetry of the nucleus in this isotopic region as was reported in knockout reactions. The present results are consistent with results from systematic studies of transfer reactions but inconsistent with the trends observed in knockout reaction measurements.

  1. Proton source size measurements in the eA {yields} e{prime}ppX reaction

    SciTech Connect

    Aleksey Stavinskiy; Konstantin Mikhaylov; R. Lednicky; Alexander Vlassov; Et. Al.

    2004-06-01

    Two-proton correlations at small relative momentum q were studied in the eA({sup 3}He, {sup 4}He, C, Fe) {yields} e{prime}ppX reaction at E{sub 0} = 4.46 GeV using the CLAS detector at Jefferson Lab. The enhancement of the correlation function at small q was found to be in accordance with theoretical expectation. Emission region sizes were extracted and proved to be dependent on A and proton momentum. The size of the two-proton emission region on the lightest possible nucleus, He, was measured for the first time.

  2. Energy spectrum control for modulated proton beams

    SciTech Connect

    Hsi, Wen C.; Moyers, Michael F.; Nichiporov, Dmitri; Anferov, Vladimir; Wolanski, Mark; Allgower, Chris E.; Farr, Jonathan B.; Mascia, Anthony E.; Schreuder, Andries N.

    2009-06-15

    In proton therapy delivered with range modulated beams, the energy spectrum of protons entering the delivery nozzle can affect the dose uniformity within the target region and the dose gradient around its periphery. For a cyclotron with a fixed extraction energy, a rangeshifter is used to change the energy but this produces increasing energy spreads for decreasing energies. This study investigated the magnitude of the effects of different energy spreads on dose uniformity and distal edge dose gradient and determined the limits for controlling the incident spectrum. A multilayer Faraday cup (MLFC) was calibrated against depth dose curves measured in water for nonmodulated beams with various incident spectra. Depth dose curves were measured in a water phantom and in a multilayer ionization chamber detector for modulated beams using different incident energy spreads. Some nozzle entrance energy spectra can produce unacceptable dose nonuniformities of up to {+-}21% over the modulated region. For modulated beams and small beam ranges, the width of the distal penumbra can vary by a factor of 2.5. When the energy spread was controlled within the defined limits, the dose nonuniformity was less than {+-}3%. To facilitate understanding of the results, the data were compared to the measured and Monte Carlo calculated data from a variable extraction energy synchrotron which has a narrow spectrum for all energies. Dose uniformity is only maintained within prescription limits when the energy spread is controlled. At low energies, a large spread can be beneficial for extending the energy range at which a single range modulator device can be used. An MLFC can be used as part of a feedback to provide specified energy spreads for different energies.

  3. Sparse-view proton computed tomography using modulated proton beams

    SciTech Connect

    Lee, Jiseoc; Kim, Changhwan; Cho, Seungryong; Min, Byungjun; Kwak, Jungwon; Park, Seyjoon; Lee, Se Byeong; Park, Sungyong

    2015-02-15

    Purpose: Proton imaging that uses a modulated proton beam and an intensity detector allows a relatively fast image acquisition compared to the imaging approach based on a trajectory tracking detector. In addition, it requires a relatively simple implementation in a conventional proton therapy equipment. The model of geometric straight ray assumed in conventional computed tomography (CT) image reconstruction is however challenged by multiple-Coulomb scattering and energy straggling in the proton imaging. Radiation dose to the patient is another important issue that has to be taken care of for practical applications. In this work, the authors have investigated iterative image reconstructions after a deconvolution of the sparsely view-sampled data to address these issues in proton CT. Methods: Proton projection images were acquired using the modulated proton beams and the EBT2 film as an intensity detector. Four electron-density cylinders representing normal soft tissues and bone were used as imaged object and scanned at 40 views that are equally separated over 360°. Digitized film images were converted to water-equivalent thickness by use of an empirically derived conversion curve. For improving the image quality, a deconvolution-based image deblurring with an empirically acquired point spread function was employed. They have implemented iterative image reconstruction algorithms such as adaptive steepest descent-projection onto convex sets (ASD-POCS), superiorization method–projection onto convex sets (SM-POCS), superiorization method–expectation maximization (SM-EM), and expectation maximization-total variation minimization (EM-TV). Performance of the four image reconstruction algorithms was analyzed and compared quantitatively via contrast-to-noise ratio (CNR) and root-mean-square-error (RMSE). Results: Objects of higher electron density have been reconstructed more accurately than those of lower density objects. The bone, for example, has been reconstructed

  4. Beta-delayed proton emission in neutron-deficient lanthanide isotopes

    SciTech Connect

    Wilmarth, P.A.

    1988-09-30

    Forty-two ..beta..-delayed proton precursors with 56less than or equal toZless than or equal to71 and 63less than or equal toNless than or equal to83 were produced in heavy-ion reactions at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decay properties studied at the on-line mass separation facility OASIS. Twenty-five isotopes and eight delayed proton branches were identified for the first time. Delayed proton energy spectra and proton coincident ..gamma..-ray and x-ray spectra were measured for all precursors. In a few cases, proton branching ratios were also determined. The precursor mass numbers were determined by the separator, while the proton coincident x-ray energies provided unambiguous Z identifications. The proton coincident ..gamma..-ray intensities were used to extract final state branching ratios. Proton emission from ground and isomeric states was observed in many cases. The majority of the delayed proton spectra exhibited the smooth bell-shaped distribution expected for heavy mass precursors. The experimental results were compared to statistical model calculations using standard parameter sets. Calculations using Nilsson model/RPA ..beta..-strength functions were found to reproduce the spectral shapes and branching ratios better than calculations using either constant or gross theory ..beta..-strength functions. Precursor half-life predictions from the Nilsson model/RPA ..beta..-strength functions were also in better agreement with the measured half-lives than were gross theory predictions. The ratios of positron coincident proton intensities to total proton intensities were used to determine Q/sub EC/-B/sub p/ values for several precursors near N=82. The statistical model calculations were not able to reproduce the experimental results for N=81 precursors. 154 refs., 82 figs., 19 tabs.

  5. Quantitative proton imaging from multiple physics processes: a proof of concept.

    PubMed

    Bopp, C; Rescigno, R; Rousseau, M; Brasse, D

    2015-07-07

    Proton imaging is developed in order to improve the accuracy of charged particle therapy treatment planning. It makes it possible to directly map the relative stopping powers of the materials using the information on the energy loss of the protons. In order to reach a satisfactory spatial resolution in the reconstructed images, the position and direction of each particle is recorded upstream and downstream from the patient. As a consequence of individual proton detection, information on the transmission rate and scattering of the protons is available. Image reconstruction processes are proposed to make use of this information. A proton tomographic acquisition of an anthropomorphic head phantom was simulated. The transmission rate of the particles was used to reconstruct a map of the macroscopic cross section for nuclear interactions of the materials. A two-step iterative reconstruction process was implemented to reconstruct a map of the inverse scattering length of the materials using the scattering of the protons. Results indicate that, while the reconstruction processes should be optimized, it is possible to extract quantitative information from the transmission rate and scattering of the protons. This suggests that proton imaging could provide additional knowledge on the materials that may be of use to further improve treatment planning.

  6. Proton-proton Scattering Above 3 GeV/c

    SciTech Connect

    A. Sibirtsev, J. Haidenbauer, H.-W. Hammer S. Krewald ,Ulf-G. Meissner

    2010-01-01

    A large set of data on proton-proton differential cross sections, analyzing powers and the double-polarization parameter A{sub NN} is analyzed employing the Regge formalism. We find that the data available at proton beam momenta from 3 GeV/c to 50 GeV/c exhibit features that are very well in line with the general characteristics of Regge phenomenology and can be described with a model that includes the {rho}, {omega}, f{sub 2}, and a{sub 2} trajectories and single-Pomeron exchange. Additional data, specifically for spin-dependent observables at forward angles, would be very helpful for testing and refining our Regge model.

  7. The Proton Form Factor Ratio Measurements at Jefferson Lab

    SciTech Connect

    Punjabi, Vina A.; Perdrisat, Charles F.

    2014-03-01

    The ratio of the proton form factors, G{sub Ep}/G{sub Mp}, has been measured from Q{sup 2} of 0.5 GeV{sup 2} to 8.5 GeV{sup 2}, at the Jefferson Laboratory, using the polarization transfer method. This ratio is extracted directly from the measured ratio of the transverse and longitudinal polarization components of the recoiling proton in elastic electron-proton scattering. The discovery that the proton form factor ratio measured in these experiments decreases approximately linearly with four-momentum transfer, Q{sup 2}, for values above ~1 GeV{sup 2}, is one of the most significant results to come out of JLab. These results have had a large impact on progress in hadronic physics; and have required a significant rethinking of nucleon structure. The increasingly common use of the double-polarization technique to measure the nucleon form factors, in the last 15 years, has resulted in a dramatic improvement of the quality of all four nucleon electromagnetic form factors, G{sub Ep}, G{sub Mp}, G{sub En} and G{sub Mn}. There is an approved experiment at JLab, GEP(V), to continue the ratio measurements to 12 GeV{sup 2}. A dedicated experimental setup, the Super Bigbite Spectrometer (SBS), will be built for this purpose. It will be equipped with a focal plane polarimeter to measure the polarization of the recoil protons. The scattered electrons will be detected in an electromagnetic calorimeter. In this presentation, I will review the status of the proton elastic electromagnetic form factors and discuss a number of theoretical approaches to describe nucleon form factors.

  8. Measurement of the Wolfenstein parameters for proton-proton and proton-neutron scattering at 500 MeV

    SciTech Connect

    Marshall, J.A.

    1984-07-01

    Using liquid hydrogen and liquid deuterium targets respectively, forward angle (ten degrees to sixty degrees in the center of Mass) free proton-proton and quasielastic proton-proton and proton-neutron triple scattering data at 500 MeV have been obtained using the high resolution spectrometer at the Los Alamos Meson Physics Facility. The data are in reasonable agreement with recent predictions from phase shift analyses, indicating that the proton-nucleon scattering amplitudes are fairly well determined at 500 MeV. 32 references.

  9. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi

    2013-11-01

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 {+-} 0.0007 fm was extracted which is 7{sigma} smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these "electronic" determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup -4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  10. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi; Collaboration: PRad Collaboration

    2013-11-07

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 ± 0.0007 fm was extracted which is 7σ smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these 'electronic' determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup −4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  11. The Spin of the Proton

    SciTech Connect

    Thomas, Anthony

    2008-07-01

    doi: http://dx.doi.org/10.1016/j.ppnp.2007.12.039
    The twenty years since the announcement of the proton spin crisis by the European Muon Collaboration has seen tremendous progress in our knowledge of the distribution of spin within the proton. The problem is reviewed, beginning with the original data and the suggestion that polarized gluons may play a crucial role in resolving the problem through the U(1) axial anomaly. The discussion continues to the present day where not only have strong limits have been placed on the amount of polarized glue in the proton but the experimental determination of the spin content has become much more precise. It is now clear that the origin of the discrepancy between experiment and the naive expectation of the fraction of spin carried by the quarks and anti-quarks in the proton lies in the non-perturabtive structure of the proton. We explain how the features expected in a modern, relativistic and chirally symmetric description of nucleon str

  12. The Structure of the Proton

    DOE R&D Accomplishments Database

    Chambers, E. E.; Hofstadter, R.

    1956-04-01

    The structure and size of the proton have been studied by means of the methods of high-energy electron scattering. The elastic scattering of electrons from protons in polyethylene has been investigated at the following energies in the laboratory system: 200, 300, 400, 500, 550 Mev. The range of laboratory angles examined has been 30 degrees to 135 degrees. At the largest angles and the highest energy, the cross section for scattering shows a deviation below that expected from a point proton by a factor of about nine. The magnitude and variation with angle of the deviations determine a structure factor for the proton, and thereby determine the size and shape of the charge and magnetic-moment distributions within the proton. An interpretation, consistent at all energies and angles and agreeing with earlier results from this laboratory, fixes the rms radius at 0.77 {plus or minus} 0.10 x 10{sup -13} cm for each of the charge and moment distributions. The shape of the density function is not far from a Gaussian with rms radius 0.70 x 10{sup -13} cm or an exponential with rms radius 0.80 x 10 {sup -13} cm. An equivalent interpretation of the experiments would ascribe the apparent size to a breakdown of the Coulomb law and the conventional theory of electromagnetism.

  13. Proton therapy for Hodgkin lymphoma.

    PubMed

    Rutenberg, Michael S; Flampouri, Stella; Hoppe, Bradford S

    2014-09-01

    Hodgkin lymphoma has gone from an incurable disease to one for which the majority of patients will be cured. Combined chemotherapy and radiotherapy achieves the best disease control rates and results in many long-term survivors. As a result, a majority of long-term Hodgkin lymphoma survivors live to experience severe late treatment-related complications, especially cardiovascular disease and second malignancies. The focus of research and treatment for Hodgkin lymphoma is to maintain the current high rates of disease control while reducing treatment-related morbidity and mortality. Efforts to reduce late treatment complications focus on improvements in both systemic therapies and radiotherapy. Herein we review the basis for the benefits of proton therapy over conventional X-ray therapy. We review outcomes of Hodgkin lymphoma treated with proton therapy, and discuss the ability of protons to reduce radiation dose to organs at risk and the impact on the most significant late complications related to the treatment.

  14. Global analysis of proton elastic form factor data with two-photon exchange corrections

    SciTech Connect

    J. Arrington; W. Melnitchouk; J. A. Tjon

    2007-09-01

    We use the world's data on elastic electron-proton scattering and calculations of two-photon exchange effects to extract corrected values of the proton's electric and magnetic form factors over the full Q^2 range of the existing data. Our analysis combines the corrected Rosenbluth cross section and polarization transfer data, and is the first extraction of G_Ep and G_Mp including explicit two-photon exchange corrections and their associated uncertainties. In addition, we examine the angular dependence of the corrected cross sections, and discuss the possible nonlinearities of the cross section as a function of epsilon.

  15. GEM Detectors of Proton Charge Radius (PRad) Experiment

    NASA Astrophysics Data System (ADS)

    Bai, Xinzhan; PRad Collaboration

    2017-01-01

    The PRad experiment (E12-11-106) was recently performed at Jefferson Lab in Hall B. It was designed to measure the proton charge radius with high precision, through the elastic electron proton scattering process, using a non-magnetic-spectrometer method. PRad experiment reached very small ep scattering angles and thus it can see an unprecedented small four-momentum transfer squared region, Q2 from 2 ×10-4 to 0 . 1(GeV / c) 2 . This experiment measures the proton charge radius by extracting the electric form factor of proton with a sub-percent precision. A pair of world's largest GEM detectors, and a high resolution calorimeter(HyCal) were utilized in the experiment. In this talk, we will present the performance of GEM detectors achieved in the experiment, such as efficiency and other characteristics, and preliminary analysis results of the experimental data. This work is supported in part by NSF MRI award PHY-1229153, the U.S. Department of Energy under Contract No. DE-FG02-07ER41528, University of Virginia under Contract No. DE-FG02-03ER41240 and Thomas Jefferson National Laboratory.

  16. Proton aurora and substorm intensifications

    NASA Technical Reports Server (NTRS)

    Samson, J. C.; Xu, B.; Lyons, L. R.; Newell, P. T.; Creutzberg, F.

    1993-01-01

    Ground based measurements from the CANOPUS array of meridian scanning photometers and precipitating ion and electron data from the DMSP F9 satellite show that the electron arc which brightens to initiate substorm intensifications is formed within a region of intense proton precipitation that is well equatorward (approximately four to six degrees) of the nightside open-closed field line boundary. The precipitating protons are from a population that is energized via earthward convection from the magnetotail into the dipolar region of the magnetosphere and may play an important role in the formation of the electron arcs leading to substorm intensifications on dipole-like field lines.

  17. Search for sphalerons in proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Ellis, John; Sakurai, Kazuki

    2016-04-01

    In a recent paper, Tye and Wong (TW) have argued that sphaleron-induced transitions in high-energy proton-proton collisions should be enhanced compared to previous calculations, based on a construction of a Bloch wave function in the periodic sphaleron potential and the corresponding pass band structure. Here we convolute the calculations of TW with parton distribution functions and simulations of final states to explore the signatures of sphaleron transitions at the LHC and possible future colliders. We calculate the increase of sphaleron transition rates in proton-proton collisions at centre-of-mass energies of 13/14/33/100 TeV for different sphaleron barrier heights, while recognising that the rates have large overall uncertainties. We use a simulation to show that LHC searches for microscopic black holes should have good efficiency for detecting sphaleron-induced final states, and discuss their experimental signatures and observability in Run 2 of the LHC and beyond. We recast the early ATLAS Run-2 search for microscopic black holes to constrain the rate of sphaleron transitions at 13 TeV, deriving a significant limit on the sphaleron transition rate for the nominal sphaleron barrier height of 9 TeV.

  18. Simulation for Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Ye, Li; PRad Collaboration Collaboration

    2016-09-01

    The ``Proton Charge Radius Puzzle'' refers to 7 σ discrepancy between the proton charge radius extracted from muonic hydrogen Lamb shift measurements and that from the atomic hydrogen Lamb shift and e-p elastic scattering measurements. In order to get a better understanding of this puzzle, the PRad experiment (E12-11-106) was proposed and recently performed with 1.1 and 2.2 GeV unpolarized electron beam in Hall B at Jefferson Lab. The experiment aims to extract the electric form factor and the charge radius of proton by simultaneously measuring the e - p elastic scattering cross section and the Møller cross section at very low Q2(2 × 10-4 10-1(GeV / c) 2) region, with sub-percent precision. A windowless hydrogen gas flow target was used to better control the background. A high-efficiency and high-resolution calorimeter (HyCal) and a pair of Gas Electron Multiplier (GEM) chambers were used in the experiment. This talk will focus on comparing the detailed simulation of PRad experiment and its background with preliminary spectra from the data. This work is supported in part by NSF MRI Award PHY-1229153, the U.S. Department of Energy under Contacts No. DE-FG02-07ER41528, Thomas Jefferson National Laboratory, Mississippi State University and PRad collaboration.

  19. Spin Structure Functions of the Proton - SANE experiment

    NASA Astrophysics Data System (ADS)

    Baghdasaryan, Hovhannes

    2012-03-01

    The Spin Asymmetries of the Nucleon Experiment (SANE) is a measurement of inclusive electron scattering parallel and near perpendicular double spin asymmetries from a proton target. The main goal of the experiment was to measure A and A80 and to extract the spin asymmetries of the proton A1^p, A2^p and the spin structure functions g1^p and g2^p. Using the Thomas Jefferson National Accelerator Facility's polarized electron beam and the University of Virginia's polarized frozen ammonia (^14NH3) target in Hall C, the experiment ran in 2009, collecting data in a Q^2 region from 2.5 to 6.5 GeV^2 and between Bjorken x of 0.3 and 0.8. Particle detection was accomplished using the Big Electron Telescope Array (BETA), a novel non-magnetic detector. The physics motivation for the experiment and a brief overview of the polarized target and the detector will be presented along with the analysis developed in order to extract the proton spin asymmetries and structure functions. Results will be presented.

  20. Proton Spin Polarizabilities with Polarized Compton Scattering at MAMI

    NASA Astrophysics Data System (ADS)

    Paudyal, Dilli; A2 Collaboration

    2015-10-01

    The nucleon polarizabilities are fundamental structure observables, which describe its response to an applied electric or magnetic field. While the electric and magnetic scalar polarizabilities of the nucleon have been measured, little effort has been made to extract the spin dependent polarizabilities. These leading order spin dependent terms of the nucleon polarizabilities, γE1E1 ,γM1M1 ,γM1E2 and γE1M2 describe the spin response of a proton to electric and magnetic dipole and quadrupole interactions. We plan to extract these spin polarizabilities of the proton using real polarised Compton scattering off the proton at the MAMI tagged photon facility in Mainz, Germany. This requires precise measurement of the single and double polarization observables which are sensitive to these polarizabilities. The double polarization observables ∑2 x, ∑2 z are measured via a circulary polarized photon beam and a transversely and a linearly polarized butanol target in the resonance region (E = 250 - 310 MeV). This presentation will be focused on the status and analyis of an experiment completed at MAMI in 2014 and 2015 for the measurement of ∑2 z at different energies and angles. Supported by the Natural Sciences and Engineering Research Council of Canada (NSERC).

  1. Measurement of pion, kaon and proton production in proton-proton collisions at TeV

    NASA Astrophysics Data System (ADS)

    Adam, J.; Adamová, D.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmed, I.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Molina, R. Alfaro; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Prado, C. Alves Garcia; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Pedrosa, F. Baltasar Dos Santos; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Camejo, A. Batista; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Martinez, H. Bello; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biswas, S.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Diaz, L. Calero; Caliva, A.; Villar, E. Calvo; Camerini, P.; Carena, F.; Carena, W.; Castellanos, J. Castillo; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Sanchez, C. Ceballos; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Barroso, V. Chibante; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Balbastre, G. Conesa; Valle, Z. Conesa del; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Morales, Y. Corrales; Maldonado, I. Cortés; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Albino, R. Cruz; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; Caro, A. De; Cataldo, G. de; Cuveland, J. de; Falco, A. De; Gruttola, D. De; Marco, N. De; Pasquale, S. De; Deisting, A.; Deloff, A.; Dénes, E.; D'Erasmo, G.; Bari, D. Di; Mauro, A. Di; Nezza, P. Di; Corchero, M. A. Diaz; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Gimenez, D. Domenicis; Dönigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erhardt, F.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Eum, J.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Téllez, A. Fernández; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Girard, M. Fusco; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Dziadus, E. Gladysz; Glässel, P.; Ramirez, A. Gomez; Zamora, P. González; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Corral, G. Herrera; Hess, B. A.; Hetland, K. F.; Hilden, T. E.; Hillemanns, H.; Hippolyte, B.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacobs, P. M.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Bustamante, R. T. Jimenez; Jones, P. G.; Jung, H.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Uysal, A. Karasu; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Khan, K. H.; Khan, M. M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobayashi, T.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kouzinopoulos, C.; Kovalenko, O.; Kovalenko, V.; Kowalski, M.; Kox, S.; Meethaleveedu, G. Koyithatta; Kral, J.; Králik, I.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kumar, L.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; Pointe, S. L. La; Rocca, P. La; Fernandes, C. Lagana; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, G. R.; Lee, S.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; Monzón, I. León; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Loizides, C.; Lopez, X.; Torres, E. López; Lowe, A.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luparello, G.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Cervantes, I. Maldonado; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martin, N. A.; Blanco, J. Martin; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Pedreira, M. Martinez; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Masui, H.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; Mcdonald, D.; Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Pérez, J. Mercado; Meres, M.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Minervini, L. M.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Zetina, L. Montaño; Montes, E.; Morando, M.; Godoy, D. A. Moreira De; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Müller, H.; Mulligan, J. D.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Nattrass, C.; Nayak, K.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Silva, A. C. Oliveira Da; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Velasquez, A. Ortiz; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S. K.; Pan, J.; Pandey, A. K.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Costa, H. Pereira Da; Filho, E. Pereira De Oliveira; Peresunko, D.; Lara, C. E. Pérez; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rivetti, A.; Rocco, E.; Cahuantzi, M. Rodríguez; Manso, A. Rodriguez; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Montero, A. J. Rubio; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Castro, X. Sanchez; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Seeder, K. S.; Seger, J. E.; Sekiguchi, Y.; Selyuzhenkov, I.; Senosi, K.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, N.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Spacek, M.; Spiriti, E.; Sputowska, I.; Stassinaki, M. Spyropoulou; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Symons, T. J. M.; Szabo, A.; Toledo, A. Szanto de; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tanaka, N.; Tangaro, M. A.; Takaki, J. D. Tapia; Peloni, A. Tarantola; Tariq, M.; Tarzila, M. G.; Tauro, A.; Muñoz, G. Tejeda; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vajzer, M.; Vala, M.; Palomo, L. Valencia; Vallero, S.; Maarel, J. Van Der; Hoorne, J. W. Van; Leeuwen, M. van; Vanat, T.; Vyvre, P. Vande; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vechernin, V.; Veen, A. M.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Limón, S. Vergara; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Baillie, O. Villalobos; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; Haller, B. von; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Weber, S. G.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yano, S.; Yasnopolskiy, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yurchenko, V.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.

    2015-05-01

    The measurement of primary , , and production at mid-rapidity ( 0.5) in proton-proton collisions at 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/ for pions, from 0.2 up to 6 GeV/ for kaons and from 0.3 up to 6 GeV/ for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.

  2. Dynamics of the Plasma Membrane Proton Pump.

    PubMed

    Guerra, Federico; Bondar, Ana-Nicoleta

    2015-06-01

    Proton transfer over distances longer than that of a hydrogen bond often requires water molecules and protein motions. Following transfer of the proton from the donor to the acceptor, the change in the charge distribution may alter the dynamics of protein and water. To begin to understand how protonation dynamics couple to protein and water dynamics, here we explore how changes in the protonation state affect water and protein dynamics in the AHA2 proton pump. We find that the protonation state of the proton donor and acceptor groups largely affects the dynamics of internal waters and of specific hydrogen bonds, and the orientation of transmembrane helical segments that couple remote regions of the protein. The primary proton donor/acceptor group D684, can interact with water molecules from the cytoplasmic bulk and/or other protein groups.

  3. Determining the mechanism of cusp proton aurora.

    PubMed

    Xiao, Fuliang; Zong, Qiugang; Su, Zhenpeng; Yang, Chang; He, Zhaoguo; Wang, Yongfu; Gao, Zhonglei

    2013-01-01

    Earth's cusp proton aurora occurs near the prenoon and is primarily produced by the precipitation of solar energetic (2-10 keV) protons. Cusp auroral precipitation provides a direct source of energy for the high-latitude dayside upper atmosphere, contributing to chemical composition change and global climate variability. Previous studies have indicated that magnetic reconnection allows solar energetic protons to cross the magnetopause and enter the cusp region, producing cusp auroral precipitation. However, energetic protons are easily trapped in the cusp region due to a minimum magnetic field existing there. Hence, the mechanism of cusp proton aurora has remained a significant challenge for tens of years. Based on the satellite data and calculations of diffusion equation, we demonstrate that EMIC waves can yield the trapped proton scattering that causes cusp proton aurora. This moves forward a step toward identifying the generation mechanism of cusp proton aurora.

  4. Determining the mechanism of cusp proton aurora

    PubMed Central

    Xiao, Fuliang; Zong, Qiugang; Su, Zhenpeng; Yang, Chang; He, Zhaoguo; Wang, Yongfu; Gao, Zhonglei

    2013-01-01

    Earth's cusp proton aurora occurs near the prenoon and is primarily produced by the precipitation of solar energetic (2–10 keV) protons. Cusp auroral precipitation provides a direct source of energy for the high-latitude dayside upper atmosphere, contributing to chemical composition change and global climate variability. Previous studies have indicated that magnetic reconnection allows solar energetic protons to cross the magnetopause and enter the cusp region, producing cusp auroral precipitation. However, energetic protons are easily trapped in the cusp region due to a minimum magnetic field existing there. Hence, the mechanism of cusp proton aurora has remained a significant challenge for tens of years. Based on the satellite data and calculations of diffusion equation, we demonstrate that EMIC waves can yield the trapped proton scattering that causes cusp proton aurora. This moves forward a step toward identifying the generation mechanism of cusp proton aurora. PMID:23575366

  5. Accelerator Science: Proton vs. Electron

    ScienceCinema

    Lincoln, Don

    2016-10-19

    Particle accelerators are one of the most powerful ways to study the fundamental laws that govern the universe. However, there are many design considerations that go into selecting and building a particular accelerator. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of building an accelerator that collides pairs of protons to one that collides electrons.

  6. Alpha proton x ray spectrometer

    NASA Technical Reports Server (NTRS)

    Rieder, Rudi; Waeke, H.; Economou, T.

    1994-01-01

    Mars Pathfinder will carry an alpha-proton x ray spectrometer (APX) for the determination of the elemental chemical composition of Martian rocks and soils. The instrument will measure the concentration of all major and some minor elements, including C, N, and O at levels above typically 1 percent.

  7. Invariant Spin in the Proton

    SciTech Connect

    Thomas, Anthony W.

    2008-10-13

    We discuss recent theoretical progress in understanding the distribution of spin and orbital angular momentum in the proton. Particular attention is devoted to the effect of QCD evolution and to the distinction between 'chiral' and 'invariant' spin. This is particularly significant with respect to the possible presence of polarized strange quarks.

  8. Accelerator Science: Proton vs. Electron

    SciTech Connect

    Lincoln, Don

    2016-10-11

    Particle accelerators are one of the most powerful ways to study the fundamental laws that govern the universe. However, there are many design considerations that go into selecting and building a particular accelerator. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of building an accelerator that collides pairs of protons to one that collides electrons.

  9. Electron and Proton Auroral Dynamics

    NASA Technical Reports Server (NTRS)

    Mende, S. B.; Frey, H. U.; Gerard, J. C.; Hubert, B.; Fuselier, S.; Spann, J. F., Jr.; Gladstone, R.; Burch, J. L.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Data from the Wide-band Imaging Camera (WIC) sensitive to far ultraviolet auroras and from the Spectrographic Imager (SI) channel SI12, sensitive to proton precipitation induced Lyman alpha were analyzed during a high altitude orbit segment of the IMAGE spacecraft. This segment began during the expansive phase of a substorm. The aurora changed into a double oval configuration, consisting of a set of discrete pole-ward forms and a separate diffuse auroral oval equatorwards, Although IMF Bz was strongly southward considerable activity could be seen poleward of the discrete auroras in the region that was considered to be the polar cap. The SI12 Doppler shifted Lyman alpha signature of precipitating protons show that the proton aurora is on the equatorward side of the diffuse aurora. In the following several hours the IMF Bz field changed signed. Although the general character of the proton and electron aurora did not change, the dayside aurora moved equatorward when the Bz was negative and more bright aurora was seen in the central polar cap during periods of positive Bz.

  10. Low-Energy Proton Testing Methodology

    NASA Technical Reports Server (NTRS)

    Pellish, Jonathan A.; Marshall, Paul W.; Heidel, David F.; Schwank, James R.; Shaneyfelt, Marty R.; Xapsos, M.A.; Ladbury, Raymond L.; LaBel, Kenneth A.; Berg, Melanie; Kim, Hak S.; Phan, Anthony; Friendlich, M.R.; Rodbell, Kenneth P.; Hakey, Mark C.; Dodd, Paul E.; Reed, Robert A.; Weller, Robert A.; Mendenhall, Marcus H.; Sierawski, B.D.

    2009-01-01

    Use of low-energy protons and high-energy light ions is becoming necessary to investigate current-generation SEU thresholds. Systematic errors can dominate measurements made with low-energy protons. Range and energy straggling contribute to systematic error. Low-energy proton testing is not a step-and-repeat process. Low-energy protons and high-energy light ions can be used to measure SEU cross section of single sensitive features; important for simulation.

  11. How to resolve the proton radius puzzle?

    NASA Astrophysics Data System (ADS)

    Paz, Gil

    2016-09-01

    In 2010 the first measurement of the proton charge radius from spectroscopy of muonic hydrogen was found to be five standard deviations away from the regular hydrogen value. Six years later, this ``proton radius puzzle'' is still unresolved. One of the most promising avenues to test the muonic hydrogen result is a new muon-proton scattering experiment called MUSE. We describe how effective field theory methods will allow to directly connect muonic hydrogen spectroscopy to muon-proton scattering.

  12. Proton decay from the isoscalar giant dipole resonance in {sup 58}Ni

    SciTech Connect

    Hunyadi, M.; Hashimoto, H.; Fujimura, H.; Fujiwara, M.; Hara, K.; Itoh, M.; Nakanishi, K.; Okumura, S.; Li, T.; Garg, U.; Hoffman, J.; Nayak, B. K.; Akimune, H.; Gacsi, Z.; Harakeh, M. N.

    2009-10-15

    Proton decay from the 3({Dirac_h}/2{pi}){omega} isoscalar giant dipole resonance (ISGDR) in {sup 58}Ni has been measured using the ({alpha},{alpha}{sup '}p) reaction at a bombarding energy of 386 MeV to investigate its decay properties. We have extracted the ISGDR strength under the coincidence condition between inelastically scattered {alpha} particles at forward angles and decay protons emitted at backward angles. Branching ratios for proton decay to low-lying states of {sup 57}Co have been determined, and the results compared with predictions of recent continuum-RPA calculations. The final-state spectra of protons decaying to the low-lying states in {sup 57}Co were analyzed for a more detailed understanding of the structure of the ISGDR. It is found that there are differences in the structure of the ISGDR as a function of excitation energy.

  13. The Muon Scattering Experiment (MUSE) at PSI and the proton radius puzzle

    NASA Astrophysics Data System (ADS)

    Kohl, Michael

    2014-11-01

    The unexplained large discrepancy of the proton charge radius measurements with muonic hydrogen Lamb shift and determinations from elastic electron scattering and Lamb shift in regular hydrogen of seven standard deviations is known as the proton radius puzzle. Suggested solutions of the puzzle range from possible errors in the experiments through unexpectedly large hadronic physics effects to new physics beyond the Standard Model. A new approach to verify the radius discrepancy in a systematic manner will be pursued with the Muon Scattering Experiment (MUSE) at PSI. The experiment aims to compare elastic cross sections, the proton elastic form factors, and the extracted proton charge radius with scattering of electrons and muons of either charge and under identical conditions. The difference in the observed radius will be probed with a high precision to verify the discrepancy. An overview of the experiment and the current status will be presented.

  14. Calculation of Top Squark Production in Proton-Proton Collisions

    SciTech Connect

    Linville, Andrea J.; /Washington U., St. Louis /SLAC

    2010-08-25

    Though the Standard Model of particle physics is an elegant theory which has been studied extensively for decades, it leaves many fundamental questions unanswered and is thus widely believed to be incomplete. Possible extensions to the Standard Model (SM) have been postulated and are in the process of being investigated experimentally. The most promising extension is the Minimal Supersymmetric Model (MSSM) which relates every SM particle to a superpartner that differs by 1/2 unit of spin. The lightest supersymmetric quark, or squark, is expected to be the stop, and the search for this particle is an important experimental task. In this analysis, we use parton-model methods to predict the stop production cross section in proton-proton collisions at LHC energies.

  15. Threshold pion production from proton-proton collisions

    SciTech Connect

    Lee, T.S.H.

    1995-08-01

    We showed that the threshold production of {pi}{sup 0}pp, {pi}{sup +}np, and {pi}{sup +}d from proton-proton collisions can be consistently described by a model consisting of pion s-wave rescattering and N{bar N} pair-terms of heavy-meson exchanges. The large difference between {sigma}{sup tot}(pp {yields} {pi}{sup +}d) and {sigma}{sup tot}(pp {yields} {pi}{sup +}np) is understood from the orthogonality of the deuteron and the np scattering wave functions. In a calculation using the Paris potential, we find that the data can be reproduced best by using a soft {pi}NN form factor with {Delta} = 650 MeV for a monopole form. This is consistent with our earlier studies of pion production in the A-excitation region. A paper describing this result was submitted for publication.

  16. Proton hydrates as soft ion/ion proton transfer reagents for multiply deprotonated biomolecules

    NASA Astrophysics Data System (ADS)

    Bowers, Jeremiah J.; Hodges, Brittany D. M.; Saad, Ola M.; Leary, Julie A.; McLuckey, Scott A.

    2008-10-01

    Ion/ion proton transfer from protonated strong gaseous bases such as pyridine and 1,8-bis(dimethylamino)naphthalene (i.e., the proton sponge), to multiply charged anions derived from a sulfated pentasaccharide drug, Arixtra(TM), gives rise to extensive fragmentation of the oligosaccharide. This drug serves as a model for sulfated glycosaminoglycans, an important class of polymers in glycobiology. The extent of fragmentation appears to correlate with the proton affinity of the molecule used to transfer the proton, which in turn correlates with the reaction exothermicity. Consistent with tandem mass spectrometry results, anions with sodium counter-ions are more stable with respect to fragmentation under ion/ion proton transfer conditions than ions of the same charge state with protons counter-ions. Proton hydrates were found to give rise to much less anion fragmentation and constitute the softest protonation agents thus far identified for manipulating the charge states of multiply charged biopolymer anions. The reaction exothermicities associated with proton hydrates comprised of five or more water molecules are lower than that for protonated proton sponge, which is among the softest reagents thus far examined for ion/ion proton transfer reactions. The partitioning of ion/ion reaction exothermicity among all of the degrees of freedom of the products may also differ for proton hydrates relative to protonated molecules. However, a difference in energy partitioning need not be invoked to rationalize the results reported here.

  17. Surface-coupled proton exchange of a membrane-bound proton acceptor.

    PubMed

    Sandén, Tor; Salomonsson, Lina; Brzezinski, Peter; Widengren, Jerker

    2010-03-02

    Proton-transfer reactions across and at the surface of biological membranes are central for maintaining the transmembrane proton electrochemical gradients involved in cellular energy conversion. In this study, fluorescence correlation spectroscopy was used to measure the local protonation and deprotonation rates of single pH-sensitive fluorophores conjugated to liposome membranes, and the dependence of these rates on lipid composition and ion concentration. Measurements of proton exchange rates over a wide proton concentration range, using two different pH-sensitive fluorophores with different pK(a)s, revealed two distinct proton exchange regimes. At high pH (> 8), proton association increases rapidly with increasing proton concentrations, presumably because the whole membrane acts as a proton-collecting antenna for the fluorophore. In contrast, at low pH (< 7), the increase in the proton association rate is slower and comparable to that of direct protonation of the fluorophore from the bulk solution. In the latter case, the proton exchange rates of the two fluorophores are indistinguishable, indicating that their protonation rates are determined by the local membrane environment. Measurements on membranes of different surface charge and at different ion concentrations made it possible to determine surface potentials, as well as the distance between the surface and the fluorophore. The results from this study define the conditions under which biological membranes can act as proton-collecting antennae and provide fundamental information on the relation between the membrane surface charge density and the local proton exchange kinetics.

  18. Proton Therapy Verification with PET Imaging

    PubMed Central

    Zhu, Xuping; Fakhri, Georges El

    2013-01-01

    Proton therapy is very sensitive to uncertainties introduced during treatment planning and dose delivery. PET imaging of proton induced positron emitter distributions is the only practical approach for in vivo, in situ verification of proton therapy. This article reviews the current status of proton therapy verification with PET imaging. The different data detecting systems (in-beam, in-room and off-line PET), calculation methods for the prediction of proton induced PET activity distributions, and approaches for data evaluation are discussed. PMID:24312147

  19. Excited state of protonated benzene and toluene

    SciTech Connect

    Esteves-López, Natalia; Dedonder-Lardeux, Claude; Jouvet, Christophe

    2015-08-21

    We present photo-fragmentation electronic spectra of the simplest protonated aromatic molecules, protonated benzene and toluene, recorded under medium resolution conditions and compared with the photo-fragmentation spectrum of protonated pyridine. Despite the resolution and cold temperature achieved in the experiment, the electronic spectra of protonated benzene and toluene are structure-less, thus intrinsically broadened. This is in agreement with the large geometrical changes and the fast dynamic toward internal conversion predicted by ab initio calculations for protonated benzene [Rode et al., J. Phys. Chem. A 113, 5865–5873 (2009)].

  20. Proton conduction in biopolymer exopolysaccharide succinoglycan

    NASA Astrophysics Data System (ADS)

    Kweon, Jin Jung; Lee, Kyu Won; Kim, Hyojung; Lee, Cheol Eui; Jung, Seunho; Kwon, Chanho

    2014-07-01

    Protonic currents play a vital role in electrical signalling in living systems. It has been suggested that succinoglycan plays a specific role in alfalfa root nodule development, presumably acting as the signaling molecules. In this regard, charge transport and proton dynamics in the biopolymer exopolysaccharide succinoglycan have been studied by means of electrical measurements and nuclear magnetic resonance (NMR) spectroscopy. In particular, a dielectric dispersion in the system has revealed that the electrical conduction is protonic rather electronic. Besides, our laboratory- and rotating-frame 1H NMR measurements have elucidated the nature of the protonic conduction, activation of the protonic motion being associated with a glass transition.

  1. Compact proton spectrometers for measurements of shock

    SciTech Connect

    Mackinnon, A; Zylstra, A; Frenje, J A; Seguin, F H; Rosenberg, M J; Rinderknecht, H G; Johnson, M G; Casey, D T; Sinenian, N; Manuel, M; Waugh, C J; Sio, H W; Li, C K; Petrasso, R D; Friedrich, S; Knittel, K; Bionta, R; McKernan, M; Callahan, D; Collins, G; Dewald, E; Doeppner, T; Edwards, M J; Glenzer, S H; Hicks, D; Landen, O L; London, R; Meezan, N B

    2012-05-02

    The compact Wedge Range Filter (WRF) proton spectrometer was developed for OMEGA and transferred to the National Ignition Facility (NIF) as a National Ignition Campaign (NIC) diagnostic. The WRF measures the spectrum of protons from D-{sup 3}He reactions in tuning-campaign implosions containing D and {sup 3}He gas; in this work we report on the first proton spectroscopy measurement on the NIF using WRFs. The energy downshift of the 14.7-MeV proton is directly related to the total {rho}R through the plasma stopping power. Additionally, the shock proton yield is measured, which is a metric of the final merged shock strength.

  2. Proton conduction in biopolymer exopolysaccharide succinoglycan

    SciTech Connect

    Kweon, Jin Jung; Lee, Kyu Won; Kim, Hyojung; Lee, Cheol Eui; Jung, Seunho; Kwon, Chanho

    2014-07-07

    Protonic currents play a vital role in electrical signalling in living systems. It has been suggested that succinoglycan plays a specific role in alfalfa root nodule development, presumably acting as the signaling molecules. In this regard, charge transport and proton dynamics in the biopolymer exopolysaccharide succinoglycan have been studied by means of electrical measurements and nuclear magnetic resonance (NMR) spectroscopy. In particular, a dielectric dispersion in the system has revealed that the electrical conduction is protonic rather electronic. Besides, our laboratory- and rotating-frame {sup 1}H NMR measurements have elucidated the nature of the protonic conduction, activation of the protonic motion being associated with a glass transition.

  3. Calibration of CR-39 with monoenergetic protons

    NASA Astrophysics Data System (ADS)

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

    2009-10-01

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

  4. Single-pion production in proton-proton collisions at 1.25 GeV: measurements by HADES and a PWA

    NASA Astrophysics Data System (ADS)

    Przygoda, Witold

    2014-11-01

    We report on the single-pion production in proton-proton collisions at a kinetic energy of 1.25 GeV based on data measured with HADES. Exclusive channels npπ+ and ppπ0 were studied simultaneously. The parametrization of production cross sections of the one-pion final states by means of the resonance model has been obtained. Independently, the extraction of the leading partial waves in the data were analyzed within the framework of the partial wave analysis (PWA). Contributions for the production of ∆(1232) and N(1440) intermediate states have been deduced.

  5. ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

    SciTech Connect

    BAI, M.; AHRENS, L.; ALEKSEEV, I.G.; ALESSI, J.; BEEBE-WANG, J.; BLASKIEWICZ, M.; BRAVAR, A.; BRENNAN, J.M.; BRUNO, D.; BUNCE, G.; ET AL.

    2006-10-02

    The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.

  6. Very energetic protons in Saturn's radiation belt

    NASA Technical Reports Server (NTRS)

    Fillius, W.; Mcilwain, C.

    1980-01-01

    Very energetic protons are trapped in the inner Saturnian radiation belt. The University of California at San Diego instrument on Pioneer 11 has definitely identified protons of energy greater than 80 MeV on channel M3 and has tentatively detected protons of energy greater than 600 MeV on channel C3. The spatial distribution of the protons is distinct from that of the trapped electrons, the main difference being that the protons are strongly absorbed by the innermost moons and that the electrons are not. The source strength for injecting protons by the decay of cosmic ray albedo neutrons generated in the rings of Saturn has been estimated. The required proton lifetime is approximately 20 years.

  7. Clinical controversies: proton therapy for prostate cancer.

    PubMed

    Mouw, Kent W; Trofimov, Alexei; Zietman, Anthony L; Efstathiou, Jason A

    2013-04-01

    Proton therapy has been used in the treatment of prostate cancer for several decades, and interest surrounding its use continues to grow. Proton-based treatment techniques have evolved significantly over this period, and several centers now routinely use technologies such as pencil-beam scanning. However, whether the theoretical dosimetric advantages of the proton beam translate into clinically meaningful improvements for prostate cancer patients is unknown, and outcomes from single-arm experiences using whole courses of proton beam therapy in the treatment of early-stage prostate cancer have shown mixed results when compared with contemporary intensity-modulated radiotherapy. A randomized trial comparing proton beam therapy with intensity-modulated radiotherapy in early-stage disease has been launched and will be important in defining the role for proton therapy in this setting. We review the available evidence and present the current state of proton beam therapy for prostate cancer.

  8. Dynamic Protonation Equilibrium of Solvated Acetic Acid

    SciTech Connect

    Gu, Wei; Frigato, Tomaso; Straatsma, TP; Helms, Volkhard H.

    2007-04-13

    For the first time, the dynamic protonation equilibrium between an amino acid side chain analogue and bulk water as well as the diffusion properties of the excess proton were successfully reproduced through unbiased computer simulations. During a 50 ns Q-HOP MD simulation, two different regimes of proton transfer were observed. Extended phases of frequent proton swapping between acetic acid and nearby water were separated by phases where the proton freely diffuses in the simulation box until it is captured again by acetic acid. The pKa of acetic acid was calculated around 3.0 based on the relative population of protonated and deprotonated states and the diffusion coefficient of excess proton was computed from the average mean squared displacement in the simulation. Both calculated values agree well with the experimental measurements.

  9. Proton emission - new results and future prospects

    NASA Astrophysics Data System (ADS)

    Page, R. D.

    2016-09-01

    Proton emission is the radioactive decay mode that is expected to determine the limit of observable proton-rich nuclei for most elements. Considerable progress has been made in the study of proton-emitting nuclei since the first observation of direct proton emission nearly 50 years ago. This has led to improvements in our understanding of this decay process and provided invaluable nuclear structure data far from the valley of beta stability. The rapid fall in half-lives with increasing neutron deficiency when proton emission dominates makes it likely that for some elements, the lightest isotopes whose ground states can be observed in conventional experiments have already been reached. The enhanced stability against proton emission of the recently discovered high-lying isomer in 158Ta raises the possibility that proton emission from multiparticle isomers could be observed in nuclei beyond the expected boundaries of the nuclear landscape.

  10. Proton spin: A topological invariant

    NASA Astrophysics Data System (ADS)

    Tiwari, S. C.

    2016-11-01

    Proton spin problem is given a new perspective with the proposition that spin is a topological invariant represented by a de Rham 3-period. The idea is developed generalizing Finkelstein-Rubinstein theory for Skyrmions/kinks to topological defects, and using non-Abelian de Rham theorems. Two kinds of de Rham theorems are discussed applicable to matrix-valued differential forms, and traces. Physical and mathematical interpretations of de Rham periods are presented. It is suggested that Wilson lines and loop operators probe the local properties of the topology, and spin as a topological invariant in pDIS measurements could appear with any value from 0 to ℏ 2, i.e. proton spin decomposition has no meaning in this approach.

  11. Proton emission from triaxial nuclei

    SciTech Connect

    Delion, D.S.; Wyss, R.; Karlgren, D.; Liotta, R.J.

    2004-12-01

    Proton decay from triaxially deformed nuclei is investigated. The deformation parameters corresponding to the mother nucleus are determined microscopically and the calculated decay widths are used to probe the mean-field wave function. The proton wave function in the mother nucleus is described as a resonant state in a coupled-channel formalism. The decay width, as well as the angular distribution of the decaying particle, are evaluated and their dependence upon the triaxial deformation parameters is studied in the decay of {sup 161}Re and {sup 185}Bi. It is found that the decay width is very sensitive to the parameters defining the triaxial deformation while the angular distribution is a universal function which does not depend upon details of the nuclear structure.

  12. Monitoring proton therapy with PET

    PubMed Central

    El Fakhri, G

    2015-01-01

    Protons are being used in radiation therapy because of typically better dose conformity and reduced total energy deposited in the patient as compared with photon techniques. Both aspects are related to the finite range of a proton beam. The finite range also allows advanced dose shaping. These benefits can only be fully utilized if the end of range can be predicted accurately in the patient. The prediction of the range in tissue is associated with considerable uncertainties owing to imaging, patient set-up, beam delivery, interfractional changes in patient anatomy and dose calculation. Consequently, a significant range (of the order of several millimetres) is added to the prescribed range in order to ensure tumour coverage. Thus, reducing range uncertainties would allow a reduction of the treatment volume and reduce dose to potential organs at risk. PMID:25989699

  13. Proton Decay Searches with DUNE

    NASA Astrophysics Data System (ADS)

    Wood, Kevin

    2017-01-01

    The Deep Underground Neutrino Experiment (DUNE) will be comprised of a beam line and near detector complex at Fermilab, Illinois as well as a massive far detector located 1300 km away at Sanford Underground Research Facility (SURF), South Dakota. To achieve its rich physics program, DUNE plans to construct a 40kt fiducial volume Liquid Argon Time Projection Chamber (LArTPC) far detector almost a mile underground. The size, location, and technology of the proposed far detector make it an attractive tool to search for proton decay, which has yet to be observed. Observation of such a rare event requires high sensitivity to the signal and high background rejection rate. A particular background of interest arises from cosmic muons interacting with rock surrounding the detector and producing a variety of particles which can enter the detector and leave signatures similar to that of proton decay. In order to keep this background to a reasonable level without sacrificing signal acceptance efficiency, precise tracking, made possible by the LArTPC technology, is required. Precise 3D localization of proton decay events relies on the detector's ability to identify the prompt emission of scintillation light from proton decay events as the t0-defining signal. Therefore, low background rate and high detection efficiency of this light are the crucial to the search. This work examines these characteristics in a detailed Monte Carlo simulation using DUNE`s far detector reference design and demonstrates a high signal efficiency while keeping the expected number of cosmogenic background events sufficiently low.

  14. Proton Resonance Spectroscopy -- Final Report

    SciTech Connect

    Shriner, Jr, J F

    2009-07-27

    This report summarizes work supported by the DOE Grant DE-FG02-96ER40990 during its duration from June 1996 to May 2009. Topics studied include (1) statistical descriptions of nuclear levels and measurements of proton resonances relevant to such descriptions, including measurements toward a complete level scheme for 30P, (2) the development of methods to estimate the missing fraction of levels in a given measurement, and (3) measurements at HRIBF relevant to nuclear astrophysics.

  15. Proton synchrotron radiation at Fermilab

    SciTech Connect

    Thurman-Keup, Randy; /Fermilab

    2006-05-01

    While protons are not generally associated with synchrotron radiation, they do emit visible light at high enough energies. This paper presents an overview of the use of synchrotron radiation in the Tevatron to measure transverse emittances and to monitor the amount of beam in the abort gap. The latter is necessary to ensure a clean abort and prevent quenches of the superconducting magnets and damage to the silicon detectors of the collider experiments.

  16. Proton Scattering on Liquid Argon

    NASA Astrophysics Data System (ADS)

    Bouabid, Ryan; LArIAT Collaboration

    2017-01-01

    LArIAT (Liquid Argon In A Test-beam) is a liquid argon time projection chamber (LArTPC) positioned in a charged particle beamline whose primary purpose is to study the response of LArTPC's to charged particle interactions. This previously unmeasured experimental data will allow for improvement of Monte Carlo simulations and development of identification techniques, important for future planned LArTPC neutrino experiments. LArIAT's beamline is instrumented to allow for the identification of specific particles as well as measurement of those particles' incoming momenta. Among the particles present in the beamline, the analysis presented here focuses on proton-Argon interactions. This study uses particle trajectories and calorimetric information to identify proton-Argon interaction candidates. We present preliminary data results on the measurement of the proton-Argon cross-section. Liquid Argon In A Test Beam. The work is my analysis made possible through the efforts of LArIAT detector, data, and software.

  17. Solid-state proton conductors

    NASA Astrophysics Data System (ADS)

    Jewulski, J. R.; Osif, T. L.; Remick, R. J.

    1990-12-01

    The purpose of this program was to survey the field of solid-state proton conductors (SSPC), identify conductors that could be used to develop solid-state fuel cells suitable for use with coal derived fuel gases, and begin the experimental research required for the development of these fuel cells. This document covers the following topics: the history of developments and current status of the SSPC, including a review of proton conducting electrolyte structures, the current status of the medium temperature SSPC development, electrodes for moderate temperature (SSPC) fuel cell, basic material and measurement techniques applicable for SSPC development, modeling, and optimization studies. Correlation and optimization studies are described which include correlation studies on proton conduction and oxide cathode optimization for the SSPC fuel cell. Experiments with the SSPC fuel cells are presented which include the fabrication of the electrolyte disks, apparatus for conducting measurements, the strontium-cerium based electrolyte, the barium-cerium based electrolyte with solid foil electrodes, the barium-cerium based electrolyte with porous electrodes, and conduction mechanisms.

  18. Solid-state proton conductors

    SciTech Connect

    Jewulski, J.R.; Osif, T.L.; Remick, R.J.

    1990-12-01

    The purpose of this program was to survey the field of solid-state proton conductors (SSPC), identify conductors that could be used to develop solid-state fuel cells suitable for use with coal derived fuel gases, and begin the experimental research required for the development of these fuel cells. This document covers the following topics: the history of developments and current status of the SSPC, including a review of proton conducting electrolyte structures, the current status of the medium temperature SSPC development, electrodes for moderate temperature (SSPC) fuel cell, basic material and measurement techniques applicable for SSPC development, modeling and optimization studies. Correlation and optimization studies, to include correlation studies on proton conduction and oxide cathode optimization for the SSPC fuel cell. Experiments with the SSPC fuel cells including the fabrication of the electrolyte disks, apparatus for conducting measurements, the strontium-cerium based electrolyte, the barium-cerium based electrolyte with solid foil electrodes, the barium-cerium based electrolyte with porous electrodes, and conduction mechanisms. 164 refs., 27 figs., 13 tabs.

  19. Family symmetries and proton decay

    SciTech Connect

    Murayama, Hitoshi |; Kaplan, D.B.

    1994-08-01

    The proton decay modes p {yields} K{sup 0}e{sup +} and p {yields} K{sup 0}{mu}{sup +} may be visible in certain supersymmetric theories, and if seen would provide evidence for new flavor physics at extremely short distances. These decay modes can arise from the dimension five operator (Q{sub 1}Q{sub 1}Q{sub 2}L{sub 1,2}), where Q{sub i} and L{sub i} are i{sup th} generation quark and lepton superfields respectively. Such an operator is not generated at observable levels due to gauge or Higgs boson exchange in a minimal GUT. However in theories that explain the fermion mass hierarchy, it may be generated at the Planck scale with a strength such that the decays p {yields} K{sup 0}{ell}{sup +} are both compatible with the proton lifetime and visible at Super-Kamiokande. Observable proton decay can even occur in theories without unification.

  20. The M. D. Anderson proton therapy system

    SciTech Connect

    Smith, Alfred; Gillin, Michael; Bues, Martin; Zhu, X. Ronald; Suzuki, Kazumichi; Mohan, Radhe; Woo, Shiao; Lee, Andrew; Komaki, Ritsko; Cox, James; Hiramoto, Kazuo; Akiyama, Hiroshi; Ishida, Takayuki; Sasaki, Toshie; Matsuda, Koji

    2009-09-15

    extracted from the synchrotron (energy can be changed pulse to pulse). The PTC-H is fully integrated with DICOM-RT ION interfaces for imaging, treatment planning, data management, and treatment control functions. Results: The proton therapy system passed all acceptance tests for both passive scattering and pencil beam scanning. Treatments with passive scattering began in May 2006 and treatments with the scanning system began in May 2008. The PTC-H was the first commercial system to demonstrate capabilities for IMPT treatments and the first in the United States to treat using SFUD techniques. The facility has been in clinical operation since May 2006 with up-time of approximately 98%. Conclusions: As with most projects for which a considerable amount of new technology is developed and which have duration spanning several years, at project completion it was determined that several upgrades would improve the overall system performance. Some possible upgrades are discussed. Overall, the system has been very robust, accurate, reproducible, and reliable. The authors found the pencil beam scanning system to be particularly satisfactory; prostate treatments can be delivered on the scanning nozzle in less time than is required on the passive scattering nozzle.

  1. Highly enantioselective proton-initiated polycyclization of polyenes.

    PubMed

    Surendra, Karavadhi; Corey, E J

    2012-07-25

    This report describes the synthesis of a range of chiral polycyclic molecules (tricyclic to pentacyclic) from achiral polyene precursors by enantioselective proton-initiated polycyclization promoted by the 1:1 complex of o,o'-dichloro-BINOL and SbCl(5). Excellent yields (ca. 90% per ring formed) and enantioselectivety (20:1 to 50:1) were obtained. The process is practical as well as efficient, because the chiral ligand is both readily prepared from R,R- or S,S-BINOL and easily recovered from the reaction mixture by extraction.

  2. Emission of neutron-proton and proton-proton pairs in electron scattering induced by meson-exchange currents

    NASA Astrophysics Data System (ADS)

    Simo, I. Ruiz; Amaro, J. E.; Barbaro, M. B.; De Pace, A.; Caballero, J. A.; Megias, G. D.; Donnelly, T. W.

    2016-11-01

    We use a relativistic model of meson-exchange currents to compute the proton-neutron and proton-proton yields in (e ,e') scattering from 12C in the 2p-2h channel. We compute the response functions and cross section with the relativistic Fermi gas model for a range of kinematics from intermediate- to high-momentum transfers. We find a large contribution of neutron-proton configurations in the initial state, as compared to proton-proton pairs. The different emission probabilities of distinct species of nucleon pairs are produced in our model only by meson-exchange currents, mainly by the Δ isobar current. We also analyze the effect of the exchange contribution and show that the direct-exchange interference strongly affects the determination of the n p /p p ratio.

  3. Proton pump inhibitors and risk of dementia

    PubMed Central

    Thongprayoon, Charat; Panjawatanan, Panadeekarn; Ungprasert, Patompong

    2016-01-01

    Background Proton pump inhibitors (PPIs) are one of the most commonly prescribed medications. Recent studies have raised a concern over increased risk of dementia among PPIs users but the results of those studies were inconsistent. We conducted this systematic review and meta-analysis to summarize all available data. Methods A literature search was performed in MEDLINE and EMBASE database from inception to April 2016. Observational studies that reported risk of dementia among PPIs users compared with non-users were included. Point estimates were extracted from individual studies and pooled risk ratios (RR) with 95% confidence intervals (CI) were calculated using a random-effect, generic inverse variance method. Results Four studies were included in the analysis. Pooled RR of dementia among PPIs users compared with non-users was 1.08 (95% CI, 0.82–1.43). Sensitivity analysis including only cohort studies demonstrated a higher risk with pooled RR of 1.44 (95% CI, 1.36–1.52). Conclusions Our study demonstrated an increased risk of dementia among PPIs users. Whether this association is causal requires further investigations. PMID:27429966

  4. A Proton Recoil Telescope for Neutron Spectroscopy

    NASA Astrophysics Data System (ADS)

    Cinausero, M.; Barbui, M.; Prete, G.; Rizzi, V.; Andrighetto, A.; Pesente, S.; Fabris, D.; Lunardon, M.; Nebbia, G.; Viesti, G.; Moretto, S.; Morando, M.; Zenoni, A.; Bocci, F.; Donzella, A.; Bonomi, G.; Fontana, A.

    2006-05-01

    The N2P research program funded by the INFN committee for Experimental Nuclear Physics (CSNIII) has among his goals the construction of a Proton Recoil Telescope (PRT), a detector to measure neutron energy spectra. The interest in such a detector is primarily related to the SPES project for rare beams production at the Laboratori Nazionali di Legnaro. For the SPES project it is, in fact, of fundamental importance to have reliable information about energy spectra and yield for neutrons produced by d or p projectiles on thick light targets to model the ''conversion target'' in which the p or d are converted in neutrons. These neutrons, in a second stage, will induce the Uranium fission in the ''production target''. The fission products are subsequently extracted, selected and re-accelerated to produce the exotic beam. The neutron spectra and angular distribution are important parameters to define the final production of fission fragments. In addition, this detector can be used to measure neutron spectra in the field of cancer therapy (this topic is nowadays of particular interest to INFN, for the National Centre for Hadron therapy (CNAO) in Pavia) and space applications.

  5. New Physics and the Proton Radius Problem

    SciTech Connect

    Carl E. Carlson, Benjamin C. Rislow

    2012-08-01

    Background: The recent disagreement between the proton charge radius extracted from Lamb shift measurements of muonic and electronic hydrogen invites speculation that new physics may be to blame. Several proposals have been made for new particles that account for both the Lamb shift and the muon anomalous moment discrepancies. Purpose: We explore the possibility that new particles' couplings to the muon can be fine-tuned to account for all experimental constraints. Method: We consider two fine-tuned models, the first involving new particles with scalar and pseudoscalar couplings, and the second involving new particles with vector and axial couplings. The couplings are constrained by the Lamb shift and muon magnetic moments measurements while mass constraints are obtained by kaon decay rate data. Results: For the scalar-pseudoscalar model, masses between 100 to 200 MeV are not allowed. For the vector model, masses below about 200 MeV are not allowed. The strength of the couplings for both models approach that of electrodynamics for particle masses of about 2 GeV. Conclusions: New physics with fine tuned couplings may be entertained as a possible explanation for the Lamb shift discrepancy.

  6. {beta}-delayed proton decays near the proton drip line

    SciTech Connect

    Xu, S.-W.; Li, Z.-K.; Xie, Y.-X.; Pan, Q.-Y.; Huang, W.-X.; Wang, X.-D.; Yu, Y.; Xing, Y.-B.; Shu, N.-C.; Chen, Y.-S.; Xu, F.-R.; Wang, K.

    2005-05-01

    We briefly reviewed and summarized the experimental study on {beta}-delayed proton decays published by our group over the last 8 years, namely the experimental observation of {beta}-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N{approx}Z by utilizing the p-{gamma} coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for {sup 85}Mo, {sup 92}Rh, as well as the predicted 'waiting point' nuclei {sup 89}Ru and {sup 93}Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Moeller et al. [At. Data Nucl. Data Tables 66,131(1997)]. These data considerably influenced the predictions of the mass abundances of the nuclides produced in the rp process. (2) The experimental assignments of spin and parity for the drip-line nuclei {sup 142}Ho and {sup 128}Pm could not be well predicted by any of the nuclear models. Nevertheless, the configuration-constrained nuclear potential-energy surfaces calculated by means of a Woods-Saxon-Strutinsky method could reproduce the assignments. (3) The ALICE code overestimated by one or two orders of magnitude the production-reaction cross sections of the nine studied rare-earth nuclei, while the HIVAP code overestimated them by approximately one order of magnitude.

  7. Systematic measurements of proton-induced reactions on enriched molybdenum

    NASA Astrophysics Data System (ADS)

    Lamere, Edward; Gilardy, Gwenaelle; Meisel, Zach; Moran, Michael; Seymore, Christopher; Skulski, Michael; Simonetti, Antonio; Couder, Manoel

    2016-09-01

    Between 2008 and 2010, shortages in the world-wide supply of Mo highlighted weaknesses in the current fission-based production method of mTc, a critical medical isotope. This crisis sparked interest in developing the direct production of mTc from proton-induced reactions on enriched Mo targets as an alternative. One complication with this method is that mTc must be chemically extracted from the irradiated target. Therefore, radiopharmaceuticals produced from proton bombardment will contain a mixture of all Tc-species with open production channels, affecting radiochemical purity, specific activity and total production yield of mTc-factors critical for the feasibility of this production method. Reactions on trace impurities in the enriched targets have been shown to impact these factors dramatically. Precise cross-section measurements for all Mo +p reactions that lead to Tc or Mo species are required for proper assessment of this production technique. Cross-section measurements for the main reaction of interest, mTc(p,2n), have been performed in recent years, however, other reactions producing Tc have been mostly neglected. We will introduce a systematic study of proton-induced reactionson 92, 94-98, 100 Mo currently being performed at Notre Dame. Preliminary results will be presented. NRC-HQ-12-G-38-0073.

  8. High-energy proton radiation belt.

    NASA Technical Reports Server (NTRS)

    White, R. S.

    1973-01-01

    The experiments and theories to explain the high-energy protons trapped in the earth's radiation belt are reviewed. The theory of cosmic ray albedo neutron decay injection of protons into the radiation belt is discussed. Radial diffusion and change in the earth's dipole moment are considered along with losses of protons by ionization and nuclear collision. It is found that the measured albedo neutron escape current is sufficient to supply trapped protons above 30 MeV. The theoretical calculations of the trapped protons are in agreement with the measurements for L less than or equal to 1.7 both on and off the equator. For L greater than or equal to 1.7, additional trapped proton differential energy measurements should be made before the theory can be adequately tested. It appears that an additional loss mechanism such as pitch angle scattering may be required.

  9. An observation of proton-induced latchup

    NASA Technical Reports Server (NTRS)

    Nichols, Donald K.; Coss, James R.; Watson, R. K.; Schwartz, Harvey R.; Pease, Ronald L.

    1992-01-01

    Proton-induced latchup in a CMOS microprocessor known to have a very low heavy-ion-induced latchup threshold LET was observed. The latchup cross section vs. proton energy for three different bias conditions is displayed. Average measures of latchup current within an 11-ms window following the onset of latchup are provided, as a function of bias and incident proton energy. These data can be interpreted in terms of the present understanding of SEE phenomena.

  10. Molecular mechanisms for generating transmembrane proton gradients.

    PubMed

    Gunner, M R; Amin, Muhamed; Zhu, Xuyu; Lu, Jianxun

    2013-01-01

    Membrane proteins use the energy of light or high energy substrates to build a transmembrane proton gradient through a series of reactions leading to proton release into the lower pH compartment (P-side) and proton uptake from the higher pH compartment (N-side). This review considers how the proton affinity of the substrates, cofactors and amino acids are modified in four proteins to drive proton transfers. Bacterial reaction centers (RCs) and photosystem II (PSII) carry out redox chemistry with the species to be oxidized on the P-side while reduction occurs on the N-side of the membrane. Terminal redox cofactors are used which have pKas that are strongly dependent on their redox state, so that protons are lost on oxidation and gained on reduction. Bacteriorhodopsin is a true proton pump. Light activation triggers trans to cis isomerization of a bound retinal. Strong electrostatic interactions within clusters of amino acids are modified by the conformational changes initiated by retinal motion leading to changes in proton affinity, driving transmembrane proton transfer. Cytochrome c oxidase (CcO) catalyzes the reduction of O2 to water. The protons needed for chemistry are bound from the N-side. The reduction chemistry also drives proton pumping from N- to P-side. Overall, in CcO the uptake of 4 electrons to reduce O2 transports 8 charges across the membrane, with each reduction fully coupled to removal of two protons from the N-side, the delivery of one for chemistry and transport of the other to the P-side.

  11. Recent Development in Proton Spin Physics

    SciTech Connect

    Yuan, Feng

    2008-12-10

    In the naive model of the proton, its 1/2 spin is carried by its quark constituents. However, experiments over the last several decades have shown that the quark spin only contribute a small portion of the proton spin. In this talk, I will present recent developments exploring this proton spin puzzle, and focus on the progress made in the last few years on the longitudinal spin physics, the generalized parton distribution physics, and the transverse spin physics.

  12. Molecular mechanisms for generating transmembrane proton gradients

    PubMed Central

    Gunner, M.R.; Amin, Muhamed; Zhu, Xuyu; Lu, Jianxun

    2013-01-01

    Membrane proteins use the energy of light or high energy substrates to build a transmembrane proton gradient through a series of reactions leading to proton release into the lower pH compartment (P-side) and proton uptake from the higher pH compartment (N-side). This review considers how the proton affinity of the substrates, cofactors and amino acids are modified in four proteins to drive proton transfers. Bacterial reaction centers (RCs) and photosystem II (PSII) carry out redox chemistry with the species to be oxidized on the P-side while reduction occurs on the N-side of the membrane. Terminal redox cofactors are used which have pKas that are strongly dependent on their redox state, so that protons are lost on oxidation and gained on reduction. Bacteriorhodopsin is a true proton pump. Light activation triggers trans to cis isomerization of a bound retinal. Strong electrostatic interactions within clusters of amino acids are modified by the conformational changes initiated by retinal motion leading to changes in proton affinity, driving transmembrane proton transfer. Cytochrome c oxidase (CcO) catalyzes the reduction of O2 to water. The protons needed for chemistry are bound from the N-side. The reduction chemistry also drives proton pumping from N- to P-side. Overall, in CcO the uptake of 4 electrons to reduce O2 transports 8 charges across the membrane, with each reduction fully coupled to removal of two protons from the N-side, the delivery of one for chemistry and transport of the other to the P-side. PMID:23507617

  13. Molecular Mechanism of Biological Proton Transport

    SciTech Connect

    Pomes, R.

    1998-09-01

    Proton transport across lipid membranes is a fundamental aspect of biological energy transduction (metabolism). This function is mediated by a Grotthuss mechanism involving proton hopping along hydrogen-bonded networks embedded in membrane-spanning proteins. Using molecular simulations, the authors have explored the structural, dynamic, and thermodynamic properties giving rise to long-range proton translocation in hydrogen-bonded networks involving water molecules, or water wires, which are emerging as ubiquitous H{sup +}-transport devices in biological systems.

  14. Compact Proton Accelerator for Cancer Therapy

    SciTech Connect

    Chen, Y; Paul, A C

    2007-06-12

    An investigation is being made into the feasibility of making a compact proton dielectric wall (DWA) accelerator for medical radiation treatment based on the high gradient insulation (HGI) technology. A small plasma device is used for the proton source. Using only electric focusing fields for transporting and focusing the beam on the patient, the compact DWA proton accelerator m system can deliver wide and independent variable ranges of beam currents, energies and spot sizes.

  15. Two-photon exchange corrections in elastic lepton-proton scattering

    NASA Astrophysics Data System (ADS)

    Tomalak, Oleksandr; Vanderhaeghen, Marc

    2016-09-01

    In recent years, two experimental approaches, with and without polarized protons, gave strikingly different results for the ratio of the electric to magnetic proton form factors. Even more recently, a mysterious discrepancy (``the proton radius puzzle'') has been observed in the extraction of the proton charge radius from the muonic hydrogen versus regular hydrogen and electron-proton scattering. Two-photon exchange (TPE) contributions are the largest source of the hadronic uncertainty in these experiments. To determine TPE corrections to the S level in muonic hydrogen, the forward virtual Compton scattering is calculated within dispersion relation (DR) formalism. Comparing a box graph model with the DRs at fixed low momentum transfer, we develop and test the subtracted DR formalism for TPE in electron-proton scattering. Its relative effect on the cross section is in the 1 - 2 % range. We include the inelastic states both in the approximation of the near-forward unpolarized virtual Compton scattering as well as using the empirical information on the πN states contribution. We compare the resulting TPE with MAMI, VEPP-3 and CLAS data, and make predictions for the OLYMPUS and the forthcoming MUSE experiments.

  16. Proton Therapy At Siteman Cancer Center: The State Of The Art

    NASA Astrophysics Data System (ADS)

    Bloch, Charles

    2011-06-01

    Barnes-Jewish Hospital is on the verge of offering proton radiation therapy to its patients. Those treatments will be delivered from the first Monarch 250, a state-of-the-art cyclotron produced by Still River Systems, Inc., Littleton, MA. The accelerator is the world's first superconducting synchrocyclotron, with a field-strength of 10 tesla, providing the smallest accelerator for high-energy protons currently available. On May 14, 2010 it was announced that the first production unit had successfully extracted 250 MeV protons. That unit is scheduled for delivery to the Siteman Cancer Center, an NCI-designated Comprehensive Cancer Center at Washington University School of Medicine. At a weight of 20 tons and with a diameter of less than 2 meters the compact cyclotron will be mounted on a gantry, another first for proton therapy systems. The single-energy system includes 3 contoured scatterers and 14 different range modulators to provide 24 distinct beam delivery configurations. This allows proton fields up to 25 cm in diameter, with a maximum range from 5.5 to 32 cm and spread-out-Bragg-peak extent up to 20 cm. Monte Carlo simulations have been run using MCNPX to simulate the clinical beam properties. Those calculations have been used to commission a commercial treatment planning system prior to final clinical measurements. MCNPX was also used to calculate the neutron background generated by protons in the scattering system and patient. Additional details of the facility and current status will be presented.

  17. Simultaneous Quantitative Imaging of Electrical Properties and Proton Density from B1 Maps Using MRI.

    PubMed

    Liu, Jiaen; Van de Moortele, Pierre-Francois; Zhang, Xiaotong; Wang, Yicun; He, Bin

    2016-03-29

    Electrical conductivity and permittivity of biological tissues are important diagnostic parameters and are useful for calculating subject-specific specific absorption rate distribution. On the other hand, water proton density also has clinical relevance for diagnosis purposes. These two kinds of tissue properties are inevitably associated in the technique of electrical properties tomography (EPT), which can be used to map in vivo electrical properties based on the measured B1 field distribution at Larmor frequency using magnetic resonance imaging (MRI). The signal magnitude in MR images is locally proportional to both the proton density of tissue and the receive B1 field; this is a source of artifact in receive B1-based EPT reconstruction because these two quantities cannot easily be disentangled. In this study, a new method was proposed for simultaneously extracting quantitative conductivity, permittivity and proton density from the measured magnitude of transmit B1 field, proton density-weighted receive B1 field, and transceiver phase, in a multi-channel radiofrequency (RF) coil using MRI, without specific assumptions to derive the proton density distribution. We evaluated the spatial resolution, sensitivity to contrast, and accuracy of the method using numerical simulations of B1 field in a phantom and in a realistic human head model. Using the proposed method, conductivity, permittivity and proton density were then experimentally obtained ex vivo in a pork tissue sample on a 7T MRI scanner equipped with a 16-channel microstrip transceiver RF coil.

  18. Simultaneous Quantitative Imaging of Electrical Properties and Proton Density From B1 Maps Using MRI.

    PubMed

    Jiaen Liu; Van de Moortele, Pierre-Francois; Xiaotong Zhang; Yicun Wang; Bin He

    2016-09-01

    Electrical conductivity and permittivity of biological tissues are important diagnostic parameters and are useful for calculating subject-specific specific absorption rate distribution. On the other hand, water proton density also has clinical relevance for diagnosis purposes. These two kinds of tissue properties are inevitably associated in the technique of electrical properties tomography (EPT), which can be used to map in vivo electrical properties based on the measured B1 field distribution at Larmor frequency using magnetic resonance imaging (MRI). The signal magnitude in MR images is locally proportional to both the proton density of tissue and the receive B1 field; this is a source of artifact in receive B1-based EPT reconstruction because these two quantities cannot easily be disentangled. In this study, a new method was proposed for simultaneously extracting quantitative conductivity, permittivity and proton density from the measured magnitude of transmit B1 field, proton density-weighted receive B1 field, and transceiver phase, in a multi-channel radiofrequency (RF) coil using MRI, without specific assumptions to derive the proton density distribution. We evaluated the spatial resolution, sensitivity to contrast, and accuracy of the method using numerical simulations of B1 field in a phantom and in a realistic human head model. Using the proposed method, conductivity, permittivity and proton density were then experimentally obtained ex vivo in a pork tissue sample on a 7T MRI scanner equipped with a 16-channel microstrip transceiver RF coil.

  19. Indirect self-modulation instability measurement concept for the AWAKE proton beam

    NASA Astrophysics Data System (ADS)

    Turner, M.; Petrenko, A.; Biskup, B.; Burger, S.; Gschwendtner, E.; Lotov, K. V.; Mazzoni, S.; Vincke, H.

    2016-09-01

    AWAKE, the Advanced Proton-Driven Plasma Wakefield Acceleration Experiment, is a proof-of-principle R&D experiment at CERN using a 400 GeV / c proton beam from the CERN SPS (longitudinal beam size σz = 12 cm) which will be sent into a 10 m long plasma section with a nominal density of ≈ 7 ×1014 atoms /cm3 (plasma wavelength λp = 1.2 mm). In this paper we show that by measuring the time integrated transverse profile of the proton bunch at two locations downstream of the AWAKE plasma, information about the occurrence of the self-modulation instability (SMI) can be inferred. In particular we show that measuring defocused protons with an angle of 1 mrad corresponds to having electric fields in the order of GV/m and fully developed self-modulation of the proton bunch. Additionally, by measuring the defocused beam edge of the self-modulated bunch, information about the growth rate of the instability can be extracted. If hosing instability occurs, it could be detected by measuring a non-uniform defocused beam shape with changing radius. Using a 1 mm thick Chromox scintillation screen for imaging of the self-modulated proton bunch, an edge resolution of 0.6 mm and hence an SMI saturation point resolution of 1.2 m can be achieved.

  20. Compensation of the beam-beam effect in proton-proton colliders

    SciTech Connect

    Tsyganov, E.; Meinke, R.; Nexsen, W.; Zinchenko, A.

    1993-10-01

    Compensation of the beam-beam effect in high-energy proton-proton colliders using a low-energy electron beam is proposed. It is concluded that such compensation looks feasible. Requirements for such a device are formulated.

  1. Surface proton transport of fully protonated poly(aspartic acid) thin films on quartz substrates

    NASA Astrophysics Data System (ADS)

    Nagao, Yuki; Kubo, Takahiro

    2014-12-01

    Thin film structure and the proton transport property of fully protonated poly(aspartic acid) (P-Asp100) have been investigated. An earlier study assessed partially protonated poly(aspartic acid), highly oriented thin film structure and enhancement of the internal proton transport. In this study of P-Asp100, IR p-polarized multiple-angle incidence resolution (P-MAIR) spectra were measured to investigate the thin film structure. The obtained thin films, with thicknesses of 120-670 nm, had no oriented structure. Relative humidity dependence of the resistance, proton conductivity, and normalized resistance were examined to ascertain the proton transport property of P-Asp100 thin films. The obtained data showed that the proton transport of P-Asp100 thin films might occur on the surface, not inside of the thin film. This phenomenon might be related with the proton transport of the biological system.

  2. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-12-03

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  3. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2008-07-08

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  4. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-06-25

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  5. Proton beam therapy control system

    DOEpatents

    Baumann, Michael A.; Beloussov, Alexandre V.; Bakir, Julide; Armon, Deganit; Olsen, Howard B.; Salem, Dana

    2010-09-21

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  6. Nuclear interaction cross sections for proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Jones, D. T. L.; Arendse, G. J.; Cowley, A. A.; Richter, W. A.; Lawrie, J. J.; Newman, R. T.; Pilcher, J. V.; Smit, F. D.; Steyn, G. F.; Koen, JW; Stander, JA

    Model calculations of proton-induced nuclear reaction cross sections are described for biologically-important targets. Measurements made at the National Accelerator Centre are presented for double-differential proton, deuteron, triton, helium-3 and alpha particle spectra, for 150 and 200 MeV protons incident on C, N, and O. These data are needed for Monte Carlo simulations of radiation transport and absorbed dose in proton therapy. Data relevant to the use of positron emission tomography to locate the Bragg peak are also described.

  7. Molecular mechanisms for proton transport in membranes.

    PubMed Central

    Nagle, J F; Morowitz, H J

    1978-01-01

    Likely mechanisms for proton transport through biomembranes are explored. The fundamental structural element is assumed to be continuous chains of hydrogen bonds formed from the protein side groups, and a molecular example is presented. From studies in ice, such chains are predicted to have low impedance and can function as proton wires. In addition, conformational changes in the protein may be linked to the proton conduction. If this possibility is allowed, a simple proton pump can be described that can be reversed into a molecular motor driven by an electrochemical potential across the membrane. PMID:272644

  8. Transverse relaxation of scalar-coupled protons.

    PubMed

    Segawa, Takuya F; Baishya, Bikash; Bodenhausen, Geoffrey

    2010-10-25

    In a preliminary communication (B. Baishya, T. F. Segawa, G. Bodenhausen, J. Am. Chem. Soc. 2009, 131, 17538-17539), we recently demonstrated that it is possible to obtain clean echo decays of protons in biomolecules despite the presence of homonuclear scalar couplings. These unmodulated decays allow one to determine apparent transverse relaxation rates R(2) (app) of individual protons. Herein, we report the observation of R(2) (app) for three methyl protons, four amide H(N) protons, and all 11 backbone H(α) protons in cyclosporin A. If the proton resonances overlap, their R(2) (app) rates can be measured by transferring their magnetization to neighboring (13)C nuclei, which are less prone to overlap. The R(2) (app) rates of protons attached to (13)C are faster than those attached to (12)C because of (13)C-(1)H dipolar interactions. The differences of these rates allow the determination of local correlation functions. Backbone H(N) and H(α) protons that have fast decay rates R(2) (app) also feature fast longitudinal relaxation rates R(1) and intense NOESY cross peaks that are typical of crowded environments. Variations of R(2) (app) rates of backbone H(α) protons in similar amino acids reflect differences in local environments.

  9. Extracellular proton release by stimulated neutrophils

    SciTech Connect

    van Zwieten, R.; Wever, R.; Hamers, M.N.; Weening, R.S.; Roos, D.

    1981-07-01

    We have tried to elucidate the mechanism of phagosome acidification in human neutrophils. Assuming that phenomena occurring at the plasma membrane reflect reactions in the phagocytic vacuoles, we have stimulated human neutrophils with agents that induce a ''respiratory burst,'' and we have measured the release of protons into the extracellular medium. Phorbol myristate acetate, N-formyl-methionyl-leucyl-phenylalanine and serum-opsonized zymosan particles each caused a rapid release of protons, concomitant with the increase in oxygen consumption. The stimulated release of protons was strictly coupled to the increase respiration of the cells, because inhibition of the respiration of either anaerobiosis, chlorpromazine, or glycolytic inhibitors also inhibited the release of protons. Also, in the presence of the above-mentioned stimulating agents, neutrophils from three patients with chronic granulomatous disease enhanced neither respiration not proton release. In normal cells, the ratio of deltaH+/-deltaO2 was 1.04 +/- 0.19 (mean +/ SD, n . 13). The mechanism of this proton release is not clear. The amount of lactic and carbonic acid produced by stimulated neutrophils was inadequate to explain the amount of protons released. Perhydroxyl radicals were also ruled out as the source of the protons. Because the cells did not release measurable amounts of phosphate ions, a phosphate-hydroxyl-ion antiport was also excluded. Finally, the lack of any effect of uncouplers renders it unlikely that a respiration-driven proton gradient is built up across the plasma membrane.

  10. Cascaded proton acceleration by collisionless electrostatic shock

    SciTech Connect

    Xu, T. J.; Shen, B. F. E-mail: zhxm@siom.ac.cn; Zhang, X. M. E-mail: zhxm@siom.ac.cn; Yi, L. Q.; Wang, W. P.; Zhang, L. G.; Xu, J. C.; Zhao, X. Y.; Shi, Y.; Liu, C.; Pei, Z. K.

    2015-07-15

    A new scheme for proton acceleration by cascaded collisionless electrostatic shock (CES) is proposed. By irradiating a foil target with a moderate high-intensity laser beam, a stable CES field can be induced, which is employed as the accelerating field for the booster stage of proton acceleration. The mechanism is studied through simulations and theoretical analysis, showing that a 55 MeV seed proton beam can be further accelerated to 265 MeV while keeping a good energy spread. This scheme offers a feasible approach to produce proton beams with energy of hundreds of MeV by existing available high-intensity laser facilities.

  11. Phonon coupling effects in proton scattering from Ca40

    NASA Astrophysics Data System (ADS)

    Mackintosh, R. S.; Keeley, N.

    2014-10-01

    Background: Formal optical model theory shows that coupling to vibrational nuclear states generates a nonlocal and l-dependent dynamical polarization potential (DPP). Little is established concerning the DPP, yet its properties are crucial for explaining the departures of optical model potentials (OMPs) from global behavior and for the rigorous extraction of spectroscopic information from direct reactions. Purpose: To appraise the application of channel coupling followed by S-matrix inversion for the systematic exploration of the contribution of the coupling of collective states to the nucleon OMP and to identify properties of nuclear potentials indicative of l-dependence. Methods: S-matrix to potential, Slj→V(r )+l .sVSO(r), inversion provides local potentials that precisely reproduce the elastic channel S-matrix from coupled channel (CC) calculations. Subtracting the elastic channel uncoupled (bare) potential yields a local and l-independent representation of the DPP. The dependence of this local DPP upon the nature of the coupled states and upon other parameters can be studied. Results: All components of the DPP arising from coupling to vibrational states are substantially undulatory with a point-by-point magnitude therefore disproportionate to their contribution to volume integrals. Information relating to dynamical nonlocality is found. The proton charge leads to a substantial difference between DPPs for protons and neutrons. Conclusions: Undulatory features in potentials found in precision fits to elastic scattering data are significant, are a consequence of coupling to inelastic channels and must be allowed for in phenomenology; they are indirect evidence of l-dependence. Within the model, coupling to excited states magnifies the effect of the proton charge on the difference between proton-nucleus and neutron-nucleus interactions. Coupled channel plus inversion is a procedure of wide applicability, complementary to evaluation of the Feshbach formalism.

  12. Charged kaon and proton production in B-hadron decays

    NASA Astrophysics Data System (ADS)

    Tegenfeldt, Fredrik Per

    The production of charged kaons and protons in B-hadron decays has been measured in e+e- annihilations at centre-of-mass energies corresponding to the Z0 mass. In total 1.6 million hadronic Z0 decays were analysed, corresponding to about 690000 B-hadron decays. They were collected using the DELPHI detector at the LEP collider at CERN during 1994 and 1995. Events containing B-hadron decays were identified using special characteristics of the B-hadron decay topology. In particular, the long lifetime of the B-hadron leads to decay vertices significantly displaced relative the interaction point. These so called secondary vertices were reconstructed using a powerful micro vertex detector. In order to discriminate B-hadron decay products from fragmentation tracks, a method was used where the impact parameter measured by the vertex detector was employed as a discriminating variable. The tracks were thus divided into two classes, one compatible with the interaction point and the other compatible with a secondary vertex. An unfolding method was used to extract the true B-hadron decay tracks from the two classes. Charged kaons and protons were identified using the Ring Imaging CHerenkov (RICH) detector and corrected for misidentification using an efficiency matrix. The analysis resulted in charged kaon and proton spectra from B-hadron decays, including previously unmeasured momentum regions. Integrating the spectra yielded the following multiplicities n(B- hadron-->K+/- X)=0.683+/-0.021(stat) +/-0.017(syst) n(B- hadron-->p/p X)=0.127+/-0.013(stat) +/-0.019(syst) where the proton multiplicity does not include Λ baryon decay products.

  13. Fluid extraction

    DOEpatents

    Wai, Chien M.; Laintz, Kenneth E.

    1999-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  14. A Tandetron as proton injector for the eye tumor therapy in Berlin

    SciTech Connect

    Roehrich, J.; Damerow, T.; Hahn, W.; Mueller, U.; Denker, A.; Reinholz, U.

    2012-02-15

    The therapy of eye tumors with fast protons is an excellent tool giving very high local control rates. At the Helmholtz-Zentrum Berlin (HZB) almost 1800 patients were treated since 1998. A 2 MV Tandetron was installed as injector for the k = 132 HZB cyclotron. Using the standard 358 duoplasmatron ion source with direct extraction of negative hydrogen ions an extremely stable proton beam can be delivered, both on the short-term and the long-term scale. The hair-needle filaments made from thoriated tungsten wires have safe operation times of more than 1000 h.

  15. Nucleon Resonance Electrocouplings from the CLAS Data on Exclusive Meson Electroproduction off Protons

    SciTech Connect

    Victor I. Mokeev, Inna G. Aznauryan, Volker D. Burkert

    2011-12-01

    {gamma}{sub v}NN* transition helicity amplitudes (electrocouplings) of several prominent excited proton states are determined for the first time in independent analyses of {pi}{sup +}n, {pi}{sup 0}p, and {pi}{sup +}{pi}{sup -}p electroproduction off protons. Consistent results on resonance electrocouplings obtained from major meson electroproduction channels offer an evidence for reliable extraction of these fundamental quantities. Analysis of {pi}{sup +}{pi}{sup -}p electroproduction has extended considerably information on electrocouplings of high lying N* states, which decay preferentially to the N{pi}{pi} final states.

  16. Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS

    SciTech Connect

    Silvia Niccolai

    2012-04-01

    This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH{sub 3}) and deuterons (ND{sub 3}) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

  17. Parameterization of spectral distributions for pion and kaon production in proton-proton collisions.

    PubMed

    Schneider, J P; Norbury, J W; Cucinotta, F A

    1995-04-01

    Accurate semi-empirical parameterizations of the energy-differential cross sections for charged pion and kaon production from proton-proton collisions are presented at energies relevant to cosmic rays. The parameterizations depend on the outgoing meson momentum and also the proton energy, and are able to be reduced to very simple analytical formulas suitable for cosmic-ray transport.

  18. Parameterization of spectral distributions for pion and kaon production in proton-proton collisions

    NASA Technical Reports Server (NTRS)

    Schneider, John P.; Norbury, John W.; Cucinotta, Frank A.

    1995-01-01

    Accurate semi-empirical parameterizations of the energy-differential cross sections for charged pion and kaon production from proton-proton collisions are presented at energies relevant to cosmic rays. The parameterizations depend on the outgoing meson momentum and also the proton energy, and are able to be reduced to very simple analytical formulas suitable for cosmic-ray transport.

  19. 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.

  20. Proton transport in triflic acid hydrates studied via path integral car-parrinello molecular dynamics.

    PubMed

    Hayes, Robin L; Paddison, Stephen J; Tuckerman, Mark E

    2009-12-31

    The mono-, di-, and tetrahydrates of trifluoromethanesulfonic acid, which contain characteristic H(3)O(+), H(5)O(2)(+), and H(9)O(4)(+) structures, provide model systems for understanding proton transport in materials with high perfluorosulfonic acid density such as perfluorosulfonic acid membranes commonly employed in hydrogen fuel cells. Ab initio molecular dynamics simulations indicate that protons in these solids are predisposed to transfer to the water most strongly bound to sulfonate groups via a Grotthuss-type mechanism, but quickly return to the most solvated defect structure either due to the lack of a nearby species to stabilize the new defect or a preference for the proton to be maximally hydrated. Path integral molecular dynamics of the mono- and dihydrate reveal significant quantum effects that facilitate proton transfer to the "presolvated" water or SO(3)(-) in the first solvation shell and increase the Zundel character of all the defects. These trends are quantified in free energy profiles for each bonding environment. Hydrogen bonding criteria for HOH-OH(2) and HOH-O(3)S are extracted from the two-dimensional potential of mean force. The quantum radial distribution function, radius of gyration, and root-mean-square displacement position correlation function show that the protonic charge is distributed over two or more water molecules. Metastable structural defects with one excess proton shared between two sulfonate groups and another Zundel or Eigen type cation defect are found for the mono- and dihydrate but not for the tetrahydrate crystal. Results for the tetrahydrate native crystal exhibit minor differences at 210 and 250 K. IR spectra are calculated for all native and stable defect structures. Graph theory techniques are used to characterize the chain lengths and ring sizes in the hydrogen bond network. Low conductivities when limited water is present may be attributable to trapping of protons between SO(3)(-) groups and the increased

  1. MCNP5 for proton radiography.

    SciTech Connect

    Hughes, H. G.; Brown, F. B.; Bull, J. S.; Goorley, J. T.; Little, R. C.; Liu, L. C.; Mashnik, S. G.; Prael, R. E.; Selcow, Elizabeth Carol,; Sierk, A. J.; Sweezy, J. E.; Zumbro, J. D.; Mokhov, N. V.; Striganov, S.; Gudima, K. K.

    2004-01-01

    The developmental version of MCNPS has recently been extended to provide for continuous-energy transport of high-energy protons. This enhancement involves the incorporation of several significant new physics models into the code. Multiple Coulomb scattering is treated with an advanced model that takes account of projectile and nuclear target form factors. In the next version, this model will provide a coupled sampling of both angular deflection and collisional energy loss, including straggling. The proton elastic scattering model is also new, based on recent theoretical work. Charged particle transport in the presence of magnetic fields is accomplished either by using transfer maps from the COSY INFINITY code (in void regions) or by using an algorithm adapted from the MARS code (in void regions or in scattering materials). Work is underway to validate and implement the latest versions of the Cascade-Exciton Model and the Los Alamos Quark-Gluon-String Model, which will process inelastic nuclear interactions and generate secondary particles.

  2. New interplanetary proton fluence model

    NASA Technical Reports Server (NTRS)

    Feynman, Joan; Armstrong, T. P.; Dao-Gibner, L.; Silverman, S.

    1990-01-01

    A new predictive engineering model for the interplanetary fluence of protons with above 10 MeV and above 30 MeV is described. The data set used is a combination of observations made from the earth's surface and from above the atmosphere between 1956 and 1963 and observations made from spacecraft in the vicinity of earth between 1963 and 1985. The data cover a time period three times as long as the period used in earlier models. With the use of this data set the distinction between 'ordinary proton events' and 'anomalously large events' made in earlier work disappears. This permitted the use of statistical analysis methods developed for 'ordinary events' on the entire data set. The greater than 10 MeV fluences at 1 AU calculated with the new model are about twice those expected on the basis of models now in use. At energies above 30 MeV, the old and new models agree. In contrast to earlier models, the results do not depend critically on the fluence from any one event and are independent of sunspot number. Mission probability curves derived from the fluence distribution are presented.

  3. PROTONATED POLYCYCLIC AROMATIC HYDROCARBONS REVISITED

    SciTech Connect

    Ricca, Alessandra; Bauschlicher, Charles W. Jr; Allamandola, Louis J. E-mail: Charles.W.Bauschlicher@nasa.gov

    2011-02-01

    We reconsider the contribution that singly protonated polycyclic aromatic hydrocarbons (PAHs; HPAH{sup +}s) might make to the Class A component of the 6.2 {mu}m interstellar emission feature in light of the recent experimental measurements of protonated naphthalene and coronene. Our calculations on the small HPAH{sup +}s have a band near 6.2 {mu}m, as found in experiment. While the larger HPAH{sup +}s still have emission near 6.2 {mu}m, the much larger intensity of the band near 6.3 {mu}m overwhelms the weaker band at 6.2 {mu}m, so that the 6.2 {mu}m band is barely visible. Since the large PAHs are more representative of those in the interstellar medium, our work suggests that large HPAH{sup +}s cannot be major contributors to the observed emission at 6.2 {mu}m (i.e., Class A species). Saturating large PAH cations with hydrogen atoms retains the 6.2 {mu}m Class A band position, but the rest of the spectrum is inconsistent with observed spectra.

  4. Treatment planning for conformal proton radiation therapy.

    PubMed

    Bussière, Mark R; Adams, Judith A

    2003-10-01

    Clinical results from various trials have demonstrated the viability of protons in radiation therapy and radiosurgery. This has motivated a few large medical centers to design and build expensive hospital based proton facilities based proton facilities (current cost estimates for a proton facility is around 100 million US dollars). Until this development proton therapy was done using retrofitted equipment originally designed for nuclear experiments. There are presently only three active proton therapy centers in the United States, 22 worldwide. However, more centers are under construction and being proposed in the US and abroad. The important difference between proton and x-ray therapy is in the dose distribution. X-rays deposit most of their dose at shallow depths of a few centimeters with a gradual decay with depth in the patient. Protons deliver most of their dose in the Bragg peak, which can be delivered at most clinically required depths followed by a sharp fall-off. This sharp falloff makes protons sensitive to variations in treatment depths within patients. Treatment planning incorporates all the knowledge of protons into a process, which allows patients to be treated accurately and reliably. This process includes patient immobilization, imaging, targeting, and modeling of planned dose distributions. Although the principles are similar to x-ray therapy some significant differences exist in the planning process, which described in this paper. Target dose conformality has recently taken on much momentum with the advent of intensity modulated radiation therapy (IMRT) with photon beams. Proton treatments provide a viable alternative to IMRT because they are inherently conformal avoiding normal tissue while irradiating the intended targets. Proton therapy will soon bring conformality to a new high with the development of intensity modulated proton therapy (IMPT). Future challenges include keeping the cost down, increasing access to conventional proton therapy as

  5. M2 Proton Channel: Toward a Model of a Primitive Proton Pump

    NASA Astrophysics Data System (ADS)

    Wei, Chenyu; Pohorille, Andrew

    2015-06-01

    Transmembrane proton transfer was essential to early cellular systems in order to transduce energy for metabolic functions. The reliable, efficient and controlled generation of proton gradients became possible only with the emergence of active proton pumps. On the basis of features shared by most modern proton pumps we identify the essential mechanistic steps in active proton transport. Further, we discuss the mechanism of action of a small, transmembrane M2 proton channel from influenza A virus as a model for proton transport in protocells. The M2 channel is a 94-residue long, α-helical tetramer that is activated at low pH and exhibits high selectivity and directionality. A shorter construct, built of transmembrane fragments that are only 24 amino acids in length, exhibits very similar proton transport properties. Molecular dynamics simulations on the microsecond time-scale carried out for the M2 channel provided atomic level details on the activation of the channel in response to protonation of the histidine residue, His37. The pathway of proton conduction is mediated by His37, which accepts and donates protons at different interconverting conformation states when pH is lower than 6.5. The Val27 and Trp41 gates and the salt bridge between Asp44 and Arg45 further enhance the directionality of proton transport. It is argued that the architecture and the mechanism of action similar to that found in the M2 channel might have been the perfect starting point for evolution towards the earliest proton pumps, indicating that active proton transport could have readily emerged from simple, passive proton channels.

  6. Theoretical Analysis of Proton Relays in Electrochemical Proton-Coupled Electron Transfer

    SciTech Connect

    Auer, Benjamin; Fernandez, Laura; Hammes-Schiffer, Sharon

    2011-06-01

    The coupling of long-range electron transfer to proton transport over multiple sites plays a vital role in many biological and chemical processes. Recently a molecule with a hydrogen-bond relay inserted between the proton donor and acceptor sites in a proton-coupled electron transfer (PCET) system was studied electrochemically. The standard rate constants and kinetic isotope effects (KIEs) were measured experimentally for this system and a related single proton transfer system. In the present paper, these systems are studied theoretically using vibronically nonadiabatic rate constant expressions for electrochemical PCET. Application of this approach to proton relays requires the calculation of multidimensional proton vibrational wavefunctions and incorporation of multiple proton donor-acceptor motions. The calculated KIEs and relative standard rate constants for the single and double proton transfer systems are in agreement with the experimental data. The calculations indicate that the standard rate constant is lower for the double proton transfer system because of the smaller overlap integral between the ground state reduced and oxidized proton vibrational wavefunctions for this system, resulting in greater contributions from excited electron-proton vibronic states with higher free energy barriers. The decrease in proton donor-acceptor distances due to thermal fluctuations and the contributions from excited electron-proton vibronic states play important roles in proton relay systems. The theory suggests that the PCET rate constant may be increased by decreasing the equilibrium proton donor-acceptor distances or modifying the thermal motions of the molecule to facilitate the concurrent decrease of these distances. The submission of this journal article in ERIA is a requirement of the EFRC subcontract with Pennsylvania State University collaborators to get publications to OSTI.

  7. M2 proton channel: toward a model of a primitive proton pump.

    PubMed

    Wei, Chenyu; Pohorille, Andrew

    2015-06-01

    Transmembrane proton transfer was essential to early cellular systems in order to transduce energy for metabolic functions. The reliable, efficient and controlled generation of proton gradients became possible only with the emergence of active proton pumps. On the basis of features shared by most modern proton pumps we identify the essential mechanistic steps in active proton transport. Further, we discuss the mechanism of action of a small, transmembrane M2 proton channel from influenza A virus as a model for proton transport in protocells. The M2 channel is a 94-residue long, α-helical tetramer that is activated at low pH and exhibits high selectivity and directionality. A shorter construct, built of transmembrane fragments that are only 24 amino acids in length, exhibits very similar proton transport properties. Molecular dynamics simulations on the microsecond time-scale carried out for the M2 channel provided atomic level details on the activation of the channel in response to protonation of the histidine residue, His37. The pathway of proton conduction is mediated by His37, which accepts and donates protons at different interconverting conformation states when pH is lower than 6.5. The Val27 and Trp41 gates and the salt bridge between Asp44 and Arg45 further enhance the directionality of proton transport. It is argued that the architecture and the mechanism of action similar to that found in the M2 channel might have been the perfect starting point for evolution towards the earliest proton pumps, indicating that active proton transport could have readily emerged from simple, passive proton channels.

  8. On proton CT reconstruction using MVCT-converted virtual proton projections

    SciTech Connect

    Wang Dongxu; Mackie, T. Rockwell; Tome, Wolfgang A.

    2012-06-15

    Purpose: To describe a novel methodology of converting megavoltage x-ray projections into virtual proton projections that are otherwise missing due to the proton range limit. These converted virtual proton projections can be used in the reconstruction of proton computed tomography (pCT). Methods: Relations exist between proton projections and multispectral megavoltage x-ray projections for human tissue. Based on these relations, these tissues can be categorized into: (a) adipose tissue; (b) nonadipose soft tissues; and (c) bone. These three tissue categories can be visibly identified on a regular megavoltage x-ray computed tomography (MVCT) image. With an MVCT image and its projection data available, the x-ray projections through heterogeneous anatomy can be converted to the corresponding proton projections using predetermined calibration curves for individual materials, aided by a coarse segmentation on the x-ray CT image. To show the feasibility of this approach, mathematical simulations were carried out. The converted proton projections, plotted on a proton sinogram, were compared to the simulated ground truth. Proton stopping power images were reconstructed using either the virtual proton projections only or a blend of physically available proton projections and virtual proton projections that make up for those missing due to the range limit. These images were compared to a reference image reconstructed from theoretically calculated proton projections. Results: The converted virtual projections had an uncertainty of {+-}0.8% compared to the calculated ground truth. Proton stopping power images reconstructed using a blend of converted virtual projections (48%) and physically available projections (52%) had an uncertainty of {+-}0.86% compared with that reconstructed from theoretically calculated projections. Reconstruction solely from converted virtual proton projections had an uncertainty of {+-}1.1% compared with that reconstructed from theoretical projections

  9. Chemical Principles Revisited. Proton Magnetic Resonance Spectroscopy.

    ERIC Educational Resources Information Center

    McQuarrie, Donald A.

    1988-01-01

    Discusses how to interpret nuclear magnetic resonance (NMR) spectra and how to use them to determine molecular structures. This discussion is limited to spectra that are a result of observation of only the protons in a molecule. This type is called proton magnetic resonance (PMR) spectra. (CW)

  10. First Polarized Proton Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Roser, T.; Ahrens, L.; Alessi, J.; Bai, M.; Beebe-Wang, J.; Brennan, J. M.; Brown, K. A.; Bunce, G.; Cameron, P.; Courant, E. D.; Drees, A.; Fischer, W.; Fliller, R.; Glenn, W.; Huang, H.; Luccio, A. U.; MacKay, W. W.; Makdisi, Y.; Montag, C.; Pilat, F.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Trbojevic, D.; Tsoupas, N.; van Zeijts, J.; Zelenski, A.; Zeno, K.; Deshpande, A.; Kurita, K.; Krueger, K.; Spinka, H.; Underwood, D.; Syphers, M.; Alekseev, I.; Svirida, D.; Ranjbar, V.; Tojo, J.; Jinnouchi, O.; Okamura, M.; Saito, N.

    2003-05-01

    We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180° about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV.

  11. Proton Therapy Research and Treatment Center

    SciTech Connect

    Goodnight, J.E. Jr. . Cancer Center); Alonso, J.R. )

    1992-05-01

    This Grant proposal outlines the steps that will be undertaken to bring the UC Davis Proton Therapy Research and Treatment, known locally as the Proton Therapy Facility (PTF), through its design and construction phases. This application concentrates on the design phase of the PTF project.

  12. Physics at an upgraded Fermilab proton driver

    SciTech Connect

    Geer, S.; /Fermilab

    2005-07-01

    In 2004 the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future, primarily motivated by the recent exciting developments in neutrino physics. Over the last few months a physics study has developed the physics case for the Fermilab Proton Driver. The potential physics opportunities are discussed.

  13. CONFIGURATION MANUAL POLARIZED PROTON COLLIDER AT RHIC.

    SciTech Connect

    ROSER,T.; MACKAY,W.W.; ALEKSEEV,I.; BAI,M.; BROWN,K.; BUNCE,G.; CAMERON,P.; COURANT,E.; ET AL.

    2001-03-01

    In this report, the authors present their design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. They provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  14. Reduced Calibration Curve for Proton Computed Tomography

    SciTech Connect

    Yevseyeva, Olga; Assis, Joaquim de; Diaz, Katherin

    2010-05-21

    The pCT deals with relatively thick targets like the human head or trunk. Thus, the fidelity of pCT as a tool for proton therapy planning depends on the accuracy of physical formulas used for proton interaction with thick absorbers. Although the actual overall accuracy of the proton stopping power in the Bethe-Bloch domain is about 1%, the analytical calculations and the Monte Carlo simulations with codes like TRIM/SRIM, MCNPX and GEANT4 do not agreed with each other. A tentative to validate the codes against experimental data for thick absorbers bring some difficulties: only a few data is available and the existing data sets have been acquired at different initial proton energies, and for different absorber materials. In this work we compare the results of our Monte Carlo simulations with existing experimental data in terms of reduced calibration curve, i.e. the range - energy dependence normalized on the range scale by the full projected CSDA range for given initial proton energy in a given material, taken from the NIST PSTAR database, and on the final proton energy scale - by the given initial energy of protons. This approach is almost energy and material independent. The results of our analysis are important for pCT development because the contradictions observed at arbitrary low initial proton energies could be easily scaled now to typical pCT energies.

  15. Ring current proton decay by charge exchange

    NASA Technical Reports Server (NTRS)

    Smith, P. H.; Hoffman, R. A.; Fritz, T.

    1975-01-01

    Explorer 45 measurements during the recovery phase of a moderate magnetic storm have confirmed that the charge exchange decay mechanism can account for the decay of the storm-time proton ring current. Data from the moderate magnetic storm of 24 February 1972 was selected for study since a symmetrical ring current had developed and effects due to asymmetric ring current losses could be eliminated. It was found that after the initial rapid decay of the proton flux, the equatorially mirroring protons in the energy range 5 to 30 keV decayed throughout the L-value range of 3.5 to 5.0 at the charge exchange decay rate calculated by Liemohn. After several days of decay, the proton fluxes reached a lower limit where an apparent equilibrium was maintained, between weak particle source mechanisms and the loss mechanisms, until fresh protons were injected into the ring current region during substorms. While other proton loss mechanisms may also be operating, the results indicate that charge exchange can entirely account for the storm-time proton ring current decay, and that this mechanism must be considered in all studies involving the loss of proton ring current particles.

  16. Configuration Manual Polarized Proton Collider at RHIC

    SciTech Connect

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S. Y.; Luccio, A.; MacKay, W. W.; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Svirida, D.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.

    2006-01-01

    In this report we present our design to accelerate and store polarized protons in RHIC, with the level of polarization, luminosity, and control of systematic errors required by the approved RHIC spin physics program. We provide an overview of the physics to be studied using RHIC with polarized proton beams, and a brief description of the accelerator systems required for the project.

  17. Strangeness production with protons and pions

    SciTech Connect

    Dover, C.B.

    1993-04-01

    We discuss the spectrum of physics questions related to strangeness which could be addressed with intense beams of protons and pions in the few GeV region. We focus on various aspects of strangeness production, including hyperon production in pp collisions, studies of hyperon-nucleon scattering, production of hypernuclei in proton and pion-nucleus collisions, and spin phenomena in hypernuclei.

  18. 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.

  19. MO-A-18C-01: Proton Therapy I: Basics of Proton Therapy

    SciTech Connect

    Arjomandy, B; Sahoo, N; Pankuch, M

    2014-06-15

    The goal of this session is to introduce the audience to the physics, dosimetry and treatment planning procedures used in proton therapy. The course material covers the basic physics of proton interaction with matter and physical characteristics of clinical proton beams. It will provide information on proton delivery systems and beam delivery techniques for scattered and scanning proton beams. It will include the requirements for dosimetry measurements and present the equipment needed for commissioning of proton beams for clinical use and quality assurance checks as well as methods used for proton beam calibration and dose verification of patient treatment fields. The session covers the treatment planning strategies for various anatomical sites, methods to address uncertainties in proton therapy and uncertainty mitigation to generate robust treatment plans. Challenges involved in the motion management in proton therapy will also be discussed. Learning Objectives: Gain knowledge on physics, dosimetry, treatment planning and quality assurance for proton therapy. Understand the uncertainties associated with proton therapy and currently used strategies for their mitigation in treatment planning.

  20. Proton conducting ceramic membranes for hydrogen separation

    DOEpatents

    Elangovan, S.; Nair, Balakrishnan G.; Small, Troy; Heck, Brian

    2011-09-06

    A multi-phase proton conducting material comprising a proton-conducting ceramic phase and a stabilizing ceramic phase. Under the presence of a partial pressure gradient of hydrogen across the membrane or under the influence of an electrical potential, a membrane fabricated with this material selectively transports hydrogen ions through the proton conducting phase, which results in ultrahigh purity hydrogen permeation through the membrane. The stabilizing ceramic phase may be substantially structurally and chemically identical to at least one product of a reaction between the proton conducting phase and at least one expected gas under operating conditions of a membrane fabricated using the material. In a barium cerate-based proton conducting membrane, one stabilizing phase is ceria.

  1. Commissioning of the PRIOR proton microscope

    DOE PAGES

    Varentsov, D.; Antonov, O.; Bakhmutova, A.; ...

    2016-02-18

    Recently, a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR Facility for Anti-proton and Ion Research) has been designed, constructed, and successfully commissioned at GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5–4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 μm spatial and 10 ns temporal resolutions of the proton microscope have been demonstrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This study describes the PRIOR setup as well asmore » the results of the first static and dynamic protonradiography experiments performed at GSI.« less

  2. Commissioning of the PRIOR proton microscope

    SciTech Connect

    Varentsov, D.; Antonov, O.; Bakhmutova, A.; Barnes, C. W.; Bogdanov, A.; Danly, C. R.; Efimov, S.; Endres, M.; Fertman, A.; Golubev, A. A.; Hoffmann, D. H. H.; Ionita, B.; Kantsyrev, A.; Krasik, Ya. E.; Lang, P. M.; Lomonosov, I.; Mariam, F. G.; Markov, N.; Mintsev, V. B.; Nikolaev, D.; Panyushkin, V.; Rodionova, M.; Schanz, M.; Schoenberg, K.; Semennikov, A.; Shestov, L.; Skachkov, V. S.; Turtikov, V.; Udrea, S.; Vasylyev, O.; Weyrich, K.; Wilde, C.; Zubareva, A.; Merrill, F. E.

    2016-02-18

    Recently, a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR Facility for Anti-proton and Ion Research) has been designed, constructed, and successfully commissioned at GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5–4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 μm spatial and 10 ns temporal resolutions of the proton microscope have been demonstrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This study describes the PRIOR setup as well as the results of the first static and dynamic protonradiography experiments performed at GSI.

  3. Selective excitation enables assignment of proton resonances and (1)H-(1)H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy.

    PubMed

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of (1)H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as (13)C or (15)N. In this method, after the initial preparation of proton magnetization and cross-polarization to (13)C nuclei, transverse magnetization of desired (13)C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific (13)C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of (1)H-(1)H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  4. Selective excitation enables assignment of proton resonances and 1H-1H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-01

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of 1H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as 13C or 15N. In this method, after the initial preparation of proton magnetization and cross-polarization to 13C nuclei, transverse magnetization of desired 13C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific 13C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of 1H-1H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  5. Selective excitation enables assignment of proton resonances and {sup 1}H-{sup 1}H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    SciTech Connect

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of {sup 1}H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as {sup 13}C or {sup 15}N. In this method, after the initial preparation of proton magnetization and cross-polarization to {sup 13}C nuclei, transverse magnetization of desired {sup 13}C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific {sup 13}C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of {sup 1}H-{sup 1}H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  6. Extractant composition

    DOEpatents

    Smith, Barbara F.; Jarvinen, Gordon D.; Ryan, Robert R.

    1990-01-01

    An organic extracting solution useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  7. Liquid hydrogen in protonic chabazite.

    PubMed

    Zecchina, Adriano; Bordiga, Silvia; Vitillo, Jenny G; Ricchiardi, Gabriele; Lamberti, Carlo; Spoto, Giuseppe; Bjørgen, Morten; Lillerud, Karl Petter

    2005-05-04

    Due to its fully reversible nature, H(2) storage by molecular adsorption could represent an advantage with respect to dissociative processes, where kinetic effects during the charging and discharging processes are present. A drawback of this strategy is represented by the extremely weak interactions that require low temperature and high pressure. High surface area materials hosting polarizing sites can represent a viable way toward more favorable working conditions. Of these, in this contribution, we have studied hydrogen adsorption in a series of zeolites using volumetric techniques and infrared spectroscopy at 15 K. We have found that in H-SSZ-13 zeolite the cooperative role played by high surface area, internal wall topology, and presence of high binding energy sites (protons) allows hydrogen to densify inside the nanopores at favorable temperature and pressure conditions.

  8. The "heartbeat of the proton"

    NASA Astrophysics Data System (ADS)

    Weisskopf, Victor F.

    Once Nino came to my office to tell me about his ideas of studying lepton pair production at PS. I was still not Director General, but Research Director at CERN. In addition to (e+e-) and (μ+μ-) pairs, he wanted to search for (e±μ∓) pairs as a signature of a new lepton carrying its own lepton number. He told me that if such a lepton existed with one GeV mass, it would have escaped detection in hadron accelerator experiments for two reasons: i) it would decay with a lifetime of order 10-11 sec and ii) because there is no π → μ mechanism for such a heavy new lepton: for its production a time-like photon would be needed. Time-like photons could be produced in hadronic interactions: for example in (bar{p}p) annihilation. This was before Lederman-Schwartz and Steinberger had discovered the two neutrinos. To think of a "sequential" Heavy Lepton and to work out the possible ways to get it in a hadron machine was for me extremely interesting Nino had just finished his first high precision work on the muon (g-2). It was some time after the Rochester Conference in 1960. I gave Nino the following suggestion: if you want to search for something so revolutionary as a Heavy Lepton carrying its own lepton number you should work out a proposal for a series of experiments where the study of lepton pairs (e+e-) and (μ+μ-) could be justified in terms of physics accepted by the community. In addition a high intensity antiproton beam was needed. He came later to tell me that he had two very good friends, both excellent engineers: Mario Morpurgo and Guido Petrucci. A very high intensity antiproton beam could be built to study the electromagnetic form factor of the proton in the time-like region. If the proton was "point-like" in the time-like region, the rate of time-like photons yielding (e+e-) and (μ+μ-) pairs could be accessible to experimental observation, thus allowing to establish some limits on the new Heavy Lepton mass, or to see it, via the (e±μ∓) channel. The

  9. Simulations of neutron and proton detection for a 4π plastic scintillator detector

    NASA Astrophysics Data System (ADS)

    Petkovic, Tomislav; Simicevic, N.; Trezeciak, R.; Ullrich, H.

    1997-02-01

    Neutron detection efficiencies for a 4 (pi) plastic scintillator detector were calculated with the Monte Carlo code of Cecil et al for various threshold of 2.5, 5, 7.5, 10 and 20 MeVee, assuming an isotropic distribution of neutrons emerging form the center of the target. A good agreement between the data obtained from the reaction (pi) +4He yields pppn with 120 MeV pions and efficiency calculations has been found. Proton reaction losses for 15, 20 and 35 cm thick plastic detectors were calculated using the GEANT code for proton energies up to 150 MeV. Reaction losses were extracted from the simulated spectra. Our correction curve for proton reaction losses gives slightly higher values than the data of Measday and Serre and the calculation of Janni.

  10. Density slope of the symmetry energy L (ρ0) constrained by proton radioactivity

    NASA Astrophysics Data System (ADS)

    Wan, Niu; Xu, Chang; Ren, Zhongzhou

    2016-10-01

    Background: Recently, the cluster radioactivity of heavy nuclei decaying to 208Pb was successfully used to constrain the density slope of the symmetry energy L (ρ0) at saturation density ρ0. Purpose: By using well-measured experimental decay energy and half-life, proton radioactivity is proposed to further constrain L (ρ0) in this work. Method: From the Hugenholtz-Van Hove theorem, L (ρ0) is found to be directly related to the magnitude of the symmetry potential, which can be extracted from the proton radioactivity within the density-dependent cluster model. Results: By investigating the radioactivity of proton emitters with large isospin asymmetry, the value of the density slope is found to be L (ρ0)=51.8 ±7.2 MeV.

  11. Beam Loss Studies for the 2-MW LBNE Proton Beam Line

    SciTech Connect

    Drozhdin, A.I.; Childress, S.R.; Mokhov, N.V.; Tropin, I.S.; Zwaska, R.; /Fermilab

    2012-05-01

    Severe limits are put on allowable beam loss during extraction and transport of a 2.3 MW primary proton beam for the Long Baseline Neutrino Experiment (LBNE) at Fermilab. Detailed simulations with the STRUCT and MARS codes have evaluated the impact of beam loss of 1.6 x 10{sup 14} protons per pulse at 120 GeV, ranging from a single pulse full loss to sustained small fractional loss. It is shown that loss of a single beam pulse at 2.3 MW will result in a catastrophic event: beam pipe destruction, damaged magnets and very high levels of residual radiation inside and outside the tunnel. Acceptable beam loss limits have been determined and robust solutions developed to enable efficient proton beam operation under these constraints.

  12. Generation of high purity cw proton beams from microwave driven sources

    SciTech Connect

    Spence, D.; Lykke, K.R.

    1995-07-01

    We describe a technique we have developed to significantly increase the proton fraction extracted from high pressure (mTorr) electron cyclotron resonance (ECR) sources of the type developed by Chalk River Laboratories (CRL). Specifically, this proton enhancement is achieved by the addition of environmentally benign additives (H{sub 2}O being the most effective) to the plasma, in molecular concentrations of the order of 1%. Typically, operating under non- resonant source conditions, this technique will enhance the proton fraction from about 75% to greater than 95% for a power input of 700W at 2.45 GHz. Similar results are achieved for deuteron beams. We believe this technique is capable of similar results in arc-discharge (bucket) sources, Penning sources and any other gas discharge sources, under suitable conditions.

  13. Development of a tritium monitor combined with an electrochemical tritium pump using a proton conducting oxide

    SciTech Connect

    Tanaka, M.; Sugiyama, T.

    2015-03-15

    The detection of low level tritium is one of the key issues for tritium management in tritium handling facilities. Such a detection can be performed by tritium monitors based on proton conducting oxide technique. We tested a tritium monitoring system composed of a commercial proportional counter combined with an electrochemical hydrogen pump equipped with CaZr{sub 0.9}In{sub 0.1}O{sub 3-α} as proton conducting oxide. The hydrogen pump operated at 973 K under electrolysis conditions using tritiated water vapor (HTO). The proton conducting oxide extracts tritium molecules (HT) from HTO and tritium concentration is measured by the proportional counter. The advantage of the proposed tritium monitoring system is that it is able to convert HTO into molecular hydrogen.

  14. Feasibility studies of time-like proton electromagnetic form factors at overlinePANDA at FAIR

    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, F.; Lisowski, E.; 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.; Pyszniak, 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.; Alexeev, G.; Arefiev, V. A.; Astakhov, V.; Barabanov, M. Yu.; Batyunya, B. V.; Davydov, Y.; Dodokhov, V. Kh.; Efremov, A.; Fechtchenko, A.; Fedunov, A. G.; Galoyan, A.; Grigoryan, S.; Koshurnikov, E. K.; Lobanov, Y. Yu.; Lobanov, V. I.; Makarov, A. F.; Malinina, L. V.; Malyshev, V.; Olshevskiy, A. G.; 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.; Vodopianov, 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.; Savrie, 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.; Wohlfahrt, B.; Zaunick, H.; Ireland, D.; Rosner, G.; Seitz, B.; Deepak, P. N.; Kulkarni, A.; Apostolou, A.; Babai, M.; Kavatsyuk, M.; Lemmens, P. J.; 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.; Sanchez, S.; 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.; Martínez, M.; Michel, M.; Mora Espí, 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, V.; Balanutsa, P.; 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.; 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.

    2016-10-01

    Simulation results for future measurements of electromagnetic proton form factors at overlinePANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel bar{p}p→ e+e- is studied on the basis of two different but consistent procedures. The suppression of the main background channel, i.e. bar{p}p→ π+π-, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.

  15. {sup 12}O resonant structure evaluated by the two-proton emission process

    SciTech Connect

    Leite, T. N.; Teruya, N.; Dimarco, A.; Duarte, S. B.; Tavares, O. A. P.

    2009-07-15

    The characteristics of the {sup 12}O resonant ground state are investigated through the analysis of the experimental data for the two-proton decay process. The sequential and simultaneous two-proton emission decay modes have been considered in a statistical calculation of the decay energy distribution. The resonant structures of {sup 11}N have been employed as intermediate states for the sequential mode, having their parameters determined by considering the structure of single particle resonance in quantum scattering problem. The width of the {sup 12}O resonant ground state has been extracted from a best fit to the experimental data. The contributions from the different channels to the decay energy distribution have been evaluated, and width and peak location parameters of the {sup 12}O resonant ground state are compared with results of other works for the sequential and simultaneous two-proton decay modes.

  16. Blockage of intracellular proton extrusion with proton extrusions with proton pump inhibitor induces apoptosis in gastric cancer.

    PubMed

    Yeo, Marie; Kim, Dong-Kyu; Park, Hee Jin; Cho, Sung Won; Cheong, Jae Youn; Lee, Kwang Jae

    2008-01-01

    Proton pump inhibitors have been used for treatment of acid-related gastroesophageal diseases and they act as potent inhibitors of gastric acid pump, H(+)/K(+)-ATPase. Since cancer cells in vivo often exist in an ischemic microenvironment with a lower pH, maintenance of cellular pH is important for cell survival. In this study, we evaluated whether blocking of proton extrusion with proton pump inhibitors could inhibit the viability of gastric cancer cells. Treatment of human gastric cancer cells with proton pump inhibitors significantly attenuated cell viability in a time- and dose-dependent manner. The pro-apoptotic activity of proton pump inhibitors was mediated by release of cytochrome c and caspases activation. Gastric cancer cells showed the resistance to acidity of culture medium, which was related with a remarkable increase of extracellular signal-regulated protein kinase 1/2 (ERK1/2) phosphorylation in the acidic condition. This ERK1/2 phosphorylation was completely inhibited by pretreatment with proton pump inhibitors, suggesting that its inhibitory action on phosphorylation of ERK1/2 might contribute to the induction of apoptosis in gastric cancer cells. In conclusion, our results suggest novel therapeutic approaches for gastric cancer with proton pump inhibitors.

  17. SYNCHROTRON RADIATION, FREE ELECTRON LASER, APPLICATION OF NUCLEAR TECHNOLOGY, ETC. Design of a multi-cusp ion source for proton therapy

    NASA Astrophysics Data System (ADS)

    Wu, Xiao-Bing; Huang, Tao; Ouyang, Hua-Fu; Zhang, Hua-Shun; Gong, Ke-Yun

    2010-12-01

    The permanent magnets of the discharge chamber in a multi-cusp proton source are studied and designed. The three electrode extraction system is adopted and simulated. A method to extract different amounts of current while keeping the beam emittance unchanged is proposed.

  18. Radiative Capture of Polarized Protons by Tritium at Low Energies

    NASA Astrophysics Data System (ADS)

    Wagenaar, Douglas Jay

    A study of the ('3)H((')p,(gamma))('4)He reaction was made at low proton energies in order to better understand the multipole nature of the emitted (gamma)-rays. Angular distributions of cross section and analyzing power were measured for incident proton energies of 2.0, 5.0, and 9.0 MeV. In addition, the analyzing power at 90(DEGREES) was measured at eleven proton bombarding energies ranging from 0.8 to 9.0 MeV. The coefficients a(,k) and b(,k) were determined from fitting Legendre and associated Legendre polynomial series, respectively, to the angular distributions. The extracted b(,1)-coefficients showed energy structure suggestive of multipole contributions from other than E1 or E2 radiations. A transition matrix element (T-matrix) analysis of the three angular distributions was performed to extract the relative E1 and E2 cross sections and their component singlet and triplet strengths. The triplet (or spin-flip) E2 strength was found to be large (albeit with large error) at 5.0 and 9.0 MeV and negligible at 2.0 MeV. The T-matrix analysis was expanded to include the possibilities of E3, M1, and M2 matrix elements. The E3 and M2 matrix elements failed to give reasonable fits to the data when they were combined with the E1 and E2 elements. Only when M1 strength was included in the T-matrix analysis could viable fits be found at all angular distribution energies. A direct-capture model calculation was performed for the ('3)H((')p,(gamma))- ('4)He reaction for proton energies up to 9.0 MeV. Good agreement was achieved with all experimental a(,k)- and b(,k)-coefficients except b(,1). The model also failed to predict the behavior of the A(90(DEGREES)) data. When M1 was added to the calculation in strengths comparable to those found in the T-matrix analysis, however, good agreement with the b(,1)-coefficient and the A(90(DEGREES)) curve resulted. It was concluded that M1 strengths of 0.5 to 1% of the total cross section are present in the ('3)H(p,(gamma))('4)He

  19. Extractable resources

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The use of information from space systems in the operation of extractive industries, particularly in exploration for mineral and fuel resources was reviewed. Conclusions and recommendations reported are based on the fundamental premise that survival of modern industrial society requires a continuing secure flow of resources for energy, construction and manufacturing, and for use as plant foods.

  20. High order magnetic optics for high dynamic range proton radiography at a kinetic energy of 800 MeV

    NASA Astrophysics Data System (ADS)

    Sjue, S. K. L.; Mariam, F. G.; Merrill, F. E.; Morris, C. L.; Saunders, A.

    2016-01-01

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the proton imaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane. Comparison with a series of static calibration images demonstrates the model's accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets.

  1. Nucleon Density Distribution of the Proton Drip-Line Nucleus 12N Studied via Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Fukuda, Mitsunori; Morita, Yusuke; Nishimura, Daiki; Takechi, Maya; Iwamoto, Kodai; Wakabayashi, Masaru; Kamisho, Yasuto; Ohno, Junichi; Tanaka, Masaomi; Kanbe, Ryosuke; Yamaoka, Shintaro; Mihara, Mototsugu; Matsuta, Kensaku; Yoshinaga, Kenta; Zhu, Ifan; Khono, Junpei; Yamaki, Sayaka; Suzuki, Takeshi; Yamaguchi, Takayuki; Suzuki, Shinji; Nagashima, Masayuki; Abe, Kohsuke; Tashiro, Keisuke; Honma, Akira; Ohtsubo, Takashi; Izumikawa, Takuji; Sato, Shinji; Fukuda, Shigekazu; Kitagawa, Atsushi

    Reaction cross sections for the proton drip-line nucleus 12N on Be, C, and Al targets have been measured at intermediate energies from 60A to 200A MeV. The results are compared with the systematics for stable nuclei and also with the experimental reaction cross section data for 12C to show 5-20% enhancement of the present 12N data. The nucleon density distribution of 12N has been extracted through the χ2-fitting procedure, which is consistent with a single particle nature of the loosely-bound valence proton in the p orbital though the error of the density is still large. The large one-proton removal cross sections observed at the same time also supports the long proton tail in the density distribution.

  2. High order magnetic optics for high dynamic range proton radiography at a kinetic energy of 800 MeV

    SciTech Connect

    Sjue, S. K. L. Mariam, F. G.; Merrill, F. E.; Morris, C. L.; Saunders, A.

    2016-01-15

    Flash radiography with 800 MeV kinetic energy protons at Los Alamos National Laboratory is an important experimental tool for investigations of dynamic material behavior driven by high explosives or pulsed power. The extraction of quantitative information about density fields in a dynamic experiment from proton generated images requires a high fidelity model of the proton imaging process. It is shown that accurate calculations of the transmission through the magnetic lens system require terms beyond second order for protons far from the tune energy. The approach used integrates the correlated multiple Coulomb scattering distribution simultaneously over the collimator and the image plane. Comparison with a series of static calibration images demonstrates the model’s accurate reproduction of both the transmission and blur over a wide range of tune energies in an inverse identity lens that consists of four quadrupole electromagnets.

  3. Channeling of protons through BN nanotubes

    NASA Astrophysics Data System (ADS)

    Borka Jovanović, V.; Borka, D.

    2015-07-01

    In this paper we study the angular and spatial distributions of protons channeled through boron-nitride (BN) nanotubes. The BN nanotubes have very similar structures like carbon nanotubes, but they are more thermally and chemically stable, and they also present good candidates for future channeling experiments. We present the angular and spatial distributions of MeV energy protons through the straight short (10, 10) single-wall BN nanotubes (SWBNNs). They were generated by a computer simulation method Borka et al. (2011, 2012a,b). Also, the effect of focusing of channeled protons is observed. A possible application of the obtained results for characterization of BN nanotubes is discussed. Analysis of angular and spatial distributions could be used to provide detailed information on the projectile-target interaction potentials inside BN nanotubes. We also varied the proton incident angle and energy and demonstrate that we can get a significant rearrangement of the propagating protons within the BN nanotube. This investigation may be used for proton beam guiding, to locate atomic impurities in nanotubes as well as for creating nanosized proton beams to be used in materials science, biology and medicine.

  4. [Current situation and perspectives of proton therapy].

    PubMed

    Doyen, J; Bondiau, P-Y; Bénézéry, K; Chand, M-È; Thariat, J; Leysalle, A; Gérard, J-P; Habrand, J-L; Hannoun-Lévi, J-M

    2015-05-01

    Proton beam therapy is indicated as a treatment for some rare tumours and paediatric tumours because the technique allows a good local control with minimal toxicity; the growing number of centres that use proton beam therapy is associated with an increase of dosimetric and clinical data for other malignant tumours as well. This paper reviews potential indications of proton beam therapy. A systematic review on Medline was performed with the following keywords proton beam therapy, cancer, heavy particle, charged particle. No phase III trial has been published using proton beam therapy in comparison with the best photon therapy, but numerous retrospective and dosimetric studies have revealed an advantage of proton beam therapy compared to photons, above all in tumours next to parallel organs at risk (thoracic and abdominal tumours). This could be accompanied with a better safety profile and/or a better tumoural control; numerous phase 0, I, II, III and IV studies are ongoing to examine these hypotheses in more common cancers. Use of proton beam therapy is growing for common cancers within clinical trials but some indications could be applied sooner since in silico analysis showed major advantages with this technique.

  5. Updating the Jovian Proton Radiation Environment - 2015

    NASA Technical Reports Server (NTRS)

    Garrett, Henry; Martinez-Sierra, Luz Maria; Evans, Robin

    2015-01-01

    Since publication in 1983 by N. Divine and H. Garrett, the Jet Propulsion Laboratory's plasma and radiation models have been the design standard for NASA's missions to Jupiter. These models consist of representations of the cold plasma and electrons, the warm and auroral electrons and protons, and the radiation environment (electron, proton, and heavy ions). To date, however, the high-energy proton model has been limited to an L-shell of 12. With the requirement to compute the effects of the high energy protons and other heavy ions on the proposed Europa mission, the extension of the high energy proton model from approximately 12 L-shell to approximately 50 L-shell has become necessary. In particular, a model of the proton environment over that range is required to estimate radiation effects on the solar arrays for the mission. This study describes both the steps taken to extend the original Divine proton model out to an approximately 50 L-shell and the resulting model developed to accomplish that goal. In addition to hydrogen, the oxygen, sulfur, and helium heavy ion environments have also been added between approximately 6 L-shell and approximately 50 L-shell. Finally, selected examples of the model's predictions are presented to illustrate the uses of the tool.

  6. A New Proton Dose Algorithm for Radiotherapy

    NASA Astrophysics Data System (ADS)

    Lee, Chungchi (Chris).

    This algorithm recursively propagates the proton distribution in energy, angle and space at one level in an absorbing medium to another, at slightly greater depth, until all the protons are stopped. The angular transition density describing the proton trajectory is based on Moliere's multiple scattering theory and Vavilov's theory of energy loss along the proton's path increment. These multiple scattering and energy loss distributions are sampled using equal probability spacing to optimize computational speed while maintaining calculational accuracy. Nuclear interactions are accounted for by using a simple exponential expression to describe the loss of protons along a given path increment and the fraction of the original energy retained by the proton is deposited locally. Two levels of testing for the algorithm are provided: (1) Absolute dose comparisons with PTRAN Monte Carlo simulations in homogeneous water media. (2) Modeling of a fixed beam line including the scattering system and range modulator and comparisons with measured data in a homogeneous water phantom. The dose accuracy of this algorithm is shown to be within +/-5% throughout the range of a 200-MeV proton when compared to measurements except in the shoulder region of the lateral profile at the Bragg peak where a dose difference as large as 11% can be found. The numerical algorithm has an adequate spatial accuracy of 3 mm. Measured data as input is not required.

  7. Proton transfer through the water gossamer.

    PubMed

    Hassanali, Ali; Giberti, Federico; Cuny, Jérôme; Kühne, Thomas D; Parrinello, Michele

    2013-08-20

    The diffusion of protons through water is understood within the framework of the Grotthuss mechanism, which requires that they undergo structural diffusion in a stepwise manner throughout the water network. Despite long study, this picture oversimplifies and neglects the complexity of the supramolecular structure of water. We use first-principles simulations and demonstrate that the currently accepted picture of proton diffusion is in need of revision. We show that proton and hydroxide diffusion occurs through periods of intense activity involving concerted proton hopping followed by periods of rest. The picture that emerges is that proton transfer is a multiscale and multidynamical process involving a broader distribution of pathways and timescales than currently assumed. To rationalize these phenomena, we look at the 3D water network as a distribution of closed directed rings, which reveals the presence of medium-range directional correlations in the liquid. One of the natural consequences of this feature is that both the hydronium and hydroxide ion are decorated with proton wires. These wires serve as conduits for long proton jumps over several hydrogen bonds.

  8. Strangeness asymmetry in the proton sea

    NASA Astrophysics Data System (ADS)

    Alberg, Mary

    2015-10-01

    Meson cloud models describe the proton sea in terms of fluctuations of the proton into meson-baryon pairs. The leading contributions to proton strangeness are from states which contain a kaon and a Lambda or Sigma hyperon. We use a Fock state expansion of the proton in terms of these states to determine the strangeness distributions of the proton in a convolution model, in which the fluctuations are represented by meson-baryon splitting functions, which determine the total strangeness of the proton. Strangeness asymmetry, the difference between momentum distributions of the s and sbar quarks in the proton, arises because the quarks are constituents of different hadrons. For the parton distributions of the s(sbar) quarks in the bare baryons(mesons) of the Fock states, we use light cone wave functions or our statistical model, which expands the bare hadrons in terms of quark-gluon states. We show that strangeness asymmetry depends strongly on the parton distributions used for the hadrons in the cloud. We compare our results to NuTeV and to global parton distributions. This research has been supported in part by NSF Award 1205686.

  9. Transition in the Temperature-Dependence of GFP Fluorescence: From Proton Wires to Proton Exit

    PubMed Central

    Leiderman, Pavel; Huppert, Dan; Agmon, Noam

    2006-01-01

    In green fluorescent protein, photo-excitation leads to excited-state proton transfer from its chromophore, leaving behind a strongly fluorescing anion, while the proton is commonly thought to migrate internally to Glu-222. X-ray data show that the protein contains more extended hydrogen-bonded networks that can support proton migration (i.e., proton wires). Here we study the temperature-dependence of the transient fluorescence from both the acid and anionic forms up to 15 ns. At low temperatures, we find that the (lifetime-corrected) fluorescence of the acidic form decays asymptotically as t−1/2, following quantitatively the solution of a one-dimensional diffusion equation for reversible geminate recombination with quenching. This indicates proton migration along the internal proton wires. A small degree of geminate proton quenching is attributed to the formation of the zwitterion by proton migration on a side-branch of the proton wire. Above 230 K, the fluorescence kinetics undergo a transition, exhibiting an asymptotic t−3/2 decay, and the quenching effect disappears. We interpret these findings as evidence for a conformational change enabling the rotation of Thr-203, which eventually allows the proton to escape to the exterior solution. PMID:16284263

  10. Proton energy and scattering angle radiographs to improve proton treatment planning: a Monte Carlo study

    NASA Astrophysics Data System (ADS)

    Biegun, A. K.; Takatsu, J.; Nakaji, T.; van Goethem, M. J.; van der Graaf, E. R.; Koffeman, E. N.; Visser, J.; Brandenburg, S.

    2016-12-01

    The novel proton radiography imaging technique has a large potential to be used in direct measurement of the proton energy loss (proton stopping power, PSP) in various tissues in the patient. The uncertainty of PSPs, currently obtained from translation of X-ray Computed Tomography (xCT) images, should be minimized from 3-5% or higher to less than 1%, to make the treatment plan with proton beams more accurate, and thereby better treatment for the patient. With Geant4 we simulated a proton radiography detection system with two position-sensitive and residual energy detectors. A complex phantom filled with various materials (including tissue surrogates), was placed between the position sensitive detectors. The phantom was irradiated with 150 MeV protons and the energy loss radiograph and scattering angles were studied. Protons passing through different materials in the phantom lose energy, which was used to create a radiography image of the phantom. The multiple Coulomb scattering of a proton traversing different materials causes blurring of the image. To improve image quality and material identification in the phantom, we selected protons with small scattering angles. A good quality proton radiography image, in which various materials can be recognized accurately, and in combination with xCT can lead to more accurate relative stopping powers predictions.

  11. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    SciTech Connect

    Adikaram, D.; Rimal, D.; Weinstein, L. B.; Raue, B.; Khetarpal, P.; Bennett, R.; Arrington, J.; Brooks, W.; Adhikari, K.; Afanasev, A.; Amaryan, M.; Anderson, M.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A.; Bono, J.; Boiarinov, S.; Briscoe, W.; Burkert, V.; Carman, D.; Careccia, S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J.; Fradi, A.; Garillon, B.; Gilfoyle, G.; Giovanetti, K.; Girod, F.; Goetz, J.; Gohn, W.; Golovatch, E.; Gothe, R.; Griffioen, K.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S.; Hyde, C. E.; Ilieva, Y.; Ireland, D.; Ishkhanov, B.; Jenkins, D.; Jiang, H.; Jo, H.; Joo, K.; Joosten, S.; Kalantarians, N.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F.; Koirala, S.; Kubarovsky, V.; Kuhn, S.; Livingston, K.; Lu, H.; MacGregor, I.; Markov, N.; Mattione, P.; Mayer, M.; McKinnon, B.; Mestayer, M.; Meyer, C.; Mirazita, M.; Mokeev, V.; Montgomery, R.; Moody, C.; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabati, F.; Salgado, C.; Schott, D.; Schumacher, R.; Seder, E.; Sharabian, Y.; Simonyan, A.; Skorodumina, I.; Smith, E.; Smith, G.; Sober, D.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N.; Watts, D.; Wei, X.; Wood, M.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z.; Zonta, I.

    2015-02-10

    There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentum transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ε at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.

  12. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    NASA Astrophysics Data System (ADS)

    Adikaram, D.; Rimal, D.; Weinstein, L. B.; Raue, B.; Khetarpal, P.; Bennett, R. P.; Arrington, J.; Brooks, W. K.; Adhikari, K. P.; Afanasev, A. V.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bono, J.; Boiarinov, S.; Briscoe, W. J.; Burkert, V. D.; Carman, D. S.; Careccia, S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joo, K.; Joosten, S.; Kalantarians, N.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mattione, P.; Mayer, M.; McKinnon, B.; Mestayer, M. D.; Meyer, C. A.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Moutarde, H.; Movsisyan, A.; Camacho, C. Munoz; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Peña, C.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Sharabian, Y. G.; Simonyan, A.; Skorodumina, I.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tian, Ye; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-02-01

    There is a significant discrepancy between the values of the proton electric form factor, GEp, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GEp from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ɛ ) and momentum transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ɛ at Q2=1.45 GeV2 . This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2 - 3 GeV2 .

  13. Towards a Resolution of the Proton Form Factor Problem: New Electron and Positron Scattering Data

    DOE PAGES

    Adikaram, D.; Rimal, D.; Weinstein, L. B.; ...

    2015-02-10

    There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpE from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (epsilon) and momentummore » transfer (Q2) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ε at Q2=1.45 GeV2. This measurement is consistent with the size of the form factor discrepancy at Q2≈1.75 GeV2 and with hadronic calculations including nucleon and Delta intermediate states, which have been shown to resolve the discrepancy up to 2-3 GeV2.« less

  14. Towards a resolution of the proton form factor problem: new electron and positron scattering data.

    PubMed

    Adikaram, D; Rimal, D; Weinstein, L B; Raue, B; Khetarpal, P; Bennett, R P; Arrington, J; Brooks, W K; Adhikari, K P; Afanasev, A V; Amaryan, M J; Anderson, M D; Anefalos Pereira, S; Avakian, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Bono, J; Boiarinov, S; Briscoe, W J; Burkert, V D; Carman, D S; Careccia, S; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Dodge, G E; Dupre, R; Egiyan, H; El Alaoui, A; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A; Fradi, A; Garillon, B; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Hicks, K; Holtrop, M; Hughes, S M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Jenkins, D; Jiang, H; Jo, H S; Joo, K; Joosten, S; Kalantarians, N; Keller, D; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, V; Kuhn, S E; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mattione, P; Mayer, M; McKinnon, B; Mestayer, M D; Meyer, C A; Mirazita, M; Mokeev, V; Montgomery, R A; Moody, C I; Moutarde, H; Movsisyan, A; Camacho, C Munoz; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Peña, C; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Puckett, A J R; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Salgado, C; Schott, D; Schumacher, R A; Seder, E; Sharabian, Y G; Simonyan, A; Skorodumina, I; Smith, E S; Smith, G D; Sober, D I; Sokhan, D; Sparveris, N; Stepanyan, S; Stoler, P; Strauch, S; Sytnik, V; Taiuti, M; Tian, Ye; Trivedi, A; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Wei, X; Wood, M H; Zachariou, N; Zana, L; Zhang, J; Zhao, Z W; Zonta, I

    2015-02-13

    There is a significant discrepancy between the values of the proton electric form factor, G(E)(p), extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of G(E)(p) from the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual photon polarization (ϵ) and momentum transfer (Q(2)) simultaneously, as well as to cancel luminosity-related systematic errors. The cross section ratio increases with decreasing ϵ at Q(2)=1.45  GeV(2). This measurement is consistent with the size of the form factor discrepancy at Q(2)≈1.75  GeV(2) and with hadronic calculations including nucleon and Δ intermediate states, which have been shown to resolve the discrepancy up to 2-3  GeV(2).

  15. β-particle energy-summing correction for β-delayed proton emission measurements

    NASA Astrophysics Data System (ADS)

    Meisel, Z.; del Santo, M.; Crawford, H. L.; Cyburt, R. H.; Grinyer, G. F.; Langer, C.; Montes, F.; Schatz, H.; Smith, K.

    2017-02-01

    A common approach to studying β-delayed proton emission is to measure the energy of the emitted proton and corresponding nuclear recoil in a double-sided silicon-strip detector (DSSD) after implanting the β-delayed proton-emitting (βp) nucleus. However, in order to extract the proton-decay energy, the measured energy must be corrected for the additional energy implanted in the DSSD by the β-particle emitted from the βp nucleus, an effect referred to here as β-summing. We present an approach to determine an accurate correction for β-summing. Our method relies on the determination of the mean implantation depth of the βp nucleus within the DSSD by analyzing the shape of the total (proton + recoil + β) decay energy distribution shape. We validate this approach with other mean implantation depth measurement techniques that take advantage of energy deposition within DSSDs upstream and downstream of the implantation DSSD.

  16. Baseline measures for net-proton distributions in high energy heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Netrakanti, P. K.; Luo, X. F.; Mishra, D. K.; Mohanty, B.; Mohanty, A.; Xu, N.

    2016-03-01

    We report a systematic comparison of the recently measured cumulants of the net-proton distributions for 0-5% central Au + Au collisions in the first phase of the Beam Energy Scan (BES) Program at the Relativistic Heavy Collider facility to various kinds of possible baseline measures. These baseline measures correspond to an assumption that the proton and anti-proton distributions follow Poisson statistics, Binomial statistics, obtained from a transport model calculation and from a hadron resonance gas model. The higher order cumulant net-proton data for the center of mass energies (√{sNN}) of 19.6 and 27 GeV are observed to deviate from most of the baseline measures studied. The deviations are predominantly due to the difference in shape of the proton distributions between data and those obtained in the baseline measures. We also present a detailed study on the relevance of the independent production approach as a baseline for comparison with the measurements at various beam energies. Our studies point to the need of either more detailed baseline models for the experimental measurements or a description via QCD calculations in order to extract the exact physics process that leads to deviation of the data from the baselines presented.

  17. Radiograaff, a proton irradiation facility for radiobiological studies at a 4 MV Van de Graaff accelerator

    NASA Astrophysics Data System (ADS)

    Constanzo, J.; Fallavier, M.; Alphonse, G.; Bernard, C.; Battiston-Montagne, P.; Rodriguez-Lafrasse, C.; Dauvergne, D.; Beuve, M.

    2014-09-01

    A horizontal beam facility for radiobiological experiments with low-energy protons has been set up at the 4 MV Van de Graaff accelerator of the Institut de Physique Nucléaire de Lyon. A homogeneous irradiation field with a suitable proton flux is obtained by means of two collimators and two Au-scattering foils. A monitoring chamber contains a movable Faraday cup, a movable quartz beam viewer for controlling the intensity and the position of the initial incident beam and four scintillating fibers for beam monitoring during the irradiation of the cell samples. The beam line is ended by a thin aluminized Mylar window (12 μm thick) for the beam extraction in air. The set-up was simulated by the GATE v6.1 Monte-Carlo platform. The measurement of the proton energy distribution, the evaluation of the fluence-homogeneity over the sample and the calibration of the monitoring system were performed using a silicon PIPS detector, placed in air in the same position as the biological samples to be irradiated. The irradiation proton fluence was found to be homogeneous to within ±2% over a circular field of 20 mm diameter. As preliminary biological experiment, two Human Head and Neck Squamous Carcinoma Cell lines (with different radiosensitivities) were irradiated with 2.9 MeV protons. The measured survival curves are compared to those obtained after X-ray irradiation, giving a Relative Biological Efficiency between 1.3 and 1.4.

  18. Acceleration tests of a 3 GHz proton linear accelerator (LIBO) for hadrontherapy

    NASA Astrophysics Data System (ADS)

    De Martinis, C.; Giove, D.; Amaldi, U.; Berra, P.; Crandall, K.; Mauri, M.; Weiss, M.; Zennaro, R.; Rosso, E.; Szeless, B.; Vretenar, M.; Masullo, M. R.; Vaccaro, V.; Calabretta, L.; Rovelli, A.

    2012-07-01

    This paper describes the acceleration tests performed at the Catania LNS Laboratory on a 3 GHz linac module of the side coupled type, which boosts the proton energy of a beam extracted from a cyclotron from 62 to 72 MeV. The output proton energy was measured with two devices: a NaI(Tl) crystal and a bending magnet. The experimental spectra are in good agreement with the calculated ones. From their shape it is obtained that (18±3.0)% of the transmitted protons fall in a ±2 MeV interval centered around 72 MeV. This result is in good agreement with the 20% value derived from the simulation of the acceleration process. The measured energy of the accelerated protons was used to check that the shunt impedance of the structure is equal to the computed one within 3%. This was the first time that a 3 GHz structure has been used to accelerate protons, and the results of the tests have demonstrated that a high frequency linac can be used as a cyclotron booster.

  19. Liposomes from mammalian liver mitochondria are more polyunsaturated and leakier to protons than those from reptiles.

    PubMed

    Brand, M D; Couture, P; Hulbert, A J

    1994-06-01

    Liposomes were prepared from phospholipids extracted from liver mitochondria of the rat (Rattus norvegicus) and an agamid lizard, the bearded dragon (Amphibolurus vitticeps) and liposome proton conductance was measured at an imposed membrane potential of 160 mV as well as the fatty acid composition of the liposomes. Despite presumed changes in fatty acid composition during liposome preparation, the mammalian liposomes had a significantly lower content of the monounsaturated oleic acid and a significantly greater content of the omega-3 polyunsaturated docosahexaenoic acid. There were significant direct correlations between the liposome arachidonic and docosahexanoic acid content and bilayer proton flux and a significant inverse correlation between liposome oleic acid content and bilayer proton flux. "Apparent valinomycin-catalysed proton flux" was significantly directly correlated with liposome docosahexaenoic acid content and inversely correlated with oleic acid content. It is suggested that the high content of long-chain polyunsaturates in the mammalian mitochondrial membrane is responsible for an increased proton leak across the mitochondrial inner membrane and thus partly responsible for the high metabolic rate in endothermic mammals compared to their ectothermic reptilian predecessors.

  20. Space Environments and Effects: Trapped Proton Model

    NASA Technical Reports Server (NTRS)

    Huston, S. L.; Kauffman, W. (Technical Monitor)

    2002-01-01

    An improved model of the Earth's trapped proton environment has been developed. This model, designated Trapped Proton Model version 1 (TPM-1), determines the omnidirectional flux of protons with energy between 1 and 100 MeV throughout near-Earth space. The model also incorporates a true solar cycle dependence. The model consists of several data files and computer software to read them. There are three versions of the mo'del: a FORTRAN-Callable library, a stand-alone model, and a Web-based model.

  1. Proton computed tomography images with algebraic reconstruction

    NASA Astrophysics Data System (ADS)

    Bruzzi, M.; Civinini, C.; Scaringella, M.; Bonanno, D.; Brianzi, M.; Carpinelli, M.; Cirrone, G. A. P.; Cuttone, G.; Presti, D. Lo; Maccioni, G.; Pallotta, S.; Randazzo, N.; Romano, F.; Sipala, V.; Talamonti, C.; Vanzi, E.

    2017-02-01

    A prototype of proton Computed Tomography (pCT) system for hadron-therapy has been manufactured and tested in a 175 MeV proton beam with a non-homogeneous phantom designed to simulate high-contrast material. BI-SART reconstruction algorithms have been implemented with GPU parallelism, taking into account of most likely paths of protons in matter. Reconstructed tomography images with density resolutions r.m.s. down to 1% and spatial resolutions <1 mm, achieved within processing times of 15‧ for a 512×512 pixels image prove that this technique will be beneficial if used instead of X-CT in hadron-therapy.

  2. Proton Radiography: Its uses and Resolution Scaling

    SciTech Connect

    Mariam, Fesseha G.

    2012-08-09

    Los Alamos National Laboratory has used high energy protons as a probe in flash radiography for over a decade. In this time the proton radiography project has used 800 MeV protons, provided by the LANSCE accelerator facility at LANL, to diagnose over five-hundred dynamic experiments in support of stockpile stewardship programs as well as basic materials science. Through this effort significant experience has been gained in using charged particles as direct radiographic probes to diagnose transient systems. The results of this experience will be discussed through the presentation of data from experiments recently performed at the LANL pRad.

  3. Third Zemach moment of the proton

    SciTech Connect

    Ian C. Cloet, Gerald A. Miller

    2011-01-01

    Modern electron scattering experiments have determined the proton electric form factor, G_{Ep}(Q^2), to high precision. We utilize this data, represented by the different form factor parametrizations, to compute the third Zemach moment of the proton charge distribution. We find that existing data rule out a value of the third Zemach moment large enough to explain the current puzzle with the proton charge radius determined from the Lamb shift in muonic hydrogen. This is in contrast with the recent claim of De Rujula [arXiv:1008.3861].

  4. Proton transport in triflic acid pentahydrate studied via ab initio path integral molecular dynamics.

    PubMed

    Hayes, Robin L; Paddison, Stephen J; Tuckerman, Mark E

    2011-06-16

    Trifluoromethanesulfonic acid hydrates provide a well-defined system to study proton dissociation and transport in perfluorosulfonic acid membranes, typically used as the electrolyte in hydrogen fuel cells, in the limit of minimal water. The triflic acid pentahydrate crystal (CF(3)SO(3)H·5H(2)O) is sufficiently aqueous that it contains an extended three-dimensional water network. Despite it being extended, however, long-range proton transport along the network is structurally unfavorable and would require considerable rearrangement. Nevertheless, the triflic acid pentahydrate crystal system can provide a clear picture of the preferred locations of local protonic defects in the water network, which provides insights about related structures in the disordered, low-hydration environment of perfluorosulfonic acid membranes. Ab initio molecular dynamics simulations reveal that the proton defect is most likely to transfer to the closest water that has the expected presolvation and only contains water in its first solvation shell. Unlike the tetrahydrate of triflic acid (CF(3)SO(3)H·4H(2)O), there is no evidence of the proton preferentially transferring to a water molecule bridging two of the sulfonate groups. However, this could be an artifact of the crystal structure since the only such water molecule is separated from the proton by long O-O distances. Hydrogen bonding criteria, using the two-dimensional potential of mean force, are extracted. Radial distribution functions, free energy profiles, radii of gyration, and the root-mean-square displacement computed from ab initio path integral molecular dynamics simulations reveal that quantum effects do significantly extend the size of the protonic defect and increase the frequency of proton transfer events by nearly 15%. The calculated IR spectra confirm that the dominant protonic defect mostly exists as an Eigen cation but contains some Zundel ion characteristics. Chain lengths and ring sizes determined from the

  5. First Operation of the Abort Gap Monitor for LHC

    SciTech Connect

    Lefevre, Thibaut; Bart Pedersen, Stephane; Boccardi, Andrea; Bravin, Enrico; Goldblatt, A.; Jeff, Adam; Roncarolo, Federico; Fisher, Alan; /SLAC

    2012-07-06

    The Large Hadron Collider (LHC) beam-dump system relies on extraction kickers that need 3 microseconds to rise to their nominal field. Since particles transiting the kickers during the rise will not be dumped properly, the proton population in this interval must always remain below quench and damage limits. A specific monitor to measure the particle population of this gap has been designed based on the detection of synchrotron radiation using a gated photomultiplier. Since the quench and damage limits change with the beam energy, the acceptable population in the abort gap and the settings of the monitor must adapt accordingly. This paper presents the design of the monitor, the calibration procedure and the detector performance with beam.

  6. Proton Spectroscopic Factors Deduced from Helium-3 Global Phenomenological and Microscopic Optical Model Potentials

    NASA Astrophysics Data System (ADS)

    Jenny, Lee; Pang, Dan-Yang; Han, Yin-Lu; B. Tsang, M.

    2014-09-01

    Global phenomenological GDP08 and microscopic helium-3 optical model potentials have been recently derived. We evaluate these two potential sets by comparing the elastic scattering data of 25 MeV 3He on 16O, 18O, 19F, 23Na, 24Mg, 25Mg, 26Mg, 27Al, 28Si, 30Si, 31P, 32S, 34S, 35Cl, 37Cl, and 39K isotopes. Using the deuteron angular distributions calculated with the distorted wave Born approximation model, we extract the ground-state proton spectroscopic factors from (3He, d) reactions on the same set of nuclei. The extracted proton spectroscopic factors are compared with the large-basis shell-model calculations.

  7. Two-photon exchange contribution to elastic electron-proton scattering

    NASA Astrophysics Data System (ADS)

    Yurov, Mikhail

    2015-04-01

    Two experimental techniques, Rosenbluth separation and recoil polarization transfer, used to extract proton's electromagnetic form factors ratio GE/GM yield markedly different results. Modern theoretical calculations suggest that two-photon exchange might be responsible for the observed discrepancy and that it is epsilon dependent. Jefferson Lab Experiment E05-017 was designed to measure the two-photon exchange contribution over a wide range of ɛ and Q2. In contrast with the conventional Rosenbluth method, E05-017 detected the elastically scattered proton rather than the electron. This approach returns a much more precise extraction of the form factor ratios. After a brief description of the experimental goals and techniques, the current status of the analysis will be presented.

  8. A Generalized Weizsacker-Williams Method Applied to Pion Production in Proton-Proton Collisions

    NASA Technical Reports Server (NTRS)

    Ahern, Sean C.; Poyser, William J.; Norbury, John W.; Tripathi, R. K.

    2002-01-01

    A new "Generalized" Weizsacker-Williams method (GWWM) is used to calculate approximate cross sections for relativistic peripheral proton-proton collisions. Instead of a mass less photon mediator, the method allows for the mediator to have mass for short range interactions. This method generalizes the Weizsacker-Williams method (WWM) from Coulomb interactions to GWWM for strong interactions. An elastic proton-proton cross section is calculated using GWWM with experimental data for the elastic p+p interaction, where the mass p+ is now the mediator. The resulting calculated cross sections is compared to existing data for the elastic proton-proton interaction. A good approximate fit is found between the data and the calculation.

  9. Mechanism of Proton Transport in Proton Exchange Membranes: Insights from Computer Simulation

    SciTech Connect

    Gregory A. Voth

    2010-11-30

    The solvation and transport of hydrated protons in proton exchange membranes (PEMs) such as NafionTM will be described using a novel multi-state reactive molecular dynamics (MD) approach, combined with large scale MD simulation to help probe various PEM morphological models. The multi-state MD methodology allows for the treatment of explicit (Grotthuss) proton shuttling and charge defect delocalization which, in turn, can strongly influence the properties of the hydrated protons in various aqueous and complex environments. A significant extension of the methodology to treat highly acidic (low pH) environments such as the hydrophilic domains of a PEM will be presented. Recent results for proton solvation and transport in NafionTM will be described which reveal the significant role of Grotthuss shuttling and charge defect delocalization on the excess proton solvation structures and transport properties. The role of PEM hydration level and morphology on these properties will also be described.

  10. MO-B-18C-01: Proton Therapy II: Proton Stereotactic Radiotherapy

    SciTech Connect

    Winey, B; Daartz, J

    2014-06-15

    Proton stereotactic radiotherapy shares fundamental principles with general proton therapy physics, specifically range uncertainties and broad beam measurement techniques. Significant differences emerge when treating with smaller field sizes that suffer lateral disequilibrium and when fractions are reduced. This session will explore the history and scope of proton stereotactic radiotherapy in clinical practice. Uncertainties and treatment planning methods specific to stereotactic treatments will be discussed. The session will include an overview of the physical properties of small proton fields and resulting needs for accurate measurements and modeling of dose distributions for radiosurgery treatment planning. Learning Objectives: Understand the clinical rationale for proton radiosurgery. Understand the similarities and differences from general proton therapy. Understand the similarities and differences from photon stereotactic radiosurgery. Understand the basic physics and clinical physics methods for measuring and commissioning a radiosurgery program.

  11. URANIUM EXTRACTION

    DOEpatents

    Harrington, C.D.; Opie, J.V.

    1958-07-01

    The recovery of uranium values from uranium ore such as pitchblende is described. The ore is first dissolved in nitric acid, and a water soluble nitrate is added as a salting out agent. The resulting feed solution is then contacted with diethyl ether, whereby the bulk of the uranyl nitrate and a portion of the impurities are taken up by the ether. This acid ether extract is then separated from the aqueous raffinate, and contacted with water causing back extractioa of the uranyl nitrate and impurities into the water to form a crude liquor. After separation from the ether extract, this crude liquor is heated to about 118 deg C to obtain molten uranyl nitrate hexahydratc. After being slightly cooled the uranyl nitrate hexahydrate is contacted with acid free diethyl ether whereby the bulk of the uranyl nitrate is dissolved into the ethcr to form a neutral ether solution while most of the impurities remain in the aqueous waste. After separation from the aqueous waste, the resultant ether solution is washed with about l0% of its volume of water to free it of any dissolved impurities and is then contacted with at least one half its volume of water whereby the uranyl nitrate is extracted into the water to form an aqueous product solution.

  12. 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.

  13. Proton production cross sections of {sup 14}C from silicon and oxygen: Implications for cosmic-ray studies

    SciTech Connect

    Sisterson, J.M.; Jull, A.J.T.; Beverding, A.

    1993-12-31

    The production rates of {sup 14}C from proton spallation of silicon, and oxygen have been measured over a wide range of energies from 31 to 450 MeV. {sup 14}C was measured by accelerator mass spectrometry (AMS) after extraction of carbon from the samples by melting in a flow of oxygen.

  14. Proton energy optimization and reduction for intensity-modulated proton therapy.

    PubMed

    Cao, Wenhua; Lim, Gino; Liao, Li; Li, Yupeng; Jiang, Shengpeng; Li, Xiaoqiang; Li, Heng; Suzuki, Kazumichi; Zhu, X Ronald; Gomez, Daniel; Zhang, Xiaodong

    2014-11-07

    Intensity-modulated proton therapy (IMPT) is commonly delivered via the spot-scanning technique. To 'scan' the target volume, the proton beam is controlled by varying its energy to penetrate the patient's body at different depths. Although scanning the proton beamlets or spots with the same energy can be as fast as 10-20 m s(-1), changing from one proton energy to another requires approximately two additional seconds. The total IMPT delivery time thus depends mainly on the number of proton energies used in a treatment. Current treatment planning systems typically use all proton energies that are required for the proton beam to penetrate in a range from the distal edge to the proximal edge of the target. The optimal selection of proton energies has not been well studied. In this study, we sought to determine the feasibility of optimizing and reducing the number of proton energies in IMPT planning. We proposed an iterative mixed-integer programming optimization method to select a subset of all available proton energies while satisfying dosimetric criteria. We applied our proposed method to six patient datasets: four cases of prostate cancer, one case of lung cancer, and one case of mesothelioma. The numbers of energies were reduced by 14.3%-18.9% for the prostate cancer cases, 11.0% for the lung cancer cases and 26.5% for the mesothelioma case. The results indicate that the number of proton energies used in conventionally designed IMPT plans can be reduced without degrading dosimetric performance. The IMPT delivery efficiency could be improved by energy layer optimization leading to increased throughput for a busy proton center in which a delivery system with slow energy switch is employed.

  15. Proton energy optimization and reduction for intensity-modulated proton therapy

    NASA Astrophysics Data System (ADS)

    Cao, Wenhua; Lim, Gino; Liao, Li; Li, Yupeng; Jiang, Shengpeng; Li, Xiaoqiang; Li, Heng; Suzuki, Kazumichi; Zhu, X. Ronald; Gomez, Daniel; Zhang, Xiaodong

    2014-10-01

    Intensity-modulated proton therapy (IMPT) is commonly delivered via the spot-scanning technique. To ‘scan’ the target volume, the proton beam is controlled by varying its energy to penetrate the patient’s body at different depths. Although scanning the proton beamlets or spots with the same energy can be as fast as 10-20 m s-1, changing from one proton energy to another requires approximately two additional seconds. The total IMPT delivery time thus depends mainly on the number of proton energies used in a treatment. Current treatment planning systems typically use all proton energies that are required for the proton beam to penetrate in a range from the distal edge to the proximal edge of the target. The optimal selection of proton energies has not been well studied. In this study, we sought to determine the feasibility of optimizing and reducing the number of proton energies in IMPT planning. We proposed an iterative mixed-integer programming optimization method to select a subset of all available proton energies while satisfying dosimetric criteria. We applied our proposed method to six patient datasets: four cases of prostate cancer, one case of lung cancer, and one case of mesothelioma. The numbers of energies were reduced by 14.3%-18.9% for the prostate cancer cases, 11.0% for the lung cancer cases and 26.5% for the mesothelioma case. The results indicate that the number of proton energies used in conventionally designed IMPT plans can be reduced without degrading dosimetric performance. The IMPT delivery efficiency could be improved by energy layer optimization leading to increased throughput for a busy proton center in which a delivery system with slow energy switch is employed.

  16. Parameterized spectral distributions for meson production in proton-proton collisions

    NASA Technical Reports Server (NTRS)

    Schneider, John P.; Norbury, John W.; Cucinotta, Francis A.

    1995-01-01

    Accurate semiempirical parameterizations of the energy-differential cross sections for charged pion and kaon production from proton-proton collisions are presented at energies relevant to cosmic rays. The parameterizations, which depend on both the outgoing meson parallel momentum and the incident proton kinetic energy, are able to be reduced to very simple analytical formulas suitable for cosmic ray transport through spacecraft walls, interstellar space, the atmosphere, and meteorites.

  17. Proton radius from electron-proton scattering and chiral perturbation theory

    NASA Astrophysics Data System (ADS)

    Horbatsch, Marko; Hessels, Eric A.; Pineda, Antonio

    2017-03-01

    We determine the root-mean-square proton charge radius, Rp, from a fit to low-Q2 electron-proton elastic-scattering cross-section data with the higher moments fixed (within uncertainties) to the values predicted by chiral perturbation theory. We obtain Rp=0.855 (11 ) fm. This number falls between the value obtained from muonic hydrogen analyses and the CODATA value (based upon atomic hydrogen spectroscopy and electron-proton scattering determinations).

  18. Proton-conducting cerate ceramics

    SciTech Connect

    Pederson, L.R.; Coffey, G.W.; Bates, J.L.; Weber, W.J.

    1996-08-01

    Single-cell solid oxide fuel cells were constructed using strontium cerate as the electrolyte and their performance tested. Like certain zirconates, hafnates, and tantalates, the cerate perovskites are among a class of solid electrolytes that conduct protons at elevated temperatures. Depending on the temperature and chemical environment, these ceramics also support electronic and oxygen ion currents. A maximum power output of {approx}100 mW per cm{sup 2} electrolyte surface area was obtained at 900{degrees}C using 4% hydrogen as the fuel and air as the oxidant. A series of rare earth/ceria/zirconia were prepared and their electrical properties characterized. Rare earth dopants included ytterbia, yttria, terbia, and europia. Ionic conductivities were highest for rare earth/ceria and rare earth zirconia compositions; a minimum in ionic conductivity for all series were found for equimolar mixtures of ceria and zirconia. Cerium oxysulfide is of interest in fossil energy applications because of its high chemical stability and refractory nature. An alternative synthesis route to preparing cerium oxysulfide powders has been developed using combustion techniques.

  19. [Proton therapy and particle accelerators].

    PubMed

    Fukumoto, Sadayoshi

    2012-01-01

    Since the high energy accelerator plan was changed from a 40 GeV direct machine to a 12GeV cascade one, a 500 MeV rapid cycling booster synchrotron was installed between the injector linac and the 12 GeV main ring at KEK, National Lab. for High Energy Physics. The booster beams were used not only for injection to the main ring but also for medical use. Their energy was reduced to 250 MeV by a graphite block for clinical trial of cancer therapy. In 1970's, pi(-) or heavy ions were supposed to be promising. Although advantage of protons with Bragg Peak was pointed out earlier, they seemed effective only for eye melanoma at that time. In early 1980's, it was shown that they were effective for deep-seated tumor by Tsukuba University with KEK beams. The first dedicated facility was built at Loma Linda University Medical Center. Its synchrotron was made by Fermi National Accelerator Lab. Since a non-resonant accelerating rf cavity was installed, operation of the synchrotron became much easier. Later, innovation of the cyclotron was achieved. Its weight was reduced from 1,000 ton to 200 ton. Some of the cyclotrons are equipped with superconducting coils.

  20. Pharmacology of Proton Pump Inhibitors

    PubMed Central

    Shin, Jai Moo; Sachs, George

    2010-01-01

    The gastric H,K-ATPase is the primary target for the treatment of acid-related diseases. Proton pump inhibitors (PPIs) are weak bases composed of two moieties, a substituted pyridine with a primary pKa of about 4.0, which allows selective accumulation in the secretory canaliculus of the parietal cell, and a benzimidazole with a second pKa of about 1.0. PPIs are acid-activated prodrugs that convert to sulfenic acids or sulfenamides that react covalently with one or more cysteines accessible from the luminal surface of the ATPase. Because of covalent binding, their inhibitory effects last much longer than their plasma half-life. However, the short half-life of the drug in the blood and the requirement for acid activation impair their efficacy in acid suppression, particularly at night. PPIs with longer half-life promise to improve acid suppression. All PPIs give excellent healing of peptic ulcers and produce good results in reflux esophagitis. PPIs combined with antibiotics eradicate Helicobacter pylori. PMID:19006606

  1. Hydrogen Bonds in Excited State Proton Transfer

    NASA Astrophysics Data System (ADS)

    Horke, D. A.; Watts, H. M.; Smith, A. D.; Jager, E.; Springate, E.; Alexander, O.; Cacho, C.; Chapman, R. T.; Minns, R. S.

    2016-10-01

    Hydrogen bonding interactions between biological chromophores and their surrounding protein and solvent environment significantly affect the photochemical pathways of the chromophore and its biological function. A common first step in the dynamics of these systems is excited state proton transfer between the noncovalently bound molecules, which stabilizes the system against dissociation and principally alters relaxation pathways. Despite such fundamental importance, studying excited state proton transfer across a hydrogen bond has proven difficult, leaving uncertainties about the mechanism. Through time-resolved photoelectron imaging measurements, we demonstrate how the addition of a single hydrogen bond and the opening of an excited state proton transfer channel dramatically changes the outcome of a photochemical reaction, from rapid dissociation in the isolated chromophore to efficient stabilization and ground state recovery in the hydrogen bonded case, and uncover the mechanism of excited state proton transfer at a hydrogen bond, which follows sequential hydrogen and charge transfer processes.

  2. Memory device using movement of protons

    DOEpatents

    Warren, W.L.; Vanheusden, K.J.R.; Fleetwood, D.M.; Devine, R.A.B.

    1998-11-03

    An electrically written memory element is disclosed utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure laterally through the exposed edges of the silicon dioxide layer during a high temperature anneal in an atmosphere containing hydrogen gas. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronic elements on the same silicon substrate. With the addition of an optically active layer, the memory element becomes an electrically written, optically read optical memory element. 19 figs.

  3. Memory device using movement of protons

    DOEpatents

    Warren, William L.; Vanheusden, Karel J. R.; Fleetwood, Daniel M.; Devine, Roderick A. B.

    2000-01-01

    An electrically written memory element utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure laterally through the exposed edges of the silicon dioxide layer during a high temperature anneal in an atmosphere containing hydrogen gas. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronic elements on the same silicon substrate. With the addition of an optically active layer, the memory element becomes an electrically written, optically read optical memory element.

  4. Memory device using movement of protons

    DOEpatents

    Warren, William L.; Vanheusden, Karel J. R.; Fleetwood, Daniel M.; Devine, Roderick A. B.

    1998-01-01

    An electrically written memory element utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure laterally through the exposed edges of the silicon dioxide layer during a high temperature anneal in an atmosphere containing hydrogen gas. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronic elements on the same silicon substrate. With the addition of an optically active layer, the memory element becomes an electrically written, optically read optical memory element.

  5. Memory device using movement of protons

    DOEpatents

    Warren, William L.; Vanheusden, Karel J. R.; Fleetwood, Daniel M.; Devine, Roderick A. B.; Archer, Leo B.; Brown, George A.; Wallace, Robert M.

    2000-01-01

    An enhancement of an electrically written memory element utilizing the motion of protons within a dielectric layer surrounded by layers on either side to confine the protons within the dielectric layer with electrode means attached to the surrounding layers to change the spatial position of the protons within the dielectric layer. The device is preferably constructed as a silicon-silicon dioxide-silicon layered structure with the protons being introduced to the structure during an anneal in an atmosphere containing hydrogen gas. Device operation is enhanced by concluding this anneal step with a sudden cooling. The device operates at low power, is preferably nonvolatile, is radiation tolerant, and is compatible with convention silicon MOS processing for integration with other microelectronics elements on the same silicon substrate.

  6. Physics at a new Fermilab proton driver

    SciTech Connect

    Geer, Steve; /Fermilab

    2006-04-01

    In 2004, motivated by the recent exciting developments in neutrino physics, the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future. At the end of 2004 the APS ''Study on the Physics of Neutrinos'' concluded that the future US neutrino program should have, as one of its components, ''A proton driver in the megawatt class or above and neutrino superbeam with an appropriate very large detector capable of observing Cp violation and measuring the neutrino mass-squared differences and mixing parameters with high precision''. The presently proposed Fermilab Proton Driver is designed to accomplish these goals, and is based on, and would help develop, Linear Collider technology. In this paper the Proton Driver parameters are summarized, and the potential physics program is described.

  7. Proton-Conducting Metal-Organic Frameworks

    NASA Astrophysics Data System (ADS)

    Ford, Jamie; Simmons, Jason; Yildirim, Taner

    2010-03-01

    Vehicles powered by polymer electrolyte membrane (PEM) fuel cells are an exciting alternative to current fossil fuel technology. The membranes in these cells serve as both charge transporter, ferrying protons from the anode to the cathode, and gas diffusion barrier, preventing the backflow of oxygen to the anode. Currently, hydrated sulfonated polymers are the preferred material for these membranes. The presence of water, however, limits the operating temperature to 100 C, reducing the electrode kinetics and CO tolerance of the entire system. In an effort to increase the efficiency and operating temperature of these fuel cells, we are investigating the proton conductivity of new host/guest materials based on metal-organic frameworks (MOFs) loaded with imidazole. These thermally stable frameworks provide well-defined pores that accommodate imidazole networks and form proton-conducting pathways. Here, we will present the structure and proton dynamics of these materials as elucidated by elastic and inelastic neutron scattering measurements.

  8. Design of a Gated Molecular Proton Channel

    SciTech Connect

    Gu, Wei; Zhou, Bo; Geyer, Tihamer; Hutter, Michael C.; Fang, Haiping; Helms, Volkhard H.

    2011-01-17

    The generation of an electrochemical pH gradient across biological membranes using energy from photosynthesis and respiration provides the universal driving force in cells for the production of adenosine triphosphate (ATP), the energy unit of life. Creating such an electrochemical potential requires the transportation of protons against a thermodynamic gradient. In biological proton pumps, chemical energy is used to induce protein conformational changes during each catalytic cycle where one or a few protons are pumped against a proton concentration gradient across the membrane. On the other hand, membrane channels also exist that mediate continuous particle exchange and may be switched between open and closed states. Being able to design nanochannels with similar functions would be of great importance for creating novel molecular devices with a wide range of applications such as molecular motors, fuel cells, rechargeable nanobatteries that provide energy to other nanomachines, and the generation of locally and temporally controlled pH jumps on microfluidic chips.

  9. Proton pumping accompanies calcification in foraminifera

    PubMed Central

    Toyofuku, Takashi; Matsuo, Miki Y.; de Nooijer, Lennart Jan; Nagai, Yukiko; Kawada, Sachiko; Fujita, Kazuhiko; Reichart, Gert-Jan; Nomaki, Hidetaka; Tsuchiya, Masashi; Sakaguchi, Hide; Kitazato, Hiroshi

    2017-01-01

    Ongoing ocean acidification is widely reported to reduce the ability of calcifying marine organisms to produce their shells and skeletons. Whereas increased dissolution due to acidification is a largely inorganic process, strong organismal control over biomineralization influences calcification and hence complicates predicting the response of marine calcifyers. Here we show that calcification is driven by rapid transformation of bicarbonate into carbonate inside the cytoplasm, achieved by active outward proton pumping. Moreover, this proton flux is maintained over a wide range of pCO2 levels. We furthermore show that a V-type H+ ATPase is responsible for the proton flux and thereby calcification. External transformation of bicarbonate into CO2 due to the proton pumping implies that biomineralization does not rely on availability of carbonate ions, but total dissolved CO2 may not reduce calcification, thereby potentially maintaining the current global marine carbonate production. PMID:28128216

  10. OLYMPUS and the proton form factor puzzle

    NASA Astrophysics Data System (ADS)

    Ice, Lauren; Alarcon, Ricardo; Olympus Collaboration

    2012-02-01

    Recent measurements of the proton electric to magnetic form factor ratio using polarization techniques reveal a large discrepancy with measurements found using the Rosenbluth separation technique. It has been proposed that this discrepancy is due to a non-negligible multiple photon exchange contribution in the electron-proton elastic scattering cross section. The OLYMPUS experiment will measure the multiple photon exchange contribution by finding the cross section ratio of positron-proton to electron-proton scattering within 1%. The experiment will be carried out at the DESY laboratory in Hamburg Germany using the electron and positron storage ring DORIS and an internal unpolarized hydrogen gas target. The scattered particles will be detected using the Bates Large Acceptance Spectrometer Toroid (BLAST).

  11. Improvement Plans of Fermilab's Proton Accelerator Complex

    SciTech Connect

    Shiltsev, Vladimir

    2016-01-01

    The flagship of Fermilab's long term research program is the Deep Underground Neutrino Experiment (DUNE), located Sanford Underground Research Facility (SURF) in Lead, South Dakota, which will study neutrino oscillations with a baseline of 1300 km. The neutrinos will be produced in the Long Baseline Neutrino Facility (LBNF), a proposed new beam line from Fermilab's Main Injector. The physics goals of the DUNE require a proton beam with a power of some 2.4 MW at 120 GeV, which is roughly four times the current maximum power. Here I discuss current performance of the Fermilab proton accelerator complex, our plans for construction of the SRF proton linac as key part of the Proton Improvement Plan-II (PIP-II), outline the main challenges toward multi-MW beam power operation of the Fermilab accelerator complex and the staged plan to achieve the required performance over the next 15 years.

  12. Polarized proton beams since the ZGS

    SciTech Connect

    Krisch, A.D.

    1994-12-31

    The author discusses research involving polarized proton beams since the ZGS`s demise. He begins by reminding the attendee that in 1973 the ZGS accelerated the world`s first high energy polarized proton beam; all in attendance at this meeting can be proud of this accomplishment. A few ZGS polarized proton beam experiments were done in the early 1970`s; then from about 1976 until 1 October 1979, the majority of the ZGS running time was polarized running. A great deal of fundamental physics was done with the polarized beam when the ZGS ran as a dedicated polarized proton beam from about Fall 1977 until it shut down on 1 October 1979. The newly created polarization enthusiats then dispersed; some spread polarized seeds al over the world by polarizing beams elsewhere; some wound up running the High Energy and SSC programs at DOE.

  13. Proton pumping accompanies calcification in foraminifera

    NASA Astrophysics Data System (ADS)

    Toyofuku, Takashi; Matsuo, Miki Y.; de Nooijer, Lennart Jan; Nagai, Yukiko; Kawada, Sachiko; Fujita, Kazuhiko; Reichart, Gert-Jan; Nomaki, Hidetaka; Tsuchiya, Masashi; Sakaguchi, Hide; Kitazato, Hiroshi

    2017-01-01

    Ongoing ocean acidification is widely reported to reduce the ability of calcifying marine organisms to produce their shells and skeletons. Whereas increased dissolution due to acidification is a largely inorganic process, strong organismal control over biomineralization influences calcification and hence complicates predicting the response of marine calcifyers. Here we show that calcification is driven by rapid transformation of bicarbonate into carbonate inside the cytoplasm, achieved by active outward proton pumping. Moreover, this proton flux is maintained over a wide range of pCO2 levels. We furthermore show that a V-type H+ ATPase is responsible for the proton flux and thereby calcification. External transformation of bicarbonate into CO2 due to the proton pumping implies that biomineralization does not rely on availability of carbonate ions, but total dissolved CO2 may not reduce calcification, thereby potentially maintaining the current global marine carbonate production.

  14. Polywater: proton nuclear magnetic resonance spectrum.

    PubMed

    Page, T F; Jakobsen, R J; Lippincott, E R

    1970-01-02

    In the presence of water, the resonance of the strongly hydrogenbonded protons characteristic of polywater appears at 5 parts per million lower applied magnetic field than water. Polywater made by a new method confirms the infrared spectrum reported originally.

  15. Proton magnetic resonance spectrum of polywater.

    PubMed

    Petsko, G A

    1970-01-09

    With the aid of a time average computer, the proton magnetic resonance spectrum of anomalous water (polywater) is obtained. The spectrum conisists of a single broad resonance shifted approximately 300 hertz downfield from the resonance of ordinary water.

  16. Third Zemach moment of the proton

    SciTech Connect

    Cloeet, Ian C.; Miller, Gerald A.

    2011-01-15

    Modern electron scattering experiments have determined the proton electric form factor G{sub Ep}(Q{sup 2}) to high precision. We utilize this data, represented by the different empirical form-factor parametrizations, to compute the third Zemach moment of the proton charge distribution. We find that existing data rule out a value of the third Zemach moment large enough to explain the current puzzle with the proton charge radius, determined from the Lamb shift in muonic hydrogen. This is in contrast to the recent paper of De Rujula. We also demonstrate that the size of the third Zemach moment is largely governed by the fourth moment of the conventional charge distributions , which enables us to obtain a rigorous upper bound on the magnitude of the third Zemach moment of the proton.

  17. Measuring the proton selectivity of graphene membranes

    SciTech Connect

    Walker, Michael I.; Keyser, Ulrich F.; Braeuninger-Weimer, Philipp; Weatherup, Robert S.; Hofmann, Stephan

    2015-11-23

    By systematically studying the proton selectivity of free-standing graphene membranes in aqueous solutions, we demonstrate that protons are transported by passing through defects. We study the current-voltage characteristics of single-layer graphene grown by chemical vapour deposition (CVD) when a concentration gradient of HCl exists across it. Our measurements can unambiguously determine that H{sup +} ions are responsible for the selective part of the ionic current. By comparing the observed reversal potentials with positive and negative controls, we demonstrate that the as-grown graphene is only weakly selective for protons. We use atomic layer deposition to block most of the defects in our CVD graphene. Our results show that a reduction in defect size decreases the ionic current but increases proton selectivity.

  18. Chemical isolation of .sup.82 Sr from proton-irradiated Mo targets

    DOEpatents

    Grant, Patrick M.; Kahn, Milton; O'Brien, Jr., Harold A.

    1976-01-01

    Spallation reactions are induced in Mo targets with 200-800 MeV protons to produce microcurie to millicurie amounts of a variety of radionuclides. A six-step radiochemical procedure, incorporating precipitation, solvent extractions, and ion exchange techniques, has been developed for the separation and purification of Sr radioactivities from other spallation products and the bulk target material. Radiostrontium can be quantitatively recovered in a sufficiently decontaminated state for use in biomedical generator development.

  19. Isotopic production cross sections in proton-nucleus collisions at 200 MeV

    SciTech Connect

    Machner, H.; Aschman, D.G.; Steyn, D.; Baruth-Ram, K.; Carter, J.; Sideras-Haddad, E.; Sellschop, J.P.F.; Cowley, A.A.; Goldenbaum, F.; Nangu, B.M.; Spoelstra, B.; Pilcher, J.V.; Smit, F.D.

    2006-04-15

    Intermediate-mass fragments from the interaction of {sup 27}Al, {sup 59}Co, and {sup 197}Au with 200-MeV protons were measured in an angular range from 20 deg. to 120 deg. in the laboratory system. The fragments, ranging from isotopes of helium up to isotopes of carbon, were isotopically resolved. Double-differential cross sections, energy-differential cross sections, and total cross sections were extracted.

  20. Proton nuclear magnetic resonance of intact friend leukemia cells: phosphorylcholine increase during differentiation

    SciTech Connect

    Agris, P.F.; Campbell, I.D.

    1982-06-18

    Proton nuclear magnetic resonance of intact Friend leukemia cells was used to analyze their erythroid-like differentiation. The technique, which requires only 10/sup 8/ to 10/sup 9/ cells and approximately 2 minutes for acquisition of each spectrum, demonstrated the occurrence of many signal changes during differentiation. With cell extracts, 64 signals were assigned to 12 amino acids and 19 other intermediary metabolites, and a dramatic signal change was attributed to a fourfrease in cytoplasmic phosphorylcholines.

  1. Proton transfer in microbial electrolysis cells

    DOE PAGES

    Borole, Abhijeet P.; Lewis, Alex J.

    2017-02-15

    Proton transfer and electron transfer are of prime importance in the development of microbial electrochemical cells. While electron transfer is primarily controlled by biology, proton transfer is controlled by process engineering and cell design. To develop commercially feasible technologies around the concept of a bioelectrochemical cell, real feedstocks have to be explored and associated limitations have to be identified. Here in this study, the proton transfer rate was quantified for a microbial electrolysis cell (MEC) and its dependence on process parameters was investigated using a proton balance model. The reaction system consisted of a biomass-derived pyrolytic aqueous stream as amore » substrate producing hydrogen in a flow-through MEC. The proton transfer rate increased with anode flow rate and organic loading rate up to a maximum of 0.36 ± 0.01 moles per m2 per h, equivalent to a hydrogen production rate of 9.08 L per L per day. Higher rates of hydrogen production, reaching 11.7 ± 0.2 L per L per day were achieved, when additional protons were provided via the cathode buffer. Electrochemical impedance spectroscopy shows that proton transfer was the dominant resistance in the production of hydrogen. The quantification of proton transfer rates for MECs with potential for biorefinery application and the demonstration of high hydrogen production rates approaching those required for commercial consideration indicate the strong potential of this technology for renewable hydrogen production. Understanding the transport phenomenon in bioelectrochemical cells is of great significance since these systems have potential for wide-ranging applications including energy production, bioremediation, chemical and nanomaterial synthesis, electro-fermentation, energy storage, desalination, and produced water treatment. Electron transfer in anode biofilms has been investigated extensively, but proton transfer studies are also important, since many cathodic half reactions

  2. Enhanced proton treatment in mouse tumors through proton irradiated nanoradiator effects on metallic nanoparticles

    NASA Astrophysics Data System (ADS)

    Kim, Jong-Ki; Seo, Seung-Jun; Kim, Hong-Tae; Kim, Ki-Hong; Chung, Myung-Hwan; Kim, Kye-Ryung; Ye, Sung-Jun

    2012-12-01

    The impact of protons on metallic nanoparticles (MNPs) produces the potent release of MNP-induced secondary electrons and characteristic x-rays. To determine the ability of secondary radiations to enhance proton treatment, the therapeutic irradiation of tumors was investigated in mice receiving 100-300 mg MNPs/kg intravenously prior to single dose, 10-41 Gy, proton irradiation. A proton beam was utilized to irradiate nanoparticles with a single Bragg peak set to occur inside a tumor volume (fully absorbed) or to occur after the beam had traversed the entire body. The dose-dependent increase in complete tumor regression (CTR) was 37-62% in the fully-absorbed irradiation group or 50-100% in the traversing irradiation group, respectively, compared with the proton-alone control mice (p < 0.01). One year survival was 58-100% versus 11-13% proton alone. The dose-dependent increase of intracellular reactive oxygen species level was 12-36% at 10 Gy compared with the proton-alone control cell. Therapeutic effective drug concentration that led to 100% CTR with a proton dose of 31 Gy was measured either 41 µg Au/g tissue or 59 µg Fe/g tissue. MNP-based proton treatment increased not only percent CTR and survival in vivo but also ROS generation in vitro, suggesting tumor dose enhancement from secondary radiation as one potent pathway of therapeutic enhancement.

  3. Study on strontium isotope abundance-ratio measurements by using a 13-MeV proton beam

    NASA Astrophysics Data System (ADS)

    Jeong, Cheol-Ki; Jang, Han; Lee, Goung-Jin

    2016-09-01

    The Rb-Sr dating method is used in dating Paleozoic and Precambrian rocks. This method measures the 87Rb and the 87Sr concentrations by using thermal ionization mass spectrometry (TIMS) [J. Hefne et al., Inter. J. Phys. Sci. 3(1), 28 (2008)]. In addition, it calculates the initial 87Sr/86Sr ratio to increase the reliability of Rb-Sr dating. In this study, the 87Sr/86Sr ratio was measured by using a 13-MeV proton accelerator. Proton kinetic energies are in the range of tens of megaelectronvolts, and protons have large absorption cross-sections for ( p, n) reactions with most substances. After absorbing a proton with such a high kinetic energy, an element is converted into a nuclide with its atomic number increased by one via nuclear transmutation. These nuclides usually have short half-lives and return to the original state through radioactive decay. When a strontium sample is irradiated with protons, nuclear transmutation occurs; thus, the strontium isotope present in the sample changes to a yttrium isotope, which is an activated radioisotope. Based on this, the 87Sr/86Sr ratio was calculated by analyzing the gamma-rays emitted by each yttrium isotope. The KIRAMS-13 cyclotron at the Cyclotron Center of Chosun University, where 13-MeV protons can be extracted, was utilized in our experiment. The 87Sr/86Sr isotope ratio was computed for samples irradiated with these protons, and the result was similar to the isotope ratio for the Standard Reference Material, i.e., 98.2 ± 3.4%. As part of the analysis, proton activation analyses were performed using 13-MeV protons, and the experimental results of this research suggest a possible approach for measuring the strontium-isotope abundance ratio of samples.

  4. Periods of High Intensity Solar Proton Flux

    NASA Technical Reports Server (NTRS)

    Xapsos, Michael A.; Stauffer, Craig A.; Jordan, Thomas M.; Adams, James H.; Dietrich, William F.

    2012-01-01

    Analysis is presented for times during a space mission that specified solar proton flux levels are exceeded. This includes both total time and continuous time periods during missions. Results for the solar maximum and solar minimum phases of the solar cycle are presented and compared for a broad range of proton energies and shielding levels. This type of approach is more amenable to reliability analysis for spacecraft systems and instrumentation than standard statistical models.

  5. Proton conducting membrane using a solid acid

    NASA Technical Reports Server (NTRS)

    Haile, Sossina M. (Inventor); Chisholm, Calum (Inventor); Boysen, Dane A. (Inventor); Narayanan, Sekharipuram R. (Inventor)

    2006-01-01

    A solid acid material is used as a proton conducting membrane in an electrochemical device. The solid acid material can be one of a plurality of different kinds of materials. A binder can be added, and that binder can be either a nonconducting or a conducting binder. Nonconducting binders can be, for example, a polymer or a glass. A conducting binder enables the device to be both proton conducting and electron conducting.

  6. Patient positioning in the proton radiotherapy era

    PubMed Central

    2010-01-01

    The main hindrance to the diffusion of proton therapy facilities is the high cost for gantry installations. An alternative technical option is provided by fixed-beam treatment rooms, where the patient is rotated and translated in space with a robotic arm solution to enable beam incidence from various angles. The technological efforts based on robotic applications made up to now for patient positioning in proton beam facilities are described here, highlighting their limitations and perspectives. PMID:20465816

  7. A Summary of Major Solar Proton Events

    DTIC Science & Technology

    1990-01-01

    the Earth’s surface, the name solr proton event was introduced to distinguish between those solar proton events detected at ground level (GLE) and... aw > 20 - _j okM>. 0 160- wU 140- ir Ca: 120- Z: IL 0100 2 >. 60 I :D Q. C W- 40- 20-o V II I I 5 10 YEARS FROM SUNSPOT MINIMUM Fig. 8. The summation

  8. Proton Therapy Dose Characterization and Verification

    DTIC Science & Technology

    2013-10-01

    protons actually stop in the transponder. Besides the published paper, a poster version was presented at the American Radium Society Annual Meeting... Radium Society Annual Meeting (2012). Radiobiology: Eblan, M, Cengel, KA: Biology of Proton Therapy, Old and New Considerations. Radiation Medicine...spectrometer (RRMD-III). Radiat Res 162, 687-692. Bragg W H and Kleeman R 1904 On the ionization curves of radium , Philosophical Magazine S6, 726

  9. Electron/proton spectrometer certification documentation analyses

    NASA Technical Reports Server (NTRS)

    Gleeson, P.

    1972-01-01

    A compilation of analyses generated during the development of the electron-proton spectrometer for the Skylab program is presented. The data documents the analyses required by the electron-proton spectrometer verification plan. The verification plan was generated to satisfy the ancillary hardware requirements of the Apollo Applications program. The certification of the spectrometer requires that various tests, inspections, and analyses be documented, approved, and accepted by reliability and quality control personnel of the spectrometer development program.

  10. AGS polarized proton operation in run 8.

    SciTech Connect

    Huang,H.; Ahrens, L.; Bai, M.; Brown, K.A.; Gardner, C.; Glenn, J.W.; Lin, F.; Luccio, A.U.; MacKay, W.W.; Roser, T.; Tepikian, S.; Tsoupas, N.; Yip, K.; Zeno, K.

    2008-06-23

    Dual partial snake scheme has been used for the Brookhaven AGS (Alternating Gradient Synchrotron) polarized proton operation for several years. It has provided polarized proton beams with 1.5 x 10{sup 11} intensity and 65% polarization for RHIC spin program. There is still residual polarization loss. Several schemes such as putting horizontal tune into the spin tune gap, and injection-on-the-fly were tested in the AGS to mitigate the loss. This paper presents the experiment results and analysis.

  11. Proton Computed Tomography: iterative image reconstruction and dose evaluation

    NASA Astrophysics Data System (ADS)

    Civinini, C.; Bonanno, D.; Brianzi, M.; Carpinelli, M.; Cirrone, G. A. P.; Cuttone, G.; Lo Presti, D.; Maccioni, G.; Pallotta, S.; Randazzo, N.; Scaringella, M.; Romano, F.; Sipala, V.; Talamonti, C.; Vanzi, E.; Bruzzi, M.

    2017-01-01

    Proton Computed Tomography (pCT) is a medical imaging method with a potential for increasing accuracy of treatment planning and patient positioning in hadron therapy. A pCT system based on a Silicon microstrip tracker and a YAG:Ce crystal calorimeter has been developed within the INFN Prima-RDH collaboration. The prototype has been tested with a 175 MeV proton beam at The Svedberg Laboratory (Uppsala, Sweden) with the aim to reconstruct and characterize a tomographic image. Algebraic iterative reconstruction methods (ART), together with the most likely path formalism, have been used to obtain tomographies of an inhomogeneous phantom to eventually extract density and spatial resolutions. These results will be presented and discussed together with an estimation of the average dose delivered to the phantom and the dependence of the image quality on the dose. Due to the heavy computation load required by the algebraic algorithms the reconstruction programs have been implemented to fully exploit the high calculation parallelism of Graphics Processing Units. An extended field of view pCT system is in an advanced construction stage. This apparatus will be able to reconstruct objects of the size of a human head making possible to characterize this pCT approach in a pre-clinical environment.

  12. Eta(547) and Eta(958) Meson Photoproduction on the Proton

    SciTech Connect

    Dugger, Michael

    2001-12-01

    Photoproduction of η and η' mesons has been studied at the Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) using a tagged photon beam incident on a hydrogen target with photon energies from the respective production thresholds up to 2.4 GeV. The photoproduced mesons were identified via missing mass reconstruction using recoil proton momentum and time of flight information. Data were obtained in a range of √s from threshold to 2.2 GeV for each meson. In this study, differential cross-section measurements for the γp →pη and γp → pη' reactions are presented, and the results compared to recent data. An isobar analysis of the differential cross-sections is performed. The predicted differential cross-sections from the isobar analysis are used to predict behavior in unmeasured regions of phase space, and to infer total cross sections. For the γp → pη reaction, a value of the S11(1535) proton helicity amplitude also was extracted and compared to recent analyses. The data presented greatly extends the energy and angle coverage for differential cross-sections of η photoproduction, and significantly improves the accuracy with which η' cross sections are known.

  13. Contrasting Extraction Types.

    ERIC Educational Resources Information Center

    Postal, Paul M.

    1994-01-01

    This paper grounds a novel typology yielding three major types of English (L(eft)-extraction, defined by their relationship to resumptive pronouns (RPs): (1) B-extractions, which require RPs in their extraction sites, (2) A1-extractions, which allow RPs in their extraction sites, and (3) A2-extractions, which forbid RPs in their extraction sites.…

  14. Proton radiation for localized prostate cancer.

    PubMed

    Coen, John J; Zietman, Anthony L

    2009-06-01

    Proton radiation is an emerging therapy for localized prostate cancer that is being sought with increasing frequency by patients. The physical properties of a proton beam make it ideal for clinical applications; the Bragg peak allows for deposition of dose at a well-defined depth with essentially no exit dose. Thus, high doses can be delivered to a target while largely sparing adjacent normal tissue. Proton radiation has proven effective in dose escalation for prostate cancer. This is important, as high-dose conformal radiation is now the standard form of external radiation for this disease. Intensity-modulated radiation therapy, which uses X-rays, is another means of delivering high radiation doses to the prostate and is currently the most widely used form of external radiation in the US. At present prices, it is probably more cost-effective than proton radiation; this could change. Clear dosimetric superiority of protons in the high-dose region has not yet been demonstrated. A dosimetric advantage may emerge as pencil-beam scanning replaces passive scanning, and intensity-modulated proton therapy becomes possible. This technique would be particularly well suited to partial prostate 'boosts', hypofractionation regimens and stereotactic delivery of radiation, all new approaches to prostate cancer that are being investigated.

  15. In vivo proton range verification: a review

    NASA Astrophysics Data System (ADS)

    Knopf, Antje-Christin; Lomax, Antony

    2013-08-01

    Protons are an interesting modality for radiotherapy because of their well defined range and favourable depth dose characteristics. On the other hand, these same characteristics lead to added uncertainties in their delivery. This is particularly the case at the distal end of proton dose distributions, where the dose gradient can be extremely steep. In practice however, this gradient is rarely used to spare critical normal tissues due to such worries about its exact position in the patient. Reasons for this uncertainty are inaccuracies and non-uniqueness of the calibration from CT Hounsfield units to proton stopping powers, imaging artefacts (e.g. due to metal implants) and anatomical changes of the patient during treatment. In order to improve the precision of proton therapy therefore, it would be extremely desirable to verify proton range in vivo, either prior to, during, or after therapy. In this review, we describe and compare state-of-the art in vivo proton range verification methods currently being proposed, developed or clinically implemented.

  16. Proton microscopy at GSI and FAIR

    SciTech Connect

    Merrill, Frank E; Mariam, Fesseha G; Golubev, A A; Turtikov, V I; Varentsov, D

    2009-01-01

    Proton radiography was invented in the 1990's at Los Alamos National Laboratory (LANL) as a diagnostic to study dynamic material properties under extreme pressures, strain and strain rate. Since this time hundreds of dynamic proton radiography experiments have been performed at LANL and facilities have been commissioned at the Institute for Theoretical and Experimental Physics (ITEP) in Russia for similar applications in dynamic material studies. Recently an international collaboration was formed to develop a new proton radiography capability for the study of dynamic material properties at the Facility for Anti-proton and Ion Research (FAIR) located at Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt, Germany. This new Proton microscope for FAIR (PRIOR) will provide radiographic imaging of dynamic systems with unprecedented spatial, temporal and density resolution, resulting in a window for understanding dynamic material properties at new length scales. These dynamic experiments will be driven with many energy sources including heavy ions, high explosives and lasers. The design of the proton microscope and expected radiographic performance is presented.

  17. Ring current proton decay by charge exchange

    NASA Technical Reports Server (NTRS)

    Smith, P. H.; Hoffman, R. A.; Fritz, T. A.

    1976-01-01

    Explorer 45 (S3-A) measurements were made during the recovery phase of the moderate magnetic storm of February 24, 1972, in which a symmetric ring current had developed and effects due to asymmetric ring current losses could be eliminated. It was found that after the initial rapid decay of the proton flux, which is a consequence of the dissipation of the asymmetric ring current, the equatorially mirroring protons in the energy range 5-30 keV decayed throughout the L value range of 3.5-5.0 at the charge exchange decay rate calculated by Liemohn (1961). After several days of decay, the proton fluxes reached a lower limit where an apparent equilibrium was maintained, between weak particle source mechanisms and the loss mechanisms, until fresh protons were injected into the ring current region during substorms. While other proton loss mechanisms may also be operating, the results indicate that charge exchange is more than sufficient as a particle loss mechanism for the storm time proton ring current decay.

  18. Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy

    SciTech Connect

    Zhang, Rongchun; Mroue, Kamal H.; Ramamoorthy, Ayyalusamy

    2015-10-14

    Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110–120 kHz), {sup 1}H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong {sup 1}H–{sup 1}H homonuclear dipolar couplings and narrow {sup 1}H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) {sup 1}H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about {sup 1}H–{sup 1}H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic

  19. Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy.

    PubMed

    Zhang, Rongchun; Mroue, Kamal H; Ramamoorthy, Ayyalusamy

    2015-10-14

    Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110-120 kHz), (1)H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong (1)H-(1)H homonuclear dipolar couplings and narrow (1)H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) (1)H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about (1)H-(1)H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic-level structural and dynamical

  20. a Survey of Giant Resonance Excitations with 200 Mev Protons

    NASA Astrophysics Data System (ADS)

    Tinsley, James Royce

    The giant resonance region in ('60)Ni, ('90)Zr, ('120)Sn, and ('208)Pb has been studied using inelastic scattering of 200 MeV protons. Angular distributions were obtained for the giant quadrupole resonance, giant octupole resonance, and for the combined giant dipole and giant monopole resonance between 4 and 20 degrees. The 2(H/2PI)(omega) component of the giant hexadecapole resonance has been directly observed for the first time in ('208)Pb. In the other nuclei, upper limits on the amount of hexadecapole strength contained within the giant quadrupole resonance have been obtained. Peaks are observed in ('60)Ni and ('90)Zr that are consistent with recently reported M1 states. Discrepancies between sum rules extracted from this data and from previous work are discussed. Possible explanations include DWBA breakdown or difficulties in estimating the magnitude of the continuum. Systematics obtained for the giant resonances are compared to earlier work.

  1. d / u Ratio in the Proton at Seaquest

    NASA Astrophysics Data System (ADS)

    Morton, Daniel; E906 SeaQuest Collaboration

    2017-01-01

    The Fermilab E906 SeaQuest experiment measures muons produced from a 120 GeV proton beam incident on liquid Hydrogen, Deuterium and solid C, Fe and W targets. Muons produced through the Drell Yan process are used to measure nuclear effects, in particular for light sea quarks that the SeaQuest spectrometer is optimized to measure. The ratio of d to u quarks was expected to be one when only considering gluon splitting, but was found to deviate from that significantly in past experiments. Using the ratios of deuterium to hydrogen cross sections, the ratio of d / u quarks will be extracted for Björken x values up to .45. This probes a higher x region than previous experiments.

  2. The proton-deuteron scattering length in pionless EFT

    NASA Astrophysics Data System (ADS)

    König, Sebastian; Hammer, Hans-Werner

    2015-10-01

    We present a fully perturbative calculation of the quartet-channel proton-deuteron scattering length up to next-to-next-to-leading order (NNLO) in pionless effective field theory. In particular, we use a framework that consistently extracts the Coulomb-modified effective range function for a screened Coulomb potential in momentum space and allows for a clear linear extrapolation back to the physical limit without screening. We find a natural convergence pattern as we go to higher orders in the EFT expansion. Our NNLO result of (10 . 9 +/- 0 . 4) fm agrees with older experimental determinations but deviates from more recent results around 14 fm. As a resolution of this discrepancy, we discuss the scheme dependence of Coulomb subtractions in a three-body system. Supported in part by the NSF, DOE (NUCLEI SciDAC), as well as by the DFG and BMBF.

  3. The proton-deuteron scattering length in pionless EFT

    NASA Astrophysics Data System (ADS)

    König, Sebastian; Hammer, Hans-Werner

    2016-03-01

    We present a fully perturbative calculation of the quartet-channel proton-deuteron scattering length (4ap-d) up to next-to-next-to-leading order (NNLO) in pionless effective field theory. In particular, we use a framework that consistently extracts the Coulomb-modified effective range function for a screened Coulomb potential in momentum space. We find a natural convergence pattern as we go to higher orders in the EFT expansion. Our NNLO result of (10.9 ± 0.4) fm agrees with older experimental determinations but deviates from more recent calculations, which find values around 14 fm. To resolve this discrepancy, we discuss the scheme dependence of Coulomb subtractions in a three-body system.

  4. Measurement of Neutron Proton Going to Proton Proton Negative Pion at 443 Mev

    NASA Astrophysics Data System (ADS)

    Bachman, Mark Gregory

    Experiment E372 at TRIUMF measured the analyzing powers (A_{rm NO}, A_ {rm SO}, A_{rm LO}) and relative differential cross section for the reaction np to pppi ^- at 443 MeV. We directed a polarized neutron beam on to a liquid hydrogen target and measured the scattered events in a large solid angle detector capable of measuring the velocities and directions of all of the protons produced in the reaction as well as many of the pions. Kinematic analysis of the events allowed us to remove almost all background and resulted in a clean set of np to pppi^- events. These events were binned against appropriate kinematic variables to produce yields which correspond to relative differential cross sections, and asymmetries which correspond to A _{rm NO}, A_{rm SO}, and A_{rm LO }. These results are the first of their kind for this energy. Comparisons to a theoretical model of Kloet and Lomon and a preliminary study using partial waves are presented.

  5. Moving protons with pendant amines: proton mobility in a nickel catalyst for oxidation of hydrogen.

    PubMed

    O'Hagan, Molly; Shaw, Wendy J; Raugei, Simone; Chen, Shentan; Yang, Jenny Y; Kilgore, Uriah J; DuBois, Daniel L; Bullock, R Morris

    2011-09-14

    Proton transport is ubiquitous in chemical and biological processes, including the reduction of dioxygen to water, the reduction of CO(2) to formate, and the production/oxidation of hydrogen. In this work we describe intramolecular proton transfer between Ni and positioned pendant amines for the hydrogen oxidation electrocatalyst [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+) (P(Cy)(2)N(Bn)(2) = 1,5-dibenzyl-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane). Rate constants are determined by variable-temperature one-dimensional NMR techniques and two-dimensional EXSY experiments. Computational studies provide insight into the details of the proton movement and energetics of these complexes. Intramolecular proton exchange processes are observed for two of the three experimentally observable isomers of the doubly protonated Ni(0) complex, [Ni(P(Cy)(2)N(Bn)(2)H)(2)](2+), which have N-H bonds but no Ni-H bonds. For these two isomers, with pendant amines positioned endo to the Ni, the rate constants for proton exchange range from 10(4) to 10(5) s(-1) at 25 °C, depending on isomer and solvent. No exchange is observed for protons on pendant amines positioned exo to the Ni. Analysis of the exchange as a function of temperature provides a barrier for proton exchange of ΔG(‡) = 11-12 kcal/mol for both isomers, with little dependence on solvent. Density functional theory calculations and molecular dynamics simulations support the experimental observations, suggesting metal-mediated intramolecular proton transfers between nitrogen atoms, with chair-to-boat isomerizations as the rate-limiting steps. Because of the fast rate of proton movement, this catalyst may be considered a metal center surrounded by a cloud of exchanging protons. The high intramolecular proton mobility provides information directly pertinent to the ability of pendant amines to accelerate proton transfers during catalysis of hydrogen oxidation. These results may also have broader implications for proton movement in

  6. Moving Protons with Pendant Amines: Proton Mobility in a Nickel Catalyst for Oxidation of Hydrogen

    SciTech Connect

    O'Hagan, Molly; Shaw, Wendy J.; Raugei, Simone; Chen, Shentan; Yang, Jenny Y.; Kilgore, Uriah J.; DuBois, Daniel L.; Bullock, R. Morris

    2011-05-19

    Proton transport is ubiquitous in chemical and biological processes, including the reduction of dioxygen to water, the reduction of CO₂ to formate, and the production/oxidation of hydrogen. In this work we describe intramolecular proton transfer between Ni and positioned pendant amines for the hydrogen oxidation electrocatalyst [Ni(PCy₂NBn₂H)₂]²⁺ (PCy₂NBn₂ = 1,5-dibenzyl-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane). Rate constants are determined by variable-temperature one-dimensional NMR techniques and two-dimensional EXSY experiments. Computational studies provide insight into the details of the proton movement and energetics of these complexes. Intramolecular proton exchange processes are observed for two of the three experimentally observable isomers of the doubly protonated Ni(0) complex, [Ni(PCy₂NBn₂H)₂]²⁺, which have N–H bonds but no Ni–H bonds. For these two isomers, with pendant amines positioned endo to the Ni, the rate constants for proton exchange range from 10⁴ to 10⁵ s⁻¹ at 25 °C, depending on isomer and solvent. No exchange is observed for protons on pendant amines positioned exo to the Ni. Analysis of the exchange as a function of temperature provides a barrier for proton exchange of ΔG = 11–12 kcal/mol for both isomers, with little dependence on solvent. Density functional theory calculations and molecular dynamics simulations support the experimental observations, suggesting metal-mediated intramolecular proton transfers between nitrogen atoms, with chair-to-boat isomerizations as the rate-limiting steps. Because of the fast rate of proton movement, this catalyst may be considered a metal center surrounded by a cloud of exchanging protons. The high intramolecular proton mobility provides information directly pertinent to the ability of pendant amines to accelerate proton transfers during catalysis of hydrogen oxidation

  7. [Safety of proton pump inhibitors].

    PubMed

    Esplugues, Juan V; Martí-Cabrera, Miguel; Ponce, Julio

    2006-11-25

    The significant inhibitory capacity of gastric acid secretion of PPIs makes them the drugs of choice for treating acid-related diseases. The considerable prevalence of these diseases and the need for maintaining the administration of the drug during considerably long periods results in this therapeutic group being one of the most widely used. However, in spite of their extensive use, there continue to emerge concerns about their potential toxicity; concerns surrounding the specificity of their mechanism of action and a consequential suspicion that something so potent must involve harmful effects. PPIs act selectively on the final stage of the process of gastric acid secretion, namely the H+/K+-ATPase or proton pump. This enzyme represents an essential step in the process of secretion of H+, and PPIs exert a very specific action on the parietal cell, as they need an environment with very low pH levels, which only exist in this cell. In the present article, the adverse effects of PPIs are reviewed, with special emphasis on those related to their continued administration and on the special circumstances of patients, as in the case of the elderly, those with liver failure, pregnant and breastfeeding mothers and children. All the PPIs on the market share a common chemical basis and there are no great differences in their potential adverse effects, the possibility of them promoting opportunist infections or their capacity to generate pharmacokinetic interactions with other drugs, which, if occur, are generally insignificant. After two decades of use, PPIs have proved to be very effective and safe drugs.

  8. Proton clouds to measure long-range contacts between nonexchangeable side chain protons in solid-state NMR.

    PubMed

    Sinnige, Tessa; Daniëls, Mark; Baldus, Marc; Weingarth, Markus

    2014-03-26

    We show that selective labeling of proteins with protonated amino acids embedded in a perdeuterated matrix, dubbed 'proton clouds', provides general access to long-range contacts between nonexchangeable side chain protons in proton-detected solid-state NMR, which is important to study protein tertiary structure. Proton-cloud labeling significantly improves spectral resolution by simultaneously reducing proton line width and spectral crowding despite a high local proton density in clouds. The approach is amenable to almost all canonical amino acids. Our method is demonstrated on ubiquitin and the β-barrel membrane protein BamA.

  9. The study of the proton-proton collisions at the beam momentum 1581 MeV/c

    NASA Astrophysics Data System (ADS)

    Ermakov, K. N.; Medvedev, V. I.; Nikonov, V. A.; Rogachevsky, O. V.; Sarantsev, A. V.; Sarantsev, V. V.; Sherman, S. G.

    2014-06-01

    The new data on the elastic pp and single-pion production reaction pp → pnπ + taken at the incident proton momentum 1581 MeV/ c are presented. To extract contributions of the leading partial waves the single-pion production data are analyzed in the framework of the event-by-event maximum-likelihood method together with pp → ppπ + data measured earlier and the pp → pnπ + data taken at 1628 MeV/ c. The analysis shows that at 1581 MeV/ c the largest contributions stem from the 3 P 2, 3 P 1, 3 P 0 and 3 F 2 initial partial waves. From these partial waves we also deduce contributions for the production of the Δ(1232) and N(1440) states.

  10. Connection between the taxonomic substates and protonation of histidines 64 and 97 in carbonmonoxy myoglobin.

    PubMed Central

    Müller, J D; McMahon, B H; Chien, E Y; Sligar, S G; Nienhaus, G U

    1999-01-01

    Infrared spectra of heme-bound CO in sperm whale carbonmonoxy myoglobin and two mutants (H64L and H97F) were studied in the pH range from 4.2 to 9.5. Comparison of the native protein with the mutants shows that the observed pH effects can be traced to protonations of two histidine residues, H64 and H97, near the active site. Their imidazole sidechains experience simple, uncoupled Henderson-Hasselbalch type protonations, giving rise to four different protonation states. Because two of the protonation states are linked by a pH-independent equilibrium, the overall pH dependence of the spectra is described by a linear combination of three independent components. Global analysis, based on singular value decomposition and matrix least-squares algorithms enabled us to extract the pK values of the two histidines and the three basis spectra of the protonating species. The basis spectra were decomposed into the taxonomic substates A(0), A(1), and A(3), previously introduced in a heuristic way to analyze CO stretch spectra in heme proteins at fixed pH (see for instance, Biophys. J. 71:1563-1573). Moreover, an additional, weakly populated substate, called A(x), was identified. Protonation of H97 gives rise to a blue shift of the individual infrared lines by about 2 cm(-1), so that the A substates actually appear in pairs, such as A(0) and A(0)(+). The blue shift can be explained by reduced backbonding from the heme iron to the CO. Protonation of the distal histidine, H64, leads to a change of the infrared absorption from the A(1) or A(3) substate lines to A(0). This behavior can be explained by a conformational change upon protonation that moves the imidazole sidechain of H64 away from the CO into the high-dielectric solvent environment, which avoids the energetically unfavorable situation of an uncompensated electric charge in the apolar, low-dielectric protein interior. Our results suggest that protonation reactions serve as an important mechanism to create taxonomic

  11. Current Theoretical Challenges in Proton-Coupled Electron Transfer: Electron-Proton Nonadiabaticity, Proton Relays, and Ultrafast Dynamics

    SciTech Connect

    Hammes-Schiffer, Sharon

    2011-06-16

    Proton-coupled electron transfer (PCET) reactions play an important role in a wide range of biological and chemical processes. The motions of the electrons, transferring protons, solute nuclei, and solvent nuclei occur on a wide range of timescales and are often strongly coupled. As a result, the theoretical description of these processes requires a combination of quantum and classical methods. This perspective discusses three of the current theoretical challenges in the field of PCET. The first challenge is the calculation of electron-proton nonadiabatic effects, which are significant for these reactions because the hydrogen tunneling is often faster than the electronic transition. The second challenge is the modeling of electron transfer coupled to proton transport along hydrogen-bonded networks. The third challenge is the simulation of the ultrafast dynamics of nonequilibrium photoinduced PCET reactions in solution. Insights provided by theoretical studies may assist in the design of more effective catalysts for energy conversion processes. The proton relay portion of this review is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

  12. Current Theoretical Challenges in Proton-Coupled Electron Transfer: Electron Proton Nonadiabaticity, Proton Relays, and Ultrafast Dynamics

    SciTech Connect

    Hammes-Schiffer, Sharon

    2011-06-16

    Proton-coupled electron transfer (PCET) reactions play an important role in a wide range of biological and chemical processes. The motions of the electrons, transferring protons, solute nuclei, and solvent nuclei occur on a wide range of time scales and are often strongly coupled. As a result, the theoretical description of these processes requires a combination of quantum and classical methods. This Perspective discusses three of the current theoretical challenges in the field of PCET. The first challenge is the calculation of electron proton nonadiabatic effects, which are significant for these reactions because the hydrogen tunneling is often faster than the electronic transition. The second challenge is the modeling of electron transfer coupled to proton transport along hydrogen-bonded networks. The third challenge is the simulation of the ultrafast dynamics of nonequilibrium photoinduced PCET reactions in solution. Insights provided by theoretical studies may assist in the design of more effective catalysts for energy conversion processes. The proton relay portion of this review is based upon work supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

  13. Measurements of spin correlation in top-antitop quark events from proton-proton collisions ats=7  TeVusing the ATLAS detector

    DOE PAGES

    Aad, G.; Abbott, B.; Abdallah, J.; ...

    2014-12-24

    Measurements of spin correlation in top quark pair production are presented using data collected with the ATLAS detector at the LHC with proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 4.6  fb⁻¹. Events are selected in final states with two charged leptons and at least two jets and in final states with one charged lepton and at least four jets. Four different observables sensitive to different properties of the top quark pair production mechanism are used to extract the correlation between the top and antitop quark spins. Some of these observables are measured formore » the first time. The measurements are in good agreement with the Standard Model prediction at next-to-leading-order accuracy.« less

  14. Performance of photon reconstruction and identification with the CMS detector in proton-proton collisions at √s = 8 TeV

    SciTech Connect

    Khachatryan, Vardan

    2015-08-10

    A description is provided of the performance of the CMS detector for photon reconstruction and identification in proton-proton collisions at a centre-of-mass energy of 8 TeV at the CERN LHC. Details are given on the reconstruction of photons from energy deposits in the electromagnetic calorimeter (ECAL) and the extraction of photon energy estimates. Furthermore, the reconstruction of electron tracks from photons that convert to electrons in the CMS tracker is also described, as is the optimization of the photon energy reconstruction and its accurate modelling in simulation, in the analysis of the Higgs boson decay into two photons. In the barrel section of the ECAL, an energy resolution of about 1% is achieved for unconverted or late-converting photons from H → γγ decays. Furthermore, different photon identification methods are discussed and their corresponding selection efficiencies in data are compared with those found in simulated events.

  15. Performance of photon reconstruction and identification with the CMS detector in proton-proton collisions at √s = 8 TeV

    DOE PAGES

    Khachatryan, Vardan

    2015-08-10

    A description is provided of the performance of the CMS detector for photon reconstruction and identification in proton-proton collisions at a centre-of-mass energy of 8 TeV at the CERN LHC. Details are given on the reconstruction of photons from energy deposits in the electromagnetic calorimeter (ECAL) and the extraction of photon energy estimates. Furthermore, the reconstruction of electron tracks from photons that convert to electrons in the CMS tracker is also described, as is the optimization of the photon energy reconstruction and its accurate modelling in simulation, in the analysis of the Higgs boson decay into two photons. In themore » barrel section of the ECAL, an energy resolution of about 1% is achieved for unconverted or late-converting photons from H → γγ decays. Furthermore, different photon identification methods are discussed and their corresponding selection efficiencies in data are compared with those found in simulated events.« less

  16. COMPACT PROTON INJECTOR AND FIRST ACCELERATOR SYSTEM TEST FOR COMPACT PROTON DIELECTRIC WALL CANCER THERAPY ACCELERATOR

    SciTech Connect

    Chen, Y; Guethlein, G; Caporaso, G; Sampayan, S; Blackfield, D; Cook, E; Falabella, S; Harris, J; Hawkins, S; Nelson, S; Poole, B; Richardson, R; Watson, J; Weir, J; Pearson, D

    2009-04-23

    A compact proton accelerator for cancer treatment is being developed by using the high-gradient dielectric insulator wall (DWA) technology [1-4]. We are testing all the essential DWA components, including a compact proton source, on the First Article System Test (FAST). The configuration and progress on the injector and FAST will be presented.

  17. Proton-proton physics with the ALICE muon spectrometer at the LHC

    SciTech Connect

    Bastid, N.

    2008-09-15

    ALICE, the dedicated heavy-ion experiment at the LHC, has also an important proton-proton physics program. The ALICE muon spectrometer will be presented and the corresponding physics analysis will be reviewed. A particular emphasis will be placed on heavy-flavor measurement.

  18. SPS Beam Steering for LHC Extraction

    SciTech Connect

    Gianfelice-Wendt, Eliana; Bartosik, Hannes; Cornelis, Karel; Norderhaug Drøsdal, Lene; Goddard, Brennan; Kain, Verena; Meddahi, Malika; Papaphilippou, Yannis; Wenninger, Jorg

    2014-07-01

    The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

  19. How proton pulse characteristics influence protoacoustic determination of proton-beam range: simulation studies.

    PubMed

    Jones, Kevin C; Seghal, Chandra M; Avery, Stephen

    2016-03-21

    The unique dose deposition of proton beams generates a distinctive thermoacoustic (protoacoustic) signal, which can be used to calculate the proton range. To identify the expected protoacoustic amplitude, frequency, and arrival time for different proton pulse characteristics encountered at hospital-based proton sources, the protoacoustic pressure emissions generated by 150 MeV, pencil-beam proton pulses were simulated in a homogeneous water medium. Proton pulses with Gaussian widths ranging up to 200 μs were considered. The protoacoustic amplitude, frequency, and time-of-flight (TOF) range accuracy were assessed. For TOF calculations, the acoustic pulse arrival time was determined based on multiple features of the wave. Based on the simulations, Gaussian proton pulses can be categorized as Dirac-delta-function-like (FWHM < 4 μs) and longer. For the δ-function-like irradiation, the protoacoustic spectrum peaks at 44.5 kHz and the systematic error in determining the Bragg peak range is <2.6 mm. For longer proton pulses, the spectrum shifts to lower frequencies, and the range calculation systematic error increases (⩽ 23 mm for FWHM of 56 μs). By mapping the protoacoustic peak arrival time to range with simulations, the residual error can be reduced. Using a proton pulse with FWHM = 2 μs results in a maximum signal-to-noise ratio per total dose. Simulations predict that a 300 nA, 150 MeV, FWHM = 4 μs Gaussian proton pulse (8.0 × 10(6) protons, 3.1 cGy dose at the Bragg peak) will generate a 146 mPa pressure wave at 5 cm beyond the Bragg peak. There is an angle dependent systematic error in the protoacoustic TOF range calculations. Placing detectors along the proton beam axis and beyond the Bragg peak minimizes this error. For clinical proton beams, protoacoustic detectors should be sensitive to <400 kHz (for -20 dB). Hospital-based synchrocyclotrons and cyclotrons are promising sources of proton pulses for generating clinically measurable protoacoustic

  20. Positron-proton to electron-proton elastic cross section ratios from CLAS

    NASA Astrophysics Data System (ADS)

    Adikaram, Dasuni; Rimal, Dipak; Weinstein, Larry; Raue, Brian

    2014-03-01

    There is a significant discrepancy between the ratio of the electromagnetic form factors of the proton measured by the Rosenbluth and the polarization transfer technique. The most likely explanation of this discrepancy is the inclusion of two-photon exchange (TPE) amplitude contributions to the elastic electron-proton cross section. The CLAS TPE experiment measured the TPE contribution in the wide range of Q2 and ɛ range using a comparison of positron-proton to electron-proton elastic cross sections (R = σ (e+ p) / σ (e- p)). Preliminary results will be presented, along with the estimations of systematic uncertainties. A detailed comparison of new results with previous R measurements and theoretical calculations will be presented. Implications of the CLAS TPE measurements on the elastic electron-proton cross section will be also discussed.