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Sample records for ags polarized proton

  1. Acceleration of polarized proton at the AGS

    SciTech Connect

    Lee, Y Y

    1980-01-01

    The unexpected importance of high energy spin effects and the success of the ZGS in correcting many intrinsic and imperfection depolarizing resonances led us to attempt to accelerate polarized protons in the AGS. A collaborative effort is underway by the groups in Argonne, Michigan, Rice, Yale and Brookhaven to improve and modify the AGS to accelerate polarized protons. With the appropriate funding the first polarized proton acceleration at the AGS should be possible by 1983.

  2. 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.

  3. Polarized proton acceleration at the Brookhaven AGS

    SciTech Connect

    Ahrens, L.A.

    1986-01-01

    At the conclusion of polarized proton commissioning in February 1986, protons with an average polarization of 45%, momentum of 21.7 GeV/c, and intensity of 2 x 10/sup 10/ protons per pulse, were extracted to an external polarimeter at the Brookhaven AGS. In order to maintain this polarization, five intrinsic and nearly forty imperfection depolarizing resonances had to be corrected. An apparent interaction between imperfection and intrinsic resonances occurring at very nearly the same energy was observed and the correction of imperfection resonances using ''beat'' magnetic harmonics discovered in the previous AGS commissioning run was further confirmed.

  4. POLARIZED PROTON ACCELERATION IN AGS AND RHIC.

    SciTech Connect

    ROSER,T.

    2007-09-10

    As the first hadron accelerator and collider consisting of two independent superconducting rings RHIC has operated with a wide range of beam energies and particle species including polarized proton beams. The acceleration of polarized beams in both the injector and the collider rings is complicated by numerous depolarizing spin resonances. Partial and full Siberian snakes have made it possible to overcome the depolarization and beam polarizations of up to 65% have been reached at 100 GeV in RHIC.

  5. THOUGHTS AND ''FACTS'' FROM THE AGS POLARIZED PROTON RUNS DURING THE 1980S.

    SciTech Connect

    AHRENS,L.

    2002-11-06

    This workshop's focus is on considering ways for improving the proton beam polarization that the AGS delivers to the RHIC. This talk attempts to review the first decade of AGS polarization--the 1980's; to briefly describe some aspects of the machine situation, the depolarization avoidance strategies employed and the success achieved in AGS from the perspective of one of those involved.

  6. An overview of Booster and AGS polarized proton operation during Run 15

    SciTech Connect

    Zeno, K.

    2015-10-20

    This note is an overview of the Booster and AGS for the 2015 Polarized Proton RHIC run from an operations perspective. There are some notable differences between this and previous runs. In particular, the polarized source intensity was expected to be, and was, higher this year than in previous RHIC runs. The hope was to make use of this higher input intensity by allowing the beam to be scraped down more in the Booster to provide a brighter and smaller beam for the AGS and RHIC. The RHIC intensity requirements were also higher this run than in previous runs, which caused additional challenges because the AGS polarization and emittance are normally intensity dependent.

  7. ACCELERATION OF POLARIZED PROTONS IN THE AGS WITH TWO HELICAL PARTIAL SNAKES.

    SciTech Connect

    HUANG,H.; AHRENS,L.; BAI,M.; ET AL.

    2005-05-16

    The RHIC spin program requires 2 x 10{sup 11} proton/bunch with 70% polarization. As the injector to RHIC, AGS is the bottleneck for preserving polarization: there is no space for a full snake to overcome numerous depolarizing resonances. An ac dipole and a partial snake have been used to preserve beam polarization in the past few years. Two helical snakes have been built and installed in the AGS. With careful setup of optics at injection and along the ramp, this combination can eliminate all depolarizing resonances encountered during acceleration. This paper presents the setup and preliminary results.

  8. ACCELERATION OF POLARIZED PROTONS IN THE AGS WITH TWO HELICAL PARTIAL SNAKES.

    SciTech Connect

    HUANG, H.; AHRENS, L.A.; BAI, M.; BRAVAR, A.; BROWN, K.; COURANT, E.D.; GARDNER, C.; GLENN, J.W.; LUCCIO, A.U.; MACKAY, W.W.; PTITSYN, V.; ROSER, T.; TEPIKIAN, S.; TSOUPAS, N.; WOOD, J.; YIP, K.; ZELENSKI, A.; ZENO, K.

    2006-06-26

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult: the depolarizing resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions and are not feasible in the AGS since straight sections are too short. Recently, two helical partial snakes with double pitch design have been built and installed in the AGS. With careful setup of optics at injection and along the ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances encountered during acceleration. This paper presents the accelerator setup and preliminary results.

  9. Polarized Proton Acceleration in the AGS with Two Helical Partial Snakes

    SciTech Connect

    Huang, H.; Ahrens, L. A.; Bai, M.; Bravar, A.; Brown, K.; Courant, E. D.; Gardner, C.; Glenn, J. W.; Luccio, A. U.; MacKay, W. W.; Ptitsyn, V.; Roser, T.; Tepikian, S.; Tsoupas, N.; Wood, J.; Yip, K.; Zelenski, A.; Zeno, K.; Lin, F.; Okamura, M.

    2007-06-13

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult: the depolarizing resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions and are not feasible in the AGS since straight sections are too short. Recently, two helical partial snakes have been built and installed in the AGS. With careful setup of optics at injection and along the ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances encountered during acceleration. This paper presents the accelerator setup and preliminary results.

  10. 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.

  11. 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.

  12. 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

    The Relativistic Heavy Ion Collider (RHIC) operation as the polarized proton collider presents unique challenges since both luminosity(L) and spin polarization(P) are important. With longitudinally polarized beams at the experiments, the figure of merit is LP{sup 4}. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system is installed to improve longitudinal match at injection and to increase luminosity. The beam dump was upgraded to increase bunch intensity. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control is also improved this year. Additional efforts are put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point is chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper. Siberian snakes are essential tools to preserve polarization when accelerating polarized beams to higher energy. At the same time, the higher order resonances still can cause polarization loss. As seen in RHIC, the betatron tune has to be carefully set and maintained on the ramp and during the store to avoid polarization loss. In addition, the orbit control is also critical to preserve polarization. The higher polarization during this run comes from several improvements over last run. First we have a much better orbit on the ramp. The orbit feedback brings down the vertical rms orbit error to 0.1mm, much better than the 0.5mm last run. With correct BPM offset and vertical realignment, this rms orbit error is indeed small. Second, the jump quads in the AGS improved input polarization for RHIC. Third, the vertical tune was pushed further away from 7/10 snake resonance. The tune feedback maintained the tune at the desired value through the ramp. To calibrate the analyzing power of RHIC polarimeters at any energy above

  13. Polarization preservation in the AGS

    SciTech Connect

    Ratner, L.G.

    1983-01-01

    The successful operation of a high energy polarized beam at the Argonne Zero Gradient Synchrotron (ZGS) with the concommitant development of depolarizing resonance correction techniques has led to the present project of commissioning such a beam at the Brookhaven Alternating Gradient Synchrotron (AGS). A description of the project was presented at the 1981 National Accelerator Conference. I would like to now present a more detailed description of how we plan to preserve the polarization during acceleration, and to present our game plan for tuning through some 50 resonances and reaching our goal of a 26 GeV polarized proton beam with greater than 60% polarization.

  14. Polarized proton beams in RHIC

    SciTech Connect

    Zelenski, A.

    2010-10-04

    The polarized beam for RHIC is produced in the optically-pumped polarized H{sup -} ion source and then accelerated in Linac to 200 MeV for strip-injection to Booster and further accelerated 24.3 GeV in AGS for injection in RHIC. In 2009 Run polarized protons was successfully accelerated to 250 GeV beam energy. The beam polarization of about 60% at 100 GeV beam energy and 36-42% at 250 GeV beam energy was measured with the H-jet and p-Carbon CNI polarimeters. The gluon contribution to the proton spin was studied in collisions of longitudinally polarized proton beams at 100 x 100 GeV. At 250 x 250 GeV an intermediate boson W production with the longitudinally polarized beams was studied for the first time.

  15. Commissioning the polarized beam in the AGS

    SciTech Connect

    Ratner, L.G.; Brown, H.; Chiang, I.H.; Courant, E.; Gardner, C.; Lazarus, D.; Lee, Y.Y.; Makdisi, Y.; Sidhu, S.; Skelly, J.

    1985-01-01

    After the successful operation of a high energy polarized proton beam at the Argonne Laboratory Zero Gradient Synchrotron (ZGS) was terminated, plans were made to commission such a beam at the Brookhaven National Laboratory Alternating Gradient Synchrotron (AGS). On February 23, 1984, 2 ..mu..A of polarized H/sup -/ was accelerated through the Linac to 200 MeV with a polarization of about 65%. 1 ..mu..A was injected into the AGS and acceleration attempts began. Several relatively short runs were then made during the next three months. Dedicated commissioning began in early June, and on June 26 the AGS polarized beam reached 13.8 GeV/c to exceed the previous ZGS peak momentum of 12.75 GeV/c. Commissioning continued to the point where 10/sup 10/ polarized protons were accelerated to 16.5 GeV/c with 40% polarization. Then, two experiments had a short polarized proton run. We plan to continue commissioning efforts in the fall of this year to reach higher energy, higher intensity, and higher polarization levels. We present a brief description of the facility and of the methods used for preserving the polarization of the accelerating beam.

  16. Fighting the Residual Polarization Loss in the AGS

    SciTech Connect

    Huang, H.; Ahrens, L. A.; Bai, M.; Brown, K.; Gardner, C.; Glenn, J. W.; Lin, F.; Luccio, A. U.; MacKay, W. W.; Roser, T.; Tepikian, S.; Tsoupas, N.; Yip, K.; Zelenski, A.; Zeno, K.

    2009-08-04

    A dual partial snake scheme has been used for AGS polarized proton operation for several years. It has provided polarized proton beams with 1.5x10{sup 11} protons per bunch and 65% polarization for the RHIC spin program. There is still residual polarization loss due to both snake resonances and horizontal resonances as shown in the data. Several schemes were tested or proposed in the AGS to mitigate the loss, such as putting horizontal tune into the spin tune gap, injection into a accelerating bucket, and tune jump across the horizontal resonances. This paper presents the experiment and simulation results and analyses.

  17. Gluon polarization in the proton

    SciTech Connect

    Bass, Steven D.; Casey, Andrew; Thomas, Anthony W.

    2011-03-15

    We combine heavy-quark renormalization group arguments with our understanding of the nucleon's wave function to deduce a bound on the gluon polarization {Delta}g in the proton. The bound is consistent with the values extracted from spin experiments at COMPASS and RHIC.

  18. Workshop on acceleration of polarized protons: summary report

    SciTech Connect

    Lee, Y.Y.; Terwilliger, K.M.

    1982-01-01

    The workshop sessions concentrated on polarized protons in circular accelerators and storage rings. Topics such as polarized electrons were discussed only when the subject was relevant to proton phenomena. Of major interest was the possible applicability of the new idea of spin matching for crossing depolarizing resonances. On the experimental side, some remarkable new data were presented by the SATURNE II Group. They have successfully crossed both intrinsic and imperfection depolarizing resonances by the spin flip method with minimal depolarization-the first group to do so. They also obtained some results which apparently cannot be explained with our present understanding of spin phenomena. The workshop concluded that more experimental measurements are needed to understand the physics and that such studies would be very important for the future acceleration of polarized protons at KEK and the AGS. The workshop included status reports from the four laboratories which have programs of polarized particle acceleration--or approved projects to accelerate polarized protons.

  19. 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.

  20. 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.

  1. Muon calculations for the polarized proton beamline

    SciTech Connect

    Cossairt, J.D.

    1986-11-01

    Monte Carlo calculations of the muon intensities due to the new polarized proton beam using the program CASIM are reported. Results are reported in terms of tissue absorbed dose per incident proton. (LEW)

  2. 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.

  3. Polarized proton parameters for the 2015 PP-on-Au setup in RHIC

    SciTech Connect

    Gardner, C. J.

    2015-08-25

    Values are given for RHIC circumference shifts due to snakes for various situations. Relevant parameters are tabulated for polarized protons (PP) in the booster and in AGS and RHIC for PP-on-Au stores.

  4. Polarized proton parameters for the 2015 PP-on-Aluminum setup in RHIC

    SciTech Connect

    Gardner, C. J.

    2015-10-02

    Values are given for RHIC circumference shifts due to snakes for various situations. Relevant parameters are tabulated for polarized protons (PP) in the booster and in AGS and RHIC for PP-on-Aluminum stores.

  5. RHIC Polarized proton performance in run-8

    SciTech Connect

    Montag,C.; Bai, M.; MacKay, W.W.; Roser, T.; Abreu, N.; Ahrens, L.; Barton, D.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Bunce, G.; Calaga, R.; Cameron, P.; Connolly, R.; D'Ottavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hayes, T.; Huang, H.; Ingrassia, P.; Kayran, D.A.; Kewisch, J.; Lee, R.C.; Lin, F.; Litvinenko, V.N.; Luccio, A.U.; Luo, Y.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Michnoff, R.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Robert-Demolaize, G.; Russo, T.; Satogata, T.; Schultheiss, C.; Sivertz, M.; Smith, K.; Tepikian, S.; D. Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2008-10-06

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the 'Yellow' RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8, and we discuss possible causes of the not as high as previously achieved polarization performance of the 'Yellow' ring.

  6. RHIC OPERATION WITH LONGITUDINALLY POLARIZED PROTONS.

    SciTech Connect

    HUANG,H.BAI,M.BEEBE-WANG,J.ET AL.

    2004-07-05

    Polarized proton beams have been accelerated, stored and collided at 100GeV per beam in the Relativistic Heavy Ion Collider (RHIC) with longitudinal polarization. The essential equipment includes four Siberian snakes, eight spin rotators and fast relative polarimeters in each of the two RHIC rings as well as local polarimeters at the STAR and PHENIX detectors. This paper summarizes the performance of RHIC as a polarized proton collider in the FY03 run with emphasis on polarization issues. Preliminary data from the FY04 run is also shown.

  7. Surface spin polarization induced ferromagnetic Ag nanoparticles

    NASA Astrophysics Data System (ADS)

    Shih, Po-Hsun; Li, Wen-Hsien; Wu, Sheng Yun

    2016-05-01

    We report on the observation of ferromagnetic spin polarized moments in 4.5 nm Ag nanoparticles. Both ferromagnetic and diamagnetic responses to an applied magnetic field were detected. The spin polarized moments shown under non-linear thermoinduced magnetization appeared on the surface atoms, rather than on all the atoms in particles. The saturation magnetization departed substantially from the Bloch T3/2-law, showing the existence of magnetic anisotropy. The Heisenberg ferromagnetic spin wave model for Ha-aligned moments was then employed to identify the magnetic anisotropic energy gap of ~0.12 meV. Our results may be understood by assuming the surface magnetism model, in which the surface atoms give rise to polarized moments while the core atoms produce diamagnetic responses.

  8. ACCELERATING POLARIZED PROTONS TO 250 GEV

    SciTech Connect

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

    2007-06-25

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

  9. FIDDLING CARBON STRINGS WITH POLARIZED PROTON BEAMS.

    SciTech Connect

    HUANG, H.; KURITA, K.

    2006-05-01

    An innovative polarimeter based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region was first tested in the Brookhaven AGS successfully. CNI Polarimeters were then installed in the AGS and both RHIC rings. The polarimeter consists of ultra-thin carbon targets and silicon strip detectors. The waveform digitizers are used for signal readout, which allows deadtime-less data processing on the fly. Polarimeters are crucial instrumentation for the RHIC spin physics program. This paper summarizes the polarimeter design issues and operation results.

  10. Polarization measurement of laser-accelerated protons

    SciTech Connect

    Raab, Natascha; Engels, Ralf; Engin, Ilhan; Greven, Patrick; Holler, Astrid; Lehrach, Andreas; Maier, Rudolf; Büscher, Markus; Cerchez, Mirela; Swantusch, Marco; Toncian, Monika; Toncian, Toma; Willi, Oswald; Gibbon, Paul; Karmakar, Anupam

    2014-02-15

    We report on the successful use of a laser-driven few-MeV proton source to measure the differential cross section of a hadronic scattering reaction as well as on the measurement and simulation study of polarization observables of the laser-accelerated charged particle beams. These investigations were carried out with thin foil targets, illuminated by 100 TW laser pulses at the Arcturus laser facility; the polarization measurement is based on the spin dependence of hadronic proton scattering off nuclei in a Silicon target. We find proton beam polarizations consistent with zero magnitude which indicates that for these particular laser-target parameters the particle spins are not aligned by the strong magnetic fields inside the laser-generated plasmas.

  11. Proton spin polarizabilities from polarized Compton scattering

    SciTech Connect

    B. Pasquini; D. Drechsel; M. Vanderhaeghen

    2007-07-01

    Polarized Compton scattering off the proton is studied within the framework of subtracted dispersion relations for photon energies up to 300 MeV. As a guideline for forthcoming experiments, we focus the attention on the role of the proton's spin polarizabilities and investigate the most favorable conditions to extract them with a minimum of model dependence. We conclude that a complete separation of the four spin polarizabilities is possible, at photon energies between threshold and the $\\Delta(1232)$ region, provided one can achieve polarization measurements with an accuracy of a few percent.

  12. An AGS experiment to test bunching for the proton driver of the muon collider.

    SciTech Connect

    Norem, J.

    1998-04-27

    The proton driver for the muon collider must produce short pulses of protons in order to facilitate muon cooling and operation with polarized beams. In order to test methods of producing these bunches they have operated the AGS near transition and studied procedures which involved moving the transition energy {gamma} to the beam energy. They were able to produce stable bunches with RMS widths of {sigma} = 2.2-2.7 ns for longitudinal bunch areas of {minus}1.5 V-s, in addition to making measurements of the lowest two orders of the momentum compaction factor.

  13. Simulation of proton RF capture in the AGS Booster

    SciTech Connect

    Khiari, F.Z.; Luccio, A.U.; Weng, W.T.

    1988-01-01

    RF capture of the proton beam in the AGS Booster has been simulated with the longitudinal phase-space tracking code ESME. Results show that a capture in excess of 95% can be achieved with multiturn injection of a chopped beam.

  14. Polarized proton beam for eRHIC

    SciTech Connect

    Huang, H.; Meot, F.; Ptitsyn, V.; Roser, T.

    2015-05-03

    RHIC has provided polarized proton collisions from 31 GeV to 255 GeV in the past decade. To preserve polarization through numerous depolarizing resonances through the whole accelerator chain, harmonic orbit correction, partial snakes, horizontal tune jump system and full snakes have been used. In addition, close attentions have been paid to betatron tune control, orbit control and beam line alignment. The polarization of 60% at 255 GeV has been delivered to experiments with 1.8×1011 bunch intensity. For the eRHIC era, the beam brightness has to be maintained to reach the desired luminosity. Since we only have one hadron ring in the eRHIC era, existing spin rotator and snakes can be converted to six snake configuration for one hadron ring. With properly arranged six snakes, the polarization can be maintained at 70% at 250 GeV. This paper summarizes the effort and plan to reach high polarization with small emittance for eRHIC.

  15. RHIC Proton Luminosity and Polarization Improvement

    SciTech Connect

    Zhang, S. Y.

    2014-01-17

    The RHIC proton beam polarization can be improved by raising the Booster scraping, which also helps to reduce the RHIC transverse emittance, and therefore to improve the luminosity. By doing this, the beam-beam effect would be enhanced. Currently, the RHIC working point is constrained between 2/3 and 7/10, the 2/3 resonance would affect intensity and luminosity lifetime, and the working point close to 7/10 would enhance polarization decay in store. Run 2013 shows that average polarization decay is merely 1.8% in 8 hours, and most fills have the luminosity lifetime better than 14 hours, which is not a problem. Therefore, even without beam-beam correction, there is room to improve for RHIC polarization and luminosity. The key to push the Booster scraping is to raise the Booster input intensity; for that, two approaches can be used. The first is to extend the LINAC tank 9 pulse width, which has been successfully applied in run 2006. The second is to raise the source temperature, which has been successfully applied in run 2006 and run 2012.

  16. A LOW GAMMA_T INJECTION LATTICE FOR POLARIZED PROTONS IN RHIC

    SciTech Connect

    MONTAG,C.

    2007-06-25

    Polarized protons are injected into the Relativistic Heavy Jon Collider (RHIC) just above transition energy. When installation of a cold partial Siberian snake in the AGS required lowering the injection energy by {Delta}{gamma} = 0.56, the transition energy in RHIC had to be lowered accordingly to ensure proper longitudinal matching. This paper presents lattice modifications implemented to lower the transition energy by {Delta}{gamma}{sub t} = 0.8.

  17. Recent results of gluon and sea quark polarization measurements in polarized proton-proton collisions at STAR

    NASA Astrophysics Data System (ADS)

    Li, Xuan; Star Collaboration

    2014-09-01

    The STAR experiment at RHIC is carrying out a comprehensive high-energy spin physics program to understand the internal structure and dynamics of the proton in polarized proton-proton collisions at = 200 GeV and = 500/510 GeV. STAR has the capability, with nearly full azimuthal coverage, to reconstruct leptons, hadrons and jets in the mid-rapidity region (|η| < 1). The results for inclusive jet longitudinal double spin asymmetries taken during the 2009 RHIC run indicate the first non-zero gluon contribution (Δg(x,Q2)/g(x,Q2)) to the proton spin for 0.05 < x < 1 (Bjorken-x: momentum fraction of partons). Recent longitudinal single-spin asymmetry measurements of W+/- bosons at = 500/510 GeV in polarized proton-proton collisions provide a direct probe of the polarized anti-u and anti-d quark distributions (Δū(x, Q2), Δbar d(x, Q2)). These results better constrain the polarized gluon and sea quark distributions of the proton in the RHIC sensitive kinematic region. Future measurements with continuing high energy polarized proton-proton run at RHIC and detector upgrade will explore the gluonic contribution to the proton spin in extended range.

  18. Polarization Transfer in Proton Compton Scattering at High Momentum Transfer

    SciTech Connect

    Hamilton, D.J.; Annand, J.R.M.; Mamyan, V.H.; Aniol, K.A.; Margaziotis, D.J.; Bertin, P.Y.; Camsonne, A.; Laveissiere, G.; Bosted, P.; Paschke, K.; Calarco, J.R.; Chang, G.C.; Horn, T.; Savvinov, N.; Chang, T.-H.; Danagoulian, A.; Nathan, A.M.; Roedelbronn, M.; Chen, J.-P.

    2005-06-24

    Compton scattering from the proton was investigated at s=6.9 GeV{sup 2} and t=-4.0 GeV{sup 2} via polarization transfer from circularly polarized incident photons. The longitudinal and transverse components of the recoil proton polarization were measured. The results are in disagreement with a prediction of perturbative QCD based on a two-gluon exchange mechanism, but agree well with a prediction based on a reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton.

  19. Polarization Transfer in Proton Compton Scattering at High Momentum Transfer

    SciTech Connect

    D.J. Hamilton; Vahe Mamyan

    2004-10-01

    Compton scattering from the proton was investigated at s = 6.9 GeV{sup 2} and t = -4.0 TeV{sup 2} via polarization transfer from circularly polarized incident photons. The longitudinal and transverse components of the recoil proton polarization were measured. The results are in excellent agreement with a prediction based on a reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton and in disagreement with a prediction of pQCD based on a two-gluon exchange mechanism.

  20. Evidence for polarization of gluons in the proton.

    PubMed

    de Florian, Daniel; Sassot, Rodolfo; Stratmann, Marco; Vogelsang, Werner

    2014-07-01

    We discuss the impact of recent high-statistics Relativistic Heavy Ion Collider data on the determination of the gluon polarization in the proton in the context of a global QCD analysis of polarized parton distributions. We find evidence for a nonvanishing polarization of gluons in the region of momentum fraction and at the scales mostly probed by the data. Although information from low momentum fractions is presently lacking, this finding is suggestive of a significant contribution of gluon spin to the proton spin, thereby limiting the amount of orbital angular momentum required to balance the proton spin budget. PMID:25032920

  1. Study of the Polarization Deterioration During Physics Stores in RHIC Polarized Proton Runs

    NASA Astrophysics Data System (ADS)

    Duan, Z.; Qin, Q.; Bai, M.; Roser, T.

    2016-02-01

    As the only high energy polarized proton collider in the world, the Relativistic Heavy Ion Collider (RHIC) has achieved a great success in colliding polarized proton beams up to 255GeV per beam energy with over 50% average store polarizations for spin physics studies. With the help of Siberian snakes as well as outstanding beam control during the acceleration, polarization loss during acceleration up to 100 GeV is negligible. However, about 10% polarization loss was observed between acceleration from 100 GeV to 255 GeV. In addition, a mild polarization deterioration during long store for physics data taking was also observed. In this paper, studies in understanding the store depolarizing mechanism is reported, including the analysis of polarization deterioration data based on the past couple of RHIC polarized proton runs.

  2. Polarized beams at the ZGS and the AGS

    SciTech Connect

    Ratner, L.G.

    1989-01-01

    I have had, and still do, a feeling of deja Vu as I have gone through the development of the polarized beam at the AGS. There were many similarities both scientifically and sociologically, and of course, some significant differences between the AGS and the ZGS. We traded the 12 GeV ZGS for the 28 GeV AGS, we traded Ron Martin for Derek Lowenstein, but having the lowest energy, high energy machine did not change. Paraphrasing some remarks of Bob Sachs, the AGS replaced the ZGS as the tail of the dog, and it appears that now the tail loppers are again on the loose. You will probably see them again somewhere in the world using body english to help polarize a beam. Basically, I would like to describe a little of the progression of events and the hardware in both accelerators that allowed Kent and his colleagues to do a great deal of very interesting spin physics. 6 refs., 30 figs.

  3. Studies of Unstable Nuclei with Spin-Polarized Proton Target

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Satoshi; Uesaka, Tomohiro; Wakui, Takashi; Chebotaryov, Sergey; Kawahara, Tomomi; Kawase, Shoichiro; Milman, Evgeniy; Tang, Tsz Leung; Tateishi, Kenichiro; Teranishi, Takashi

    2016-02-01

    Roles of spin-dependent interactions in unstable nuclei have been investigated via the direct reaction of radioactive ions with a solid spin-polarized proton target. The target has a unique advantage of a high polarization of 20-30% under low magnetic field of 0.1 T and at a high temperature of 100 K, which allow us to detect recoil protons with good angular resolution. Present status of on-going experimental studies at intermediate energies, such as proton elastic scattering and (p, 2p) knockout reaction, and new physics opportunities expected with low-energy RI beams are overviewed.

  4. Polarized proton collisions at 205 GeV at RHIC.

    PubMed

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

    2006-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions. PMID:16712305

  5. The AGS (alternating gradient synchrotron): Performance and potential

    SciTech Connect

    Ratner, L.G.

    1989-01-01

    This report discusses the following topics on the Brookhaven AGS: basic parameters, description of the accelerator complex and proton operation; operation with heavy ions and polarized protons; AGS upgrades and expanded potential. (LSP)

  6. Polarization Status of Magnetic Fluctuations at Proton Scales

    NASA Astrophysics Data System (ADS)

    Bruno, Roberto; Telloni, Daniele; D'Amicis, Raffaella; DeMarco, Rossana; Marcucci, Federica

    2016-04-01

    We study the polarization status of magnetic field fluctuations at proton scales looking for possible links between the large-scale and small-scale features of solar wind fluctuations across the frequency break separating fluid and kinetic regimes. The main goal is to correlate the occurrence of proton temperature anisotropy, low proton β∥ values and, magnetic field fluctuations polarization to the particular state of turbulence found within the inertial range. We found clear correlations between each type of polarization, either left or right, and turbulence status. Moreover, for the first time in literature, we show that left-handed and right handed polarized fluctuations occupy different areas of the temperature anisotropy-β∥ plot, as expected for Alfvén Ion Cyclotron and Kinetic Alfvén waves, respectively.

  7. Experiments with Fermilab polarized proton and polarized antiproton beams

    SciTech Connect

    Yokosawa, A.

    1990-01-01

    We summarize activities concerning the Fermilab polarized beams. They include a brief description of the polarized-beam facility, measurements of beam polarization by polarimeters, asymmetry measurements in the {pi}{degree} production at high p{sub {perpendicular}} and in the {Lambda} ({Sigma}{degree}), {pi}{sup {plus minus}}, {pi}{degree} production at large x{sub F}, and {Delta}{sigma}{sub L}(pp, {bar p}p) measurements. 18 refs.

  8. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    Jiang, X.; Benmokhtar, F.; Glashauser, C.; McCormick, K.; Ransome, R. D.; Arrington, J.; Holt, R. J.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Camsonne, A.

    2007-05-04

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  9. Recoil-Proton Polarization in High-Energy Deuteron Photodisintegration with Circularly Polarized Photons

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J. P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D. W. Higinbotham; R. J. Holt; C. W. de Jager; M. K. Jones; L. J. Kaufman; E. R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K. D. Paschke; C. F. Perdrisat; V. Punjabi; I. A. Qattan; R. D. Ransome; P. E. Reimer; B. Reitz; A. Saha; E. C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G. M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; and L. Zhu

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  10. Proton Form Factor Measurements Using Polarization Method: Beyond Born Approximation

    SciTech Connect

    Pentchev, Lubomir

    2008-10-13

    Significant theoretical and experimental efforts have been made over the past 7 years aiming to explain the discrepancy between the proton form factor ratio data obtained at JLab using the polarization method and the previous Rosenbluth measurements. Preliminary results from the first high precision polarization experiment dedicated to study effects beyond Born approximation will be presented. The ratio of the transferred polarization components and, separately, the longitudinal polarization in ep elastic scattering have been measured at a fixed Q{sup 2} of 2.5 GeV{sup 2} over a wide kinematic range. The two quantities impose constraints on the real part of the ep elastic amplitudes.

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

    SciTech Connect

    Yokosawa, A.

    1988-05-04

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

  12. Radiative corrections to polarization observables in electron-proton scattering

    NASA Astrophysics Data System (ADS)

    Borisyuk, Dmitry; Kobushkin, Alexander

    2014-08-01

    We consider radiative corrections to polarization observables in elastic electron-proton scattering, in particular, for the polarization transfer measurements of the proton form factor ratio μGE/GM. The corrections are of two types: two-photon exchange (TPE) and bremsstrahlung (BS); in the present work we pay special attention to the latter. Assuming small missing energy or missing mass cutoff, the correction can be represented in a model-independent form, with both electron and proton radiation taken into account. Numerical calculations show that the contribution of the proton radiation is not negligible. Overall, at high Q2 and energies, the total correction to μGE/GM grows, but is dominated by TPE. At low energies both TPE and BS may be significant; the latter amounts to ˜0.01 for some reasonable cut-off choices.

  13. Azimuthal asymmetries in single polarized proton-proton Drell-Yan processes

    SciTech Connect

    Lu Zhun; Ma Boqiang; Zhu Jiacai

    2011-10-01

    We study the azimuthal asymmetries in proton-proton Drell-Yan processes with one incident proton being transversely or longitudinally polarized. We consider particularly the asymmetries contributed by the leading-twist chiral-odd quark distributions. We analyze the asymmetries with sin(2{phi}+{phi}{sub S}) and sin(2{phi}-{phi}{sub S}) modulations in transverse single polarized p{sup {up_arrow}p} Drell-Yan and sin2{phi} asymmetries in longitudinal single polarized p{sup {yields}p} Drell-Yan at the Relativistic Heavy Ion Collider, the Japan Proton Accelerator Research Complex, E906 (Fermi Lab), and the Nuclotron-based Ion Collider Facility (Joint Institute for Nuclear Research). We show that the measurements of the asymmetries in those facilities can provide valuable information of the chiral-odd structure of the nucleon both in the valence and sea regions.

  14. Empirical Determination of Solar Proton Access to the Polar Atmosphere

    NASA Astrophysics Data System (ADS)

    Neal, Jason; Rodger, Craig; Green, Janet; Whittaker, Ian

    2014-05-01

    Violent expulsions on the Sun's surface release high energy solar protons that ultimately affect ionization levels and the local chemical composition in the upper atmosphere as well as High Frequency (HF) communication used by aircraft. The geomagnetic field screens the low altitude equatorial region, but these protons can access the atmosphere over the poles. The latitudes over which the solar protons can reach vary with geomagnetic indices such as Kp and Dst. In this study we use observations from Low Earth Orbit to determine the atmospheric access of solar protons and hence the flights paths most likely to be affected. Observations taken by up to six polar orbiting satellites during 15 solar proton events are analyzed. From this we determine 16,850 proton rigidity cutoff estimates across 3 energy channels. Empirical fits are undertaken to estimate the most likely behavior of the cutoff dependence with geomagnetic activity. We provide simple equations by which the geomagnetic latitude (spatial extent) at which the protons impact the atmosphere can be determined from a given Kp or Dst value. The variation found in the cutoff with Kp is similar to that used in existing operational models, although the changing Kp value is found to lead the variation in the cutoffs by ~3 hours .We also suggest a ~1-2° equatorward shift in latitude would provide greater accuracy. This solar proton access can be used as an input into coupled chemistry climate models and give the likely polar regions to be effected by Polar Cap Absorption (PCA) which causes HF radio 'blackout zones'. We find that a Kp predictive model can provide additional warning to the variation in proton cutoffs. Hence a prediction of the cutoff latitudes can be made ~3 hours to as much as 7 hours into the future, meeting suggested minimum planning times required by the aviation industry.

  15. NICA Facility in Polarized Proton and Deuteron Mode

    NASA Astrophysics Data System (ADS)

    Kovalenko, A. D.; Butenko, A. V.; Kekelidze, V. D.; Mikhaylov, V. A.; Kondratenko, A. M.; Kondratenko, M. A.; Filatov, Yu. N.

    2016-02-01

    NICA project at JINR is aimed at the experiments with polarized protons and deuterons at both as fixed target and colliding mode over beam momentum range from 2 to 13.5GeV/c. Polarized beams are injected into collider from the Nuclotron-superconducting synchrotron. Dynamic solenoid “Siberian snakes” are proposed to prevent resonance depolarization of proton beam during acceleration in the Nuclotron up to momentum of 6 GeV/c and further in the collider up to the maximum momentum after storage and stochastic cooling of necessary number of particles in each ring. By means of pair of the Snakes placed in the opposite collider straight sections “spin transparency” mode is provided. Stabilization and control of the polarization is reached due to “weak field” solenoids integrated in the lattice. The proposed scheme of the polarization control is universal and can be used for different ion spices (p, d, t, He3…).

  16. Spin polarization and additional magneto-optical activity of nonmagnetic layers in Fe/Ag CMF

    NASA Astrophysics Data System (ADS)

    Xu, Y. B.; Zhai, H. R.; Lu, M.; Jin, Q. Y.; Miao, Y. Z.

    1992-08-01

    The experimental magneto-optical Kerr rotation spectra of Fe/Ag compositionally modulated films reported by Katayama et al. are studied theoretically. It is found that the free electrons of Ag are spin polarized. The magnitude of the polarization is about 1% with a direction opposite to that of Fe. The polarized Ag also gives rise to an additional magneto-optical activity as in Pt and Pd.

  17. Acceleration of polarized protons in circular accelerators

    SciTech Connect

    Courant, E.D.; Ruth, R.D.

    1980-09-12

    The theory of depolarization in circular accelerators is presented. The spin equation is first expressed in terms of the particle orbit and then converted to the equivalent spinor equation. The spinor equation is then solved for three different situations: (1) a beam on a flat top near a resonance, (2) uniform acceleration through an isolated resonance, and (3) a model of a fast resonance jump. Finally, the depolarization coefficient, epsilon, is calculated in terms of properties of the particle orbit and the results are applied to a calculation of depolarization in the AGS.

  18. Helical dipole magnets for polarized protons in RHIC

    SciTech Connect

    Syphers, M.; Courant, E.; Fischer, W.

    1997-07-01

    Superconducting helical dipole magnets will be used in the Brookhaven Relativistic Heavy Ion Collider (RHIC) to maintain polarization of proton beams and to perform localized spin rotations at the two major experimental detector regions. Requirements for the helical dipole system are discussed, and magnet prototype work is reported.

  19. Direct Photon Production and Gluon Polarization Measurements in Proton-Proton Collisions at PHENIX

    NASA Astrophysics Data System (ADS)

    Feege, Nils; Phenix Collaboration

    2015-10-01

    Direct photons probe the hard scattering process in proton-proton collisions. The channel that dominates their production in these collisions is ``the inverse QCD Compton effect,'' g + q --> γ + q . Calculating this process requires no photon fragmentation function, which facilitates comparisons between theories and experiments. In polarized p+p collisions, direct photons help determine the proton spin structure. At leading order, the longitudinal double-spin asymmetry ALL is directly proportional to the product of quark and gluon polarizations. The polarized quark distributions are known from polarized lepton-proton scattering experiments. Using them together with ALL measurements allows to access both the magnitude and sign of the polarized gluon distribution. The PHENIX experiment has collected data from polarized p+p collisions at RHIC at center of mass energies of 200 GeV and 500 GeV. This talk presents the status of direct photon cross section measurements and ALL measurements at midrapidity (| η | < 0 . 35) using these data.

  20. Polarized Structure Functions: Proton/Deuteron Measurements in Hall C

    SciTech Connect

    Oscar A. Rondon

    2005-02-01

    The study of the nucleon polarized structure functions has matured beyond the inclusive measurements of the past to the investigation of all eight quark distribution functions in the nucleon. Jefferson Lab's Hall C program of polarized structure functions studies started with a measurement of the proton and deuteron spin structure in the resonances at Q2 {approx} 1.3 [GeV/c]2. This work will be extended for the proton to more than 5 [GeV/c]2 for both DIS and the resonances in the upcoming SANE experiment. SANE will use a novel non-magnetic very large solid angle detector, BETA. Semi-inclusive asymmetries will be measured to determine the flavor composition of the nucleon spin in the recently approved Semi-SANE experiment. The 11 GeV energy upgrade will open new opportunities to study other functions, such as the transversity, Collins and Sievers functions, using vertical polarized targets.

  1. Polarized Structure Functions: Proton/Deuteron Measurements in Hall C

    SciTech Connect

    Rondon, Oscar A.

    2005-02-10

    The study of the nucleon polarized structure functions has matured beyond the inclusive measurements of the past to the investigation of all eight quark distribution functions in the nucleon. Jefferson Lab's Hall C program of polarized structure functions studies started with a measurement of the proton and deuteron spin structure in the resonances at Q2 {approx} 1.3 [GeV/c]2. This work will be extended for the proton to more than 5 [GeV/c]2 for both DIS and the resonances in the upcoming SANE experiment. SANE will use a novel non-magnetic very large solid angle detector, BETA. Semi-inclusive asymmetries will be measured to determine the flavor composition of the nucleon spin in the recently approved Semi -- SANE experiment. The 11 GeV energy upgrade will open new opportunities to study other functions, such as the transversity, Collins and Sievers functions, using vertical polarized targets.

  2. Helical Dipole Magnets for Polarized Protons in RHIC

    NASA Astrophysics Data System (ADS)

    Syphers, M.; Courant, E.; Fischer, W.; Luccio, A.; Mariam, F.; Peggs, S.; Pilat, F.; Roser, T.; Tepikian, S.; Tsoupas, N.; Willen, E.; Katayama, T.; Hatanaka, K.; Kawaguchi, T.; Okamura, M.; Tominaka, T.; Wu, H.; Ptitsin, V.; Shatunov, Y.

    1997-05-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) will be able to support experiments using polarized proton beams. Siberian Snakes are used to maintain polarization in this high energy superconducting collider. To make efficient use of available space while taking advantage of high field superconducting magnets, 4 Tesla helical dipole magnets will be used. These magnets generate a central dipole field in which the field direction rotates through 360^circ about the longitudinal axis over the length of the device. An arrangement of four such magnets can produce the desired change in the spin direction while keeping the proton orbit outside of the ``Snake'' unaltered. Similar magnet arrangements will be used to produce longitudinal polarization at the two major interaction points in RHIC. The basic requirements and layout of these magnets are described, as well as tolerances on field quality and integrated field strengths. First results of tests of prototype helical magnets will be discussed.

  3. The recoil proton polarization in. pi. p elastic scattering

    SciTech Connect

    Seftor, C.J.

    1988-09-01

    The polarization of the recoil proton for ..pi../sup +/p and ..pi../sup -/p elastic scattering has been measured for various angles at 547 MeV/c and 625 MeV/c by a collaboration involving The George Washington University; the University of California, Los Angeles; and Abilene Christian University. The experiment was performed at the P/sup 3/ East experimental area of the Los Alamos Meson Physics Facility. Beam intensities varied from 0.4 to 1.0 x 10/sup 7/ ..pi../sup -/'s/sec and from 3.0 to 10.0 x 10/sup 7/ ..pi../sup +/'s/sec. The beam spot size at the target was 1 cm in the horizontal direction by 2.5 cm in the vertical direction. A liquid-hydrogen target was used in a flask 5.7 cm in diameter and 10 cm high. The scattered pion and recoil proton were detected in coincidence using the Large Acceptance Spectrometer (LAS) to detect and momentum analyze the pions and the JANUS recoil proton polarimeter to detect and measure the polarization of the protons. Results from this experiment are compared with previous measurements of the polarization, with analyzing power data previously taken by this group, and to partial-wave analysis predictions. 12 refs., 53 figs., 18 tabs.

  4. Current-induced spin polarization in transition metals and Bi/Ag bilayers observed by spin-polarized positron beam

    NASA Astrophysics Data System (ADS)

    Zhang, Hongjun; Yamamoto, Shunya; Fukaya, Yuki; Maekawa, Masaki; Li, Hui; Kawasuso, Atsuo; Seki, Takeshi; Saitoh, Eiji; Takanashi, Koki; JAEA Team; Tohoku Team

    2015-03-01

    Current-induced spin polarization (CISP) on the outermost surfaces of Au, Cu, Pt, Pd, Ta, and W films were studied by spin-polarized positron beam (SPPB). The Au and Cu surfaces showed no significant CISP. In contrast, the Pt, Pd, Ta, and W films exhibited large CISP (3 ~ 15% per charge current of 105 A/cm2) and the CISP of Ta and W were opposite to those of Pt and Pd. The sign of the CISP obeys the same rule in spin Hall effect suggesting that the spin-orbit coupling is mainly responsible for the CISP. The outermost spin poalrization of Bi/Ag/Al2O3andAg/Bi/Al2O3 (charge currents directly connected to Ag layers) were probed by SPPB. The opposite outermost spin polarization of Bi/Ag/Al2O3andAg/Bi/Al2O3 clarified the charge-to-spin conversion in Bi/Ag bilayers. Nevertheless, the magnitudes of the outermost spin polarization of Bi(0.3 ~5)/Ag(25)/Al2O3 (numbers in parentheses denote thickness in nm) and Ag(25 ~500)/Bi(8)/Al2O3 decrease exponentially with increasing Bi thickness and Ag thickness, respectively. This provides probably the first direct evidence for spin diffusion mechanism. Financial support from JSPS Kakenhi Grant 24310072.

  5. 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).

  6. A STUDY OF POLARIZED PROTON ACCELERATION IN J-PARC.

    SciTech Connect

    LUCCIO, A.U.; BAI, M.; ROSER, T.

    2006-10-02

    We have studied the feasibility of polarized proton acceleration in rhe J-PARC accelerator facility, consisting of a 400 MeV linac, a 3 GeV rapid cycling synchrotron (RCS) and a 50 GeV synchrotron (MR). We show how the polarization of the beam can be preserved using an rf dipole in the RCS and two superconductive partial helical Siberian snakes in the MR. The lattice of the MR will be modified with the addition of quadrupoles to compensate for the focusing properties of the snakes.

  7. A Study of Polarized Proton Acceleration in J-PARC

    SciTech Connect

    Luccio, A. U.; Bai, M.; Roser, T.; Molodojentsev, A.; Ohmori, C.; Sato, H.; Hatanaka, K.

    2007-06-13

    We have studied the feasibility of polarized proton acceleration in rhe J-PARC accelerator facility, consisting of a 400 MeV linac, a 3 GeV rapid cycling synchrotron (RCS) and a 50 GeV synchrotron (MR). We show how the polarization of the beam can be preserved using an rf dipole in the RCS and two superconductve partial helical Siberian snakes in the MR. The lattice of the MR will be modified with the addition of quadrupoles to compensate for the focusing properties of the snakes.

  8. RHIC UPGRADES FOR HEAVY IONS AND POLARIZED PROTONS.

    SciTech Connect

    FISCHER, W.; ALESSI, J.; BEN-ZVI, I.; LITVINENKO, V.; ROSER, T.

    2005-10-24

    The Relativistic Heavy Ion Collider (RHIC), in operation since 2000, has exceeded its design parameters. The Enhanced Design parameters, expected to be reached in 2009, call for a 4-fold increase over the heavy ion design luminosity, and a 15-fold increase over the proton design luminosity, the latter with an average polarization of 70%. Also in 2009, it is planned to commission a new Electron Beam Ion Source, offering increased reliability and ion species that cannot be supplied currently. The upgrade to RHIC 11, based on electron cooling of the beams, aims to increase the average heavy ion luminosity by an order of magnitude, and the polarized proton luminosity by a factor 2-5. Plans for an electron-ion collider eRHIC is covered in another article in these proceedings.

  9. RHIC 100 GeV Polarized Proton Luminosity

    SciTech Connect

    Zhang, S. Y.

    2014-01-17

    A big problem in RHIC 100 GeV proton run 2009 was the significantly lower luminosity lifetime than all previous runs. It is shown in this note that the beam intensity decay in run 2009 is caused by the RF voltage ramping in store. It is also shown that the beam decay is not clearly related to the beam momentum spread, therefore, not directly due to the 0.7m. β* Furthermore, the most important factor regarding the low luminosity lifetime is the faster transverse emittance growth in store, which is also much worse than the previous runs, and is also related to the RF ramping. In 100 GeV proton run 2012a, the RF ramping was abandoned, but the β* was increased to 0.85m, with more than 20% loss of luminosity, which is not necessary. It is strongly suggested to use smaller β* in 100 GeV polarized proton run 2015/2016

  10. Polarized anti-protons with the spin splitter

    SciTech Connect

    Rossmanith, Robert

    1988-05-01

    In this paper a method for polarizing protons, antiprotons and ions using the Stern-Gerlach effect will be discussed. A test of this effect, forseen for the low energy antiproton storage ring LEAR at CERN, is described. In this test particles with different spin directions are separated by a combination of a solenoid together with several skew quadrupoles: this device is called a spin splitter.

  11. Solar proton impact on polar ozone and aerosols

    NASA Astrophysics Data System (ADS)

    Kasatkina, E.; Shumilov, O.; Kyro, E.; Kivi, R.

    The influence of solar proton events of Ground Level Event (GLE) type on ozone layer through the aerosol creation at high latitudes on the base of some experimental data and model simulation is discussed. For analysis we used ozone total content measurements from TOMS and ground based ozonometers installed at high latitudes (Barentsburg, corrected geomagnetic latitude: 74.9; Murmansk, 64.5; Sodankyla, 63.5). Ozonesonde data from Sodankyla observatory have also been used. A possible trigger mechanism of ozone destruction by incident solar protons including ion nucleation mechanism and heterogeneous chemistry is discussed. The model calculations of altitude distribution of CN (condensation nuclei), plausible centres of sulfate aerosol and Polar Startospheric Cloud (PSC) formation, are presented. Analysis of experimental data and model calculations permits us to explain some distinctions observed in ozone total content variations during several GLEs. For example, aerosol content increased significantly during moderate 21-24 May 1990 GLEs, when polar ozone "miniholes" (ozone total content depletions up to 20%)have been observed. Other GLEs (more intensive ones: 2 May 1998, 14 July 2000, 15 April 2001) caused no considerable enhancement in aerosol layer. In other words the value of aerosol increase during GLE depends on the spectrum of incident solar protons. These results demonstrate that only moderate GLEs can increase aerosol content significantly and cause ozone "minihole" creation.

  12. The BESS-Polar Proton & Helium flux measurements

    NASA Astrophysics Data System (ADS)

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

    The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) instrument pro-vides precise measurements of the elemental and isotopic composition of the light Galactic cosmic radiation (GCR) component. The ability to determine the charge sign of incident par-ticles enables the instrument to search for GCR antimatter, which is a major objective of the BESS program. Since 1993, the US-Japan BESS collaboration has conducted 11 successful balloon flights, nine northern-latitude flights of 1-day duration and most recently two long-duration balloon flights (8.5 days in 2004 & 24.5 days in 2007/2008), with the BESS-Polar instrument. The BESS-Polar instrument is the current effort of BESS program specifically designed for long-duration, low-geomagnetic cutoff Antarctic flights with significantly increased transparency for incident CR particle allowing to study anti/proton down to 100 MeV and a faster data acquisition enables processing of all CR events without event selection. The first BESS-Polar flight was launched on Dec 13, 2004 from Williams Field, near McMurdo Station in Antarctica. The instrument recorded data for 8.5 days, limited by the cryogenic life time of the superconducting magnet. During this flight the BESS-Polar instrument recorded 0.9 x 109 CR events. In this paper, we present the absolute proton and helium flux for the first BESS-Polar flight as well as the time variation of the fluxes due to solar activity.

  13. The Quest for Spinning Glue in High-Energy Polarized Proton-Proton Collisions at RHIC

    SciTech Connect

    Surrow, Bernd

    2007-10-26

    The STAR experiment at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) is carrying out a spin physics program colliding transverse or longitudinal polarized proton beams at {radical}(s) = 200-500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. These studies provide fundamental tests of Quantum Chromodynamics (QCD).One of the main objectives of the STAR spin physics program is the determination of the polarized gluon distribution function through a measurement of the longitudinal double-spin asymmetry, A{sub LL}, for various processes. Recent results will be shown on the measurement of A{sub LL} for inclusive jet production, neutral pion production and charged pion production at {radical}(s) = 200 GeV.

  14. High intensity proton acceleration at the Brookhaven AGS -- An update

    SciTech Connect

    Ahrens, L.; Alessi, J.; Blaskiewicz, M.

    1997-07-01

    The AGS accelerator complex is into its third year of 60+ {times} 10{sup 12} (teraproton = Tp) per cycle operation. The hardware making up the complex as configured in 1997 is briefly mentioned. The present level of accelerator performance is discussed. This includes beam transfer efficiencies at each step in the acceleration process, i.e. losses; which are a serious issue at this intensity level. Progress made in understanding beam behavior at the Linac-to-Booster (LtB) injection, at the Booster-to-AGS (BtA) transfer as well as across the 450 ms AGS accumulation porch is presented. The state of transition crossing, with the gamma-tr jump is described. Coherent effects including those driven by space charge are important at all of these steps.

  15. Investigation of the ratio of proton-stopping cross sections in Ag and Au

    SciTech Connect

    Semrad, D.; Golser, R.

    1987-06-01

    Knowledge of the ratio of stopping cross sections may help in determining best values from measurements. The case of Ag and Au is discussed, where theoretical considerations show that this ratio always has a value smaller than 1. This is confirmed experimentally for proton energies larger than 70 keV, in contradiction to all published stopping-power tabulations.

  16. STATUS OF SLOW EXTRACTION OF HIGH INTENSITY PROTONS FROM BROOKHAVEN'S AGS.

    SciTech Connect

    BROWN,K.A.AHRENS,L.BRENNAN,J.M.GLENN,J.W.ROSER,T.RUSSO,T.TSOUPAS,N.SMITH,K.ZENO,K.

    2003-05-12

    The Brookhaven AGS third integer resonant extraction system allows the AGS to provide high quality, high intensity 25.5 GeV/c proton beams simultaneously to four target stations and as many as 8 experiments. With the increasing intensities (over 7 x 10{sup 13} protons/pulse) and associated longer spill periods (2.4 to 3 seconds long), we continue to run with low losses and high quality low modulation continuous current beams. We have an active program of high energy physics experiments, including the high precision measurement of the muons magnetic moment [1] and the discovery of the rare Kaon decay, K+ {yields} {pi} + {nu}{bar {nu}} [2]. This program is continuing into the future with the rare symmetry violating process experiments [3] currently being designed to operate at the AGS. In this paper, we will present results from operation of high intensity slow extraction, the problems we encounter, and our solutions to those problems.

  17. Spin dependence in polarized proton-proton elastic scattering at RHIC

    NASA Astrophysics Data System (ADS)

    Plyku, Donika

    The STAR (Solenoidal Tracker At RHIC - Relativistic Heavy Ion Collider) experiment is equipped with Roman Pots, insertion devices that allow detectors to be moved close to the beam for the measurement of high energy protons scattered at very small angles. This setup, together with the unique capability of RHIC to collide spin-polarized proton beams, allows STAR to study both the dynamics and the spin-dependence of the proton-proton ( pp) elastic scattering process. Silicon strip detectors, installed inside the Roman Pots, measure tracks of protons scattered diffractively at very small angles. In a dedicated run with special beam optics during the 2009 RHIC run, the collaboration collected about 20 million elastic events with transversely polarized proton beams at the center of mass energy s = 200 GeV and four momentum transfer squared (t) range of 0.003 ≤ |t| ≤ 0.035 (GeV/c) 2, where, due to the Coulomb Nuclear Interference (CNI), a measurable single spin asymmetry arises. While the electromagnetic interaction can be determined in QED, the description of the hadronic interaction at small -t scattering requires the use of nonperturbative techniques in QCD, and, phenomenological models, rather than pQCD, are used to describe the exchange mechanism. High energy diffractive scattering at small-t is dominated by the Pomeron exchange, treated in pQCD as a color singlet combination of two gluons carrying quantum numbers of the vacuum (JPC = 0++). In this dissertation, I report on a high precision measurement of the transverse single spin asymmetry A N at s = 200 GeV in pp elastic scattering at RHIC. The measured AN and its t-dependence are consistent with the absence of a hadronic spin-flip amplitude. The major contribution to the uncertainty in AN comes from the uncertainty in the beam polarization measurement. The presented results provide a precise measurement in the non-perturbative QCD regime, where experimental data are indispensable, and, a significant

  18. High-intensity pulsed source of polarized protons with an atomic beam

    SciTech Connect

    Belov, A.S.; Esin, S.K.; Kubalov, S.A.; Kuzik, V.E.; Stepanov, A.A.; Yakushev, V.P.

    1985-10-25

    A source of polarized protons with a beam current up to 2.5 mA in the pulse, a degree of polarization 0.78 +- 0.01, a current pulse length of 120 ..mu..s, and a repetition frequency of 1 Hz is described. This is the first source of polarized protons which makes use of the charge exchange of polarized hydrogen atoms with ions of a deuterium plasma.

  19. Measuring the contribution of low Bjorken-x gluons to the proton spin with polarized proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Wolin, Scott Justin

    The PHENIX experiment is one of two detectors located at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, NY. Understanding the spin structure of the proton is a central goal at RHIC, the only polarized proton-on-proton collider in existence. The PHENIX spin program has two primary objectives. The first is to improve the constraints on the polarized parton distributions of the anti-u and anti-d quarks within the proton. The second objective is to improve the constraint on the gluon spin contribution to the proton spin, DeltaG. The focus of this thesis is the second objective. PHENIX experiment has been successful at providing the first meaningful constraints on DeltaG, along with STAR, the other detector located at RHIC. These constraints have, in fact, eliminated the extreme scenarios for gluon polarization through measurements of the double spin asymmetry, ALL, between the cross section of like and unlike sign helicity pp interactions. ALL measurements can be performed with a variety of final states at PHENIX. Until 2009, these final states were only measured for pseudo-rapidities of |eta| < 0.35. This range of eta is referred to as mid-rapidity. These mid-rapidity measurements, like the polarized DIS measurements, suffer from a limited kinematic reach. Final states containing a measured particle with pT [special character omitted] 1 GeV/c are considered to have occurred in the hard scattering domain where the pp interaction is well approximated as an interaction of a quark or gluon in one proton and a quark or gluon in the second proton. Each of these interacting particles has a momentum fraction, x, of its parent proton's momentum. The gluon polarization is dependent on the momentum fraction and the net gluon polarization can be written as the integral of the momentum fraction dependent polarization: DeltaG = f(1,0)Delta g(x)dx. The momentum fractions of the two interacting particles give information about the final state

  20. Measuring the contribution of low Bjorken-x gluons to the proton spin with polarized proton-proton collisions

    NASA Astrophysics Data System (ADS)

    Wolin, Scott Justin

    The PHENIX experiment is one of two detectors located at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in Upton, NY. Understanding the spin structure of the proton is a central goal at RHIC, the only polarized proton-on-proton collider in existence. The PHENIX spin program has two primary objectives. The first is to improve the constraints on the polarized parton distributions of the anti-u and anti-d quarks within the proton. The second objective is to improve the constraint on the gluon spin contribution to the proton spin, DeltaG. The focus of this thesis is the second objective. PHENIX experiment has been successful at providing the first meaningful constraints on DeltaG, along with STAR, the other detector located at RHIC. These constraints have, in fact, eliminated the extreme scenarios for gluon polarization through measurements of the double spin asymmetry, ALL, between the cross section of like and unlike sign helicity pp interactions. ALL measurements can be performed with a variety of final states at PHENIX. Until 2009, these final states were only measured for pseudo-rapidities of |eta| < 0.35. This range of eta is referred to as mid-rapidity. These mid-rapidity measurements, like the polarized DIS measurements, suffer from a limited kinematic reach. Final states containing a measured particle with pT [special character omitted] 1 GeV/c are considered to have occurred in the hard scattering domain where the pp interaction is well approximated as an interaction of a quark or gluon in one proton and a quark or gluon in the second proton. Each of these interacting particles has a momentum fraction, x, of its parent proton's momentum. The gluon polarization is dependent on the momentum fraction and the net gluon polarization can be written as the integral of the momentum fraction dependent polarization: DeltaG = f(1,0)Delta g(x)dx. The momentum fractions of the two interacting particles give information about the final state

  1. Spin structure of the proton from polarized inclusive deep-inelastic muon-proton scattering

    SciTech Connect

    Spin Muon Collaboration

    1997-11-01

    We have measured the spin-dependent structure function g{sub 1}{sup p} in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range 0.003{lt}x{lt}0.7 and 1GeV{sup 2}{lt}Q{sup 2}{lt}60GeV{sup 2}. A next-to-leading order QCD analysis is used to evolve the measured g{sub 1}{sup p}(x,Q{sup 2}) to a fixed Q{sub 0}{sup 2}. The first moment of g{sub 1}{sup p} at Q{sub 0}{sup 2}=10GeV{sup 2} is {Gamma}{sub 1}{sup p}=0.136{plus_minus}0.013 (stat) {plus_minus}0.009 (syst) {plus_minus}0.005 (evol). This result is below the prediction of the Ellis-Jaffe sum rule by more than two standard deviations. The singlet axial charge a{sub 0} is found to be 0.28{plus_minus}0.16. In the Adler-Bardeen factorization scheme, {Delta}g{approx_equal}2 is required to bring {Delta}{Sigma} in agreement with the quark-parton model. A combined analysis of all available proton, deuteron, and {sup 3}He data confirms the Bjorken sum rule. {copyright} {ital 1997} {ital The American Physical Society}

  2. Internal spin structure of the proton from high energy polarized e-p scattering

    SciTech Connect

    Hughes, V.W.; Baum, G.; Bergstroem, M.R.

    1981-02-01

    A review is given of experimental knowledge of the spin dependent structure functions of the proton, which is based on inclusive high energy scattering of longitudinal polarized electrons by longitudinally polarized protons in both the deep inelastic and resonance regions, and includes preliminary results from our most recent SLAC experiment. Implications for scaling, sum rules, models of proton structure, and the hyperfine structure interval in hydrogen are given. Possible future directions of research are indicated.

  3. 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.

  4. The AGS-Booster lattice

    SciTech Connect

    Lee, Y.Y.; Barton, D.S.; Claus, J.; Cottingham, J.G.; Courant, E.D.; Danby, G.T.; Dell, G.F.; Forsyth, E.B.; Gupta, R.C.; Kats, J.

    1987-01-01

    The AGS Booster has three objectives. They are to increase the space charge limit of the AGS, to increase the intensity of the polarized proton beam by accumulating many linac pulses (since the intensity is limited by the polarized ion source), and to reaccelerate heavy ions from the BNL Tandem Van de Graaff before injection into the AGS. The machine is capable of accelerating protons at 7.5 Hertz from 200 MeV to 1.5 GeV or to lower final energies at faster repetition rates. The machine will also be able to accelerate heavy ions from as low as 1 MeV/nucleon to a magnetic rigidity as high as 17.6 Tesla-meters with a one second repetition rate. As an accumulator for polarized protons, the Booster should be able to store the protons at 200 MeV for several seconds. We expect that the Booster will increase the AGS proton intensity by a factor of four, polarized proton intensity by a factor of twenty to thirty, and will also enable the AGS to accelerate all species of heavy ions (at present the AGS heavy ion program is limited to the elements lighter than sulfur because it can only accelerate fully stripped ions). The construction project started in FY 1985 and is expected to be completed in 1989. The purpose of this paper is to provide a future reference for the AGS Booster lattice.

  5. Study of Polarized Sea Quark Distributions in Polarized Proton-Proton Collisions at sq root(s) = 500 GeV with PHENIX

    SciTech Connect

    Mibe, Tsutomu

    2009-08-04

    The PHENIX spin program studies the flavor structure of the polarized sea quark distributions in polarized proton-proton collisions. Starting from 2009 run, the quark and antiquark polarization, sorted by flavor, will be investigated with the parity-violating single-spin asymmetry of W-boson production at the collision energy of sq root(s) = 500 GeV. High momentum muons from W-boson decay are detected in the PHENIX muon arms. The muon trigger is being upgraded to allow one to select high momentum muons.

  6. Measuring the anti-quark contribution to the proton spin using parity violating W production in polarized proton proton collisions

    NASA Astrophysics Data System (ADS)

    Gal, Ciprian

    Since the 1980s the spin puzzle has been at the heart of many experimental measurements. The initial discovery that only ~30% of the spin of the proton comes from quarks and anti-quarks has been refined and cross checked by several other deep inelastic scattering (DIS) and semi inclusive DIS (SIDIS) experiments. Through measurements of polarized parton distribution functions (PDFs) the individual contributions of the u, d, u, d, quarks have been measured. The flavor separation done in SIDIS experiments requires knowledge of fragmentation functions (FFs). However, due to the higher uncertainty of the anti-quark FFs compared to the quark FFs, the quark polarized PDFs (Deltau(x), Delta d(x)) are significantly better constrained than the anti-quark distributions (Deltau( x), Deltad(x). By accessing the anti-quarks directly through W boson production in polarized proton-proton collisions (ud → W+ → e+/mu+ and du→ W- → e-/mu-), the large FF uncertainties are avoided and a cleaner measurement can be done. The parity violating single spin asymmetry of the W decay leptons can be directly related to the polarized PDFs of the anti-quarks. The W+/- → e+/- measurement has been performed with the PHENIX central arm detectors at √s=510 GeV at the Relativistic Heavy Ion Collider (RHIC) and is presented in this thesis. Approximately 40 pb-1 of data from the 2011 and 2012 was analyzed and a large parity violating single spin asymmetry for W+/- has been measured. The combined data for 2011 and 2012 provide a single spin asymmetry for both charges: W+: -0.27 +/- 0.10(stat) +/- 0.01(syst) W -: 0.28 +/- 0.16(stat) +/- 0.02(syst) These results are consistent with the different theoretical predictions at the 1sigma level. The increased statistical precision enabled and required a more careful analysis of the background contamination for the this measurement. A method based on Gaussian Processes for Regression has been employed to determine this background contribution. This

  7. Constraining the polarization of the proton's glue with the eta meson

    NASA Astrophysics Data System (ADS)

    Seele, Joseph

    The division of the proton's spin among its quarks and gluons is a fundamental question in modern nuclear physics. The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) is measuring asymmetries in polarized proton-proton collisions at s = 200 GeV to garner information about the polarizations of the quarks and gluons. Measurements of the double helicity asymmetry for high pT mid-rapidity eta meson production in proton-proton collisions at s = 200 GeV are presented in this work. In order to obtain information about the polarizations of the quarks and gluons in the proton using the eta meson, the eta meson fragmentation functions must be known. No set existed, therefore a first global fit to the eta meson fragmentation functions was performed. The fit benefits from the inclusion of measurements of the cross section for eta meson production in proton-proton collisions. Therefore, a measurement of the cross section for high pT mid-rapidity eta meson production in proton-proton collisions at s = 200 GeV is performed to aid the fit. With the eta fragmentation functions, the measurement of the double helicity asymmetry is used to constrain the contribution of the spins of the gluons to the spin of the proton. Using a model and the work in this thesis, an estimate of the gluon contribution to the proton's spin is calculated and compared to other evaluations.

  8. Enhancement of proton energy by polarization switch in laser acceleration of multi-ion foils

    SciTech Connect

    Liu, Tung-Chang; Shao, Xi; Liu, Chuan-Sheng; Eliasson, Bengt; Wang, Jyhpyng; Chen, Shih-Hung

    2013-10-15

    We present a scheme to significantly increase the energy of quasi-monoenergetic protons accelerated by a laser beam without increasing the input power. This improvement is accomplished by first irradiating the foil several wave periods with circular polarization and then switching the laser to linear polarization. The polarization switch increases the electron temperature and thereby moves more electrons ahead of the proton layer, resulting in a space charge electric field pushing the protons forwards. The scaling of the proton energy evolution with respect to the switching time is studied, and an optimal switching time is obtained. The proton energy for the case with optimal switching time can reach about 80 MeV with an input laser power of 70 TW, an improvement of more than 30% compared to the case without polarization switch.

  9. Inclusive proton polarization in. gamma. sup 3,4 He r arrow pX reactions

    SciTech Connect

    Zybalov, A.A.; Karasev, S.P.; Konovalov, O.G.; Marekhin, S.V.; Sorokin, P.V.; Storozhenko, Y.O.; Tenishev, A.E. )

    1989-05-01

    This paper presents the first measured data on the inclusive proton polarization in the interaction of photons with {sup 3}He and {sup 4}He nuclei. The proton energy (170 MeV) and emission angle (72{degree}) were chosen such that the proton yield from the meson photoproduction reaction on free nucleons should be kinematically forbidden, and the photon energy in the disintegration of the two-nucleon pair in the nucleus should be such that ensures an essential polarization of the proton from the deuteron photodisintegration. The measurements were performed using the Kharkov 2 GeV electron linac facilities. (AIP)

  10. BNL alternating gradient synchrotron with four helical magnets to minimize the losses of the polarized proton beam

    NASA Astrophysics Data System (ADS)

    Tsoupas, N.; Huang, H.; MacKay, W. W.; Meot, F.; Roser, T.; Trbojevic, D.

    2013-04-01

    The principle of using multiple partial helical magnets to preserve the polarization of the proton beam during its acceleration was applied successfully to the alternating gradient synchrotron (AGS) which currently operates with two partial helical magnets. In this paper we further explore this idea by using four partial helical magnets placed symmetrically in the AGS ring. This provides many advantages over the present setup of the AGS, which uses two partial helical magnets. First, the symmetric placement of the four helical magnets and their relatively lower field of operation allows for better control of the AGS optics with reduced values of the beta functions especially near beam injection and allows both the vertical and horizontal tunes to be placed within the “spin tune gap,” therefore eliminating the horizontal and vertical intrinsic spin resonances of the AGS during the acceleration cycle. Second, it provides a wider spin tune gap. Third, the vertical spin direction during beam injection and extraction is closer to vertical. Although the spin tune gap, which is created with four partial helices, can also be created with a single or two partial helices, the high field strength of a single helical magnet which is required to generate such a spin tune gap makes the use of the single helical magnet impractical, and that of the two helical magnets rather difficult. In this paper we will provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and compare them with those from the present setup of the AGS that uses two partial helical magnets. Although in this paper we specifically discuss the effect of the four partial helices on the AGS, this method which can eliminate simultaneously the vertical and horizontal intrinsic spin resonances is a general method and can be applied to any medium energy synchrotron which operates in similar energy range like the AGS and provides the required space to accommodate the four

  11. Measurement of Longitudinal Spin Asymmetries for Weak Boson Production in Polarized Proton-Proton Collisions at RHIC

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    We report measurements of single- and double-spin asymmetries for W± and Z/γ* boson production in longitudinally polarized p+p collisions at √s =510 GeV by the STAR experiment at RHIC. The asymmetries for W± were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  12. Plasmonic ultra-broadband polarizers based on Ag nano wire-slit arrays

    NASA Astrophysics Data System (ADS)

    Han, Chunrui; Tam, Wing Yim

    2015-02-01

    We propose ultra-broadband reflective and absorptive polarizers in the visible range using multi-scaled Ag nano wire-slit arrays. The nano arrays can be tuned from reflective to absorptive by incorporating Ag wires/strips with different lengths/widths. The ultra-broadband nature of the absorptive array, with averaged absorption as high as ˜80%, is due to collective excitations of plasmonic resonances in the Ag wires/strips with different length scales. The nano arrays are realized experimentally by using a simple two-times shadowing vapor deposition method. They exhibit broadband transmission difference, in good agreement with simulations. Our multi-scaled nano array design has potential applications as broadband linear polarizers and anti-reflective materials in both optics and photovoltaics.

  13. AGS II

    SciTech Connect

    Palmer, R.B.

    1984-01-01

    Interest in rare K decays, neutrino oscillations and other fields have generated an increasing demand for running, and improved intensity and duty cycle, at the AGS. Current projects include acceleration of polarized protons and light ions (up to mass 32). Future plans are for a booster to increase intensity and allow heavy ions (up to mass 200), and a stretcher to give 100% duty cycle. A later upgrade could yield an average current of 32 ..mu.. amps. 6 figures, 2 tables.

  14. Recoil-proton polarization in high-energy deuteron photodisintegration with circularly plarized photons.

    SciTech Connect

    Jiang, X.; Arrington, J.; Benmokhtar, F.; Camsonne, A.; Chen, J. P.; Holt, R. J.; Qattan, I. A.; Reimer, P. E.; Schulte, E. C.; Wijesooriya, K.; Physics; Rutgers Univ.; Univ. Blaise Pascal; Thomas Jefferson National Accelerator Facility

    2007-05-01

    We measured the angular dependence of the three recoil-proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily. Transverse polarizations are not well described, but suggest isovector dominance.

  15. Angular dependence of recoil proton polarization in high-energy \\gamma d \\to p n

    SciTech Connect

    X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J.P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D.W. Higinbotham; R.J. Holt; C.W. de Jager; M.K. Jones; L.J. Kaufman; E.R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K.D. Paschke; C.F. Perdrisat; V. Punjabi; I.A. Qattan; R.D. Ransome; P.E. Reimer; B. Reitz; A. Saha; E.C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G.M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; L. Zhu

    2007-02-26

    We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance.

  16. Twist-3 effect from the longitudinally polarized proton for ALT in hadron production from pp collisions

    NASA Astrophysics Data System (ADS)

    Koike, Yuji; Pitonyak, Daniel; Yoshida, Shinsuke

    2016-08-01

    We compute the contribution from the longitudinally polarized proton to the twist-3 double-spin asymmetry ALT in inclusive (light) hadron production from proton-proton collisions, i.e., p↑ p → → h X. We show that using the relevant QCD equation-of-motion relation and Lorentz invariance relation allows one to eliminate the twist-3 quark-gluon correlator (associated with the longitudinally polarized proton) in favor of one-variable twist-3 quark distributions and the (twist-2) transversity parton density. Including this result with the twist-3 pieces associated with the transversely polarized proton and unpolarized final-state hadron (which have already been calculated in the literature), we now have the complete leading-order cross section for this process.

  17. AgI microplate monocrystals with polar {0001} facets: spontaneous photocarrier separation and enhanced photocatalytic activity.

    PubMed

    Kuang, Qin; Zheng, Xiaoli; Yang, Shihe

    2014-02-24

    Elucidating the facet-dependent photocatalytic activity of semiconductor photocatalysts is important in improving the overall efficiency of photocatalysis. Furthermore, combining facet control with selective deposition of oxidation and/or reduction cocatalysts on specific faces of semiconductor photocatalysts is potentially an effective strategy to synergistically optimize the functionality of photocatalysts. In the present study, high-purity wurtzite-type β-AgI platelet microcrystals with polar {0001} facets were prepared by a facile polyvinylpyrrolidone-assisted precipitation reaction. The polar-faceted AgI microplates were used as archetypes to demonstrate preferential diametric migration (i.e., effective separation) of photogenerated electrons and holes along the c axis. Such vectorial electron-hole separation stems from the asymmetric surface structures, which give rise to distinct photoexcited reaction behaviors on the ±(0001) polar facets of wurtzite-type semiconductors. Furthermore, on selective deposition of Ag and MnOx (1.5AgI microplates in degrading organic pollutants was dramatically enhanced thanks to the broad light-absorption range, strong dye-adsorption ability, and effective spatial separation of photocarriers. PMID:24449437

  18. Photoinduced Ag deposition on periodically poled lithium niobate: Wavelength and polarization screening dependence

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Nemanich, Robert J.

    2011-05-01

    This research addresses the wavelength dependence of the fabrication of Ag nanostructures through photoinduced deposition using single crystal ferroelectric lithium niobate as a template. The photoinduced deposition involves ultraviolent light illumination of polarity patterned lithium niobate while immersed in a AgNO3 solution. The results focus on the differences of the Ag nanostructure formation process on the positive and negative domains and domain boundaries. The results indicate that for below-band-gap excitation, a very low density of nanostructures is observed. However, for all above-gap-excitation wavelengths, deposition occurs on both polarity surfaces and at the domain boundaries. The density is greatest at the domain boundaries and reduced densities of smaller nanostructures are observed to form on both the positive and negative domains. The deposition on the domain surfaces is greatest for the shortest wavelengths, whereas the domain selectivity is increased for wavelengths just above the band gap. The external screening and weak band bending of single crystal lithium niobate introduces an enhanced electric field at the domain boundary. The enhanced electric field leads to migration of electrons to the domain boundary and consequently enhanced formation of Ag nanoparticles along the boundary. The variation in the reduction rate versus illumination wavelength is attributed to the light absorption depth and the competition between the photochemical and photoelectric deposition processes. To explore the transition from surface to bulk screening of the polarization charge, oxygen implanted PPLN surfaces were prepared and used for the Ag photoinduced deposition. Consistent with the transition to internal (bulk) screening, the Ag nanoparticle formation on the oxygen implanted PPLN surfaces showed suppressed boundary nanowire formation.

  19. Three proton hole structure in 106Ag

    NASA Astrophysics Data System (ADS)

    Das, B.; Rather, N.; Chattopadhyay, S.; Rajbanshi, S.; Goswami, A.; Datta, P.; Roy, S.; Palit, R.; Pal, S.; Saha, S.; Sethi, J.; Biswas, S.; Singh, P.; Jain, H. C.

    2016-06-01

    The negative parity non-yrast band of 106Ag has been studied to investigate the falling trend in magnetic dipole transition rates. In this context, the level lifetimes of the excited levels of this band have been measured using the Doppler shift attenuation method. The comparison of the experimental Routhian and the transition rates with the numerical results of the shears mechanism with the principal axis cranking calculation indicates that this band is generated due to the shears mechanism involving the three proton hole configuration.

  20. First results of proton injection commissioning of the AGS Booster synchrotron

    SciTech Connect

    Reece, R.K.; Ahrens, L.; Alessi, J.; Bleser, E.; Brennan, J.M.; Luccio, A.; Skelly, J.; Soukas, A.; van Asselt, W.; Weng, W.T.; Witkover, R.

    1991-01-01

    Beam performance for the injection phase of proton beam commissioning of the AGS Booster synchrotron will be presented. The beam from the 200 MeV Linac is transported through a new beam line into the Booster. This Linac-to Booster (LTB) beam line includes a 126{degree} bend and brings the injected beam onto the Booster injection orbit through the backleg of a main ring dipole magnet. Transfer of beam from the Linac to the Booster, spiralling beam and closing the orbit in the Booster ring are discussed. Injection and transport through one sector of the ring has been accomplished. 8 refs., 1 fig.

  1. p-Carbon CNI polarimetry in the AGS and RHIC.

    SciTech Connect

    Huang,H.; Alekseev, I.; Bazilevsky, A.; Bravar, A.; Bunce, G.; Dhawan, S.; Gill, R.; Makdisi, Y.; Morozov, B.; Roser, T.; Steski, D.; Sivertz, M.; Svirida, D.; Wood, J.; Yip, K.; Zelenski, A.

    2008-06-23

    Proton polarization measurements in the AGS (Alternate Gradient Synchrotron) and RHIC (Relativistic Heavy Ion Collider) are based on proton-carbon(pC) and proton-proton elastic scattering in the Coulomb Nuclear Interference (CNI) region. The CNI polarimeters are the essential tools for polarized proton acceleration setup and operation. High intensity recoil nuclei from the scattering of the circulating proton beam in the thin carbon target is efficiently utilized in the silicon strip detectors and data acquisition system, which is capable to analyze the event rate up to a few millions/second. This makes it possible for the fast, practically non-destructive polarization measurements. The polarization measurement on the beam energy ramp was implemented in AGS and RHIC, providing locations of polarization losses. Polarimeter operation in the scanning mode also gives polarization profile and beam profile (including bunch by bunch values for the later one). This paper summarizes the recent modifications. Results of polarization measurements are also discussed.

  2. Lambda and Antilambda Polarization in Proton-Proton Interactions from Sqrt. S = 31 TO 62 GEV.

    NASA Astrophysics Data System (ADS)

    Sherwood, Peter

    This thesis presents measurements of Lambda^0, |Lambda ^0, and Sigma^0 production made using experiment R608 at the CERN ISR. The Lambda^0 cross sections have been measured in the range 0.20 < x _{rm F}< 0.96 and for p _{rm t} up to 2.2 GeV/c. The invariant cross section, E*d^3sigma /dp^3, is presented in x _{rm F} bins, plotted against p_{rm t}^2 . The function Aexp(-(bp _{rm t}^2 + cp _{rm t}^4)) was found to be a good fit to the data. The cross section was integrated with respect to p_{rm t} ^2 to obtain the x_{ rm F} dependence. The Lambda ^0 shows a rapid fall-off with x _{rm F} up to x_ {rm F}~ 0.4, and thereafter exhibits a small decline to zero at x_{ rm F}~ 1, as is typical for baryons produced in proton fragmentation processes. The |Lambda^0 cross section was measured in the region 0.2 < x_{rm F}< 0.5. The invariant cross section was found to be well described by the function Aexp(-bp _{rm t}^2). Unlike the Lambda^0, the |Lambda^0 cross section falls rapidly with x_{rm F}. The Sigma^0 cross section was measured in the region 0.5 < p_{rm t}< 1.2 GeV/c and 0.3 < x_{rm F}< 0.7. In this region, the Lambda ^0/Sigma^0 ratio is 0.376 +/- 0.044. The Sigma^0 is thus the dominant contributor to non-direct Lambda^0 production. The Lambda^0 polarization was measured as function of surds for 31 polarization was found to increase with p_{rm t}, and x_{rm F}. At an average p_{rm t} of 1.1 GeV, it was found to depend linearly on x _{rm F}, with approximately -40% at x_{rm F} = 0.8. The |Lambda ^0 polarization was measured, and was found to be 3.8 +/- 1.5%.

  3. Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton

    NASA Astrophysics Data System (ADS)

    Fanelli, C.; Cisbani, E.; Hamilton, D. J.; Salmé, G.; Wojtsekhowski, B.; Ahmidouch, A.; Annand, J. R. M.; Baghdasaryan, H.; Beaufait, J.; Bosted, P.; Brash, E. J.; Butuceanu, C.; Carter, P.; Christy, E.; Chudakov, E.; Danagoulian, S.; Day, D.; Degtyarenko, P.; Ent, R.; Fenker, H.; Fowler, M.; Frlez, E.; Gaskell, D.; Gilman, R.; Horn, T.; Huber, G. M.; de Jager, C. W.; Jensen, E.; Jones, M. K.; Kelleher, A.; Keppel, C.; Khandaker, M.; Kohl, M.; Kumbartzki, G.; Lassiter, S.; Li, Y.; Lindgren, R.; Lovelace, H.; Luo, W.; Mack, D.; Mamyan, V.; Margaziotis, D. J.; Markowitz, P.; Maxwell, J.; Mbianda, G.; Meekins, D.; Meziane, M.; Miller, J.; Mkrtchyan, A.; Mkrtchyan, H.; Mulholland, J.; Nelyubin, V.; Pentchev, L.; Perdrisat, C. F.; Piasetzky, E.; Prok, Y.; Puckett, A. J. R.; Punjabi, V.; Shabestari, M.; Shahinyan, A.; Slifer, K.; Smith, G.; Solvignon, P.; Subedi, R.; Wesselmann, F. R.; Wood, S.; Ye, Z.; Zheng, X.

    2015-10-01

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θcmp=70 ° . The longitudinal transfer KLL, measured to be 0.645 ±0.059 ±0.048 , where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ˜3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude.

  4. Polarization transfer in wide-angle Compton scattering and single-pion photoproduction from the proton

    SciTech Connect

    Fanelli, Cristiano V.

    2015-10-06

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The WACS polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θPcm = 70°. The longitudinal transfer KLL, measured to be 0.645 ± 0.059 ± 0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the GPD-based calculations, which indicates a significant unknown contribution to the scattering amplitude.

  5. Polarization transfer in wide-angle Compton scattering and single-pion photoproduction from the proton

    DOE PAGESBeta

    Fanelli, Cristiano V.

    2015-10-06

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The WACS polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θPcm = 70°. The longitudinal transfer KLL, measured to be 0.645 ± 0.059 ± 0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton.more » However, the observed value is ~3 times larger than predicted by the GPD-based calculations, which indicates a significant unknown contribution to the scattering amplitude.« less

  6. Polarization Transfer in Wide-Angle Compton Scattering and Single-Pion Photoproduction from the Proton.

    PubMed

    Fanelli, C; Cisbani, E; Hamilton, D J; Salmé, G; Wojtsekhowski, B; Ahmidouch, A; Annand, J R M; Baghdasaryan, H; Beaufait, J; Bosted, P; Brash, E J; Butuceanu, C; Carter, P; Christy, E; Chudakov, E; Danagoulian, S; Day, D; Degtyarenko, P; Ent, R; Fenker, H; Fowler, M; Frlez, E; Gaskell, D; Gilman, R; Horn, T; Huber, G M; de Jager, C W; Jensen, E; Jones, M K; Kelleher, A; Keppel, C; Khandaker, M; Kohl, M; Kumbartzki, G; Lassiter, S; Li, Y; Lindgren, R; Lovelace, H; Luo, W; Mack, D; Mamyan, V; Margaziotis, D J; Markowitz, P; Maxwell, J; Mbianda, G; Meekins, D; Meziane, M; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Mulholland, J; Nelyubin, V; Pentchev, L; Perdrisat, C F; Piasetzky, E; Prok, Y; Puckett, A J R; Punjabi, V; Shabestari, M; Shahinyan, A; Slifer, K; Smith, G; Solvignon, P; Subedi, R; Wesselmann, F R; Wood, S; Ye, Z; Zheng, X

    2015-10-01

    Wide-angle exclusive Compton scattering and single-pion photoproduction from the proton have been investigated via measurement of the polarization transfer from a circularly polarized photon beam to the recoil proton. The wide-angle Compton scattering polarization transfer was analyzed at an incident photon energy of 3.7 GeV at a proton scattering angle of θ_{cm}^{p}=70°. The longitudinal transfer K_{LL}, measured to be 0.645±0.059±0.048, where the first error is statistical and the second is systematic, has the same sign as predicted for the reaction mechanism in which the photon interacts with a single quark carrying the spin of the proton. However, the observed value is ~3 times larger than predicted by the generalized-parton-distribution-based calculations, which indicates a significant unknown contribution to the scattering amplitude. PMID:26550716

  7. Excitation of plasmons in Ag/Fe/W structure by spin-polarized electrons

    SciTech Connect

    Samarin, Sergey N.; Kostylev, Mikhail; Williams, J. F.; Artamonov, Oleg M.; Baraban, Alexander P.; Guagliardo, Paul

    2015-09-07

    Using Spin-polarized Electron-Energy Loss Spectroscopy (SPEELS), the plasmon excitations were probed in a few atomic layers thick Ag film deposited on an Fe layer or on a single crystal of W(110). The measurements were performed at two specular geometries with either a 25° or 72° angle of incidence. On a clean Fe layer (10 atomic layers thick), Stoner excitation asymmetry was observed, as expected. Deposition of a silver film on top of the Fe layer dramatically changed the asymmetry of the SPEELS spectra. The spin-effect depends on the kinematics of the scattering: angles of incidence and detection. The spin-dependence of the plasmon excitations in the silver film on the W(110) surface and on the ferromagnetic Fe film is suggested to arise from the spin-active Ag/W or Ag/Fe interfaces.

  8. Measurement of proton polarization in the d(gamma-vector,p-vector)n reaction

    SciTech Connect

    Steffen Strauch; JLAB Hall A Collaboration

    2000-12-12

    Recoil proton polarization was measured in deuteron photodisintegration at 90 deg. {sub cm} for photon energies up to 2.5 GeV. The induced polarization p{sub y} is consistent with zero above 1 GeV, consistent with expectations from quark models and in disagreement with meson-baryon calculations. Polarization transfer observables are non-zero, indicating that hadron helicity is not conserved.

  9. RHIC Performance as a 100 GeV Polarized Proton Collider in Run-9

    SciTech Connect

    Montag, C.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; DOttavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hahn, H.; Harvey, M.; Hayes, T.; Huang, H.; Ingrassia, P.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Lee, R.C.; Luccio, A.U.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Menga, P.M.; Michnoff, R.; Minty, M.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Pozdeyev, E.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Sivertz, M.; Smith, K.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    During the second half of Run-9, the Relativisitc Heavy Ion Collider (RHIC) provided polarized proton collisions at two interaction points. The spin orientation of both beams at these collision points was controlled by helical spin rotators, and physics data were taken with different orientations of the beam polarization. Recent developments and improvements will be presented, as well as luminosity and polarization performance achieved during Run-9.

  10. Polarization Transfer Coefficient Measurements in the Deuteron Breakup Reaction HYDROGEN-1(POLARIZED Deuteron, Polarized Proton)x at 2.1 GEV.

    NASA Astrophysics Data System (ADS)

    Cheung, Naipor Eric

    The polarization of the protons emerging at 0 ^circ from the inclusive deuteron breakup reaction ^1H(vec d,vec p)X was measured using a deuteron beam with kinetic energy of 2.1 GeV. The momentum of the protons was selected by the magnetic spectrometer SPES4 and the polarization was measured with the polarimeter POMME. This experiment was performed at eight different proton momenta. When those momenta are Lorentz transformed to the deuteron rest frame, they corresponded to values from 0.00 to 0.34 GeV/c. The result of the measurements is expressed in terms of polarization transfer coefficient which is defined as the ratio of the measured proton polarization P_{p} to the deuteron beam vector polarization P _{Z}:kappa_{o} = P_{p}/P_{Z}. The values of kappa_{o} decreased from 0.995 to -0.320 across the proton momentum range of this experiment. The trend of kappa_{o} is in general agreement with the expected behavior arising from the D state in the deuteron wave function. The impulse approximation predicts quite well the general shape of kappa_{o}. Multiple scattering and relativistic effect based on different models of reaction mechanism are discussed.

  11. ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC

    SciTech Connect

    MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

    2007-06-25

    The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

  12. Multiple Partial Siberian Snakes in the AGS

    SciTech Connect

    Takano, J.; Ahrens, L. A.; Bai, M.; Brown, K.; Courant, E. D.; Gardner, C. J.; Glenn, J. W.; Huang, H.; Luccio, A. U.; MacKay, W. W.; Okamura, M.; Roser, T.; Tepikian, S.; Tsoupas, N.; Yip, K.; Zelenski, A.; Zeno, K.; Hattori, T.; Lin, F.

    2007-06-13

    Polarized protons are accelerated up to 24.3 GeV in the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL). To accelerate the beam with preserving the polarization, two different types of helical dipole partial Siberian snake have been installed to the AGS. One is a superconducting magnet (Cold Snake, CSNK), and the other is a normal conducting one (Warm Snake, WSNK). With these snake magnets, the polarization at the AGS extraction achieved 65%. However, the AGS has spin mismatches at the injection and extraction. This description shows calculated results to have better spin matching with using two or three snakes.

  13. Spin filtering neutrons with a proton target dynamically polarized using photo-excited triplet states

    NASA Astrophysics Data System (ADS)

    Haag, M.; van den Brandt, B.; Eichhorn, T. R.; Hautle, P.; Wenckebach, W. Th.

    2012-06-01

    In a test of principle a neutron spin filter has been built, which is based on dynamic nuclear polarization (DNP) using photo-excited triplet states. This DNP method has advantages over classical concepts as the requirements for cryogenic equipment and magnets are much relaxed: the spin filter is operated in a field of 0.3 T at a temperature of about 100 K and has performed reliably over periods of several weeks. The neutron beam was also used to analyze the polarization of the target employed as a spin filter. We obtained an independent measurement of the proton spin polarization of ˜0.13 in good agreement with the value determined with NMR. Moreover, the neutron beam was used to measure the proton spin polarization as a function of position in the naphthalene sample. The polarization was found to be homogeneous, even at low laser power, in contradiction to existing models describing the photo-excitation process.

  14. Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC.

    PubMed

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

    2014-08-15

    We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  15. Radiation pressure acceleration of protons to 93 MeV with circularly polarized petawatt laser pulses

    NASA Astrophysics Data System (ADS)

    Kim, I. Jong; Pae, Ki Hong; Choi, Il Woo; Lee, Chang-Lyoul; Kim, Hyung Taek; Singhal, Himanshu; Sung, Jae Hee; Lee, Seong Ku; Lee, Hwang Woon; Nickles, Peter V.; Jeong, Tae Moon; Kim, Chul Min; Nam, Chang Hee

    2016-07-01

    The radiation pressure acceleration (RPA) of charged particles has been a challenging task in laser-driven proton/ion acceleration due to its stringent requirements in laser and target conditions. The realization of radiation-pressure-driven proton acceleration requires irradiating ultrathin targets with an ultrahigh contrast and ultraintense laser pulses. We report the generation of 93-MeV proton beams achieved by applying 800-nm 30-fs circularly polarized laser pulses with an intensity of 6.1 × 10 20 W / cm 2 to 15-nm-thick polymer targets. The radiation pressure acceleration was confirmed from the obtained optimal target thickness, quadratic energy scaling, polarization dependence, and three-dimensional particle-in-cell simulations. We expect this clear demonstration of RPA to facilitate the realization of laser-driven proton/ion sources delivering energetic and short-pulse particle beams for novel applications.

  16. The Proton Coulomb Form Factor from Polarized Inclusive e-p Scattering

    SciTech Connect

    Chris Harris

    2001-08-01

    The proton form factors provide information on the fundamental properties of the proton and provide a test for models based on QCD. In 1998 at Jefferson Lab (JLAB) in Newport News, VA, experiment E93026 measured the inclusive e-p scattering cross section from a polarized ammonia (15NH3) target at a four momentum transfer squared of Q2 = 0.5 (GeV/c)2. Longitudinally polarized electrons were scattered from the polarized target and the scattered electron was detected. Data has been analyzed to obtain the asymmetry from elastically scattered electrons from hydrogen in 15NH3. The asymmetry, Ap, has been used to determine the proton elastic form factor GEp. The result is consistent with the dipole model and data from previous experiments. However, due to the choice of kinematics, the uncertainty in the measurement is large.

  17. Protonation-induced red-coloured circularly polarized luminescence of [5]carbohelicene fused by benzimidazole.

    PubMed

    Sakai, Hayato; Kubota, Takako; Yuasa, Junpei; Araki, Yasuyuki; Sakanoue, Tomo; Takenobu, Taishi; Wada, Takehiko; Kawai, Tsuyoshi; Hasobe, Taku

    2016-07-12

    Benzimidazole-fused [5]carbohelicene ([5]HeliBI) was newly synthesized to examine the spectroscopic and chiroptical properties. The reversible protonation and deprotonation processes of [5]HeliBI were successfully investigated using (1)H NMR, absorption and fluorescence spectral measurements. We also confirmed the circularly polarized luminescence of protonated [5]HeliBI (H(+)-[5]HeliBI). This is the first observation of red-coloured CPL of a helicene derivative. PMID:27319321

  18. Proposal for the use of the AGS linac for proton therapy

    SciTech Connect

    Alessi, J.G.; Chanana, A.; Dilmanian, F.A.; Lee, Y.Y.; Raparia, D.; Wielopolski, L.

    1994-10-01

    The BNL 200 MeV linac presently provides beam for the AGS high energy physics program and for isotope production at the Brookhaven Linac Isotope Producer (BLIP,) facility. There is now a proposal to develop a proton therapy facility which would also use the linac beam. Approximately 1% of the current in each linac beam pulse would be diverted from BLIP, down an existing transport line, to the proposed new facility. This paper focuses on the basic design of the facility, particularly the accelerator issues. The planned transport line layout is presented, along with a description of the energy and intensity control, and beam delivery systems. In the initial phase, we are planning one 360{degrees} vertical gantry and one horizontal treatment room.

  19. Neutron densities in 120Sn observed by polarized proton scattering

    NASA Astrophysics Data System (ADS)

    Sakaguchi, H.; Takeda, H.; Taki, T.; Yosoi, M.; Itoh, M.; Kawabata, T.; Ishikawa, T.; Uchida, M.; Tsukahara, N.; Noro, T.; Yoshimura, M.; Fujimura, H.; Yoshida, H.; Obayashi, E.; Tamii, A.; Akimune, H.

    2001-06-01

    Cross sections, analyzing powers and spin rotation parameters of proton elastic scattering from 58Ni and 120Sn have been measured at intermediate energies. By elastic scattering off N~=Z nuclei like 58Ni at intermediate energies we can study medium modification of the nucleon-nucleon (NN) interaction inside the nucleus, because proton distributions in target nuclei are constrained by charge distributions measured by electron scattering and neutron distributions can be assumed to be the same as proton's. In order to explain our experimental data of 58Ni at large scattering angles, it was found to be necessary to use experimental densities deduced from charge densities measured by electron scattering and to modify the coupling constants and the masses of exchanged σ and ω mesons in the RIA, assuming linear dependencies of meson properties to nuclear densities. Parameters of the medium effect have been searched to reproduce the data. For N≠Z nuclei, neutron density distribution can be extracted from the elastic scattering, assuming the same medium modifications fixed by the 58Ni data and using proton distributions obtained from charge distributions. We have searched neutron density distributions obtained from charge distributions. We have searched neutron density distribution so as to reproduce 120Sn data at the proton incident energy of 300 MeV. Deduced neutron distribution has an increase at the nuclear center, which is consistent with the 3s1/2 orbit wave function as expected in 120Sn. At energies other than 300 MeV, experimental data of 120Sn have been also well reproduced by the neutron distribution obtained at 300 MeV. .

  20. 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.

  1. Recoil polarization measurements of the proton electromagnetic form factor ratio at high momentum transfer

    SciTech Connect

    Andrew Puckett

    2009-12-01

    Electromagnetic form factors are fundamental properties of the nucleon that describe the effect of its internal quark structure on the cross section and spin observables in elastic lepton-nucleon scattering. Double-polarization experiments have become the preferred technique to measure the proton and neutron electric form factors at high momentum transfers. The recently completed GEp-III experiment at the Thomas Jefferson National Accelerator Facility used the recoil polarization method to extend the knowledge of the proton electromagnetic form factor ratio GpE/GpM to Q2 = 8.5 GeV2. In this paper we present the preliminary results of the experiment.

  2. Possibilities of polarized protons in Sp anti p S and other high energy hadron colliders

    SciTech Connect

    Courant, E.D.

    1984-01-01

    The requirements for collisions with polarized protons in hadron colliders above 200 GeV are listed and briefly discussed. Particular attention is given to the use of the ''Siberan snake'' to eliminate depolarizing resonances, which occur when the spin precession frequency equals a frequency contained in the spectrum of the field seen by the beam. The Siberian snake is a device which makes the spin precession frequency essentially constant by using spin rotators, which precess the spin by 180/sup 0/ about either the longitudinal or transverse horizontal axis. It is concluded that operation with polarized protons should be possible at all the high energy hadron colliders. (LEW)

  3. Surface electronic structure of polar NiO thin film grown on Ag(111)

    NASA Astrophysics Data System (ADS)

    Das, Jayanta; Menon, Krishnakumar S. R.

    2015-06-01

    The growth and structure of NiO thin films on top of Ag(111) substrate were studied where the formation of faceted surface was confirmed by Low Energy Electron Diffraction. The electronic structure of polar NiO(111) surface has been probed using photoemission techniques. The core energy levels and the valence band electronic structure were excited by x-ray and ultraviolet photons respectively. The modifications in physical structure and valence band electronic structure of the film under vacuum annealing have also been enlightened.

  4. Surface electronic structure of polar NiO thin film grown on Ag(111)

    SciTech Connect

    Das, Jayanta; Menon, Krishnakumar S. R.

    2015-06-24

    The growth and structure of NiO thin films on top of Ag(111) substrate were studied where the formation of faceted surface was confirmed by Low Energy Electron Diffraction. The electronic structure of polar NiO(111) surface has been probed using photoemission techniques. The core energy levels and the valence band electronic structure were excited by x-ray and ultraviolet photons respectively. The modifications in physical structure and valence band electronic structure of the film under vacuum annealing have also been enlightened.

  5. LAMBDA Polarization with a Transversely Polarized Proton Target at the COMPASS Experiment

    SciTech Connect

    Negrini, Teresa

    2009-08-04

    The transverse polarization of LAMBDA and LAMBDA-bar hyperons is investigated at the COMPASS experiment at CERN. In 2007 a 160 GeV/c longitudinally polarized muon beam and a transversely polarized NH{sub 3} target were employed to study events in semi-inclusive deep-inelastic scattering. Preliminary results for the LAMBDA and LAMBDA-bar polarizations extracted from this new data set are presented as a function of x{sub Bj} and z. The polarizations of LAMBDA and LAMBDA-bar are compatible with zero within their error bars and no dependence on x{sub Bj} or z is observed.

  6. Photodynamics of intramolecular proton transfer in polar and nonpolar biflavonoid solutions

    NASA Astrophysics Data System (ADS)

    Bondarev, S. L.; Knyukshto, V. N.; Tikhomirov, S. A.; Buganov, O. V.; Pyrko, A. N.

    2012-10-01

    Using methods of steady state luminescence and femtosecond spectroscopy, we have studied the mechanism of intramolecular proton transfer in synthesized 3,7-dihydroxy-2,8-di(4-methoxyphenyl)-4H,6H-pyrano[3,2- g]chromen-4,6-dion in polar and nonpolar solutions, films, and polycrystals at 293 and 77 K. In an excited singlet state, intramolecular proton transfer occurs in two stages. At the first stage, a tautomer with one transferred proton (OTP tautomer) is formed from the Franck-Condon state within τ1 = 0.6 ps. At the second stage, the second proton is transferred within τ2 = 3.1 ps and a tautomer with two transferred protons (TTP tautomer) is formed, which fluoresces in toluene at 293 K with a high quantum yield, Φ f = 0.66, and the fluorescence spectrum of which is characterized by a large Stokes shift, 9900 cm-1. At 293 K, polar solvents (dimethylformamide, dimethyl sulfoxide, ethanol, etc.) solvate the BFV molecule in the ground state, while, in the excited state, an OTP tautomer is mainly formed. In polar ethanol at 77 K, a dual fluorescence spectrum is observed, which is caused by the fluorescence emission of polysolvates with λ{max/ f } = 460 nm and TTP phototautomers at λ{max/ f }= 610 nm.

  7. Empirical determination of solar proton access to the atmosphere: Impact on polar flight paths

    NASA Astrophysics Data System (ADS)

    Neal, Jason J.; Rodger, Craig J.; Green, Janet C.

    2013-07-01

    Violent expulsions on the Sun's surface release high energy solar protons that ultimately affect HF communication used by aircraft. The geomagnetic field screens the low altitude equatorial region, but these protons can access the atmosphere over the poles. The latitudes over which the solar protons can reach vary with geomagnetic indices such as Kp and Dst. In this study we use observations from low Earth orbit to determine the atmospheric access of solar protons and hence the flights paths most likely to be affected. Observations taken by up to six polar orbiting satellites during 15 solar proton events are analyzed. From this we determine 16,850 proton rigidity cutoff estimates across three energy channels. Empirical fits are undertaken to estimate the most likely behavior of the cutoff dependence with geomagnetic activity. The changing Kp value is found to lead the variation in the cutoffs by ~3 h. We provide simple equations by which the geomagnetic latitude at which the protons impact the atmosphere can be determined from a given Kp or Dst value. The variation found in the cutoff with Kp is similar to that used in existing operational models, although we suggest that a ~1-2° equatorward shift in latitude would provide greater accuracy. We find that a Kp predictive model can provide additional warning to the variation in proton cutoffs. Hence, a prediction of the cutoff latitudes can be made ~3 h to as much as 7 h into the future, meeting suggested minimum planning times required by the aviation industry.

  8. Polarization of Pc1/EMIC waves and related proton auroras observed at subauroral latitudes

    NASA Astrophysics Data System (ADS)

    Nomura, R.; Shiokawa, K.; Sakaguchi, K.; Otsuka, Y.; Connors, M.

    2012-02-01

    We have investigated the polarization of Pc1 geomagnetic pulsations and related proton auroras at subauroral latitudes, using an induction magnetometer and an all-sky camera at Athabasca, Canada (54.7°N, 246.7°E, magnetic latitude (mlat) 61.7°N). Isolated proton auroras often appear in association with Pc1 pulsations, because of proton scattering by electromagnetic ion cyclotron (EMIC) waves in the magnetosphere. We used the proton aurora as a proxy for the location and size of the Pc1 ionospheric source. For 27 Pc1 events with simultaneously observed proton auroras over 4 years from September 7, 2005 to September 6, 2009, we calculated the distances between the Pc1 ionospheric source and the observation site, normalized by the scale size of the source. We tried three different definitions of the scale size of Pc1 ionospheric source to calculate the normalized distances. We found that the rotation angle θ between the Pc1 polarization ellipse and the direction to the proton aurora changes from 90° to 0° as the normalized distance increases. For the definition of the scale sizes that gives most clear θ-transition from 90° to 0°, the transition occurs at the normalized distance ˜2.0-4.0, while it was ˜1.0-2.0 by the model calculation of Fujita and Tamao (1988). The averaged major axes tend to point toward the proton aurora at larger distances. The difference of the transition location may imply that the Pc1 ionospheric sources are larger than the isolated proton auroras, or that the inhomogenuity of the ionospheric conductivity by the proton precipitation affects the transition distances.

  9. Probing non polar interstellar molecules through their protonated form: Detection of protonated cyanogen (NCCNH+)★

    PubMed Central

    Agúndez, M.; Cernicharo, J.; de Vicente, P.; Marcelino, N.; Roueff, E.; Fuente, A.; Gerin, M.; Guélin, M.; Albo, C.; Barcia, A.; Barbas, L.; Bolaño, R.; Colomer, F.; Diez, M. C.; Gallego, J. D.; Gómez-González, J.; López-Fernández, I.; López-Fernández, J. A.; López-Pérez, J. A.; Malo, I.; Serna, J. M.; Tercero, F.

    2015-01-01

    Cyanogen (NCCN) is the simplest member of the series of dicyanopolyynes. It has been hypothesized that this family of molecules can be important constituents of interstellar and circumstellar media, although the lack of a permanent electric dipole moment prevents its detection through radioastronomical techniques. Here we present the first solid evidence of the presence of cyanogen in interstellar clouds through the detection of its protonated form toward the cold dark clouds TMC-1 and L483. Protonated cyanogen (NCCNH+) has been identified through the J = 5 – 4 and J = 10 – 9 rotational transitions using the 40m radiotelescope of Yebes and the IRAM 30m telescope. We derive beam averaged column densities for NCCNH+ of (8.6 ± 4.4) × 1010 cm−2 in TMC-1 and (3.9 ± 1.8) × 1010 cm−2 in L483, which translate to fairly low fractional abundances relative to H2, in the range (1-10) × 10−12. The chemistry of protonated molecules in dark clouds is discussed, and it is found that, in general terms, the abundance ratio between the protonated and non protonated forms of a molecule increases with increasing proton affinity. Our chemical model predicts an abundance ratio NCCNH+/NCCN of ~ 10−4, which implies that the abundance of cyanogen in dark clouds could be as high as (1-10) × 10−8 relative to H2, i.e., comparable to that of other abundant nitriles such as HCN, HNC, and HC3N. PMID:26543239

  10. Wavelength-tunable polarization converter utilizing the strain induced by proton exchange in lithium niobate

    NASA Astrophysics Data System (ADS)

    Wang, T.-J.; Chung, J.-S.

    2005-02-01

    A new wavelength-tunable polarization converter utilizing the strain induced by proton exchange is demonstrated in x-cut LiNbO3. The light polarization is converted by the strain-optic effect through the phase-matched coupling of two orthogonal polarizations. The stress-applying structure is designed to be composed of several proton-exchanged strip regions for maximization of the stress distribution. The principle of birefringent chain filters is utilized to design the device structure in order to avoid the requirement of large stress, which results in serious cracks on the substrate surface. The overlap integral between the optical field distribution and the stress distribution can be enhanced simply by prolonging the proton-exchange time. Besides, the stress distribution and its strength in the stress-applying structure can be fine tuned without affecting the waveguide characteristics such that the principle of the birefringent chain filters is completely satisfied. Therefore, the polarization-conversion efficiency can be optimized when utilizing this exclusive stress-tuning ability. By the thermal-optic effect, the wavelength of maximum conversion can be tuned at a rate of -0.115 nm/°C with a maximum conversion efficiency of 92.41%. The proposed polarization converter has the advantages of adequate stress distribution and strength, high parameter-tuning feasibility, low propagation loss, easy fabrication, and low fabrication cost.

  11. Measurements of Double-Polarized Compton Scattering Asymmetries and Extraction of the Proton Spin Polarizabilities

    NASA Astrophysics Data System (ADS)

    Martel, P. P.; Miskimen, R.; Aguar-Bartolome, P.; Ahrens, J.; Akondi, C. S.; Annand, J. R. M.; Arends, H. J.; Barnes, W.; Beck, R.; Bernstein, A.; Borisov, N.; Braghieri, A.; Briscoe, W. J.; Cherepnya, S.; Collicott, C.; Costanza, S.; Denig, A.; Dieterle, M.; Downie, E. J.; Fil'kov, L. V.; Garni, S.; Glazier, D. I.; Gradl, W.; Gurevich, G.; Hall Barrientos, P.; Hamilton, D.; Hornidge, D.; Howdle, D.; Huber, G. M.; Jude, T. C.; Kaeser, A.; Kashevarov, V. L.; Keshelashvili, I.; Kondratiev, R.; Korolija, M.; Krusche, B.; Lazarev, A.; Lisin, V.; Livingston, K.; MacGregor, I. J. D.; Mancell, J.; Manley, D. M.; Meyer, W.; Middleton, D. G.; Mushkarenkov, A.; Nefkens, B. M. K.; Neganov, A.; Nikolaev, A.; Oberle, M.; Ortega Spina, H.; Ostrick, M.; Ott, P.; Otte, P. B.; Oussena, B.; Pedroni, P.; Polonski, A.; Polyansky, V.; Prakhov, S.; Rajabi, A.; Reicherz, G.; Rostomyan, T.; Sarty, A.; Schrauf, S.; Schumann, S.; Sikora, M. H.; Starostin, A.; Steffen, O.; Strakovsky, I. I.; Strub, T.; Supek, I.; Thiel, M.; Tiator, L.; Thomas, A.; Unverzagt, M.; Usov, Y.; Watts, D. P.; Witthauer, L.; Werthmüller, D.; Wolfes, M.; A2 Collaboration at MAMI

    2015-03-01

    The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to extract the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the Δ (1232 ) region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields γE 1 E 1=-3.5 ±1.2 , γM 1 M 1=3.16 ±0.85 , γE 1 M 2=-0.7 ±1.2 , and γM 1 E 2=1.99 ±0.29 , in units of 1 0-4 fm4 .

  12. Polarization of Pc1/EMIC waves and related proton auroras observed at Athabasca

    NASA Astrophysics Data System (ADS)

    Nomura, R.; Shiokawa, K.; Sakaguchi, K.; Otsuka, Y.; Connors, M. G.

    2010-12-01

    Electromagnetic ion cyclotron (EMIC) waves excited in the equatorial region of the magnetosphere by the ion cyclotron instability propagate along magnetic field lines to the ionosphere and are observed as Pc1 geomagnetic pulsations (Pc1) with frequencies at 0.2-5Hz on the ground. These Pc1 waves propagate horizontally through the ionospheric duct. Magnetospheric ions are scattered by the resonance with EMIC waves and precipitate to the ionosphere to cause isolated proton auroras at subauroral latitudes. One-to-one correspondence between isolated proton auroras and Pc1 waves was found by Sakaguchi et al. [JGR, 2008]. The mechanism of ionospheric duct propagation of Pc1 has been studied theoretically for the polarization characteristics [Graifinger, JGR, 1972; Fujita and Tamao, JGR, 1988], and observationally for the possible Pc1 source [e.g., Fraser et al., JATP, 1976] and for the spatial distribution of polarization mode [Hayashi et al., Can J. Phys., 1981] using ground magnetometers. However, comparison between the actual position and size of ionospheric Pc1 sources and the polarization characteristics of Pc1 waves has not been done. In order to investigate this relation, we compare the spectral and polarization parameters of Pc1 waves observed by a 64-Hz sampling induction magnetometer and the position and area of isolated proton auroras observed by an all-sky imager at Athabasca (ATH, 54.7N, 246.7E, magnetic latitude: 61.7N), for 13 one-to-one correspondent events of Pc1 waves and isolated proton auroras reported by Sakaguchi et al. [JGR, 2008]. We found that the major axis direction of Pc1 polarization varies depending on the area of the isolated proton aurora and on the distance from ATH to the aurora. In the presentation, we will discuss these results based on a multi-event study using data from three years of 2005-2008 in the context of the model calculation by Fujita and Tamao [1988].

  13. Polarization of Ω- hyperons produced in 800 GeV proton-beryllium collisions

    NASA Astrophysics Data System (ADS)

    Luk, K. B.; James, C.; Rameika, R.; Diehl, H. T.; Teige, S.; Thomson, G. B.; Zou, Y.; Ho, P. M.; Longo, M. J.; Nguyen, A.; Duryea, J.; Guglielmo, G.; Heller, K.; Johns, K.; Thorne, K.

    1993-02-01

    The polarization of 103 211 Ω- hyperons produced in 800 GeV proton-beryllium inclusive reactions has been measured. Between 0.3polarization is found to be consistent with zero, with a mean value of -0.01+/-0.01 at =0.5 and =0.95 GeV/c. This behavior is similar to that of Λ¯0, which also does not have any quarks in common with the incident proton, but is different from Ξ¯+, which is significantly polarized in the same kinematic region.

  14. Longitudinal Spin Transfer of LAMBDA and LAMBDA-bar Hyperons in Polarized Proton-Proton Collisions at sq root(s) = 200 GeV

    SciTech Connect

    Sichtermann, Ernst

    2009-08-04

    The longitudinal spin transfer D{sub LL} of LAMBDA and LAMBDA-bar hyperons produced with large transverse momenta P{sub T} in polarized proton-proton collisions is sensitive to the helicity distribution functions of strange quarks and anti-quarks, and to polarized fragmentation functions. This contribution reports a measurement of the longitudinal spin transfer D{sub LL} in the inclusive production of LAMBDA and LAMBDA-bar hyperons at central rapidities in polarized proton-proton collisions at a center of mass energy of sq root(s) = 200 GeV. The data were collected with the STAR experiment at RHIC and correspond to a approx =3 pb{sup -1} luminosity and a approx =50% beam polarization.

  15. Simultaneously improving optical absorption of both transverse-electric polarized and transverse-magnetic polarized light for organic solar cells with Ag grating used as transparent electrode

    NASA Astrophysics Data System (ADS)

    Long, Yongbing; Li, Yuanxing; Su, Runmei

    2014-08-01

    Theoretical simulations are performed to investigate optical performance of organic solar cells with Ag grating electrode. It is demonstrated that optical absorption for both transverse-electric (TE) polarized and transverse-magnetic(TM) polarized light is simultaneously improved when compared with that for the device without the Ag grating. The improvement is respectively attributed to the resonance and the surface plasmon polaritons within the device. After an additional WO3 layer is capped on the Ag grating, absorption of TE-polarized light is further improved due to resonance of double microcavities within the device, and absorption of TM-polarized light is improved by the combined effects of the microcavity resonance and the surface plasmon polaritons. Correspondingly, the short current density for randomly polarized light is improved by 18.1% from that of the device without the Ag grating. Finally, it is demonstrated that high transmission may not be an essential prerequisite for metallic gratings when they are used as transparent electrode since absorption loss caused by low transmission can be compensated by using a capping layer to optimize optical resonance of the WMC structure within the device.

  16. Preservation and control of the proton and deuteron polarizations in the proposed electron-ion collider at Jefferson Lab

    SciTech Connect

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

    2014-01-01

    We propose a scheme of preserving the proton and deuteron beam polarizations during acceleration and storage in the proposed electron-ion collider at Jefferson Lab. This scheme allows one to provide both the longitudinal and transverse polarization orientations of the proton and deuteron beams at the interaction points of the figure-8 ion collider ring. We discuss questions of matching the polarization direction at all stages of the beam transport including the pre-booster, large booster and ion collider ring.

  17. Letter of Intent for a Drell-Yan Experiment with a Polarized Proton Target

    SciTech Connect

    Geesaman, D.; Reimer, P.; Brown, C.; Christian, D.; Diefenthaler, M.; Peng, J. -C.; Chang, W. -C.; Chen, Y. -C.; Sawada, S.; Chang, T. -H.; Huang, J.; Jiang, X.; Leitch, M.; Klein, A.; Liu, K.; Liu, M.; McGaughey, P.; Beise, E.; Nakahara, K.; Aidala, C.; Lorenzon, W.; Raymond, R.; Badman, T.; Long, E.; Slifer, K.; Zielinski, R.; Guo, R. -S.; Goto, Y.; El Fassi, L.; Myers, K.; Ransome, R.; Tadepalli, A.; Tice, B.; Chen, J. -P.; Nakano, K.; Shibata, T. -A.; Crabb, D.; Day, D.; Keller, D.; Rondon, O.

    2014-01-01

    It is well known that the proton is a spin-1/2 particle, but how the constituents (quarks and gluons) assemble to this quantized spin is still a mystery. There is a worldwide effort to map out the individual contributions to the proton spin [1,2]. It is established that the quark spins contribute around 30%, while the gluon intrinsic angular momentum is still under active investigation at the Relativistic Heavy Ion Collider [3]. Fully resolving the proton spin puzzle requires information on the orbital angular momentum (OAM) of both quarks and gluons. Recent studies have shown that the so-called transverse momentum dependent parton distribution functions (TMDs) can inform us about the OAM of the partons. One of the most important TMDs, and the main focus of this LOI, is the so-called Sivers function [4]. To summarize, we propose to make the first measurement of the Sivers function of sea quarks, which is expected to be non-zero if the sea quarks contribute orbital angular momentum to the proton spin, as expected from the pion cloud model which also partially explains the E866 results. Thus, we will be able to deduce whether or not sea quark orbital motion contributes significantly to the proton spin. Specifically, we will determine the contribution from the anti-up quarks, with Bjorken-x in the range of ~ 0.1 to 0.5. Drell-Yan production off a polarized proton target has never been measured and is complementary to the recently approved (stage-1) experiment E1027 at Fermilab [11], which will measure the Sivers function of the valence quarks using a polarized proton beam on an unpolarized proton target. If the measured sea quark Sivers function is non-zero, we will also determine its sign.

  18. POLARIZED HYDROGEN JET TARGET FOR MEASUREMENT OF RHIC PROTON BEAM POLARIZATION.

    SciTech Connect

    MAKDISI,Y.; WISE,T.; CHAPMAN,M.; GRAHAM,D.; KPONOU,A.; MAHLER,G.; MENG,W.; NASS,A.; RITTER,J.

    2005-01-28

    The performance and unique features of the RHIC polarized jet target and our solutions to the important design constraints imposed on the jet by the RHIC environment are described. The target polarization and thickness were measured to be 0.924 {+-} 2% and 1.3 {+-} 0.2 x 10{sup 12} atoms/cm{sup 2} respectively.

  19. The complete set of spin observables for the (13)C(polarized proton, polarized neutron)(13)N and (15)N(polarized proton, polarized neutron)(15)O reactions

    NASA Astrophysics Data System (ADS)

    Du, Qun Qun

    1998-12-01

    The 13C(p,n)13N and 15N(p,n)15O reactions have been a puzzle for more than ten years. The ground state transitions are Jπ=1/2- to Jπ=1/2-. These are 'mixed' transitions because they can involve quantum number changes either (/Delta T=1,/ /Delta J=0,/ /Delta/pi=0,/ /Delta S=0), or (/Delta T=1,/ /Delta J=1,/ /Delta/pi=0,/ /Delta S=1); these quantum number changes are refered to as 'Fermi' and 'Gamow-Teller' respectively. Because the quantum number changes are the same as for Fermi and Gamow-Teller beta decay. From the systematics of (p,n) and (n,p) reactions on pure Fermi transitions (e.g. 0 + to 0+) and pure Gamow-Teller transitions (e.g. 0+ to 1+), calibrations have been established of cross section per unit B(F) or unit B(GT), where 'B' refers to doubly reduced matrix elements extracted from beta decay. However, cross sections for the 13C(p,n)13N(g.s.) and 15N(p,n)15O(g.s.) reactions are substantially larger than one would then predict from the known B(F)s and B(GT)s for these transitions. To explore this anomaly, spin observables were used to extract separately the Fermi and Gamow-Teller cross sections for these reactions. To acquire the complete sets of polarization- transfer observables, a new neutron polarimeter was designed, built, commissioned and calibrated. This polarimeter, call the '2π polarimeter' because of its complete azimuthal coverage for scattered neutrons, has very good position and timing resolution (354 ps). The complete sets of spin-transfer coefficients Dij for 13C(p,n)13N (at 0o , 5.5o , and 11o ) and 15N(p,n)15O (at 0o ) at 135 MeV were measured. Following the formalism of Ichimura and Kawahigashi, we extracted the spin-longitudinal, and spin-transverse and spin-independent responses D0,/ Dq,/ Dn and Dp from the measured Dijs. The F and GT fractions of the (p,n) cross sections are then extracted as f F=D0 and fGT=Dn+Dp+Dq=1- d0. Values of Dk for both the 13C(p,n)13N(g.s) and 15N(p,n)15O(g.s.) were extracted. From these responses, we

  20. Overcoming an intrinsic depolarizing resonance with a partial snake at the Brookhaven AGS.

    SciTech Connect

    Huang, H.; Ahrens, L.; Bai, M.; Brown, K. A.; Glenn, W.; Luccio, A. U.; MacKay, W. W.; Montag, C.; Ptitsyn, V.; Roser, T.; Tsoupas, N.; Zeno, K.; Ranjbar, V.; Cadman, R. V.; Spinka, H.; Underwood, D.; High Energy Physics; BNL; Indiana Univ.

    2004-06-01

    An 11.4% partial Siberian snake was used to successfully accelerate polarized protons through a strong intrinsic depolarizing spin resonance in the Alternating Gradient Synchrotron (AGS). No noticeable depolarization was observed. This opens up the possibility of using a 20% to 30% partial Siberian snake in the AGS or other medium energy proton synchrotrons to overcome all weak and strong depolarizing spin resonances.

  1. Computational simulations of hydrogen circular migration in protonated acetylene induced by circularly polarized light.

    PubMed

    Shi, Xuetao; Li, Wen; Schlegel, H Bernhard

    2016-08-28

    The hydrogens in protonated acetylene are very mobile and can easily migrate around the C2 core by moving between classical and non-classical structures of the cation. The lowest energy structure is the T-shaped, non-classical cation with a hydrogen bridging the two carbons. Conversion to the classical H2CCH(+) ion requires only 4 kcal/mol. The effect of circularly polarized light on the migration of hydrogens in oriented C2H3 (+) has been simulated by Born-Oppenheimer molecular dynamics. Classical trajectory calculations were carried out with the M062X/6-311+G(3df,2pd) level of theory using linearly and circularly polarized 32 cycle 7 μm cosine squared pulses with peak intensity of 5.6 × 10(13) W/cm(2) and 3.15 × 10(13) W/cm(2), respectively. These linearly and circularly polarized pulses transfer similar amounts of energy and total angular momentum to C2H3 (+). The average angular momentum vectors of the three hydrogens show opposite directions of rotation for right and left circularly polarized light, but no directional preference for linearly polarized light. This difference results in an appreciable amount of angular displacement of the three hydrogens relative to the C2 core for circularly polarized light, but only an insignificant amount for linearly polarized light. Over the course of the simulation with circularly polarized light, this corresponds to a propeller-like motion of the three hydrogens around the C2 core of protonated acetylene. PMID:27586924

  2. Reaction {gamma}p {sup {yields}} {eta}' (958) p and polarization of recoil protons

    SciTech Connect

    Tryasuchev, V. A.

    2006-02-15

    On the basis of the isobar model extended by including the t-channel, the cross sections for and single-polarization features of the reaction {gamma}p {sup {yields}} {eta}'p are calculated for incident-photon energies up to 5 GeV, two poorly studied resonances, S{sub 11}(1978) and P{sub 13}(2080), being taken into account in this calculation. In order to reduce the ambiguities in the choice of resonances and their parameters that make it possible to reproduce the experimental differential cross sections, it is proposed to measure the polarization of recoil protons in the reaction being considered.

  3. Fundamental studies for the proton polarization technique in neutron protein crystallography.

    PubMed

    Tanaka, Ichiro; Kusaka, Katsuhiro; Chatake, Toshiyuki; Niimura, Nobuo

    2013-11-01

    The isotope effect in conventional neutron protein crystallography (NPC) can be eliminated by the proton polarization technique (ppt). Furthermore, the ppt can improve detection sensitivity of hydrogen (relative neutron scattering length of hydrogen) by approximately eight times in comparison with conventional NPC. Several technical difficulties, however, should be overcome in order to perform the ppt. In this paper, two fundamental studies to realise ppt are presented: preliminary trials using high-pressure flash freezing has shown the advantage of making bulk water amorphous without destroying the single crystal; and X-ray diffraction and liquid-chromatography/mass-spectrometry analyses of standard proteins after introducing radical molecules into protein crystals have shown that radical molecules could be distributed non-specifically around proteins, which is essential for better proton polarization. PMID:24121348

  4. Fundamental studies for the proton polarization technique in neutron protein crystallography

    PubMed Central

    Tanaka, Ichiro; Kusaka, Katsuhiro; Chatake, Toshiyuki; Niimura, Nobuo

    2013-01-01

    The isotope effect in conventional neutron protein crystallography (NPC) can be eliminated by the proton polarization technique (ppt). Furthermore, the ppt can improve detection sensitivity of hydrogen (relative neutron scattering length of hydrogen) by approximately eight times in comparison with conventional NPC. Several technical difficulties, however, should be overcome in order to perform the ppt. In this paper, two fundamental studies to realise ppt are presented: preliminary trials using high-pressure flash freezing has shown the advantage of making bulk water amorphous without destroying the single crystal; and X-ray diffraction and liquid-chromatography/mass-spectrometry analyses of standard proteins after introducing radical molecules into protein crystals have shown that radical molecules could be distributed non-specifically around proteins, which is essential for better proton polarization. PMID:24121348

  5. Comment on "effect of a polarized hydrogen target on the polarization of a stored proton beam".

    PubMed

    MacKay, W W; Montag, C

    2006-02-01

    Meyer [Phys. Rev. E 50, 1485 (1994)] analyzed the filtering mechanism of polarizing a stored beam by scattering from an internal polarized target. We noticed in Meyer's derivation of Eq. (4) of that paper that he had added a new twist to an old argument [W. Brückner, Physics with Antiprotons at LEAR in the ACOL Era: Proceedings of the Third LEAR Workshop, Tignes, Savoie, France, January 19-26, 1985 (Editions Frontières, Gif-sur-Yvette, France, 1985), p. 245] by allowing some particles that are spin flipped to be kept in the beam. We show that this invalidates the old result and leads to a more complicated expression for the buildup of polarization. PMID:16605487

  6. Dynamic aperture evaluation of the proposed lattices for the RHIC 2009 polarized proton run

    SciTech Connect

    Luo,Y.; Bai, M.; Beebe-Wang, J.; Fischer, W.; Montag, C.; Robert-Demolaize, G.; Satogata, T.; Tepikian, S.; Trbojevic, D.

    2009-01-02

    In the article we evaluate the dynamic apertures of the proposed lattices for the coming Relativistic Heavy Ion Collider (RHIC) 2009 polarized proton (pp) 100 GeV and 250 GeV runs. One goal of this study is to find out the appropriate {beta}* for the coming 2009 pp runs. Another goal is to study the effect of second order chromaticity correction in the RHIC pp runs.

  7. Transition of proton energy scaling using an ultrathin target irradiated by linearly polarized femtosecond laser pulses.

    PubMed

    Kim, I Jong; Pae, Ki Hong; Kim, Chul Min; Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Yu, Tae Jun; Choi, Il Woo; Lee, Chang-Lyoul; Nam, Kee Hwan; Nickles, Peter V; Jeong, Tae Moon; Lee, Jongmin

    2013-10-18

    Particle acceleration using ultraintense, ultrashort laser pulses is one of the most attractive topics in relativistic laser-plasma research. We report proton and/or ion acceleration in the intensity range of 5×10(19) to 3.3×10(20) W/cm2 by irradiating linearly polarized, 30-fs laser pulses on 10-to 100-nm-thick polymer targets. The proton energy scaling with respect to the intensity and target thickness is examined, and a maximum proton energy of 45 MeV is obtained when a 10-nm-thick target is irradiated by a laser intensity of 3.3×10(20) W/cm2. The proton acceleration is explained by a hybrid acceleration mechanism including target normal sheath acceleration, radiation pressure acceleration, and Coulomb explosion assisted-free expansion. The transition of proton energy scaling from I(1/2) to I is observed as a consequence of the hybrid acceleration mechanism. The experimental results are supported by two- and three-dimensional particle-in-cell simulations. PMID:24182274

  8. The AGS Booster control system

    SciTech Connect

    Frankel, R.; Auerbach, E.; Culwick, B.; Clifford, T.; Mandell, S.; Mariotti, R.; Salwen, C.; Schumburg, N.

    1988-01-01

    Although moderate in size, the Booster construction project requires a comprehensive control system. There are three operational modes: as a high intensity proton injector for the AGS, as a heavy ion accelerator and injector supporting a wide range of ions and as a polarized proton storage injector. These requirements are met using a workstation based extension of the existing AGS control system. Since the Booster is joining a complex of existing accelerators, the new system will be capable of supporting multiuser operational scenarios. A short discussion of this system is discussed in this paper.

  9. Measurement of proton polarization in the d({gamma},p)n reaction

    SciTech Connect

    Geesaman, D.F.; Jackson, H.E.; Jones, C.E.

    1995-08-01

    A proposal was approved by CEBAF PAC7 to measure angular distributions of the proton polarization for the d({gamma},p)n reaction in the GeV region. This proposed measurement will test the validity of extensions of conventional nuclear-physics theories to the higher energy regime. The results of the experiment will further constrain the evidence from SLAC experiments NE8 and NE17 that asymptotic scaling was observed above a photon energy of 1.3 GeV. Photoproton polarization measurements at lower energy indicate that the magnitude of the polarization increases with energy. This is consistent with the observation that polarizations are large in high-energy processes, e.g. A{sub nn} in pp {yields} pp scattering or A{sub y} in pp {yields} {pi}{sup 0}X. However, the polarizations in hadron-hadron scattering are believed to arise from Landshoff mechanisms. The higher energy photoproton experiment will permit the first measurements of polarization for a reaction, {gamma}d {yields} pn, where there are no Landshoff terms. The experiment would make use of a polarimeter installed in either the High Resolution Spectrometer in Hall A or the Short Orbit Spectrometer in Hall C at CEBAF.

  10. Measurement of Polarization Observables in the Electro-Excitation of the Proton to its First Excited State

    SciTech Connect

    Rikki Roche

    2003-04-03

    This thesis reports results from the Thomas Jefferson National Accelerator Facility (Jefferson Lab) Hall A experiment E91-011, which measured double-polarization observables in the pion electroproduction reaction from the proton. Specifically, the experiment measured the recoil proton polarization, polarized response functions, and cross section for the p{rvec e}, e{prime} {rvec p} {pi}{sup o} reaction at a center-of-mass energy centered at W = 1232 MeV--the peak of the {Delta}(1232) resonance--and at a four-momentum transfer squared of Q{sup 2} = 1.0 GeV{sup 2}/c{sup 2}. Both the recoil proton polarization and polarized response function results will be presented in this thesis.

  11. Radiative capture of polarized neutrons by polarized protons at Tn=183 MeV

    NASA Astrophysics Data System (ADS)

    Xu, G.; Pate, S. F.; Bloch, C.; Vigdor, S. E.; Bowyer, S. M.; Bowyer, T. W.; Jacobs, W. W.; Meyer, H. O.; Pierce, E.; Sowinski, J.; Whiddon, C.; Wissink, S. W.; Jolivette, P. L.; Pickar, M. A.

    1995-12-01

    In order to provide a quantitative test of theoretical calculations incorporating meson-exchange currents and intermediate Δ resonances, we measure the normal-component spin correlation coefficient CNN, the differential cross section dσ/dΩ, and the neutron and proton analyzing powers An and Ap, each as a function of angle, for n-->p-->-->dγ at Tn=183 MeV. Our n-->p-->-->dγ results, combined with the previous cross section and photon asymmetry data collected in the past decade, place quite strong constraints on model calculations. Our data are in excellent agreement with theoretical predictions by Jaus and Woolcock that incorporate meson-exchange and isobar current effects and relativistic corrections, signifying great recent progress in our understanding of these effects in the nucleon-nucleon system.

  12. Towards optical polarization control of laser-driven proton acceleration in foils undergoing relativistic transparency.

    PubMed

    Gonzalez-Izquierdo, Bruno; King, Martin; Gray, Ross J; Wilson, Robbie; Dance, Rachel J; Powell, Haydn; Maclellan, David A; McCreadie, John; Butler, Nicholas M H; Hawkes, Steve; Green, James S; Murphy, Chris D; Stockhausen, Luca C; Carroll, David C; Booth, Nicola; Scott, Graeme G; Borghesi, Marco; Neely, David; McKenna, Paul

    2016-01-01

    Control of the collective response of plasma particles to intense laser light is intrinsic to relativistic optics, the development of compact laser-driven particle and radiation sources, as well as investigations of some laboratory astrophysics phenomena. We recently demonstrated that a relativistic plasma aperture produced in an ultra-thin foil at the focus of intense laser radiation can induce diffraction, enabling polarization-based control of the collective motion of plasma electrons. Here we show that under these conditions the electron dynamics are mapped into the beam of protons accelerated via strong charge-separation-induced electrostatic fields. It is demonstrated experimentally and numerically via 3D particle-in-cell simulations that the degree of ellipticity of the laser polarization strongly influences the spatial-intensity distribution of the beam of multi-MeV protons. The influence on both sheath-accelerated and radiation pressure-accelerated protons is investigated. This approach opens up a potential new route to control laser-driven ion sources. PMID:27624920

  13. Measurement of Polarization Observables in the Electro-Excitation of the Proton to its First Excited State

    SciTech Connect

    Rikki Roche

    2003-08-01

    This thesis reports results from the Thomas Jefferson National Accelerator Facility (Jefferson Lab) Hall A experiment E91-011, which measured double-polarization observables in the pion electroproduction reaction from the proton. Specifically, the experiment measured the recoil proton polarization, polarized response functions, and cross section for the p({rvec e}, e{prime} {rvec p}) {pi}{sup o} reaction at a center-of-mass energy centered at W = 1232 MeV--the peak of the Delta(1232) resonance--and at a four-momentum transfer squared of Q{sup 2} = 1.0 GeV{sup 2}/c{sup 2}. Both the recoil proton polarization and polarized response function results will be presented in this thesis. Data were collected at Jefferson Lab, located in Newport News, Virginia during the summer of 2000. A 4.53 GeV polarized electron beam was scattered off of a cryogenic hydrogen target. The recoil proton polarization was measured in the Focal Plane Polarimeter (FPP), located in one of the two High Resolution Spectrometers (HRS) in Hall A. A maximum likelihood method was used to determine the polarized response functions directly from the measured polarizations and cross sections. A simultaneous fit of the cross sections, the recoil proton polarizations, and angular distributions of the polarized response functions will provide a determination of individual multipole amplitudes. Some of these multipole amplitudes are related to the concept of proton deformation. Both the recoil proton polarizations and polarized response functions were compared to two phenomenological models: MAID and SAID, which have all free parameters fixed, based on fits to previous world data. The measured helicity dependent observables, which are dominated by imaginary parts of Delta(1232)-resonance excitation multipole amplitudes, agree very well with the two models. The measured helicity independent observables, which are dominated by real parts of background multipole amplitudes, do not agree completely with either

  14. Elastic scattering of polarized protons on helium three at 800 MeV

    SciTech Connect

    Azizi, A.

    1985-07-01

    A set of spin dependent parameters and cross sections has been measured for polarized p-/sup 3/He elastic scattering over the range of q .7 to 4.2 fm/sup -1/. The experiment was done at the Los Alamos Meson Physics Facility (LAMPF) using the High Resolution Spectrometer (HRS) with a polarized proton beam at .8 GeV. The focal plane polarimeter of the HRS was used to determine the spin direction of the scattered proton. Since /sup 3/He is one of the simplest nuclei, polarized p-/sup 3/He scattering provides a very sensitive test of multiple scattering theories. The theoretical analysis was done by using two different wave functions for /sup 3/He as input to the multiple scattering theory. The theoretical calculations and experimental data together will give us useful information about nucleon-nucleon amplitudes and also help us to obtain a better understanding of the scattering process. 68 refs., 55 figs., 9 tabs.

  15. Run05 Proton Beam Polarization Measurements by pC-Polarimeter (ver. 1.1)

    SciTech Connect

    Nakagawa,I.; Alekseev, I.; Bazilevsky, A.; Bravar, A.; Bunce, G.; Dhawan, S.; Eyser, K.O.; Gill, R.; Haeberli, W.; Huang, H.; Makdisi, Y.; Nass, A.; Okada, H.; Stephenson, E.; Svirida, D.N.; Wise, T.; Wood, J.; Yip, K.; Zelenski, A.

    2008-07-01

    The polarization of the proton beams [1, 2] at the Relativistic Heavy Ion Collider (RHIC)[3] RHIC ring. The H-Jet polarimeter is located at the collision point allowing measurements of absolute normalization is provided by the hydrogen polarimeter, which measures over 1 {approx} 2 another measurement rather than measuring the absolute polarization. both beams. Two identical pC-polarimeters are equipped in the yellow and blue rings, where carbon ribbon target, providing fast feedback to beam operations and experiments. The days to obtain {approx} 5% statistical uncertainty (in Run05). Thus, the operation of the carbon is measured using both an atomic beam source hydrogen gas jet (H-Jet)[4, 5] and proton-carbon polarimeters was focused on better control of relative stability between one measurement to statistical accuracy within 20 to 30 seconds using an ultra-thin (typically 6 {approx} 8 {micro}g/cm{sup 2}) the rings are separated. The pC-polarimeter measures relative polarization to a few percent.

  16. Asymmetries in ozone depressions between the polar stratospheres following a solar proton event

    NASA Technical Reports Server (NTRS)

    Maeda, K.; Heath, D. F.

    1978-01-01

    Ozone depletions in the polar stratosphere during the energetic solar proton event on 4 August 1972 were observed by the backscattered ultraviolet (BUV) experiments on the Nimbus 4 satellite. The observed ozone contents, the ozone depressions and their temporal variations above the 4 mb level exhibited distinct asymmetries between the northern and southern hemispheres. Since the ozone destroying solar particles precipitate rather symmetrically into the two polar atmospheres, due to the geomagnetic dipole field, it is suggested that these asymmetries may be explained in terms of the differences in dynamics between the summer and the winter polar atmospheres. In the summer (northern) hemisphere, the stratospheric and mesospheric ozone depletion and recovery are smooth functions of time due to the preponderance of undistributed orderly flow in this region. On the other hand, the temporal variation of the upper stratospheric ozone in the winter polar atmosphere (southern hemisphere) exhibits large amplitude irregularities. These characteristic differences between the two polar atmospheres are also evident in the vertical distributions of temperatures and winds observed by balloons and rocket soundings.

  17. Observation of Counter Propagating Alfven Waves with Perpendicular Polarizations and the Associated Proton Kinetics

    NASA Astrophysics Data System (ADS)

    He, J.; Pei, Z. T.; Wang, L.; Tu, C. Y.; Marsch, E.; Yao, S.

    2014-12-01

    It is believed that MHD turbulence cascading is mainly caused by the collisions between Alfven waves, which propagate oppositely and are polarized perpendicularly to each other. Nonlinear interaction will vanish if the counter-propagating Alfven waves have their polarization aligned with each other. However, the Alfven waves satisfying these collision criteria have not yet been found in the solar wind observations. Here we report the existence of Alfven waves with opposite propagation and non-aligned polarization in the solar wind. In one case of anti-sunward magnetic sector, with RTN as the coordinates, the magnetic fluctuations in T-component (BT) are anti-correlated with the velocity fluctuations in T-component (VT), while BR and BN fluctuations are in positive correlation with VR and VN fluctuations, respectively. These features suggest a possible nonlinear interaction between outward propagating Alfven wave with polarization in T-direction and inward propagating Alfven wave with polarization in R&N-directions. Moreover, the associated proton kinetics shows the existence of field-aligned sunward beam rather than anti-sunward beam, which may indicate a parallel Landau heating by sunward kinetic Alfven waves. A statistical study including more cases is also conducted.

  18. Polarity dependence of the electrical characteristics of Ag reflectors for high-power GaN-based light emitting diodes

    SciTech Connect

    Park, Jae-Seong; Seong, Tae-Yeon; Han, Jaecheon; Ha, Jun-Seok

    2014-04-28

    We report on the polarity dependence of the electrical properties of Ag reflectors for high-power GaN-based light-emitting diodes. The (0001) c-plane samples become ohmic after annealing in air. However, the (11–22) semi-polar samples are non-ohmic after annealing, although the 300 °C-annealed sample shows the lowest contact resistivity. The X-ray photoemission spectroscopy (XPS) results show that the Ga 2p core level for the c-plane samples experiences larger shift toward the valence band than that for the semi-polar samples. The XPS depth profile results show that unlike the c-plane samples, the semi-polar samples contain some amounts of oxygen at the Ag/GaN interface regions. The outdiffusion of Ga atoms is far more significant in the c-plane samples than in the semi-polar samples, whereas the outdiffusion of N atoms is relatively less significant in the c-plane samples. On the basis of the electrical and XPS results, the polarity dependence of the electrical properties is described and discussed.

  19. Study of the proton structure by measurements of polarization transfers in real Compton scattering at Jlab

    SciTech Connect

    Fanelli, Cristiano Fanelli; Cisbani, Evarostp; Hamilton, David; Salme, G.; Wojtsekhowski, Bogdan B.

    2014-03-01

    A preliminary analysis of polarization-transfer data at large scattering angle (70°), obtained in an experiment of real Compton scattering on proton, performed in Hall-C of Jefferson Lab, is presented. It is also discussed the relevance of this kind of experiments for shedding light on the non-perturbative structure of the proton, at low energy, and on the transition from the non-perturbative regime to the perturbative one, that occurs at high energy. Moreover, the possibility to extract Compton form factors and the Generalized Parton Distributions, one of the most promising theoretical tool to determine the total angular momentum contribution of quarks and gluons to nucleon spin, is emphasized.

  20. Microstructure and anodic polarization behavior of experimental Ag-18Cu-15Pd-12Au alloy in aqueous sulfide solution.

    PubMed

    Endo, Kazuhiko; Ohno, Hiroki; Asakura, Shukuji

    2003-05-01

    The anodic corrosion behavior of an experimental Ag-15Pd-18Cu-12Au alloy in 0.1% Na(2)S solution in relation to its microstructure was investigated using potentiodynamic and potentiostatic polarization techniques with analyses of corrosion products by X-ray diffractometry, Auger electron spectroscopy, and X-ray photoelectron spectroscopy. The role of Pd in improvement of the corrosion resistance was also investigated. In the potential/current density curve, three distinct current peaks, at -520 mV (peak I), -425 mV (peak II) and -175 mV (peak III), were observed. The Ag-rich alpha(2) matrix with coarse Cu and Pd-rich lamellae was the most corrosion-susceptible region, and this region was preferentially corroded at peak I with the formation of granular deposits of Ag(2)S. A small amount of Ag-Cu mixed sulfide deposited on the Cu and Pd-rich coarse particles and dissolution of Ag as AgO(-) might have occurred in parallel with Ag(2)S formation at peak II. Enrichment of Pd on the alloy surface occurred at peak III due to preferential dissolution of Ag and Cu. A high level of corrosion resistance was attained with the formation of a thin Pd-rich sulfide film, which enhanced the passivity of the alloy in an alkaline sulfide solution. It was found that passivity is an important phenomenon not only for base metal alloys but also for noble metal alloys to maintain high levels of resistance to corrosion and tarnishing in sulfide environments. PMID:15348446

  1. Evaluating the dynamic aperture evaluation for the new RHIC 250 GeV polarized proton lattice

    SciTech Connect

    Gu, X.; Luo, Y.; Fischer, W.; Huang, H.; Tepikian, S.

    2011-03-28

    To increase luminosity in the Relativistic Heavy Ion Collider's (RHIC's) polarized proton 250 GeV operations, we are considering reducing {beta}* to 0.65 m at the interaction points (IPs), and increasing bunch intensity. The new working point near the 2/3 integer will used on the ramp to preserve polarization. In addition, we plan to adjust the betatron-phase advances between IP6 and IP8 to (k+1/2)*{pi} so to lower the dynamic beta-beat from the beam-beam interaction. The effects of all these changes will impact the dynamic aperture, and hence, it must be evaluated carefully. In this article, we present the results of tracking the dynamic aperture with the proposed lattices.

  2. Measurement of the Induced Proton Polarization Pn in the 12C(e, e', p) reaction

    SciTech Connect

    Woo, R J; Barkhuff, David; Bertozzi, William; Chen, Jian-ping; Dale, Dan; Dodson, G; Dow, K A; Epstein, Marty; Farkhondeh, Manouchehr; Finn, Mike; Gilad, Shalev; Jones, Mark K; Joo, Kyungseon; Kelly, James; Kowalski, Stanley; Lourie, Bob; Madey, Richard; Margaziotis, Dimitri; Markowitz, Pete; McIntyre, Justin; Mertz, Christoph; Milbrath, Brian; Mitchell, Joseph; Perdrisat, Charles F; Punjabi, Vina; Rutt, Paul; Sarty, Adam; Tieger, D; Tschalaer, C; Turchinetz, William; Ulmer, Paul E; Van Verst, S P; Vellidis, C; Warren, Glen; Weinstein, Lawrence

    1998-01-19

    The first measurements of the induced proton polarization Pn for the 12C(e,e',p) reaction are reported. The experiment was performed at quasifree kinematics for energy and momentum transfer (w,q) = (294 MeV, 765 MeV/c) and sampled a missing momentum range of 0-250 MeV/c. The induced polarization arises from final-state interactions and for these kinematics is dominated by the real part of the spin-orbit optical potential. The distorted-wave impulse approximation provides good agreement with data for the 1 p3/2 shell. The data for the continuum suggest that both the 1s1/2 shell and underlying l > 1 configurations contribute.

  3. Recent Results on High-Energy Spin Phenomena of Gluons and Sea-Quarks in Polarized Proton-Proton Collisions at Rhic at Bnl

    NASA Astrophysics Data System (ADS)

    Surrow, Bernd

    2014-01-01

    The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is carrying out a spin physics program in high-energy polarized proton collisions at √ {s} = 200 GeV and √ {s} = 500 GeV to gain a deeper insight into the spin structure and dynamics of the proton. One of the main objectives of the spin physics program at RHIC is the precise determination of the polarized gluon distribution function. The STAR detector is well suited for the reconstruction of various final states involving jets, π0, π±, e± and γ, which allows to measure several different processes. Recent results suggest a gluon spin contribution to the proton spin at the same level as the quark spin contribution itself. The production of W bosons in polarized p+p collisions at √ {s} = 500 GeV opens a new era in the study of the spin-flavor structure of the proton. W-(+) bosons are produced in \\bar {u} + d (\\bar {d} + u) collisions and can be detected through their leptonic decays, e- + \\bar {ν }e (e++ν e), where only the respective charged lepton is measured. Results of W-(+) production suggest a large asymmetry between the polarization of anti-u and anti-d quarks.

  4. Neutron spin structure with polarized deuterons and spectator proton tagging at EIC

    DOE PAGESBeta

    Cosyn, W.; Guzey, V.; Higinbotham, D. W.; Hyde, C.; Kuhn, S.; Nadel-Turonski, P.; Park, K.; Sargsian, M.; Strikman, M.; Weiss, C.

    2014-10-27

    The neutron's deep-inelastic structure functions provide essential information for the flavor separation of the nucleon parton densities, the nucleon spin decomposition, and precision studies of QCD phenomena in the flavor-singlet and nonsinglet sectors. Thus, traditional inclusive measurements on nuclear targets are limited by dilution from scattering on protons, Fermi motion and binding effects, final-state interactions, and nuclear shadowing at x << 0.1. An Electron-Ion Collider (EIC) would enable next-generation measurements of neutron structure with polarized deuteron beams and detection of forward-moving spectator protons over a wide range of recoil momenta (0 < pR << several 100 MeV in the nucleusmore » rest frame). The free neutron structure functions could be obtained by extrapolating the measured recoil momentum distributions to the on-shell point. The method eliminates nuclear modifications and can be applied to polarized scattering, as well as to semi-inclusive and exclusive final states. We review the prospects for neutron structure measurements with spectator tagging at EIC, the status of R&D efforts, and the accelerator and detector requirements.« less

  5. Neutron spin structure with polarized deuterons and spectator proton tagging at EIC

    SciTech Connect

    Cosyn, W.; Guzey, V.; Higinbotham, D. W.; Hyde, C.; Kuhn, S.; Nadel-Turonski, P.; Park, K.; Sargsian, M.; Strikman, M.; Weiss, C.

    2014-10-27

    The neutron's deep-inelastic structure functions provide essential information for the flavor separation of the nucleon parton densities, the nucleon spin decomposition, and precision studies of QCD phenomena in the flavor-singlet and nonsinglet sectors. Thus, traditional inclusive measurements on nuclear targets are limited by dilution from scattering on protons, Fermi motion and binding effects, final-state interactions, and nuclear shadowing at x << 0.1. An Electron-Ion Collider (EIC) would enable next-generation measurements of neutron structure with polarized deuteron beams and detection of forward-moving spectator protons over a wide range of recoil momenta (0 < pR << several 100 MeV in the nucleus rest frame). The free neutron structure functions could be obtained by extrapolating the measured recoil momentum distributions to the on-shell point. The method eliminates nuclear modifications and can be applied to polarized scattering, as well as to semi-inclusive and exclusive final states. We review the prospects for neutron structure measurements with spectator tagging at EIC, the status of R&D efforts, and the accelerator and detector requirements.

  6. The effect of atomic structure on interface spin-polarization of half-metallic spin valves: Co{sub 2}MnSi/Ag epitaxial interfaces

    SciTech Connect

    Nedelkoski, Zlatko; Hasnip, Philip J.; Kuerbanjiang, Balati; Higgins, Edward; Lazarov, Vlado K.; Sanchez, Ana M.; Bell, Gavin R.; Oogane, Mikihiko; Hirohata, Atsufumi

    2015-11-23

    Using density functional theory calculations motivated by aberration-corrected electron microscopy, we show how the atomic structure of a fully epitaxial Co{sub 2}MnSi/Ag interfaces controls the local spin-polarization. The calculations show clear difference in spin-polarization at Fermi level between the two main types: bulk-like terminated Co/Ag and Mn-Si/Ag interfaces. Co/Ag interface spin-polarization switches sign from positive to negative, while in the case of Mn-Si/Ag, it is still positive but reduced. Cross-sectional atomic structure analysis of Co{sub 2}MnSi/Ag interface, part of a spin-valve device, shows that the interface is determined by an additional layer of either Co or Mn. The presence of an additional Mn layer induces weak inverse spin-polarisation (−7%), while additional Co layer makes the interface region strongly inversely spin-polarized (−73%). In addition, we show that Ag diffusion from the spacer into the Co{sub 2}MnSi electrode does not have a significant effect on the overall Co{sub 2}MnSi /Ag performance.

  7. 20% PARTIAL SIBERIAN SNAKE IN THE AGS.

    SciTech Connect

    Huang, H; Bai, M; Brown, K A; Glenn, W; Luccio, A U; Mackay, W W; Montag, C; Ptitsyn, V; Roser, T; Tsoupas, N; Zeno, K; Ranjbar, V; Spinka, H; Underwood, D

    2002-11-06

    An 11.4% partial Siberian snake was used to successfully accelerate polarized proton through a strong intrinsic depolarizing spin resonance in the AGS. No noticeable depolarization was observed. This opens up the possibility of using a 20% to 30% partial Siberian snake in the AGS to overcome all weak and strong depolarizing spin resonances. Some design and operation issues of the new partial Siberian snake are discussed.

  8. High-intensity polarized H-(proton), deuteron and 3He++ion source development at BNL.

    SciTech Connect

    Zelenski,A.

    2008-06-23

    New techniques for the production of polarized electron, H{sup -} (proton), D (D+) and {sup 3}H{sup ++} ion beams are discussed. Feasibility studies of these techniques are in progress at BNL. An Optically Pumped Polarized H{sup -} Ion Source (OPPIS) delivers beam for polarization studies in RHIC. The polarized deuteron beam will be required for the deuteron Electron Dipole Moment (EDM) experiment, and the {sup 3}H{sup ++} ion beam is a part of the experimental program for the future eRHIC (Electron Ion) collider.

  9. Dielectric response and anhydrous proton conductivity in a chiral framework containing a non-polar molecular rotor.

    PubMed

    Yu, Shan-Shan; Liu, Shao-Xian; Duan, Hai-Bao

    2015-12-28

    Herein, we report a chiral 3D framework with the formula [Co(HPO3)2][H2DABCO] (DABCO = 1,4-diazabicyclo[2.2.2]octane). This compound exhibits two distinct dielectric anomalies, one attributed to the transfer of protons between non-polar DABCO and the inorganic framework, and the other to the in-plane oscillatory fluctuation of the DABCO molecule. It also exhibits proton conductivity under high-temperature anhydrous conditions. PMID:26584424

  10. Recent progress in the development of a polarized proton target for reactions with radioactive ion beams

    NASA Astrophysics Data System (ADS)

    Urrego-Blanco, J. P.; Bingham, C. R.; van den Brandt, B.; Galindo-Uribarri, A.; Gómez del Campo, J.; Hautle, P.; Konter, J. A.; Padilla-Rodal, E.; Schmelzbach, P. A.

    2007-08-01

    Polarization observables in nuclear reactions with stable beams have provided important information concerning structural properties of nuclei and reaction mechanisms and hold great promise in the context of exotic nuclei. We report on the development of a polarized target based on plastic foils of 20-200 μm thickness to be used with radioactive ion beams. The operation of such a target requires a moderately high magnetic field and very low temperatures. The plastic foil is placed inside a chamber attached to the mixing chamber of a 3He-4He dilution refrigerator. Cooling of the foil is achieved via a superfluid film of 4He that can be supplied through two capillaries. The chamber has two thin, highly uniform silicon nitride windows. An NMR coil is attached to the target to monitor the polarization. Results of a first test to characterize the target system, using the elastic scattering of 38 MeV 12C by protons in inverse kinematics are presented.

  11. Production polarization and magnetic moment of Ξ¯+ antihyperons produced by 800-GeV/c protons

    NASA Astrophysics Data System (ADS)

    Ho, P. M.; Longo, M. J.; Nguyen, A.; Luk, K. B.; James, C.; Rameika, R.; Duryea, J.; Guglielmo, G.; Heller, K.; Johns, K.; Diehl, H. T.; Teige, S.; Thomson, G. B.; Zou, Y.

    1990-10-01

    The polarization of Ξ¯ + hyperons produced by 800-GeV/c protons in the inclusive reaction p+Be-->Ξ¯ ++X has been measured. The average polarization of the Ξ¯ +, at a mean xF=0.39 and pt=0.76 GeV/c, is -0.097+/-0.012+/-0.009. The magnetic moment of the Ξ¯ + is 0.657+/-0.028+/-0.020 nuclear magneton.

  12. Measurement of analyzing power for proton-carbon elastic scattering in the coulomb-nuclear interference region with a 22-GeV/c polarized proton beam.

    PubMed

    Tojo, J; Alekseev, I; Bai, M; Bassalleck, B; Bunce, G; Deshpande, A; Doskow, J; Eilerts, S; Fields, D E; Goto, Y; Huang, H; Hughes, V; Imai, K; Ishihara, M; Kanavets, V; Kurita, K; Kwiatkowski, K; Lewis, B; Lozowski, W; Makdisi, Y; Meyer, H-O; Morozov, B V; Nakamura, M; Przewoski, B; Rinckel, T; Roser, T; Rusek, A; Saito, N; Smith, B; Svirida, D; Syphers, M; Taketani, A; Thomas, T L; Underwood, D; Wolfe, D; Yamamoto, K; Zhu, L

    2002-07-29

    The analyzing power for proton-carbon elastic scattering in the Coulomb-nuclear interference region of momentum transfer, 9.0x10(-3)<-t<4.1x10(-2) (GeV/c)(2), was measured with a 21.7 GeV/c polarized proton beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory. The ratio of hadronic spin-flip to nonflip amplitude, r(5), was obtained from the analyzing power to be Rer(5)=0.088+/-0.058 and Imr(5)=-0.161+/-0.226. PMID:12144435

  13. THE NEAR-INTEGER WORKING POINT FOR POLARIZED PROTONS IN THE RELATIVISTIC HEAVY ION COLLIDER

    SciTech Connect

    MONTAG,C.; BAI, M.; BEEBE-WANG, J.; CALAGA, R.; BLASKIEWICZ, M.; ET AL.

    2007-06-25

    To achieve the RHIC polarized proton enhanced luminosity goal of 150.10{sup 30} cm{sup -2}sec{sup -} on average in stores at 250 GeV, the luminosity needs to be increased by a factor of 3 compared to what was achieved in 2006. Since the number of bunches is already at its maximum of 1 1 1, limited by the injection kickers and the experiments' time resolution, the luminosity can only be increased by either increasing the bunch intensity and/or reducing the beam emittance. This leads to a larger beam-beam tuneshift parameter. Operations during 2006 has shown that the beam-beam interaction is already dominating the luminosity lifetime. To overcome this limitation, a near-integer working point is under study. We will present recent results of these studies.

  14. AGS preinjector improvement

    SciTech Connect

    Alessi, J.G.; Brennan, J.M.; Brown, H.N.; Brodowski, J.; Gough, R.; Kponou, A.; Prelec, K.; Staples, J.; Tanabe, J.; Witkover, R.

    1987-01-01

    In 1984, a polarized H/sup -/ source was installed to permit the acceleration of polarized protons in the AGS, using a low current, 750 keV RFQ Linear Accelerator as the preinjector. This RFQ was designed by LANL and has proved to be quite satisfactory and reliable. In order to improve the reliability and simplify maintenance of the overall AGS operations, it has been decided to replace one of the two 750 keV Cockcroft-Waltons (C-W) with an RFQ. The design of a new high current RFQ has been carried out by LBL and is also being constructed there. This paper describes the preinjector improvement project, centered around that RFQ, which is underway at BNL.

  15. Forming-free, bi-directional polarity conductive-bridge memory devices with Ge2Sb2Te5 solid-state electrolyte and Ag active electrode

    NASA Astrophysics Data System (ADS)

    Huang, Yin-Hsien; Chen, Hsuan-An; Wu, Hsin-Han; Hsieh, Tsung-Eong

    2015-01-01

    Preparation and characteristics of conductive-bridge random access memory devices containing Ge2Sb2Te5 (GST) chalcogenide as the solid-state electrolyte, Ag as the active electrode, and W-Ti as the counter electrode are presented. As revealed by the electrical measurement, only the samples containing crystalline GST exhibited the resistive switching behaviors. With an insertion of ZnS-SiO2 dielectric layer at the Ag/GST interface and a postannealing at 100 °C for 1 min, the sample exhibited the best electrical performance with satisfactory cycleability and retention properties. Moreover, the forming-free and bi-directional polarity features were observed in such a sample type. Microstructure and composition analyses found the finely dispersed nano-scale Ag clusters in GST and, when electrical bias is applied, the migrating Ag ions may build up the connections in between neighboring Ag clusters. Moreover, grain boundaries in polycrystalline GST might be the main paths for Ag migration. The thread-like conduction channels in GST hence form, leading to the low resistance state of sample. On the contrary, the depletion of Ag in GST broke the connections in between Ag clusters when the electrical bias is reversed. This led to the rupture of conduction channels and, hence, the high resistance state of sample. The low operational voltage, forming-free, and bi-directional polarity features observed in (AZGW)T sample might also originated from the fine dispersion of Ag clusters in GST electrolyte.

  16. The RHIC polarized H- ion source

    NASA Astrophysics Data System (ADS)

    Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Steski, D.

    2016-02-01

    A novel polarization technique had been successfully implemented for the Relativistic Heavy Ion Collider (RHIC) polarized H- ion source upgrade to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gaseous ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically pumped Rb vapor. The use of high-brightness primary beam and large cross sections of charge-exchange cross sections resulted in production of high intensity H- ion beam of 85% polarization. The source very reliably delivered polarized beam in the RHIC Run-2013 and Run-2015. High beam current, brightness, and polarization resulted in 75% polarization at 23 GeV out of Alternating Gradient Synchrotron (AGS) and 60%-65% beam polarization at 100-250 GeV colliding beams in RHIC.

  17. The RHIC polarized H⁻ ion source.

    PubMed

    Zelenski, A; Atoian, G; Raparia, D; Ritter, J; Steski, D

    2016-02-01

    A novel polarization technique had been successfully implemented for the Relativistic Heavy Ion Collider (RHIC) polarized H(-) ion source upgrade to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gaseous ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically pumped Rb vapor. The use of high-brightness primary beam and large cross sections of charge-exchange cross sections resulted in production of high intensity H(-) ion beam of 85% polarization. The source very reliably delivered polarized beam in the RHIC Run-2013 and Run-2015. High beam current, brightness, and polarization resulted in 75% polarization at 23 GeV out of Alternating Gradient Synchrotron (AGS) and 60%-65% beam polarization at 100-250 GeV colliding beams in RHIC. PMID:26932068

  18. Longitudinal spin transfer to {lambda} and {lambda} hyperons in polarized proton-proton collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Barannikova, O.; Betts, R. R.; Garcia-Solis, E. J.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Kauder, K.; Suarez, M. C.; Aggarwal, M. M.; Bhati, A. K.; Kumar, L.; Pruthi, N. K.; Ahammed, Z.; Chattopadhyay, S.; Dutta Mazumdar, M. R.; Ganti, M. S.; Ghosh, P.; Mohanty, B.; Nayak, T. K.

    2009-12-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {lambda} and {lambda} hyperons has been measured for the first time in proton-proton collisions at {radical}(s)=200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}|<1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL}=-0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {lambda} and D{sub LL}=-0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {lambda} hyperons with <{eta}>=0.5 and =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  19. Longitudinal Spin Transfer to Lambda and Lambda bar Hyperons in Polarized Proton-Proton Collisions at sqrt s = 200 GeV

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hypersons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at RHIC. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {bar {Lambda}} hyperons with <{eta}> = 0.5 and = 3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  20. Longitudinal spin transfer to {Lambda} and {bar Lambda} hyperons in polarized proton-proton collisions at {radical}{ovr s} = 200 GeV.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Bridgeman, A.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration

    2009-01-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hyperons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03 {+-} 0.13(stat) {+-} 0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12 {+-} 0.08(stat) {+-} 0.03(syst) for inclusive {bar {Lambda}} hyperons with {eta} = 0.5 and p{sub T} =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  1. Experimental results on spin physics at the AGS

    SciTech Connect

    Makdisi, Y.I.

    1986-01-01

    The AGS ran with polarized protons towards the end of 1985 and through the first two months of 1986. This comprised commissioning periods interleaved with two runs for physics at 13.5 GeV/c with beam polarization of 50 to 60%, and 18.5 GeV/c with an average beam polarization of 40%. Later, the AGS polarized beam reached peak energy of 22 GeV/c and polarization of 46%. This article describes the various spin related experimental efforts since the VI Symposium at Marseille. These will be grouped into those using unpolarized beams and the rest are the polarized proton beam users. Afterwards the future of the program is described as extensions of current experiments in addition to other measurements that are yet to be proposed.

  2. Measurement of the beam-recoil polarization in low-energy virtual Compton scattering from the proton

    NASA Astrophysics Data System (ADS)

    Doria, L.; Janssens, P.; Achenbach, P.; Ayerbe Gayoso, C.; Baumann, D.; Bensafa, I.; Benali, M.; Beričič, J.; Bernauer, J. C.; Böhm, R.; Bosnar, D.; Correa, L.; D'Hose, N.; Defaÿ, X.; Ding, M.; Distler, M. O.; Fonvieille, H.; Friedrich, J.; Friedrich, J. M.; Laveissière, G.; Makek, M.; Marroncle, J.; Merkel, H.; Mihovilovič, M.; Müller, U.; Nungesser, L.; Pasquini, B.; Pochodzalla, J.; Postavaru, O.; Potokar, M.; Ryckbosch, D.; Sánchez Majos, S.; Schlimme, B. S.; Seimetz, M.; Širca, S.; Tamas, G.; Van de Vyver, R.; Van Hoorebeke, L.; Van Overloop, A.; Walcher, Th.; Weinriefer, M.; A1 Collaboration

    2015-11-01

    Double-polarization observables in the reaction e ⃗p →e'p ⃗'γ have been measured at Q2=0.33 (GeV/c ) 2 . The experiment was performed at the spectrometer setup of the A1 Collaboration using the 855 MeV polarized electron beam provided by the Mainz Microtron (MAMI) and a recoil proton polarimeter. From the double-polarization observables the structure function PLT ⊥ is extracted for the first time, with the value (-15.4 ±3 .3(stat .)-2.4+1.5(syst.)) GeV-2 , using the low-energy theorem for virtual Compton scattering. This structure function provides a hitherto unmeasured linear combination of the generalized polarizabilities of the proton.

  3. A new medium energy beam transport line for the proton injector of AGS-RHIC

    SciTech Connect

    Okamura, M.; Briscoe, B.; Fite, J.; LoDestro, V.; Raparia, D.; Ritter, J.; Hayashizaki, N.

    2010-09-12

    In Brookhaven National Laboratory (BNL), a 750 keV medium energy beam transport line between the 201 MHz 750 keV proton RFQ and the 200 MeV Alvarez DTL is being modified to get a better transmission of the beam. Within a tight space, high field gradient quadrupoles (65 Tm) and newly designed steering magnets (6.5 mm in length) will be installed considering the cross-talk effects. Also a new half wave length 200 MHz buncher is being prepared. The beam commissioning will be done in this year. To enhance the performance of the proton linacs, the MEBT is being modified. New quadrupole magnets, steering magnets and a half wave length buncher as shown in Figure 7 will be installed and be commissioned soon.

  4. Mechanical, spin polarized electronic and magnetic properties of TmX(X = Cu, Ag): First principle study

    NASA Astrophysics Data System (ADS)

    Chand, Satish; Singh, R. P.; Govindan, A.; Singh, S. K.

    2015-10-01

    To study the mechanical, spin polarized electronic and magnetic behavior of TmX(X = Cu, Ag), full-potential linear augmented plane wave plus local orbital method has been used. The lattice parameter (a0), bulk modulus (B0) and its first-order pressure derivative (B0') have been calculated using optimization method. Mechanical properties have been studied in terms of elastic constants (Cij), Young's modulus (Y), shear modulus (G) and Poisson's ratio (v) at ambient temperature and pressure which are found to be consistent with available experimental/theoretical values. Electronic properties have been investigated in terms of band structure and density of state histograms for spin up and spin down channel. Electronic and magnetic behavior of TmX shows that studied materials are metallic ferromagnets with high spin polarization in which Tm-f state electrons are contributed mainly.

  5. Spin dynamics simulations at AGS

    SciTech Connect

    Huang, H.; MacKay, W.W.; Meot, F.; Roser, T.

    2010-05-23

    To preserve proton polarization through acceleration, it is important to have a correct model of the process. It has been known that with the insertion of the two helical partial Siberian snakes in the Alternating Gradient Synchrotron (AGS), the MAD model of AGS can not deal with a field map with offset orbit. The stepwise ray-tracing code Zgoubi provides a tool to represent the real electromagnetic fields in the modeling of the optics and spin dynamics for the AGS. Numerical experiments of resonance crossing, including spin dynamics in presence of the snakes and Q-jump, have been performed in AGS lattice models, using Zgoubi. This contribution reports on various results so obtained.

  6. Further results in the search for the direct two-proton decay of ^94Ag^m (J^π= 21^+, 6.7 MeV)

    NASA Astrophysics Data System (ADS)

    Cerny, J.; Lee, D. W.; Perajarvi, K.; Moltz, D. M.; Barquest, B. R.; Grossman, L. E.; Jeong, W.; Jewett, C. C.

    2008-10-01

    Both direct one-proton decay and direct two-proton decay of ^94Ag^m from this 0.4 s isomeric state have been reported in experiments utilizing the GSI on-line mass separator [1]. In the latter decay, coincident events between silicon E detectors with a threshold energy of 0.4 MeV and a summed decay energy of 1.9±0.1 MeV were observed with a yield of 350±210 pb in coincidence with γ-decays in the ^92Rh daughter. We utilized our helium-jet system at the LBNL 88-inch cyclotron to repeat this experiment, again employing the ^58Ni(^40Ca,p3n) reaction at 197 MeV. Reaction products were transported via a capillary to a detection area and collected on a slowly rotating wheel in front of an assembly of 24 δEgas-δEgas-ESi detector telescopes with a threshold of 0.4 MeV for identifying protons. Five of these telescopes observe the 0.79 MeV single proton decay from ^94Ag^m at the reported yield of 1.3 nb. In the 240/276 identified proton detector combinations with low background, no proton-proton coincidences have been observed. Data from the remaining 36 detector combinations require a separate analysis, which is in progress. Monte Carlo analyses of our anticipated proton-proton coincidences for both sets of detector combinations will be presented. ^ 1Mukha et al., Nature 439, 298 (2006).

  7. SPIN DYNAMICS IN AGS AND RHIC.

    SciTech Connect

    Mackay, W W; Bai, M; Courant, E D; Brown, K; Glenn, W; Huang, H; Luccio, A; Ptitsyn, V; Roser, T; Satogata, T; Ltepikian, S; Tsoupas, N; Zelenski, A

    2003-05-12

    A fundamental aspect of particle physics is the spin of the particles. With polarized beams, the internal structure of the proton may be probed in ways that are unattainable with unpolarized beams. The Relativistic Heavy Ion Collider (RHIC) has the unique capability of colliding protons with both transverse and longitudinal polarization at center-of-mass energies up to 500 GeV. In this paper we examine the methods used to accelerate and manipulate polarized proton beams in RHIC and its injectors. Special techniques include the use of a partial Siberian snake and an ac dipole in the AGS. In RHIC we use four superconducting helical Siberian snakes (two per ring) for acceleration, and eight superconducting helical rotators for independent control of polarization directions at two interaction regions.

  8. Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 8.5 GeV^2

    SciTech Connect

    Puckett, A J.R.; Jones, M K; Luo, W; Meziane, M; Pentchev, L; Perdrisat, C F; Punjabi, V; Wesselmann, F R; Ahmidouch, A; Albayrak, I; Aniol, K A; Arrington, J; Asaturyan, A; Baghdasaryan, H; Benmokhtar, F; Bertozzi, W; Bimbot, L; Bosted, P; Boeglin, W; Butuceanu, C; Carter, P; Chernenko, S; Christy, E; Commisso, M; Cornejo, J C; Covrig, S; Danagoulian, S; Daniel, A; Davidenko, A; Day, D; Dhamija, S; Dutta, D; Ent, R; Frullani, S; Fenker, H; Frlez, E; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Goncharenko, Y; Hafidi, K; Hamilton, D; Higinbotham, D W; Hinton, W; Horn, T; Hu, B; Huang, J; Huber, G M; Jensen, E; Keppel, C; Khandaker, M; King, P; Kirillov, D; Kohl, M; Kravtsov, V; Kumbartzki, G; Li, Y; Mamyan, V; Margaziotis, D J; Marsh, A; Matulenko, Y; Maxwell, J; Mbianda, G; Meekins, D; Melnik, Y; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Moffit, B; Moreno, O; Mulholland, J; Narayan, A; Nedev, S; Nuruzzaman,; Piasetzky, E; Pierce, W; Piskunov, N M; Prok, Y; Ransome, R D; Razin, D S; Reimer, P; Reinhold, J; Rondon, O; Shabestari, M; Shahinyan, A; Shestermanov, K; Sirca, S; Sitnik, I; Smykov, L; Smith, G; Solovyev, L; Solvingnon, P; Subedi, R; Tomasi-Gustafsson, E; Vasiliev, A; Veilleux, M; Wojtsekhowski, B B; Wood, S; Ye, Z; Zanevsky, Y; Zhang, X; Zhang, Y; Zheng, X; Zhu, L

    2010-06-01

    Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon’s quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5  GeV2. By extending the range of Q2 for which GEp is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.

  9. Measurement of the polarization and magnetic moment of Ξ¯+ antihyperons produced by 800-GeV/c protons

    NASA Astrophysics Data System (ADS)

    Ho, P. M.; Longo, M. J.; Nguyen, A.; Luk, K. B.; James, C.; Rameika, R.; Duryea, J.; Guglielmo, G.; Heller, K.; Johns, K.; Diehl, H. T.; Teige, S.; Thomson, G. B.; Zou, Y.

    1991-12-01

    The polarization of Ξ¯ + hyperons produced by 800-GeV/c protons in the inclusive reaction p+Be-->Ξ¯ ++X has been measured using a sample of 70 000 Ξ¯ + decays. The average polarization of the Ξ¯ +, at a mean xF=0.39 and pt=0.76 GeV/c, is -0.097+/-0.012+/-0.009, compared to -0.102+/-0.012+/-0.010 for the Ξ-. The large polarization found for the Ξ¯ + is not expected in any model for polarization of inclusively produced hyperons. The magnetic moment of the Ξ¯ + was measured to be 0.657+/-0.028+/-0.020 nuclear magnetons (μN), compared to (-0.674+/-0.021+/-0.020)μN for the Ξ-, in good agreement with CPT invariance.

  10. Single and double spin asymmetries for deeply virtual Compton scattering measured with CLAS and a longitudinally polarized proton target

    SciTech Connect

    Pisano, S.; Biselli, A.; Niccolai, S.; Seder, E.; Guidal, M.; Mirazita, M.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bosted, P.; Briscoe, B.; Brock, J.; Brooks, W. K.; Burkert, V. D.; Carlin, C.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crabb, D. G.; Crede, V.; D' Angelo, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Garcon, M.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, X.; Jo, H. S.; Joo, K.; Joosten, S.; Keith, C. D.; Keller, D.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacCormick, M.; MacGregor, Ian J. D.; Mayer, M.; McKinnon, B.; Meekins, D. G.; Meyer, C. A.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Munoz Camacho, C.; Nadel-Turonski, P.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Phelps, W.; Phillips, J. J.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatie, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Skorodumina, I.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Turisini, M.; Ungaro, M.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

    2015-03-19

    Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton e→p→e'p'γ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally polarized 14NH3 target. The three asymmetries were measured in 165 4-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of Generalized Parton Distributions. As a result, the measurement of three DVCS spin observables at the same kinematic points allows a quasi-model-independent extraction of the imaginary parts of the H and H~ Compton Form Factors, which give insight into the electric and axial charge distributions of valence quarks in the proton.

  11. Simulations on the AGS horizontal tune jump mechanism

    SciTech Connect

    Lin,F.; Huang, H.; Luccio, A. U.; Roser, T.

    2009-05-04

    A new horizontal tune jump mechanism has been proposed to overcome the horizontal intrinsic resonances and preserve the polarization of the proton beam in the Alternating Gradient Synchrotron (AGS) during the energy ramp. An adiabatic change of the AGS lattice is needed to avoid the emittance growth in both horizontal and vertical planes, as the emittance growth can deteriorate the polarization of the proton beam. Two critical questions are necessary to be answered: how fast can the lattice be changed and how much emittance growth can be tolerated from both optics and polarization points of view? Preliminary simulations, using a realistic AGS lattice and acceleration rate, have been carried out to give a first glance of this mechanism. Results with different optics are presented in this paper.

  12. Fast scaling of energetic protons generated in the interaction of linearly polarized femtosecond petawatt laser pulses with ultrathin targets

    NASA Astrophysics Data System (ADS)

    Kim, I. Jong; Pae, Ki Hong; Kim, Chul Min; Kim, Hyung Taek; Choi, Il Woo; Lee, Chang-Lyoul; Singhal, Himanshu; Sung, Jae Hee; Lee, Seong Ku; Lee, Hwang Woon; Nickles, Peter V.; Jeong, Tae Moon; Nam, Chang Hee

    2015-12-01

    Laser-driven proton/ion acceleration is a rapidly developing research field attractive for both fundamental physics and applications such as hadron therapy, radiography, inertial confinement fusion, and nuclear/particle physics. Laser-driven proton/ion beams, compared to those obtained in conventional accelerators, have outstanding features such as low emittance, small source size, ultra-short duration and huge acceleration gradient of ∼1 MeV μm-1. We report proton acceleration from ultrathin polymer targets irradiated with linearly polarized, 30-fs, 1-PW Ti:sapphire laser pulses. A maximum proton energy of 45 MeV with a broad and modulated profile was obtained when a 10-nm-thick target was irradiated at a laser intensity of 3.3 × 1020 W/cm2. The transition from slow (I1/2) to fast scaling (I) of maximum proton energy with respect to laser intensity I was observed and explained by the hybrid acceleration mechanism including target normal sheath acceleration and radiation pressure acceleration in the acceleration stage and Coulomb-explosion-assisted free expansion in the post acceleration stage.

  13. Beam Transport of 4 GeV Protons from AGS to the Proton Interrogation Target of the Neutrino Line (Z_line) and Effect of the Air on the Transported Beam

    SciTech Connect

    Tsoupas,N.; Ahrens, L.; Pile, P.; Thieberger, P.; Murray, M.M.

    2008-10-01

    As part of the preparation for the Proton Interrogation Experiment, we have calculated the beam optics for the transport of 4 GeV protons, from the AGS extraction point, to the 'Cross-Section Target Wheel 1' and to the 'Proton Interrogation Target'. In this technical note we present three possible beam-transports each corresponding to a particular Fast Extracted Beam W B setup of the AGS. In addition we present results on the effect of the atmospheric air, (which fills the drift space of the last 100 [m] of the transport line), on the size of the beam, at two locations along the drift space, one location at the middle of the drift space and the other at the end where the 'Proton Interrogation Target' is placed. All the beam transports mentioned above require the removal of the WD1 dipole magnet, which is the first magnet of the W-line, because it acts as a limiting beam aperture, and the magnet is not used in the beam transport. An alternative solution of a beam transport, which does not require the removal of the WD1 magnet, is also presented. In this solution, which models the transport line using the TURTLE computer code[7], the vertical beam sizes at the location of the WD1 magnet is minimized to allow 'lossless' beam transport at the location of the WD1 magnet. A similar solution, but using a MAD model of the line, is also presented.

  14. Structural and electronic properties of polar MnO ultrathin film grown on Ag(111)

    NASA Astrophysics Data System (ADS)

    Kundu, Asish K.; Menon, Krishnakumar S. R.

    2016-05-01

    Surface electronic structure of ultrathin polar MnO film was studied by Low-energy Electron Diffraction (LEED) and Photoemission Spectroscopic (PES) techniques. Epitaxial monolayer to facet formation with increasing film thickness has been observed by LEED. Our LEED result shows p(2x2) surface reconstruction along with facet formation, stabilize the polar MnO(111) surface. The core levels and the valence band electronic structure of MnO films have been studied as a function of film thickness using X-ray and ultraviolet photoelectron spectroscopy techniques.

  15. The growth of α-sexithiophene films on Ag(111) studied by means of PEEM with linearly polarized light.

    PubMed

    Wagner, Thorsten; Ghanbari, Ebrahim; Huber, Daniel; Zeppenfeld, Peter

    2015-12-01

    In this study, we used photo electron emission microscopy (PEEM) to investigate the growth of α-sexithiophene (α-6 T) on Ag(111) surfaces. The experiments were carried out with linearly polarized ultraviolet-light (Hg lamp with hν=4.9 eV) in order to probe the alignment of the molecules on the surface. In particular, we acquired images before, during, and after growth while changing the polarization in a stepwise manner. For the stationary states of the clean and the α-6 T covered surfaces, we monitored the local electron yield and the intensity of the ultraviolet C-light (100-280 nm) reflected from the whole sample using PEEM and a photodiode, respectively. Due to the high ionization potential (IP>5 eV), there is no direct photoelectron emission from the organic crystallites. However, the photoelectron emission of the metal/organic interface is influenced by anisotropic absorption of the incident light beam, since the adsorbed molecules act as dichroic filters with distinct orientations. PMID:26150140

  16. Polarized beams at RHIC

    SciTech Connect

    Roser, T.

    1995-11-01

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven allows for the unique possibility of colliding two 250 GeV polarized proton beams at luminosities of up to 2 {times} 10{sup 32} cm{sup {minus}2} s{sup {minus}1}. A partial Siberian Snake in the AGS has recently been successfully tested and full Siberian Snakes, spin rotators, and polarimeters for RHIC are being developed to make the acceleration of polarized beams to 250 GeV possible. High energy polarized beam collisions will open up the unique physics opportunities of studying spin effects in hard processes, which will allow the study of the spin structure of the proton and also the verification of the many well documented expectations of spin effects in perturbative QCD and parity violation in W and Z production.

  17. Measurement of spin parameters in inclusive. Lambda. and K sub S production using a polarized proton beam

    SciTech Connect

    Tonse, S.R.

    1988-01-01

    A polarized proton beam incident on a Beryllium target was used for inclusive {Lambda}(1116 meV) production at beam momenta of 13.3 GeV and 18.5 GeV. The beam polarization was transverse to the beam direction with magnitude 0.63(0.40) at 13.3(18.5) GeV. The trigger condition favored forward produced {Lambda}'s with moderately high p{sub T}(p{sub T} {approximately} 1GeV). The {Lambda} polarization was measured and found to be in agreement with results from earlier experiments which used unpolarized proton beams. Analyzing power (A) and depolarization (D{sub NN}) of the {Lambda}'s were both measured and compared with a hyperon polarization model in which the polarization arises from a Thomas precession effect. There is good agreement with its predictions: A = 0 and D{sub NN} = 0. In particular, our measurement of D{sub NN} = {minus}0.009 {plus minus} 0.015 supports the idea that the valence quarks carry all of the hadron spin, since this assumption is implicit in the model's use of SU(6) wave functions to form final state hadrons from beam fragments and sea quarks. The analyzing power of K{sub s} was also measured at 13.3(18.5)GeV and found to be {minus}0.094 {plus minus} 0.012 ({minus}0.076 {plus minus} 0.015). We use the same model to predict A of K{sub s}, taking into account K{sub s} production from various sources (K{degree}, K{degree} and K*) and find good agreement with the data. Finally a small sample of {Lambda} was isolated form the 18.5 GeV sample and was found to have A = 0.03 {plus minus} 0.1, consistent with the model's prediction of zero.

  18. Polarization Observables for K{sup +}{Lambda} and K{sup +}{Sigma}{sup 0} Photoproduction form Polarized Protons

    SciTech Connect

    Walford, Natalie K.; Klein, Franz J.W.

    2014-01-01

    The search for undiscovered excited states of the nucleon continues to be a focus of experiments at Jefferson Lab. Recent LQCD calculations have confirmed long-standing quark-model predictions of many more states than have so far been identified. A large effort for the N* program has been launched using the CLAS detector to provide the database that will allow nearly model-independent partial wave analyses to be carried out in the search for such states. Polarization observables play a crucial role in this effort, as they are essential in disentangling overlapping resonant and non-resonant amplitudes. In 2010, double-polarization data were taken at JLab using circularly polarized photons incident on a transversely polarized frozen-spin butanol target. Our current analysis yields preliminary data of the T and F asymmetries of the K{sup +}{Lambda} and K{sup +}{Sigma}{sup 0} final states, which are compared to predictions of recent multipole analyses. This work is the first of its kind and will significantly broaden the world database for these reactions.

  19. Dynamics of the correlation between polar cap radio absorption and solar energetic proton fluxes in the interplanetary medium

    NASA Astrophysics Data System (ADS)

    Kouznetsov, A.; Knudsen, D. J.; Donovan, E. F.; Spanswick, E.

    2014-03-01

    During solar energetic particle (SEP) events, large fluxes of energetic particles spreading throughout the interplanetary medium (IPM) have access to the upper polar atmosphere where they play important roles in physical and chemical processes. We examine the dynamics of the relation between solar energetic proton (SEP) fluxes detected outside the magnetosphere by SOHO, at geosynchronous orbit by GOES 8, and in low earth orbit by NOAA 15 (POES) satellites on one hand, and ionospheric absorption measured by a NORSTAR riometer in the polar cap on the other. We attempt to isolate SEP-related signals by rejecting periods influenced by electron precipitation and solar radio bursts. Under these conditions we find R2of up to 0.9 between the logarithms of SEP flux and absorption for all satellites, but with the additional restriction to periods beginning 10 h after event onsets and within tens of hours following times of maximum flux. We find that the flux-absorption correlation is poor during the first few hours of an event, which we attribute to the fact that SEP angular distributions are often highly peaked along the interplanetary magnetic field during the early stages of an event. Such highly anisotropic distributions map to small regions inside the polar caps, making it unlikely that the corresponding absorption signal will be detected by a single riometer. These observations suggest that riometers in combination with a suitable numerical tool can be used as a diagnostic of properties of energetic proton populations in the interplanetary medium.

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

    PubMed

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

    2008-04-01

    A new ion acceleration method, namely, phase-stable acceleration, using circularly-polarized laser pulses is proposed. When the initial target density n(0) and thickness D satisfy a(L) approximately (n(0)/n(c))D/lambda(L) and D>l(s) with a(L), lambda(L), l(s), and n(c) the normalized laser amplitude, the laser wavelength in vacuum, the plasma skin depth, and the critical density of the incident laser pulse, respectively, a quasiequilibrium for the electrons is established by the light pressure and the space charge electrostatic field at the interacting front of the laser pulse. The ions within the skin depth of the laser pulse are synchronously accelerated and bunched by the electrostatic field, and thereby a high-intensity monoenergetic proton beam can be generated. The proton dynamics is investigated analytically and the results are verified by one- and two-dimensional particle-in-cell simulations. PMID:18517963

  1. The +3187A/G HLA-G polymorphic site is associated with polar forms and reactive reaction in leprosy

    PubMed Central

    Lucena-Silva, N; Teixeira, M A G; Ramos, A de L; de Albuquerque, R S; Diniz, G T N; Mendes-Junior, C T; Castelli, E C; Donadi, E A

    2013-01-01

    Considering that variability in immune response genes has been associated with susceptibility to leprosy and with disease severity, leprosy presents clinicopathological variants that are highly associated with the immune response, HLA-G has a well-recognized role in the modulation of the immune response, and polymorphisms at the 3′ untranslated region (UTR) of the HLA-G gene may influence HLA-G production, we studied the polymorphic sites at the 3′ UTR of the HLA-G gene in leprosy and their association with disease severity. We evaluated by sequencing analysis the allele, genotype, and haplotype frequencies of the 3′ UTR HLA-G polymorphic sites (14-bpINDEL/+3003C-T/+3010C-G/+3027A-C/+3035C-T/+3142C-G/+3187A-G/+3196C-G) in 146 individuals presenting reactive leprosy from a highly endemic area, and associated with bacillary load and the type of reactive leprosy. A total of 128 healthy subjects were also studied. Allele, genotype, and haplotype frequencies for the 3′ UTR HLA-G polymorphisms in leprosy patients did not differ from those observed in healthy donors. The +3187A allele was responsible for protection against the development of multibacillary leprosy in a dominant model (AA + AG)/GG, OR = 0.11, P = 0.018), and the +3187A allele and +3187A-A genotype were overrepresented in type II reactive leprosy reaction. The effect of genetic factors on leprosy susceptibility may be hidden by environmental components in highly endemic areas. The HLA-G + 3187A polymorphic site, which is related to unstable mRNA production, was associated with the development of polar forms of leprosy and reactive leprosy reaction. PMID:24498610

  2. Large-amplitude, circularly polarized, compressive, obliquely propagating electromagnetic proton cyclotron waves throughout the Earth's magnetosheath: low plasma β conditions

    SciTech Connect

    Remya, B.; Reddy, R. V.; Lakhina, G. S.; Tsurutani, B. T.; Falkowski, B. J.; Echer, E.; Glassmeier, K.-H.

    2014-09-20

    During 1999 August 18, both Cassini and WIND were in the Earth's magnetosheath and detected transverse electromagnetic waves instead of the more typical mirror-mode emissions. The Cassini wave amplitudes were as large as ∼14 nT (peak to peak) in a ∼55 nT ambient magnetic field B {sub 0}. A new method of analysis is applied to study these waves. The general wave characteristics found were as follows. They were left-hand polarized and had frequencies in the spacecraft frame (f {sub scf}) below the proton cyclotron frequency (f{sub p} ). Waves that were either right-hand polarized or had f {sub scf} > f{sub p} are shown to be consistent with Doppler-shifted left-hand waves with frequencies in the plasma frame f{sub pf} < f{sub p} . Thus, almost all waves studied are consistent with their being electromagnetic proton cyclotron waves. Most of the waves (∼55%) were found to be propagating along B {sub 0} (θ{sub kB{sub 0}}<30{sup ∘}), as expected from theory. However, a significant fraction of the waves were found to be propagating oblique to B {sub 0}. These waves were also circularly polarized. This feature and the compressive ([B {sub max} – B {sub min}]/B {sub max}, where B {sub max} and B {sub min} are the maximum and minimum field magnitudes) nature (ranging from 0.27 to 1.0) of the waves are noted but not well understood at this time. The proton cyclotron waves were shown to be quasi-coherent, theoretically allowing for rapid pitch-angle transport of resonant protons. Because Cassini traversed the entire subsolar magnetosheath and WIND was in the dusk-side flank of the magnetosheath, it is surmised that the entire region was filled with these waves. In agreement with past theory, it was the exceptionally low plasma β (0.35) that led to the dominance of the proton cyclotron wave generation during this interval. A high-speed solar wind stream ((V{sub sw} ) = 598 km s{sup –1}) was the source of this low-β plasma.

  3. Orientation-and polarization-dependent optical properties of the single Ag nanowire/glass substrate system excited by the evanescent wave

    PubMed Central

    Yang, Mu; Cai, Wei; Wang, Yingjie; Sun, Mengtao; Shang, Guangyi

    2016-01-01

    As an important plasmon one-dimensional material, orientation- and polarization-dependent properties of single Ag nanowires/glass substrate system are investigated by a powerful platform consisting of evanescent wave excitation, near-/far-field detection and a micromanipulator. In the case of the nanowire perpendicular or parallel to the incident plane and p- ors-polarized evanescent excitation respectively, optical properties of the nanowire is measured both in far-field and near-field. For the perpendicular situation, scattering light from the nanowire shows strong dependence on the polarization of incident light, and period patterns along the nanowire are observed both in the near- and far-field. The chain of dipole model is used to explain the origin of this pattern. The discrepancy of the period patterns observed in the near- and far-field is due to the different resolution of the near- and far-field detection. For the parallel case, light intensity from the output end also depends on the incident polarization. Both experimental and calculation results show that the polarization dependence effect results from the surface plasmon excitation. These results on the orientation- and polarization-dependent properties of the Ag nanowires detected by the combination of near- and far-field methods would be helpful to understand interactions of one-dimensional plasmonic nanostructures with light. PMID:27157123

  4. Orientation-and polarization-dependent optical properties of the single Ag nanowire/glass substrate system excited by the evanescent wave

    NASA Astrophysics Data System (ADS)

    Yang, Mu; Cai, Wei; Wang, Yingjie; Sun, Mengtao; Shang, Guangyi

    2016-05-01

    As an important plasmon one-dimensional material, orientation- and polarization-dependent properties of single Ag nanowires/glass substrate system are investigated by a powerful platform consisting of evanescent wave excitation, near-/far-field detection and a micromanipulator. In the case of the nanowire perpendicular or parallel to the incident plane and p- ors-polarized evanescent excitation respectively, optical properties of the nanowire is measured both in far-field and near-field. For the perpendicular situation, scattering light from the nanowire shows strong dependence on the polarization of incident light, and period patterns along the nanowire are observed both in the near- and far-field. The chain of dipole model is used to explain the origin of this pattern. The discrepancy of the period patterns observed in the near- and far-field is due to the different resolution of the near- and far-field detection. For the parallel case, light intensity from the output end also depends on the incident polarization. Both experimental and calculation results show that the polarization dependence effect results from the surface plasmon excitation. These results on the orientation- and polarization-dependent properties of the Ag nanowires detected by the combination of near- and far-field methods would be helpful to understand interactions of one-dimensional plasmonic nanostructures with light.

  5. Orientation-and polarization-dependent optical properties of the single Ag nanowire/glass substrate system excited by the evanescent wave.

    PubMed

    Yang, Mu; Cai, Wei; Wang, Yingjie; Sun, Mengtao; Shang, Guangyi

    2016-01-01

    As an important plasmon one-dimensional material, orientation- and polarization-dependent properties of single Ag nanowires/glass substrate system are investigated by a powerful platform consisting of evanescent wave excitation, near-/far-field detection and a micromanipulator. In the case of the nanowire perpendicular or parallel to the incident plane and p- ors-polarized evanescent excitation respectively, optical properties of the nanowire is measured both in far-field and near-field. For the perpendicular situation, scattering light from the nanowire shows strong dependence on the polarization of incident light, and period patterns along the nanowire are observed both in the near- and far-field. The chain of dipole model is used to explain the origin of this pattern. The discrepancy of the period patterns observed in the near- and far-field is due to the different resolution of the near- and far-field detection. For the parallel case, light intensity from the output end also depends on the incident polarization. Both experimental and calculation results show that the polarization dependence effect results from the surface plasmon excitation. These results on the orientation- and polarization-dependent properties of the Ag nanowires detected by the combination of near- and far-field methods would be helpful to understand interactions of one-dimensional plasmonic nanostructures with light. PMID:27157123

  6. Dynamic nuclear polarization study of inhibitor binding to the M2(18-60) proton transporter from influenza A.

    PubMed

    Andreas, Loren B; Barnes, Alexander B; Corzilius, Björn; Chou, James J; Miller, Eric A; Caporini, Marc; Rosay, Melanie; Griffin, Robert G

    2013-04-23

    We demonstrate the use of dynamic nuclear polarization (DNP) to elucidate ligand binding to a membrane protein using dipolar recoupling magic angle spinning (MAS) NMR. In particular, we detect drug binding in the proton transporter M2(18-60) from influenza A using recoupling experiments at room temperature and with cryogenic DNP. The results indicate that the pore binding site of rimantadine is correlated with previously reported widespread chemical shift changes, suggesting functional binding in the pore. Futhermore, the (15)N-labeled ammonium of rimantadine was observed near A30 (13)Cβ and G34 (13)Cα, suggesting a possible hydrogen bond to A30 carbonyl. Cryogenic DNP was required to observe the weaker external binding site(s) in a ZF-TEDOR spectrum. This approach is generally applicable, particularly for weakly bound ligands, in which case the application of MAS NMR dipolar recoupling requires the low temperatures to quench dynamic exchange processes. For the fully protonated samples investigated, we observed DNP signal enhancements of ~10 at 400 MHz using only 4-6 mM of the polarizing agent TOTAPOL. At 600 MHz and with DNP, we measured a distance between the drug and the protein to a precision of 0.2 Å. PMID:23480101

  7. Dynamic Nuclear Polarization Study of Inhibitor Binding to the M218–60 Proton Transporter from Influenza A

    PubMed Central

    Andreas, Loren B.; Barnes, Alexander B.; Corzilius, Björn; Chou, James J.; Miller, Eric A.; Caporini, Marc; Rosay, Melanie; Griffin, Robert G

    2013-01-01

    We demonstrate the use of dynamic nuclear polarization (DNP) to elucidate ligand binding to a membrane protein using dipolar recoupling magic angle spinning (MAS) NMR. In particular, we detect drug binding in the proton transporter M218–60 from influenza A using recoupling experiments at room temperature and with cryogenic DNP. The results indicate that the pore binding site of rimantadine is correlated with previously reported widespread chemical shift changes, suggesting functional binding in the pore. Futhermore, the 15N labeled ammonium of rimantadine was observed near A30 13Cβ and G34 13Cα suggesting a possible hydrogen bond to A30 Carbonyl. Cryogenic DNP was required to observe the weaker external binding site(s) in a ZF-TEDOR spectrum. This approach is generally applicable, particularly for weakly bound ligands, in which case the application of MAS NMR dipolar recoupling requires the low temperatures to quench dynamic exchange processes. For the fully protonated samples investigated, we observed DNP signal enhancements of ~10 at 400 MHz using only 4–6 mM of the polarizing agent TOTAPOL. At 600 MHz and with DNP, we measured a distance between the drug and the protein to a precision of 0.2 Å. PMID:23480101

  8. Polarization transmission at RHIC, numerical simulations

    SciTech Connect

    Meot F.; Bai, M.; Liu, C.; Minty, M.; Ranjbar, V.

    2012-05-20

    Typical tracking simulations regarding the transmission of the polarization in the proton-proton collider RHIC are discussed. They participate in general studies aimed at understanding and improving polarization performances during polarized proton-proton runs.

  9. The AGS synchrotron with four helical magnets

    SciTech Connect

    Tsoupas N.; Huang, H.; Roser, T.; MacKay, W.W.; Trbojevic, D.

    2012-05-20

    The idea of using two partial helical magnets was applied successfully to the AGS synchrotron to preserve the proton beam polarization. In this paper we explore in details the idea of using four helical magnets placed symmetrically in the AGS ring. The placement of four helical magnets in the AGS ring provides many advantages over the present setup of the AGS which uses two partial helical magnets. First, the symmetric placement of the four helical magnets allows for a better control of the AGS optics with reduced values of the beta functions especially near beam injection, second, the vertical spin direction during beam injection and extraction is closer to vertical, and third, it provides for a larger 'spin tune gap', which allows the vertical and horizontal tunes to be placed, and prevent the horizontal and vertical intrinsic spin resonances of the AGS to occur during the acceleration cycle. Although the same spin gap can be obtained with a single or two partial helices, the required high field strength of a single helix makes its use impractical, and that of the double helix rather difficult. In this paper we will provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and compare these results with the present setup of the AGS that uses two partial helical magnets.

  10. Collinear Photon Exchange in the Beam Normal Polarization Asymmetry of Elastic Electron-Proton Scattering

    SciTech Connect

    Andrei Afanasev; N.P. Merenkov

    2004-07-01

    The parity-conserving single-spin beam asymmetry of elastic electron-proton scattering is induced by an absorptive part of the two-photon exchange amplitude. We demonstrate that this asymmetry has logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. An optical theorem is used to evaluate the asymmetry in terms of the total photoproduction cross section on the proton, predicting its magnitude at 20-30 parts per million for high electron beam energies and small scattering angles. At fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.

  11. Polarization of the light from the 3P(1)-2S(1) transition in proton beam excited helium. Ph.D. Thesis; [target gas pressure effects

    NASA Technical Reports Server (NTRS)

    Weinhous, M. S.

    1973-01-01

    Measurements of the polarization of the light from the 3 1p-2 1s transition in proton beam excited Helium have shown both a proton beam energy and Helium target gas pressure dependence. Results for the linear polarization fraction range from +2.6% at 100 keV proton energy to -5.5% at 450 keV. The zero crossover occurs at approximately 225 keV. This is in good agreement with other experimental work in the field, but in poor agreement with theoretical predictions. Measurements at He target gas pressures as low as .01 mtorr show that the linear polarization fraction is still pressure dependent at .01 mtorr.

  12. Investigation of polarized-proton target materials by differential calorimetry: preliminary results

    SciTech Connect

    Hill, D.A.; Hill, J.J.

    1980-10-15

    A simple differential calorimeter was designed and operated for an investigation of the thermodynamic properties of polarized target materials. The calibration and use of the calorimeter are discussed, after a brief exposition of our motivation for this work. The results of a preliminary study of target materials is presented with emphasis on the relevance of the glass state to dynamic polarization in chemically-doped targets.

  13. Induced Proton Polarization for pi0 Electroproduction at Q2 = 0.126 GeV2/c2 Around the Delta(1232) Resonance

    SciTech Connect

    Glen Warren; Ricardo Alarcon; Christopher Armstrong; Burin Asavapibhop; David Barkhuff; William Bertozzi; Volker Burkert; J. Chen; Jian-Ping Chen; Joseph Comfort; Daniel Dale; George Dodson; S. Dolfini; K. Dow; Martin Epstein; Manouchehr Farkhondeh; John Finn; Shalev Gilad; Ralf Gothe; Xiaodong Jiang; Mark Jones; Kyungseon Joo; A. Karabarbounis; James Kelly; Stanley Kowalski; C. Kunz; D. Liu; R.W. Lourie; Richard Madey; Demetrius Margaziotis; Pete Markowitz; Justin McIntyre; C. Mertz; Brian Milbrath; Rory Miskimen; Joseph Mitchell; S. Mukhopadhyay; Costas Papanicolas; Charles Perdrisat; Vina Punjabi; Liming Qin; Paul Rutt; Adam Sarty; Jeffrey Shaw; S.B. Soong; D. Tieger; Christoph Tschalaer; William Turchinetz; Paul Ulmer; Scott Van Verst; C. Vellidis; Lawrence Weinstein; Steven Williamson; Rhett Woo; Alaen Young

    1998-12-01

    We present a measurement of the induced proton polarization P{sub n} in {pi}{sup 0} electroproduction on the proton around the {Delta} resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W = 1231 MeV and Q{sup 2} = 0.126 GeV{sup 2}/c{sup 2}, respectively. We measured a large induced polarization, P{sub n} = -0.397 {+-} 0.055 {+-} 0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model.

  14. Opportunities for Polarized He-3 in RHIC and EIC

    SciTech Connect

    Aschenauer E.; Deshpande, A.; Fischer, W.; Derbenev, S.; Milner, R.; Roser, T.; Zelenski, A.

    2011-10-01

    The workshop on opportunities for polarized He-3 in RHIC and EIC was targeted at finding practical ways of implementing and using polarized He-3 beams. Polarized He-3 beams will provide the unique opportunity for first measurements, i.e, to a full quark flavor separation measuring single spin asymmetries for p{sup +}, p{sup -} and p{sup 0} in hadron-hadron collisions. In electron ion collisions the combination of data recorded with polarized electron proton/He-3 beams allows to determine the quark flavor separated helicity and transverse momentum distributions. The workshop had sessions on polarized He-3 sources, the physics of colliding polarized He-3 beams, polarimetry, and beam acceleration in the AGS Booster, AGS, RHIC, and ELIC. The material presented at the workshop will allow making plans for the implementation of polarized He-3 beams in RHIC.

  15. Polarization of cumulative protons in the reaction. gamma. A. -->. pX at a maximum bremsstrahlung energy 1. 6 GeV

    SciTech Connect

    Bratashevskii-breve, A.S.; Zybalov, A.A.; Karasev, S.P.; Konovalov, O.G.; Marekhin, S.V.; Sorokin, P.V.; Storozhenko, Y.O.; Tenishev, A.E.

    1987-06-01

    We present results of measurement of the polarization of cumulative protons in the reactions ..gamma..A..-->..pX for A = /sup 2/D, /sup 6/Li, /sup 12/C, and /sup 63/Cu. The experiment was performed at the Khar'kov Physicotechnical Institute 2-GeV electron linear accelerator LUE-acute-accent-2. For all nuclei except deuterium the polarization is close to zero.

  16. Direct Solar Wind Proton Access into Permanently Shadowed Lunar Polar Craters

    NASA Technical Reports Server (NTRS)

    Zimmerman, M. I.; Farrell, W. M.; Stubbs, T. J.; Halekas, J. S.

    2011-01-01

    Recent analyses of Lunar Prospector neutron spectrometer (LPNS) data have suggested that high abundances of hydrogen exist within cold traps at the lunar poles, and it has often been assumed that hydrogen-bearing volatiles sequestered in permanent shadow are topographically shielded from sputtering by solar wind protons. However, recent simulation results are presented showing that solar wind protons clearly access the floor of an idealized, shadowed lunar crater through a combination of thermal and ambipolar processes, in effect creating a plasma "miniwake". These simulations are the first to model the mini-wake environment in two spatial dimensions with a self-consistent lunar surface-plasma interaction. Progress is reported on constraining the nonzero particle fluxes and energies incident on kilometer-scale shadowed topography, such as a small crater embedded within a larger one. The importance of direct solar wind proton bombardment is discussed within the context of understanding the stability and inventory of hydrogen-bearing volatiles in shadow at the lunar poles. The support of the National Lunar Science institute, the DREAM institute, LPROPS, and the NASA Postdoctoral Program at NASA Goddard Space Flight Center administered by ORAU are gratefully acknowledged.

  17. The RHIC p-Carbon CNI Polarimeter Upgrade For The Beam Polarization And Intensity Measurements

    SciTech Connect

    Zelenski, A.; Bazilevski, A.; Bunce, G.; Gill, R.; Huang, H.; Mahler, G.; Makdisi, Y.; Morozov, B.; Nemesure, S.; Russo, T.; Steski, D.; Sivertz, M.

    2009-08-04

    Proton polarization measurements in the AGS and RHIC (Relativistic Heavy Ion Collider at the beam energies 24-250 GeV) are based on proton-carbon and proton-proton elastic scattering in the Coulomb Nuclear Interference (CNI) region. Polarimeter operation in the scanning mode also gives polarization profile and beam intensity profile (beam emittance) measurements. Bunch by bunch emittance measurement is a very powerful tool for machine setup. Presently, the polarization and beam intensity profile measurements (in both vertical and horizontal planes) are restricted by the long target switching time and possible target destruction during this complicated motion. The RHIC polarimeters were operated near the limit of the counting rate for present silicon strip detectors. The ongoing polarimeter upgrade for the 2009 run will address all these problems. The upgrade should allow significant reduction of the polarization measurement errors by making feasible the complete polarization measurements, which includes polarization profiles in both the horizontal and vertical planes.

  18. Analysis of AGS E880 polarimeter data at Gy = 12.5.

    SciTech Connect

    Cadman, R.; Huang, H.; Krueger, K.; Spinka, H.; Underwood, D.

    2012-02-23

    Data were collected with the AGS internal (E880) polarimeter at G{gamma} = 12.5 during the FY04 polarized proton run. Measurements were made with forward scintillation counters in coincidence with recoil counter telescopes, permitting an absolute calibration of the polarimeter for both nylon and carbon targets. The results are summarized and they will also be useful for an absolute calibration of the AGS CNI polarimeter at G{gamma} = 12.5.

  19. Analysis of AGS E880 polarimeter data at Ggamma = 12.5

    SciTech Connect

    Cadman, R. V.; Huang, H.; Krueger, K.; Spinka, H.; Underwood, D.

    2012-01-27

    Data were collected with the AGS internal (E880) polarimeter at G{gamma} = 12.5 during the FY04 polarized proton run. Measurements were made with forward scintillation counters in coincidence with recoil counter telescopes, permitting an absolute calibration of the polarimeter for both nylon and carbon targets. The results are summarized and they will also be useful for an absolute calibration of the AGS CNI polarimeter at G{gamma} = 12.5.

  20. Radiative effects in the processes of exclusive photon electroproduction from polarized protons

    SciTech Connect

    Igor Akushevich, Alexander Ilyichev

    2012-03-01

    Radiative effects in the electroproduction of photons in polarized ep-scattering are calculated in the leading log approximation and analyzed numerically for kinematical conditions of current measurement at Jefferson Lab. Radiative corrections to the cross sections, their azimuthal distributions and Fourier coefficients are in particular focus. Kinematical regions where the radiative corrections are considerable are identified.

  1. Precision Measurement of Parity Violation in Polarized Cold Neutron Capture on the Proton: the NPDGamma Experiment

    SciTech Connect

    Bernhard Lauss; J.D. Bowman; R. Carlini; T.E. Chupp; W. Chen; S. Corvig; M. Dabaghyan; D. Desai; S.J. Freeman; T.R. Gentile; M.T. Gericke; R.C. Gillis; G.L. Greene; F.W. Hersman; T. Ino; T. Ito; G.L. Jones; M. Kandes; M. Leuschner; B. Lozowski; R. Mahurin; M. Mason; Y. Masuda; J. Mei; G.S. Mitchell; S. Muto; H. Nann; S.A. Page; S.I. Penttila; W.D. Ramsay; S. Santra; P.-N. Seo; E.I. Sharapov; T.B. Smith; W.M. Snow; W.S. Wilburn; V. Yuan; H. Zhu

    2005-10-24

    The NPD{gamma} experiment at the Los Alamos Neutron Science Center (LANSCE) is dedicated to measure with high precision the parity violating asymmetry in the {gamma} emission after capture of spin polarized cold neutrons in para-hydrogen. The measurement will determine unambiguously the weak pion-nucleon-nucleon ({pi} NN) coupling constant (line integral){sub {pi}}{sup l}.

  2. The AGS with four helical magnets

    SciTech Connect

    Tsoupas, N.; Huang, H.; MacKay, W.W.; Roser, T.; Trbojevic, D.

    2010-02-25

    The idea of using multiple partial helical magnets was applied successfully to the AGS synchrotron, to preserve the proton beam polarization. In this paper we explore in details the idea of using four helical magnets placed symmetrically in the AGS ring. This modification provides many advantages over the present setup of the AGS that uses two partial helical magnets. First, it provides a larger 'spin tune gap' for the placement of the vertical betatron tune of the AGS during acceleration, second, the vertical spin direction during the beam injection and extraction is closer to vertical, third, the symmetric placement of the snakes allows for a better control of the AGS optics, and for reduced values of the beta and eta functions, especially near injection, fourth, the optical properties of the helical magnets also favor the placement of the horizontal betatron tune in the 'spin tune gap', thus eliminating the horizontal spin resonances. In this paper we provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and we compare these results with the present setup of the AGS that uses two partial helical magnets.

  3. Comparison of kinetic and hydrodynamic descriptions of the proton polar wind in the transition to collisionless flow

    NASA Astrophysics Data System (ADS)

    Lie-Svendsen, Øystein; Olsen, Espen Lyngdal

    1998-03-01

    We have compared kinetic and fluid model descriptions of the proton polar wind outflow, from the collision-dominated, subsonic regime at lower altitudes, through the transition to supersonic flow, and well into the supersonic flow regime. The kinetic model is based on the Fokker-Planck collision operator, and the two fluid models employed are based on the 8-moment expansion and the 16-moment bi-Maxwellian expansions, respectively. We find excellent agreement between the kinetic description and the fluid models for the proton density and flux, even in the transonic and supersonic flow regimes. The models are also in qualitative agreement for the temperature and heat flux moments, although neither fluid model reproduces the negative (downward) kinetic heat fluxes found at high altitudes. The 16-moment fluid model gives a temperature anisotropy similar to the anisotropy derived from the kinetic solution. The assumed forms for the velocity distribution, on which the fluid expansions are based, do not agree with the kinetic velocity distribution, except in the subsonic region where the departure from a Maxwellian distribution is small. Near the fluid critical point the kinetic model develops a double-hump distribution, with an isotropic, low-energy core and an anisotropic, high-energy tail, and at higher altitudes the distribution function develops a ``kidney bean'' shape.

  4. Cross polarization and magic angle sample spinning NMR spectra of model organic compounds. 1. Highly protonated molecules

    SciTech Connect

    Alemany, L.B.; Grant, D.M.; Pugmire, R.J.; Alger, T.D.; Zilm, K.W.

    1983-04-20

    CP/MAS /sup 13/C NMR spectra were obtained at various contact times on ten solid organic compounds containing a variety of simple functional groups. The spectra show that signal intensities that agree with atomic ratios can be obtained with a contact time of 2.25 ms and often with a contact time as short as about 1 ms. Computer analysis of signal intensities obtained at a minimum of ten different contact times provides T/sub CH/ data that are consistent with these experimental results. The experimental results are also consistent with the previously reported lack of significant variation in the spectra of complex organic solids obtained with contact times of about 1 to 3 ms. In general, nonprotonated carbon atoms polarize more slowly than protonated carbon atoms. The compounds exhibit a wide range of proton spin lattice relaxation times. Some compounds exhibit more resonances than are found in the /sup 13/C(/sup 1/H) spectra of the compounds in solution because the crystalline environment removes the nominal spatial equivalence found for carbon atoms related to each other by unimolecular symmetry elements.

  5. Permeation of protons, potassium ions, and small polar molecules through phospholipid bilayers as a function of membrane thickness.

    PubMed Central

    Paula, S; Volkov, A G; Van Hoek, A N; Haines, T H; Deamer, D W

    1996-01-01

    Two mechanisms have been proposed to account for solute permeation of lipid bilayers. Partitioning into the hydrophobic phase of the bilayer, followed by diffusion, is accepted by many for the permeation of water and other small neutral solutes, but transient pores have also been proposed to account for both water and ionic solute permeation. These two mechanisms make distinctively different predictions about the permeability coefficient as a function of bilayer thickness. Whereas the solubility-diffusion mechanism predicts only a modest variation related to bilayer thickness, the pore model predicts an exponential relationship. To test these models, we measured the permeability of phospholipid bilayers to protons, potassium ions, water, urea, and glycerol. Bilayers were prepared as liposomes, and thickness was varied systematically by using unsaturated lipids with chain lengths ranging from 14 to 24 carbon atoms. The permeability coefficient of water and neutral polar solutes displayed a modest dependence on bilayer thickness, with an approximately linear fivefold decrease as the carbon number varied from 14 to 24 atoms. In contrast, the permeability to protons and potassium ions decreased sharply by two orders of magnitude between 14 and 18 carbon atoms, and leveled off, when the chain length was further extended to 24 carbon atoms. The results for water and the neutral permeating solutes are best explained by the solubility-diffusion mechanism. The results for protons and potassium ions in shorter-chain lipids are consistent with the transient pore model, but better fit the theoretical line predicted by the solubility-diffusion model at longer chain lengths. PMID:8770210

  6. Permeation of protons, potassium ions, and small polar molecules through phospholipid bilayers as a function of membrane thickness

    NASA Technical Reports Server (NTRS)

    Paula, S.; Volkov, A. G.; Van Hoek, A. N.; Haines, T. H.; Deamer, D. W.

    1996-01-01

    Two mechanisms have been proposed to account for solute permeation of lipid bilayers. Partitioning into the hydrophobic phase of the bilayer, followed by diffusion, is accepted by many for the permeation of water and other small neutral solutes, but transient pores have also been proposed to account for both water and ionic solute permeation. These two mechanisms make distinctively different predictions about the permeability coefficient as a function of bilayer thickness. Whereas the solubility-diffusion mechanism predicts only a modest variation related to bilayer thickness, the pore model predicts an exponential relationship. To test these models, we measured the permeability of phospholipid bilayers to protons, potassium ions, water, urea, and glycerol. Bilayers were prepared as liposomes, and thickness was varied systematically by using unsaturated lipids with chain lengths ranging from 14 to 24 carbon atoms. The permeability coefficient of water and neutral polar solutes displayed a modest dependence on bilayer thickness, with an approximately linear fivefold decrease as the carbon number varied from 14 to 24 atoms. In contrast, the permeability to protons and potassium ions decreased sharply by two orders of magnitude between 14 and 18 carbon atoms, and leveled off, when the chain length was further extended to 24 carbon atoms. The results for water and the neutral permeating solutes are best explained by the solubility-diffusion mechanism. The results for protons and potassium ions in shorter-chain lipids are consistent with the transient pore model, but better fit the theoretical line predicted by the solubility-diffusion model at longer chain lengths.

  7. Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV.

    PubMed

    Aggarwal, M M; Ahammed, Z; Alakhverdyants, A V; Alekseev, I; Alford, J; Anderson, B D; Anson, C D; Arkhipkin, D; Averichev, G S; Balewski, J; Beavis, D R; Bellwied, R; Betancourt, M J; Betts, R R; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Biritz, B; Bland, L C; Borowski, W; Bouchet, J; Braidot, E; Brandin, A V; Bridgeman, A; Brovko, S G; Bruna, E; Bueltmann, S; Bunzarov, I; Burton, T P; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, P; Codrington, M J M; Corliss, R; Cramer, J G; Crawford, H J; Dash, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Derevschikov, A A; Derradi de Souza, R; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Dunlop, J C; Dutta Mazumdar, M R; Efimov, L G; Elnimr, M; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Eun, L; Evdokimov, O; Fatemi, R; Fedorisin, J; Fersch, R G; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gangadharan, D R; Ganti, M S; Geromitsos, A; Geurts, F; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O; Grosnick, D; Guertin, S M; Gupta, A; Guryn, W; Haag, B; Hamed, A; Han, L-X; Harris, J W; Hays-Wehle, J P; Heinz, M; Heppelmann, S; Hirsch, A; Hjort, E; Hoffmann, G W; Hofman, D J; Huang, B; Huang, H Z; Humanic, T J; Huo, L; Igo, G; Jacobs, P; Jacobs, W W; Jena, C; Jin, F; Joseph, J; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kauder, K; Keane, D; Kechechyan, A; Kettler, D; Kikola, D P; Kiryluk, J; Kisiel, A; Kizka, V; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Koroleva, L; Korsch, W; Kotchenda, L; Kouchpil, V; Kravtsov, P; Krueger, K; Krus, M; Kumar, L; Kurnadi, P; Lamont, M A C; Landgraf, J M; LaPointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lee, J H; Leight, W; LeVine, M J; Li, C; Li, L; Li, N; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Liu, H; Liu, J; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Lukashov, E V; Luo, X; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mall, O I; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Masui, H; Matis, H S; Matulenko, Yu A; McDonald, D; McShane, T S; Meschanin, A; Milner, R; Minaev, N G; Mioduszewski, S; Mischke, A; Mitrovski, M K; Mohanty, B; Mondal, M M; Morozov, B; Morozov, D A; Munhoz, M G; Naglis, M; Nandi, B K; Nayak, T K; Netrakanti, P K; Ng, M J; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Ohlson, A; Okorokov, V; Oldag, E W; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Peitzmann, T; Perkins, C; Peryt, W; Phatak, S C; Pile, P; Planinic, M; Ploskon, M A; Pluta, J; Plyku, D; Poljak, N; Poskanzer, A M; Potukuchi, B V K S; Powell, C B; Prindle, D; Pruneau, C; Pruthi, N K; Pujahari, P R; Putschke, J; Qiu, H; Raniwala, R; Raniwala, S; Ray, R L; Redwine, R; Reed, R; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Ruan, L; Sakai, S; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sangaline, E; Schambach, J; Scharenberg, R P; Schmah, A M; Schmitz, N; Schuster, T R; Seele, J; Seger, J; Selyuzhenkov, I; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Staszak, D; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarini, L H; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Timoshenko, S; Tlusty, D; Tokarev, M; Trainor, T A; Tram, V N; Trentalange, S; Tribble, R E; Tsai, O D; Ullrich, T; Underwood, D G; Van Buren, G; van Leeuwen, M; van Nieuwenhuizen, G; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Walker, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, Q; Wang, X L; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xie, W; Xu, H; Xu, N; Xu, Q H; Xu, W; Xu, Y; Xu, Z; Xue, L; Yang, Y; Yepes, P; Yip, K; Yoo, I-K; Yue, Q; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, J B; Zhang, S; Zhang, W M; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, J; Zhong, C; Zhou, W; Zhu, X; Zhu, Y H; Zoulkarneev, R; Zoulkarneeva, Y

    2011-02-11

    We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements. PMID:21405460

  8. Progress and status of the AGS Booster project

    SciTech Connect

    Weng, W.T. )

    1989-01-01

    New physics opportunities, such as: rare K-decay, neutrino and heavy ion physics demand that a rapid-cycling high vacuum and high intensity Booster be built for the AGS at Brookhaven National Laboratory. The circumference of the Booster ring is one-quarter that of the AGS. Three modes of operation for various particles are envisioned. For unpolarized protons, four Booster pulses would be injected at a 7.5 Hz repetition rate within a 400 ms flat bottom of the AGS, enabling the present 1.5 {times} 10{sup 13} ppp to be increased to 6 {times} 10{sup 13} ppp. The protons would be accelerated to 1.5 GeV although the bending capability provided for heavy ions would eventually allow protons to be accelerated to 2.5 GeV. For heavy ions the rep rates is about 1 Hz and only one pulse would be injected into the AGS. For polarized protons 20 or so pulses can be stored in the Booster ring before injecting them into the AGS. Provisions for mixed modes of operation into a super cycle has been provided for future needs. In this paper, the lattice design and magnet characteristics will be briefly reviewed and major design issues will be discussed and design choices explained. Finally, the construction status and schedule will be presented. 9 refs., 3 figs.

  9. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at s=200GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Burton, T. P.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Dash, S.; Daugherity, M.; de Moura, M. M.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, W. J.; Dong, X.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Gorbunov, Y. G.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, N.; Gutierrez, T. D.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kramer, M.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; de Toledo, A. Szanto; Tai, A.; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; van der Kolk, N.; van Leeuwen, M.; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.; Vasiliev, A. N.; Vernet, R.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, X. L.; Wang, Y.; Watson, J. W.; Webb, J. C.; Westfall, G. D.; Wetzler, A.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yurevich, V. I.; Zhan, W.; Zhang, H.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A. N.; Zuo, J. X.

    2006-12-01

    We report a measurement of the longitudinal double-spin asymmetry ALL and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at s=200GeV. The cross section data cover transverse momenta 5polarization in the polarized nucleon.

  10. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Bielcik, J.; Bielcikova, J.; Caines, H.; Catu, O.; Chikanian, A.; Du, F.; Finch, E.; Harris, J. W.; Heinz, M.; Lamont, M. A. C.; Lin, G.; Majka, R.; Nattrass, C.; Salur, S.; Sandweiss, J.; Smirnov, N.; Witt, R.; Aggarwal, M. M.; Bhati, A. K.

    2006-12-22

    We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at {radical}(s)=200 GeV. The cross section data cover transverse momenta 5polarization in the polarized nucleon.

  11. Improvement the equation of polarization curve of a proton exchange membrane fuel cell at different channel geometry

    NASA Astrophysics Data System (ADS)

    Khazaee, I.

    2015-12-01

    The polarization curve of a proton exchange membrane fuel cell is an important parameter which is expressed by the change of voltage and current of it that indicates the performance of the cell. The voltage of the cell is a function of temperature that is expressed by the Nernst equation and the equation of voltage losses such as activation loss, ohmic loss and concentration loss. In this study a new correlation for polarization curve is obtained that it in addition to temperature, a new parameter is involved in it that shows the effect of the geometry of cross-section area of channels. For this purpose three PEM fuel cells with different channels geometry of rectangular, elliptical and triangular have constructed. The active area of each cell is 25 cm2 that its weight is 1300 g. The material of the gas diffusion layer is carbon clothes, the membrane is nafion 117 and the catalyst layer is a plane with 0.004 g/cm2 platinum. Also a test bench designed and constructed for testing the cell and a series of experiments are carried out to investigate the influence of the geometry of the cell on performance of the cell. The results show that when the geometry of channel is rectangular the performance of the cell is better than the triangular and elliptical channel.

  12. Protonation of carbon single-walled nanotubes studied using 13C and 1H-13C cross polarization nuclear magnetic resonance and Raman spectroscopies.

    PubMed

    Engtrakul, Chaiwat; Davis, Mark F; Gennett, Thomas; Dillon, Anne C; Jones, Kim M; Heben, Michael J

    2005-12-14

    The reversible protonation of carbon single-walled nanotubes (SWNTs) in sulfuric acid and Nafion was investigated using solid-state nuclear magnetic resonance (NMR) and Raman spectroscopies. Magic-angle spinning (MAS) was used to obtain high-resolution 13C and 1H-13C cross polarization (CP) NMR spectra. The 13C NMR chemical shifts are reported for bulk SWNTs, H2SO4-treated SWNTs, SWNT-Nafion polymer composites, SWNT-AQ55 polymer composites, and SWNTs in contact with water. Protonation occurs without irreversible oxidation of the nanotube substrate via a charge-transfer process. This is the first report of a chemically induced change in a SWNT 13C resonance brought about by a reversible interaction with an acidic proton, providing additional evidence that carbon nanotubes behave as weak bases. Cross polarization was found to be a powerful technique for providing an additional contrast mechanism for studying nanotubes in contact with other chemical species. The CP studies confirmed polarization transfer from nearby protons to nanotube carbon atoms. The CP technique was also applied to investigate water adsorbed on carbon nanotube surfaces. Finally, the degree of bundling of the SWNTs in Nafion films was probed with the 1H-13C CP-MAS technique. PMID:16332107

  13. Investigating the proton structure through polarization transfers in real Compton scattering processes at JLAB

    SciTech Connect

    Fanelli, Cristiano V.; Salme, Giovanni; Wojtsekhowski, Bogdan B.

    2014-06-01

    In the present work, preliminary results of the analysis of polarization transfers in real Compton scattering (RCS) performed in Hall-C at JLAB are presented, for data collected at large scattering angle (θ{sub cm}=70{degrees}) in the experiment E07-002. A previous experiment, E99-114, has already demonstrated a complete inconsistence of its results with a pQCD mechanism at JLAB energy regime. This kind of experiment, therefore, is of crucial importance for understanding the nature of the reaction mechanism for such a simple process, involving a real photon. Furthermore, RCS experiments allow the extraction of Compton form factors and Generalized Parton Distributions (GPDs), the latter connected to the total angular momentum of the nucleon.

  14. Measurement of deeply virtual compton scattering with a polarized-proton target.

    PubMed

    Chen, S; Avakian, H; Burkert, V D; Eugenio, P; Adams, G; Amarian, M; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Batourine, V; Battaglieri, M; Beard, K; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Bonner, B E; Bouchigny, S; Boiarinov, S; Bosted, P; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Carnahan, B; Cazes, A; Cole, P L; Collins, P; Coltharp, P; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Crede, V; Cummings, J P; DeMasi, R; DeVita, R; De Sanctis, E; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dharmawardane, K V; Dhuga, K S; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Fatemi, R; Fedotov, G; Feldman, G; Feuerbach, R J; Forest, T A; Funsten, H; Garçon, M; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Golovatch, E; Gonenc, A; Gothe, R W; Griffioen, K A; Guidal, M; Guillo, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hardie, J; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Huertas, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Joo, K; Juengst, H G; Keith, C; Kellie, J D; Khandaker, M; Kim, K Y; Kim, K; Kim, W; Klein, A; Klein, F J; Klusman, M; Kossov, M; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Li, Ji; Lima, A C S; Livingston, K; Lu, H; Lukashin, K; MacCormick, M; Markov, N; McAleer, S; McKinnon, B; McNabb, J W C; Mecking, B A; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Minehart, R; Mirazita, M; Miskimen, R; Mokeev, V; Morand, L; Morrow, S A; Moteabbed, M; Mueller, J; Mutchler, G S; Nadel-Turonski, P; Napolitano, J; Nasseripour, R; Natasha, N; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; O'Rielly, G V; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Philips, S A; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Polli, E; Popa, I; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Rowntree, D; Rubin, P D; Sabatié, F; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabian, Y G; Shaw, J; Shvedunov, N V; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Stavinsky, A; Stepanyan, S S; Stepanyan, S; Stokes, B E; Stoler, P; Strakovsky, I I; Strauch, S; Suleiman, R; Taiuti, M; Tedeschi, D J; Thoma, U; Tkabladze, A; Tkachenko, S; Todor, L; Tur, C; Ungaro, M; Vanderhaeghen, M; Vineyard, M F; Vlassov, A V; Watts, D P; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Zana, L; Zhang, J; Zhao, B; Zhao, Z

    2006-08-18

    The longitudinal target-spin asymmetry AUL for the exclusive electroproduction of high-energy photons was measured for the first time in ep-->e;'pgamma. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from the interference of the deeply virtual Compton scattering and Bethe-Heitler processes. The amplitude of the sinvarphi moment is 0.252+/-0.042stat+/-0.020sys. Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H and H. PMID:17026221

  15. Analysis of AGS polarimeter data at G{gamma}=7.5.

    SciTech Connect

    Huang, H.; Cadman, R. V.; Spinka, H. M.; Underwood, D. G.

    2003-02-18

    Data were collected with the AGS internal polarimeter at G{gamma} = 7.5 during the recent FY02 polarized proton run. The addition of new forward scintillation counters permitted an absolute calibration of the polarimeter for both nylon and carbon targets. The results are summarized, and the polarization measured at G{gamma} = 7.5 is compared to that at 200 MeV.

  16. Ground- and excited-state proton transfers in reversed micelles. Polarity restrictions and isotope effects

    SciTech Connect

    Politi, M.J.; Brandt, O.; Fendler, J.H.

    1985-05-23

    Ground- and excited-state proton transfers have been investigated with 8-hydroxy-1,3,6-pyrenetrisulfonate, POH, in sodium bis(2-ethylhexyl) sulfosuccinate, AOT, reversed micelle solubilized water pools in isooctane. Since POH is a much stronger acid in the singlet excited state, (POH)*, than in the ground state (pK/sub a/ = 7.2, pK/sub a/* = 0.5), excitation of POH by 1-5-mJ, 8-ns, 353-nm laser pulses, at pH values such that pK/sub a/* < pH < pK/sub a/, results in the dissociation of POH, governed by k/sub off/*. PO/sup -/ reprotonation rate, K/sub on/ values, have been determined by laser flash photolysis. In reversed micelles k/sub on/ values were found to depend on the water-to-AOT ratio(w values). Deuterium solvent isotope effects of 1.3 and 2.2 have been determined for k/sub on//k/sub on/(D/sub 2/O) in w = 33 and 12 AOT solubilized reversed micelles in isooctane. Combining these values with pK/sub a/ of POH led to isotope effects of 7.8 and 8.4 on k/sub off/ in the corresponding solutions. Steady-state and subnanosecond time-resolved fluorescence measurements have been utilized for assessing POH excited-state deprotonation, governed by k/sub off/*(D/sub 2/O), and reprotonation, governed by k/sub on/*(D/sub 2/O), in pure D/sub 2/O and in AOT entrapped water and AOT-d entrapped D/sub 2/O pools in isooctane. 51 references, 10 figures, 6 tables.

  17. Polarized-target asymmetry in pion-proton bremsstrahlung at 298 MeV

    SciTech Connect

    Bosshard, A.; Amsler, C.; Bistirlich, J.A.; van den Brandt, B.; Crowe, K.M.; Doebeli, M.; Doser, M.; Haddock, R.P.; Konter, J.A.; Ljungfelt, S.; Loude, J.F.; Mango, S.; Meyer, C.A.; Perroud, J.P.; Riedlberger, J.; Renker, D.; Schaad, M.; Sober, D.I.; Truoel, P.; Weymuth, P. Lawrence Berkeley Laboratory, University of California at Berkeley, Berkeley California 94720 Paul Scherrer Institut, 5232 Villigen, Paul Scherrer Institut, Department of Physics, University of California at Los Angeles, Los Angeles, California 90024 Institut de Physique Nucleaire, Universite de Lausanne, 1015 Lausanne, Department of Physics, Catholic University of America, Washington, D.C. 10024 )

    1990-05-28

    First data are presented for the polarized-target asymmetry in the reaction {pi}{sup +}{ital p}{r arrow}{pi}{sup +}{ital p}{gamma} at an incident pion energy of 298 MeV. The geometry was chosen to maximize the sensitivity to the radiation of the magnetic dipole moment {mu}{sub {Delta}} of the {Delta}{sup ++}(1232 MeV). A fit of the asymmetry in the cross section {ital d}{sup 5}{sigma}/{ital d}{Omega}{sub {pi}} {ital d}{Omega}{sub {gamma}} {ital dk} as a function of the photon energy {ital k} to predictions from a recent isobar-model calculation with {mu}{sub {Delta}} as the only free parameter yields {mu}{sub {Delta}}=1.64({plus minus}0.19exp{Delta},{plus minus}0.14 theor){mu}{sub {ital p}}. Though this value agrees with bag-model corrections to the SU(6) prediction {mu}{sub {Delta}}=2{mu}{sub {ital p}}, further clarifications on the model dependence of the result are needed, in particular since the isobar model fails to describe both the cross section and the asymmetry at the highest photon energies.

  18. L-shell X-ray production cross sections induced by protons and alpha-particles in the 0.7-2.0 MeV/amu range for Ru and Ag

    NASA Astrophysics Data System (ADS)

    Bertol, A. P. L.; Trincavelli, J.; Hinrichs, R.; Vasconcellos, M. A. Z.

    2014-01-01

    The X-ray emissions induced by protons and alpha-particles of the elements Ag and Ru were measured on mono-elemental thin films. L-shell X-ray production cross sections were obtained for the three L-subshells, considering absorption corrections. The Ag X-ray production cross sections agree with experimental data of other authors and with theoretical models, and were used to endorse the quality of the experimental values for Ru, that were not found in the literature.

  19. Polarization of Lambda0 and anti-Lambda0 inclusively produced by 610-GeV/c Sigma- and 525-GeV/c proton beams

    SciTech Connect

    Sanchez-Lopez, J.L.; Nelson, K.D.; Engelfried, J.; Akgun, U.; Alkhazov, G.; Amaro-Reyes, J.; Atamantchouk, A.G.; Ayan, A.S.; Balatz, M.Y.; Blanco-Covarrubias, A.; Bondar, N.F.; /Ball State U. /Bogazici U. /Carnegie Mellon U. /Rio de Janeiro, CBPF /Fermilab /Serpukhov, IHEP /Beijing, Inst. High Energy Phys. /Moscow, ITEP /Heidelberg, Max Planck Inst. /Moscow State U. /St. Petersburg, INP

    2007-06-01

    We have measured the polarization of {Lambda}{sup 0} and {bar {Lambda}{sup 0}} inclusively produced by 610 GeV/c {Sigma}{sup -} and 525 GeV/c proton beams in the experiment SELEX during the 1996/7 fixed target run at Fermilab. The polarization was measured as a function of the {Lambda} longitudinal momentum fraction x{sub F} and transverse momentum p{sub t}. For the {Lambda}{sup 0} produced by {Sigma}{sup -} the polarization is increasing with x{sub F} , from slightly negative at x{sub F} {approx} 0 to about 15% at large x{sub F} ; it shows a non-monotonic behavior as a function of p{sub t}. For the proton beam, the {Lambda}{sup 0} polarization is negative and decreasing as a function of x{sub F} and p{sub t}. The {bar {Lambda}{sup 0}} polarization is compatible with 0 for both beam particles over the full kinematic range. The target dependence was examined but no statistically significant difference was found.

  20. Longitudinal double-spin asymmetry and cross section for inclusivejet production in polarized proton collisions at sqrt(s) = 200 GeV

    SciTech Connect

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

    2006-08-10

    We report a measurement of the longitudinal double-spinasymmetry A_LL and the differential cross section for inclusivemidrapidity jet production in polarized proton collisions at sqrt(s)=200GeV. The cross section data cover transverse momenta 5polarization in the polarizednucleon.

  1. Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at s=200GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bonner, B. E.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bridgeman, A.; Bruna, E.; Bueltmann, S.; Bunzarov, I.; Burton, T. P.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, P.; Clarke, R. F.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Leyva, A. Davila; Silva, L. C. De; Debbe, R. R.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; de Souza, R. Derradi; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E. J.; Geromitsos, A.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heinz, M.; Heppelmann, S.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jena, C.; Jin, F.; Jones, C. L.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kauder, K.; Keane, D.; Kechechyan, A.; Kettler, D.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Kopytine, M.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Krueger, K.; Krus, M.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, L.; Li, N.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; Matulenko, Yu. A.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitrovski, M. K.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Powell, C. B.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Rehberg, J. M.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakai, S.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sangaline, E.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Staszak, D.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; de Toledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wingfield, E.; Wissink, S. W.; Witt, R.; Wu, Y.; Xie, W.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, S.; Zhang, W. M.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, J.; Zhong, C.; Zhou, J.; Zhou, W.; Zhu, X.; Zhu, Y. H.; Zoulkarneev, R.; Zoulkarneeva, Y.

    2009-12-01

    We report a measurement of the longitudinal double-spin asymmetry ALL and the differential cross section for inclusive π0 production at midrapidity in polarized proton collisions at s=200GeV. The cross section was measured over a transverse momentum range of 1polarization in the proton. The mean transverse momentum fraction of π0’s in their parent jets was found to be around 0.7 for electromagnetically triggered events.

  2. Nucleosynthesis of elements between Sr and Ag in neutron- and proton-rich neutrino-driven winds

    NASA Astrophysics Data System (ADS)

    Arcones, A.; Bliss, J.

    2014-04-01

    Neutrino-driven winds that follow core collapse supernovae were thought to be the site where half of the heavy elements are produced by the r-process. Although recent hydrodynamic simulations show that the conditions in the wind are not enough for the r-process, lighter heavy elements like Sr, Y, and Zr can be produced. However, it is still not clear whether the conditions in the wind are slightly neutron-rich or proton-rich. Here, we investigate the nucleosynthesis in neutrino-driven winds for both these conditions and systematically explore the impact of wind parameters on abundances. Our results show the difficulty of obtaining a robust abundance pattern in neutron-rich winds, where an over production of Sr, Y, and Zr is also likely. In proton-rich conditions, the abundances smoothly change when varying wind parameters. Constraints for wind parameters and neutrino energies and luminosities will soon become available by combining nucleosynthesis studies, like the one presented here, with new and future experimental data and observations.

  3. Progress in the AGS upgrade projects

    SciTech Connect

    Sluyters, T.J.

    1989-01-01

    The objectives of the AGS Upgrade Project are to prepare the AGS for Booster injection with an increase in the proton intensity to 6 {times} 10{sup 13} particles per pulse for a new generation of experiments on rare K decay, neutrino physics, the (g-2) value of the muon, and many other areas; to increase polarized proton intensity to 10{sup 12} particles per pulse for multi-target spin physics; to accelerate heavy ions up to Au for heavy ion physics; and, of course, to improve the flexibility and reliability of the AGS. High priority has been given to those projects which will reduce, at an early stage, beam losses during injection and acceleration, such as a fast electrostatic beam chopper and a high frequency dilution cavity. Other upgrade programs in progress are: a vacuum overhaul to reduce the AGS operating pressure by a factor of 100; an upgrade of the low and high field magnet correction system; automation of the Siemens main magnet power supply, etc. 3 refs., 2 figs.

  4. Measurement of top quark polarization in top-antitop events from proton-proton collisions at √s=7  TeV using the ATLAS detector.

    PubMed

    Aad, G; Abajyan, T; Abbott, B; Abdallah, J; Abdel Khalek, S; Abdinov, O; Aben, R; Abi, B; Abolins, M; AbouZeid, O S; Abramowicz, H; Abreu, H; Abulaiti, Y; Acharya, B S; Adamczyk, L; Adams, D L; Addy, T N; Adelman, J; Adomeit, S; Adye, T; Aefsky, S; Agatonovic-Jovin, T; Aguilar-Saavedra, J A; Agustoni, M; Ahlen, S P; Ahmad, A; Ahsan, M; Aielli, G; Åkesson, T P A; Akimoto, G; Akimov, A V; Alam, M A; Albert, J; Albrand, S; Alconada Verzini, M J; Aleksa, M; Aleksandrov, I N; Alessandria, F; Alexa, C; Alexander, G; Alexandre, G; Alexopoulos, T; Alhroob, M; Aliev, M; Alimonti, G; Alio, L; Alison, J; Allbrooke, B M M; Allison, L J; Allport, P P; Allwood-Spiers, S E; Almond, J; Aloisio, A; Alon, R; Alonso, A; Alonso, F; Altheimer, A; Alvarez Gonzalez, B; Alviggi, M G; Amako, K; Amaral Coutinho, Y; Amelung, C; Ammosov, V V; Amor Dos Santos, S P; Amorim, A; Amoroso, S; Amram, N; Anastopoulos, C; Ancu, L S; Andari, N; Andeen, T; Anders, C F; Anders, G; Anderson, K J; Andreazza, A; Andrei, V; Anduaga, X S; Angelidakis, S; Anger, P; Angerami, A; Anghinolfi, F; Anisenkov, A V; Anjos, N; Annovi, A; Antonaki, A; Antonelli, M; Antonov, A; Antos, J; Anulli, F; Aoki, M; Aperio Bella, L; Apolle, R; Arabidze, G; Aracena, I; Arai, Y; Arce, A T H; Arfaoui, S; Arguin, J-F; Argyropoulos, S; Arik, E; Arik, M; Armbruster, A J; Arnaez, O; Arnal, V; Arslan, O; Artamonov, A; Artoni, G; Asai, S; Asbah, N; Ask, S; Åsman, B; Asquith, L; Assamagan, K; Astalos, R; Astbury, A; Atkinson, M; Atlay, N B; Auerbach, B; Auge, E; Augsten, K; Aurousseau, M; Avolio, G; Axen, D; Azuelos, G; Azuma, Y; Baak, M A; Bacci, C; Bach, A M; Bachacou, H; Bachas, K; Backes, M; Backhaus, M; Backus Mayes, J; Badescu, E; Bagiacchi, P; Bagnaia, P; Bai, Y; Bailey, D C; Bain, T; Baines, J T; Baker, O K; Baker, S; Balek, P; Balli, F; Banas, E; Banerjee, Sw; Banfi, D; Bangert, A; Bansal, V; Bansil, H S; Barak, L; Baranov, S P; Barber, T; Barberio, E L; Barberis, D; Barbero, M; Bardin, D Y; Barillari, T; Barisonzi, M; Barklow, T; Barlow, N; Barnett, B M; Barnett, R M; Baroncelli, A; Barone, G; Barr, A J; Barreiro, F; Barreiro Guimarães da Costa, J; Bartoldus, R; Barton, A E; Bartsch, V; Bassalat, A; Basye, A; Bates, R L; Batkova, L; Batley, J R; Battistin, M; Bauer, F; Bawa, H S; Beale, S; Beau, T; Beauchemin, P H; Beccherle, R; Bechtle, P; Beck, H P; Becker, K; Becker, S; Beckingham, M; Becks, K H; Beddall, A J; Beddall, A; Bedikian, S; Bednyakov, V A; Bee, C P; Beemster, L J; Beermann, T A; Begel, M; Belanger-Champagne, C; Bell, P J; Bell, W H; Bella, G; Bellagamba, L; Bellerive, A; Bellomo, M; Belloni, A; Beloborodova, O L; Belotskiy, K; Beltramello, O; Benary, O; Benchekroun, D; Bendtz, K; Benekos, N; Benhammou, Y; Benhar Noccioli, E; Benitez Garcia, J A; Benjamin, D P; Bensinger, J R; Benslama, K; Bentvelsen, S; Berge, D; Bergeaas Kuutmann, E; Berger, N; Berghaus, F; Berglund, E; Beringer, J; Bernard, C; Bernat, P; Bernhard, R; Bernius, C; Bernlochner, F U; Berry, T; Bertella, C; Bertolucci, F; Besana, M I; 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Wang, H; Wang, J; Wang, J; Wang, K; Wang, R; Wang, S M; Wang, T; Wang, X; Warburton, A; Ward, C P; Wardrope, D R; Warsinsky, M; Washbrook, A; Wasicki, C; Watanabe, I; Watkins, P M; Watson, A T; Watson, I J; Watson, M F; Watts, G; Watts, S; Waugh, A T; Waugh, B M; Webb, S; Weber, M S; Webster, J S; Weidberg, A R; Weigell, P; Weingarten, J; Weiser, C; Weits, H; Wells, P S; Wenaus, T; Wendland, D; Weng, Z; Wengler, T; Wenig, S; Wermes, N; Werner, M; Werner, P; Werth, M; Wessels, M; Wetter, J; Whalen, K; White, A; White, M J; White, R; White, S; Whiteson, D; Whittington, D; Wicke, D; Wickens, F J; Wiedenmann, W; Wielers, M; Wienemann, P; Wiglesworth, C; Wiik-Fuchs, L A M; Wijeratne, P A; Wildauer, A; Wildt, M A; Wilhelm, I; Wilkens, H G; Will, J Z; Williams, E; Williams, H H; Williams, S; Willis, W; Willocq, S; Wilson, J A; Wilson, A; Wingerter-Seez, I; Winkelmann, S; Winklmeier, F; Wittgen, M; Wittig, T; Wittkowski, J; Wollstadt, S J; Wolter, M W; Wolters, H; Wong, W C; Wooden, G; Wosiek, B K; Wotschack, J; Woudstra, M J; Wozniak, K W; Wraight, K; Wright, M; Wrona, B; Wu, S L; Wu, X; Wu, Y; Wulf, E; Wyatt, T R; Wynne, B M; Xella, S; Xiao, M; Xu, C; Xu, D; Xu, L; Yabsley, B; Yacoob, S; Yamada, M; Yamaguchi, H; Yamaguchi, Y; Yamamoto, A; Yamamoto, K; Yamamoto, S; Yamamura, T; Yamanaka, T; Yamauchi, K; Yamazaki, Y; Yan, Z; Yang, H; Yang, H; Yang, U K; Yang, Y; Yang, Z; Yanush, S; Yao, L; Yasu, Y; Yatsenko, E; Yau Wong, K H; Ye, J; Ye, S; Yen, A L; Yildirim, E; Yilmaz, M; Yoosoofmiya, R; Yorita, K; Yoshida, R; Yoshihara, K; Young, C; Young, C J S; Youssef, S; Yu, D R; Yu, J; Yu, J; Yuan, L; Yurkewicz, A; Zabinski, B; Zaidan, R; Zaitsev, A M; Zambito, S; Zanello, L; Zanzi, D; Zaytsev, A; Zeitnitz, C; Zeman, M; Zemla, A; Zenin, O; Zeniš, T; Zerwas, D; Zevi Della Porta, G; Zhang, D; Zhang, H; Zhang, J; Zhang, L; Zhang, X; Zhang, Z; Zhao, Z; Zhemchugov, A; Zhong, J; Zhou, B; Zhou, N; Zhu, C G; Zhu, H; Zhu, J; Zhu, Y; Zhuang, X; Zibell, A; Zieminska, D; Zimin, N I; Zimmermann, C; Zimmermann, R; Zimmermann, S; Zimmermann, S; Zinonos, Z; Ziolkowski, M; Zitoun, R; Zivković, L; Zobernig, G; Zoccoli, A; Zur Nedden, M; Zurzolo, G; Zutshi, V; Zwalinski, L

    2013-12-01

    This Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4.7  fb(-1) of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at √s=7  TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of α(ℓ)P, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving or a maximally CP violating production process. The measurements obtained, α(ℓ)P(CPC)=-0.035±0.014(stat)±0.037(syst) and α(ℓ)P(CPV)=0.020±0.016(stat)(-0.017)(+0.013)(syst), are in good agreement with the standard model prediction of negligible top quark polarization. PMID:24476258

  5. variations of the atmospheric chemical composition in the earths's polar regions after solar proton flare on July 14, 2000 (photochemical simulation)

    NASA Astrophysics Data System (ADS)

    Kukoleva, A. A.; Krivolutsky, A. A.; Ondraskova, A.

    2010-02-01

    Altitude—temporal cross-sections q( z, t) of atmospheric ionization rates by solar protons above the polar regions were calculated using the GOES-10 satellite data on solar proton fluxes for the period of solar proton flare (SPF) on July 14, 2000. The values of q( z, t) were used further in calculations of variations of the atmospheric chemical composition during the flare in the northern and southern polar regions (70°N and 70°S) by two different 1D photochemical models of the atmosphere (neutral and charged components). The calculation results have shown considerable variation of the ozone content after SPF: a decrease of [O3] was about 80% at altitudes of 65-75 km above northern and 25% in the layer of 55-65 km above the southern polar region. Such decrease of the ozone content is a result of reactions with [NO] and [OH] whose concentrations have grown substantially during SPF. According to calculations, the increase of electron concentration during SPF has reached 3-4 orders of magnitude at altitudes of 50-80 km. A comparison of the calculation results with the observational data on [NO], [NO2], and [O3] from the UARS and HALOE satellites for 70°N have shown a good qualitative correspondence, however, for variations of nitric oxides there are quantitative discrepancies.

  6. Ion dynamics during the parametric instabilities of a left-hand polarized Alfvén wave in a proton-electron-alpha plasma

    SciTech Connect

    Gao, Xinliang; Lu, Quanming; Hao, Yufei; Tao, Xin; Wang, Shui; Li, Xing

    2014-01-01

    The parametric instabilities of an Alfvén wave in a proton-electron plasma system are found to have great influence on proton dynamics, where part of the protons can be accelerated through the Landau resonance with the excited ion acoustic waves, and a beam component along the background magnetic field is formed. In this paper, with a one-dimensional hybrid simulation model, we investigate the evolution of the parametric instabilities of a monochromatic left-hand polarized Alfvén wave in a proton-electron-alpha plasma with a low beta. When the drift velocity between the protons and alpha particles is sufficiently large, the wave numbers of the backward daughter Alfvén waves can be cascaded toward higher values due to the modulational instability during the nonlinear evolution of the parametric instabilities, and the alpha particles are resonantly heated in both the parallel and perpendicular direction by the backward waves. On the other hand, when the drift velocity of alpha particles is small, the alpha particles are heated in the linear growth stage of the parametric instabilities due to the Landau resonance with the excited ion acoustic waves. Therefore, the heating occurs only in the parallel direction, and there is no obvious heating in the perpendicular direction. The relevance of our results to the preferential heating of heavy ions observed in the solar wind within 0.3 AU is also discussed in this paper.

  7. Measurements of Cosmic-Ray Proton and Helium Spectra from the BESS-Polar Long-duration Balloon Flights over Antarctica

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    The BESS-Polar Collaboration measured the energy spectra of cosmic-ray protons and helium during two long-duration balloon flights over Antarctica in 2004 December and 2007 December at substantially different levels of solar modulation. Proton and helium spectra probe the origin and propagation history of cosmic rays in the galaxy, and are essential to calculations of the expected spectra of cosmic-ray antiprotons, positrons, and electrons from interactions of primary cosmic-ray nuclei with the interstellar gas, and to calculations of atmospheric muons and neutrinos. We report absolute spectra at the top of the atmosphere for cosmic-ray protons in the kinetic energy range 0.2–160 GeV and helium nuclei in the range 0.15–80 GeV/nucleon. The corresponding magnetic-rigidity ranges are 0.6–160 GV for protons and 1.1–160 GV for helium. These spectra are compared to measurements from previous BESS flights and from ATIC-2, PAMELA, and AMS-02. We also report the ratio of the proton and helium fluxes from 1.1 to 160 GV and compare this to the ratios from PAMELA and AMS-02.

  8. Uncertainty minimization in NMR measurements of dynamic nuclear polarization of a proton target for nuclear physics experiments

    SciTech Connect

    Keller, Dustin M.

    2013-11-01

    A comprehensive investigation into the measurement uncertainty in polarization produced by Dynamic Nuclear Polarization is outlined. The polarization data taken during Jefferson Lab experiment E08-007 is used to obtain error estimates and to develop an algorithm to minimize uncertainty of the measurement of polarization in irradiated View the ^14NH_3 targets, which is readily applied to other materials. The target polarization and corresponding uncertainties for E08-007 are reported. The resulting relative uncertainty found in the target polarization is determined to be less than or equal to 3.9%.

  9. Measurement of the transverse polarization of Λ and Λ¯ hyperons produced in proton-proton collisions at s=7  TeV using the ATLAS detector

    DOE PAGESBeta

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; et al

    2015-02-10

    We measure the transverse polarization of Λ and Λ¯ hyperons produced in proton-proton collisions at a center-of mass energy of 7 TeV is measured. The analysis uses 760 μb₋1 of minimum bias data collected by the ATLAS detector at the LHC in the year 2010. The measured transverse polarization averaged over Feynman xF from 5 × 10₋5 to 0.01 and transverse momentum pT from 0.8 to 15 GeV is ₋0.010 ± 0.005(stat) ± 0.004(syst) for Λ and 0.002 ± 0.006(stat) ± 0.004(syst) for Λ¯ . It is also measured as a function of xF and pT, but we observed nomore » significant dependence on these variables. Prior to this measurement, the polarization was measured at fixed-target experiments with center-of-mass energies up to about 40 GeV. The ATLAS results are compatible with the extrapolation of a fit from previous measurements to the xF range covered by this measurement.« less

  10. Transverse Single Spin Asymmetries of Forward π0 and Jet-like Events in s = 500 GeV Polarized Proton Collisions at STAR

    NASA Astrophysics Data System (ADS)

    Pan, Yuxi

    2016-02-01

    The large transverse single spin asymmetries (SSA) of high xF inclusive hadrons produced in polarized proton collisions are usually explained by means of collinear twist-3 multi-parton correlations. In this picture these asymmetries can originate from initial-state twist-3 parton distributions in the polarized proton and/or through the coupling between proton transversity and twist-3 fragmentation functions. The measurement of SSA for forward inclusive hadrons produced in pp collisions out to high transverse momentum helps to examine the validity and interplay of these initial- and final-state models. These models can be further explored by investigating the dependence of the SSA on event topologies. We present our latest status on the measurement of SSA for forward inclusive π0 detected within 2.8 < η < 4.0 in s = 500 GeV pp collisions as well as its dependence on event topologies. We will also present our analysis of Sivers and Collins asymmetries for forward jet-like events consisting of multi-photon final states. The measurements are based on the data taken in 2011 with integrated luminosity ˜ 22 pb‑1.

  11. The booster to AGS transfer line: comparison between model and measurements

    SciTech Connect

    Brown,K.A.; Ahrens, L.; Bonati, R.; Gassner, D.; Glenn, W.; Huang, H.; Morris, J.; Nida, S.; Tsoupas, N.; Schoefer, V.; Zeno, K.

    2009-05-04

    The Booster to AGS (BtA) transfer line was to match both ions and protons into the AGS lattice. For proton beam operation the only constraint on the optics is to define a match to the AGS lattice. For ion operation there are additional constraints introduced by a stripping foil in the upstream part of the transfer line. For polarized proton operation there is the complication that the AGS lattice is distorted by the presence of two partial snake magnets. In the 2008 polarized proton run it was observed that there was a significant optical injection mismatch. Beam experiments were conducted that showed disagreement with the model of the BtA line. In addition, these studies revealed some minor problems with the instrumentation in the line. A new model and more reliable measurements of the transfer line magnet currents have been implemented. Another series of experiments was conducted to test these modifications and to collect a more complete set of data to allow better understanding of the beam dynamics during the transfer and better understanding of the instrumentation. In this paper we will present the results of these experiments and the comparison to the new model of the BtA.

  12. Recoil polarization measurements of the proton electromagnetic form factor ratio to Q2 = 8.5  GeV2.

    PubMed

    Puckett, A J R; Brash, E J; Jones, M K; Luo, W; Meziane, M; Pentchev, L; Perdrisat, C F; Punjabi, V; Wesselmann, F R; Ahmidouch, A; Albayrak, I; Aniol, K A; Arrington, J; Asaturyan, A; Baghdasaryan, H; Benmokhtar, F; Bertozzi, W; Bimbot, L; Bosted, P; Boeglin, W; Butuceanu, C; Carter, P; Chernenko, S; Christy, E; Commisso, M; Cornejo, J C; Covrig, S; Danagoulian, S; Daniel, A; Davidenko, A; Day, D; Dhamija, S; Dutta, D; Ent, R; Frullani, S; Fenker, H; Frlez, E; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Goncharenko, Y; Hafidi, K; Hamilton, D; Higinbotham, D W; Hinton, W; Horn, T; Hu, B; Huang, J; Huber, G M; Jensen, E; Keppel, C; Khandaker, M; King, P; Kirillov, D; Kohl, M; Kravtsov, V; Kumbartzki, G; Li, Y; Mamyan, V; Margaziotis, D J; Marsh, A; Matulenko, Y; Maxwell, J; Mbianda, G; Meekins, D; Melnik, Y; Miller, J; Mkrtchyan, A; Mkrtchyan, H; Moffit, B; Moreno, O; Mulholland, J; Narayan, A; Nedev, S; Nuruzzaman; Piasetzky, E; Pierce, W; Piskunov, N M; Prok, Y; Ransome, R D; Razin, D S; Reimer, P; Reinhold, J; Rondon, O; Shabestari, M; Shahinyan, A; Shestermanov, K; Sirca, S; Sitnik, I; Smykov, L; Smith, G; Solovyev, L; Solvignon, P; Subedi, R; Tomasi-Gustafsson, E; Vasiliev, A; Veilleux, M; Wojtsekhowski, B B; Wood, S; Ye, Z; Zanevsky, Y; Zhang, X; Zhang, Y; Zheng, X; Zhu, L

    2010-06-18

    Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5  GeV2. By extending the range of Q2 for which G(E)(p) is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime. PMID:20873943

  13. Quasimonoenergetic Proton Bunch Generation by Dual-Peaked Electrostatic-Field Acceleration in Foils Irradiated by an Intense Linearly Polarized Laser

    NASA Astrophysics Data System (ADS)

    Zhuo, H. B.; Chen, Z. L.; Yu, W.; Sheng, Z. M.; Yu, M. Y.; Jin, Z.; Kodama, R.

    2010-08-01

    It is found that stable proton acceleration from a thin foil irradiated by a linearly polarized ultraintense laser can be realized for appropriate foil thickness and laser intensity. A dual-peaked electrostatic field, originating from the oscillating and nonoscillating components of the laser ponderomotive force, is formed around the foil surfaces. This field combines radiation-pressure acceleration and target normal sheath acceleration to produce a single quasimonoenergetic ion bunch. A criterion for this mechanism to be operative is obtained and verified by two-dimensional particle-in-cell simulation. At a laser intensity of ˜5.5×1022W/cm2, quasimonoenergetic GeV proton bunches are obtained with ˜100MeV energy spread, less than 4° spatial divergence, and ˜50% energy conversion efficiency from the laser.

  14. OVERCOMING DEPOLARIZING RESONANCES IN THE AGS WITH TWO HELICAL PARTIAL SNAKES

    SciTech Connect

    HUANG,H.; AHRENS, L.; BAI, M.; BROWN, K.A.; GARDNER, C.J.; ET AL.

    2007-06-25

    Dual partial snake scheme has provided polarized proton beams with 1.5 x 10{sup 11} intensity and 65% polarization for the Relativistic Heavy Ion Collider (RHIC) spin program. To overcome the residual polarization loss due to horizontal resonances in the Brookhaven Alternating Gradient Synchrotron (AGS), a new string of quadrupoles have been added. The horizontal tune can then be set in the spin tune gap generated by the two partial snakes, such that horizontal resonances can also be avoided. This paper presents the accelerator setup and preliminary results.

  15. THE AGS-BASED SUPER NEUTRINO BEAM FACILITY CONCEPTUAL DESIGN REPORT

    SciTech Connect

    WENG,W.T.; DIWAN,M.; RAPARIA,D.

    2004-10-08

    After more than 40 years of operation, the AGS is still at the heart of the Brookhaven hadron accelerator complex. This system of accelerators presently comprises a 200 MeV linac for the pre-acceleration of high intensity and polarized protons, two Tandem Van der Graaffs for the pre-acceleration of heavy ion beams, a versatile Booster that allows for efficient injection of all three types of beams into the AGS and, most recently, the two RHIC collider rings that produce high luminosity heavy ion and polarized proton collisions. For several years now, the AGS has held the world intensity record with more than 7 x 10{sup 13} protons accelerated in a single pulse. The requirements for the proton beam for the super neutrino beam are summarized and a schematic of the upgraded AGS is shown. Since the present number of protons per fill is already close to the required number, the upgrade is based on increasing the repetition rate and reducing beam losses (to avoid excessive shielding requirements and to maintain activation of the machine components at workable level). It is also important to preserve all the present capabilities of the AGS, in particular its role as injector to RHIC. The AGS Booster was built not only to allow the injection of any species of heavy ion into the AGS but to allow a fourfold increase of the AGS intensity. It is one-quarter the circumference of the AGS with the same aperture. However, the accumulation of four Booster loads in the AGS takes about 0.6 s, and is therefore not well suited for high average beam power operation. To minimize the injection time to about 1 ms, a 1.2 GeV linac will be used instead. This linac consists of the existing warm linac of 200 MeV and a new superconducting linac of 1.0 GeV. The multi-turn H{sup -} injection from a source of 30 mA and 720 {micro}s pulse width is sufficient to accumulate 9 x 10{sup 13} particle per pulse in the AGS[10]. The minimum ramp time of the AGS to full energy is presently 0.5 s; this must

  16. Recoil polarization and beam-recoil double polarization measurement of eta electroproduction on the proton in the region of the S11(1535) resonance.

    PubMed

    Merkel, H; Achenbach, P; Ayerbe Gayoso, C; Bernauer, J C; Böhm, R; Bosnar, D; Cheymol, B; Distler, M O; Doria, L; Fonvieille, H; Friedrich, J; Janssens, P; Makek, M; Müller, U; Nungesser, L; Pochodzalla, J; Potokar, M; Sánchez Majos, S; Schlimme, B S; Sirca, S; Tiator, L; Walcher, Th; Weinriefer, M

    2007-09-28

    The beam-recoil double polarization P(x')(h) and P(z')(h) and the recoil polarization P(y') were measured for the first time for the p(e,e'p)eta reaction at a four-momentum transfer of Q(2) = 0.1 GeV(2)/c(2) and a center of mass production angle of theta = 120 degrees at the Mainz Microtron MAMI-C. With a center of mass energy range of 1500 MeVpolarized-target asymmetry. PMID:17930579

  17. Proton elastic form factor ratios to Q{sup 2}=3.5 GeV{sup 2} by polarization transfer

    SciTech Connect

    Punjabi, V.; Perdrisat, C.F.; Gerstner, G.; Pentchev, L.; Rutledge, G.; Strauch, S.; Wijesooriya, K.; Aniol, K.A.; Epstein, M.B.; Margaziotis, D.J.; Baker, F.T.; Templon, J.A.; Berthot, J.; Bertin, P.Y.; Besson, A.; Fonvieille, H.; Jaminion, S.; Laveissiere, G.

    2005-05-01

    The ratio of the proton elastic electromagnetic form factors, G{sub Ep}/G{sub Mp}, was obtained by measuring P{sub t} and P{sub l}, the transverse and longitudinal recoil proton polarization components, respectively, for the elastic e{sup {yields}}p{yields}ep{sup {yields}}reaction in the four-momentum transfer squared range of 0.5 to 3.5 GeV{sup 2}. In the single-photon exchange approximation, G{sub Ep}/G{sub Mp} is directly proportional to P{sub t}/P{sub l}. The simultaneous measurement of P{sub t} and P{sub l} in a polarimeter reduces systematic uncertainties. The results for G{sub Ep}/G{sub Mp} show a systematic decrease with increasing Q{sup 2}, indicating for the first time a definite difference in the distribution of charge and magnetization in the proton. The data have been reanalyzed and their systematic uncertainties have become significantly smaller than those reported previously.

  18. Proton elastic form factor ratios to Q{sup 2} = 3.5 GeV{sup 2} by polarization transfer

    SciTech Connect

    V. Punjabi; C.F. Perdrisat; et al

    2005-01-01

    The ratio of the proton elastic electromagnetic form factors, G{sub E{sub p}}/G{sub M{sub p}}, was obtained by measuring P{sub t} and P{sub {ell}}, the transverse and longitudinal recoil proton polarization components, respectively, for the elastic {rvec e}p {yields} e{rvec p} reaction in the four-momentum transfer squared range of 0.5 to 3.5 GeV{sup 2}. In the single-photon exchange approximation, the ratio G{sub E{sub p}}/G{sub M{sub p}} is directly proportional to the ratio P{sub t}/P{sub {ell}}. The simultaneous measurement of P{sub t} and P{sub {ell}} in a polarimeter reduces systematic uncertainties. The results for the ratio G{sub E{sub p}}/G{sub M{sub p}} show a systematic decrease with increasing Q{sup 2}, indicating for the first time a definite difference in the distribution of charge and magnetization in the proton. The data have been re-analyzed and systematic uncertainties have become significantly smaller than previously published results.

  19. Proton and charge transfer reactions dynamics of a hydroxyflavone derivative in a polar solvent and in a cyclodextrin nanocavity

    NASA Astrophysics Data System (ADS)

    Sanz, M.; Organero, J. A.; Douhal, A.

    2007-09-01

    In this work, we report on the observation of ultrafast intramolecular charge- and proton-transfer reactions of 4'-dimethylaminoflavonol (DMAF) in N, N-dimethyl formamide and in γ-cyclodextrin (γ-CD) solution. Upon femtosecond excitation an intramolecular charge transfer (ICT) reaction takes place to produce an ICT structure in ˜200 fs. This structure may undergo a proton transfer reaction to generate a zwitterionic (Z) form in 2-3 ps, or relaxes in its potential energy well, to later equilibrate with that of Z in hundreds of ps. Addition of γ-CD does not significantly affect the fast dynamics of the formed anion. The fs-emission signals of the parent molecule, 3-hydroxyflavone, indicate that the dimethyl amino group in DMAF enhances the rate constant of intermolecular proton-transfer and intramolecular charge-transfer reactions.

  20. Measurement of the polarization observables I(s) and I(c) for gamma-proton decaying to proton-pion-antipion using the CLAS spectrometer

    NASA Astrophysics Data System (ADS)

    Hanretty, Charles

    Predictions regarding the excited baryon spectrum provided by symmetric quark models called Constituent Quark Models (CQMs) show good agreement with experimental measurements in the low-energy region (less than ≈ 1.8 GeV). The mass region above ≈ 1.8 GeV, however, contains many resonances which are predicted to exist by these models but have not been experimentally verified [1, 2]. This describes a well known problem in Baryon Spectroscopy, the issue of missing resonances. These resonances are considered missing as the mass measurements made regarding these resonances are either absent or fairly large in their uncertainties [1]. This discrepancy between the theoretical predictions and the experimental measurements can be attributed to several sources. Firstly, the majority of the data regarding the excited baryon spectrum originates from pion-nucleon or kaon-nucleon scattering (which the missing resonances may only weakly couple to). Therefore, as suggested by recent quark model calculations, a study of reactions involving photoproduction (gammap ) may present a better opportunity for the production of these missing resonances [3]. In addition, previous analyses involved unpolarized data. This absence of polarization leads to ambiguous analysis results, therefore a constraint such as the polarization of the photons can be used in order to further constrain the kinematics of the reaction(s). The analysis of polarized photoproduction data ( g⃗p or g⃗p⃗ ) in the low-energy region (< 1.8 GeV) presents the opportunity to further study previously observed resonances, possibly resolving currently unanswered questions about their properties. An analysis of polarized photoproduction data in the high-mass region (> 1.8 GeV) allows for a study of the resonances contributions, providing insight into the issue of the missing resonances. The study of a photoproduced 3-body final state (such as g⃗p → p pi+pi-) has been indicated as a promising method for detecting

  1. Recoil Polarization and Beam-Recoil Double Polarization Measurement of {eta} Electroproduction on the Proton in the Region of the S{sub 11}(1535) Resonance

    SciTech Connect

    Merkel, H.; Achenbach, P.; Ayerbe Gayoso, C.; Bernauer, J. C.; Boehm, R.; Distler, M. O.; Doria, L.; Friedrich, J.; Mueller, U.; Nungesser, L.; Pochodzalla, J.; Sanchez Majos, S.; Schlimme, B. S.; Tiator, L.; Walcher, Th.; Weinriefer, M.; Bosnar, D.; Makek, M.; Cheymol, B.; Fonvieille, H.

    2007-09-28

    The beam-recoil double polarization P{sub x{sup '}}{sup h} and P{sub z{sup '}}{sup h} and the recoil polarization P{sub y{sup '}} were measured for the first time for the p(e-vector,e{sup '}p-vector){eta} reaction at a four-momentum transfer of Q{sup 2}=0.1 GeV{sup 2}/c{sup 2} and a center of mass production angle of {theta}=120 deg. at the Mainz Microtron MAMI-C. With a center of mass energy range of 1500 MeVpolarized-target asymmetry.

  2. Polar solvent structural parameters from protonation equilibria of aliphatic and alicyclic diamines and from absorption bands of mixed-valence transition-metal complexes

    NASA Astrophysics Data System (ADS)

    Kornyshev, A. A.; Ulstrup, J.

    1986-04-01

    We have applied non-local electrostatic theory in combination with a simple solute model to obtain solvent structural properties in terms of the short-range dielectric constant, ˜ge, and the correlation length for the solvent polarization fluctuations, A. These parameters are fitted to experimental data for the free energy of interaction between protonated amino groups in dibasic amines and for intervalence band maxima of binuclear ruthenium complexes with bridge groups of varying length. The results show that non-local screening in the outer solvent, ˜ge in the range 3.5-4 for water, and A ≈ 2-3 Å and 4 Å for acetonitrile and water, respectively, provide good fits to the data, implying the significance of solvent structural effects for these phenomena.

  3. K-italic-shell ionization cross sections for Al, Ti, V, Cr, Fe, Ni, Cu, and Ag by protons and oxygen ions in the energy range 0. 3--6. 4 MeV

    SciTech Connect

    Geretschlaeger, M.; Benka, O.

    1986-08-01

    Absolute K-italic-shell ionization cross sections have been measured for thin targets of Al, Ti, and Cu for protons in the energy range 0.3--2.0 MeV and for thin targets of Ti, V, Cr, Fe, Ni, Cu, and Ag for oxygen ions in the energy range 1.36--6.4 Mev. The experimental results are compared to the perturbed-stationary-state (PSS) approximation with energy-loss (E), Coulomb (C), and relativistic (R) corrections, i.e., the ECPSSR approximation (Brandt and Lapicki), to the semiclassical approximation (Laegsgaard, Andersen, and Lund), and to a theory for direct Coulomb ionization of the 1s-italicsigma molecular orbital (Montenegro and Sigaud (MS)). The proton results agree within 3% with empirical reference cross sections. Also, the ECPSSR provides best overall agreement for protons. For oxygen ions, ECPSSR and MS predict experimental results satisfactorily for scaled velocities xi> or =0.4. For lower scaled velocities, the experimental cross sections become considerably higher than theoretical predictions for Coulomb ionization. This deviation increases with increasing Z-italic/sub 1//Z/sub 2/; it cannot be explained by electron transfer to the projectile or by ionization due to target recoil atoms.

  4. QED radiative effects in the processes of exclusive photon electroproduction from polarized protons with the next-to-leading accuracy

    SciTech Connect

    Akushevich, Igor V.; Ilyichev, Alexander; Shumeiko, Nikolai M

    2014-08-01

    Radiative effects in the electroproduction of photons in polarized ep-scattering are calculated with the next-to-leading (NLO) accuracy. The contributions of loops and two photon emission were presented in analytical form. The covariant approach of Bardin and Shumeiko was used to extract the infrared divergence. All contributions to the radiative correction were presented in the form of the correction to the leptonic tensor thus allowing for further applications in other experiments, e.g., deep inelastic scattering. The radiative corrections (RC) to the cross sections and polarization asymmetries were analyzed numerically for kinematical conditions of the current measurement at Jefferson Lab. Specific attention was paid on analyzing kinematical conditions for the process with large radiative effect when momenta of two photons in the final state are collinear to momenta of initial and final electrons, respectively.

  5. Proton Nucleus Elastic Scattering Data.

    1993-08-18

    Version 00 The Proton Nucleus Elastic Scattering Data file PNESD contains the numerical data and the related bibliography for the differential elastic cross sections, polarization and integral nonelastic cross sections for elastic proton-nucleus scattering.

  6. The AGS Ggamma Meter and Calibrating the Gauss Clock

    SciTech Connect

    Ahrens, Leif

    2014-03-31

    During AGS Polarized Proton acceleration periods, one output from the AGS Ggamma Meter, namely the energy (or Ggamma) calculated from the magnetic field in the AGS main magnets and the beam radius- both measured in particular instant, is used to figure out the times in the AGS magnet acceleration cycle when the beam passes through a particular set of depolarizing resonances. The resonance set occur whenever a particle’s Ggamma (energy*(G/m) becomes nearly equal to n*Qx (i.e. any integer multiplied by the horizontal betatron tune). This deliverable is why the machinery is referred to as the ''Ggamma Meter'' rather than the AGS energy meter. The Ggamma Meter takes as inputs a set of measurements of frequency (F(t)), radius (r(t)), and gauss clock counts (GCC(t)). The other energy (GgammaBr) assumes the field when the gauss clock starts counting is known. The change in field to time t is given by the measured accumulated gauss clock counts multiplied by the gauss clock calibration (gauss/GCC). In order to deal with experimental data, this calibration factor gets an added ad hoc complication, namely a correction dependent on the rate of change the counting rate. The Ggamma meter takes GCC(t) and together with the past history for this cycle calculates B(t).

  7. Comments on Injector Proton Beam Study in Run 2014

    SciTech Connect

    Zhang, S. Y.

    2014-09-15

    During the entire period of injector proton study in run 2014, it seems that the beam transverse emittance out of Booster is larger than that in run 2013. The emittance measured at the BtA transfer line and also the transmission from Booster late to AGS late are presented for this argument. In addition to this problem, it seems that the multiturn Booster injection, which defines the transverse emittance, needs more attention. Moreover, for high intensity operations, the space charge effect may be already relevant in RHIC polarized proton runs. With the RHIC proton intensity improvement in the next several years, higher Booster input intensity is needed, therefore, the space charge effect at the Booster injection and early ramp may become a new limiting factor.

  8. Tribological properties of ag-based amphiphiles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most ag-based materials are amphiphilic because they comprise polar and non-polar groups within the same molecule. One of the major categories of amphiphilic ag-based materials are seed oils, which are actively investigated as substitutes for petroleum in a wide variety of consumer and industrial a...

  9. Inclusive cross section and double helicity asymmetry for {pi}{sup 0} production in p+p collisions at {radical}(s)=200 GeV: Implications for the polarized gluon distribution in the proton

    SciTech Connect

    Adare, A.; Bickley, A. A.; Ellinghaus, F.; Glenn, A.; Kinney, E.; Nagle, J. L.; Seele, J.; Wysocki, M.; Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L.; Aidala, C.; Chi, C. Y.; Cole, B. A.; D'Enterria, D.; Jia, J.

    2007-09-01

    The PHENIX experiment presents results from the Relativistic Heavy Ion Collider 2005 run with polarized proton collisions at {radical}(s)=200 GeV, for inclusive {pi}{sup 0} production at midrapidity. Unpolarized cross section results are given for transverse momenta p{sub T}=0.5 to 20 GeV/c, extending the range of published data to both lower and higher p{sub T}. The cross section is described well for p{sub T}<1 GeV/c by an exponential in p{sub T}, and, for p{sub T}>2 GeV/c, by perturbative QCD. Double helicity asymmetries A{sub LL} are presented based on a factor of 5 improvement in uncertainties as compared to previously published results, due to both an improved beam polarization of 50%, and to higher integrated luminosity. These measurements are sensitive to the gluon polarization in the proton. Using one representative model of gluon polarization it is demonstrated that the gluon spin contribution to the proton spin is significantly constrained.

  10. Review of Polarized Ion Sources

    NASA Astrophysics Data System (ADS)

    Zelenski, A.

    2016-02-01

    Recent progress in polarized ion sources development is reviewed. New techniques for production of polarized H‑ ion (proton), D‑ (D+) and 3He++ ion beams will be discussed. A novel polarization technique was successfully implemented for the upgrade of the RHIC polarized H‑ ion source to higher intensity and polarization. In this technique, a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from an external source) in the He-gas ionizer cell. Polarized electron capture from the optically-pumped Rb vapor further produces proton polarization (Optically Pumped Polarized Ion Source technique). The upgraded source reliably delivered beam for the 2013 polarized run in RHIC at S = 510 GeV. This was a major factor contributing to RHIC polarization increase to over 60 % for colliding beams. Feasibility studies of a new polarization technique for polarized 3He++ source based on BNL Electron Beam Ion Source is also discussed.

  11. Small-scale structure of O2(+) and proton hydrates in a Noctilucent Cloud and polar mesospheric summer echo of August 9/10 1991 above Kiruna

    NASA Technical Reports Server (NTRS)

    Balsiger, F.; Kopp, E.; Friedrich, M.; Torkar, K. M.; Walchli, U.

    1993-01-01

    A novel mass spectrometer designed to measure simultaneously positive ion composition in the mesosphere, was successfully launched during the NLC-91 project. Instruments supporting the mass spectrometer were a probed to measure both electrons and positive ions as well as a wave propagation experiment. The location of the Noctilucent Clouds (NLC) was determined by a particle impact sensor to detect secondary electrons and ions from the impact of NLC particle. The density of proton hydrates and of the related total ions is depleted in the NLC region at 83 km. An improved detection limit of 5 x 10(exp 4)/cu m for positive ions and improved height resolution revealed for the first time large gradients in the O2(+), H(+)(H2O)2 and H(+)(H2O)6 densities within a small height range of the order of 50 m. Such gradients at the altitude of NLC and Polar Mesospheric Summer Echoes (PMSE) are associated with strong variability of mesospheric water vapor, temperature and neutral air density.

  12. Induced proton polarization for {pi}{sup 0} electroproduction at Q{sup 2}=0.126 GeV{sup 2}/c{sup 2} around the {Delta}(1232) resonance

    SciTech Connect

    Alarcon, R.; Comfort, J.R.; Dolfini, S.; Mertz, C.; Young, A.; Gothe, R.W.; Kunz, C.; Epstein, M.; Liu, D.; Margaziotis, D.; Mukhopadhyay, S.; Armstrong, C.; Finn, J.M.; Jones, M.; McIntyre, J.I.; Perdrisat, C.; Woo, R.J.; Sarty, A.; Madey, R.; Van Verst, S.; Warren, G.A.; Bertozzi, W.; Chen, J.; Dodson, G.; Dow, K.; Farkhondeh, M.; Gilad, S.; Joo, K.; Kowalski, S.; Soong, S.; Tieger, D.; Tschalaer, C.; Turchinetz, W.; Punjabi, V.; Qin, L.; Ulmer, P.; Weinstein, L.B.; Rutt, P.; Burkert, V.; Chen, J.; Mitchell, J.; Karabarbounis, A.; Papanicolas, C.N.; Vellidis, C.; Williamson, S.; Dale, D.

    1998-12-01

    We present a measurement of the induced proton polarization P{sub n} in {pi}{sup 0} electroproduction on the proton around the {Delta} resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W=1231 MeV and Q{sup 2}=0.126 GeV{sup 2}/c{sup 2}, respectively. We measured a large induced polarization, P{sub n}={minus}0.397{plus_minus}0.055{plus_minus}0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model. {copyright} {ital 1998} {ital The American Physical Society}

  13. Optimization of the AGS superconducting helical partial snake strength.

    SciTech Connect

    Lin,F.; Huang, H.; Luccio, A.U.; Roser, T.

    2008-06-23

    Two helical partial snakes, one super-conducting (a.k.a cold snake) and one normal conducting (a.k.a warm snake), have preserved the polarization of proton beam up to 65% in the Brookhaven Alternating Gradient Synchrotron (AGS) at the extraction energy from 85% at injection. In order to overcome spin resonances, stronger partial snakes would be required. However, the stronger the partial snake, the more the stable spin direction tilted producing a stronger horizontal intrinsic resonance. The balance between increasing the spin tune gap generated by the snakes and reducing the tilted stable spin direction has to be considered to maintain the polarization. Because the magnetic field of the warm snake has to be a constant, only the cold snake with a maximum 3T magnetic field can be varied to find out the optimum snake strength. This paper presents simulation results by spin tracking with different cold snake magnetic fields. Some experimental data are also analyzed.

  14. Calculation of polarization effects

    SciTech Connect

    Chao, A.W.

    1983-09-01

    Basically there are two areas of accelerator applications that involve beam polarization. One is the acceleration of a polarized beam (most likely a proton beam) in a synchrotron. Another concerns polarized beams in an electron storage ring. In both areas, numerical techniques have been very useful.

  15. ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES.

    SciTech Connect

    ROSER,T.AHRENS,L.BAI,M.ET AL.

    2004-07-05

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

  16. Exclusive studies of 130-270 MeV {sup 3}He- and 200-MeV proton-induced reactions on {sup 27}Al, {sup nat}Ag, and {sup 197}Au

    SciTech Connect

    Ginger, D. S.; Kwiatkowski, K.; Wang, G.; Hsi, W.-C.; Hudan, S.; Cornell, E.; Souza, R. T. de; Viola, V. E.; Korteling, R. G.

    2008-09-15

    Exclusive light-charged-particle and IMF spectra have been measured with the ISiS detector array for bombardments of {sup 27}Al, {sup nat}Ag, and {sup 197}Au nuclei with 130-270-MeV {sup 3}He and 200-MeV protons. The results are consistent with previous interpretations based on inclusive data that describe the global yield of complex fragments in terms of a time-dependent process. The emission mechanism for energetic nonequilibrium fragments observed at forward angles with momenta up to twice the beam momentum is also investigated. This poorly understood mechanism, for which the angular distributions indicate formation on a time scale comparable to the nuclear transit time, are accompanied primarily by thermal-like emissions. The data are most consistent with a schematic picture in which nonequilibrium fragments are formed in a localized region of the target nucleus at an early stage in the energy-dissipation process, where the combined effects of high energy density and Fermi motion produce the observed suprathermal spectra.

  17. Proton Therapy

    MedlinePlus

    ... nucleus is surrounded by electrons. In proton therapy, beams of fast-moving protons are used to destroy ... atoms to release proton, neutron, and helium ion beams. In this highly specialized form of radiosurgery , proton ...

  18. Ranking and validation of the spallation models for description of intermediate mass fragment emission from p + Ag collisions at 480 MeV incident proton beam energy

    NASA Astrophysics Data System (ADS)

    Sharma, Sushil K.; Kamys, Bogusław; Goldenbaum, Frank; Filges, Detlef

    2016-06-01

    Double-differential cross-sections d2σ/dΩ dE for isotopically identified intermediate mass fragments ( 6Li up to 27Mg from nuclear reactions induced by 480 MeV protons impinging on a silver target were analyzed in the frame of a two-step model. The first step of the reaction was described by the intranuclear cascade model INCL4.6 and the second one by four different models (ABLA07,GEM2, GEMINI++, and SMM). The experimental spectra reveal the presence of low-energy, isotropic as well as high-energy, forward-peaked contributions. The INCL4.6 model offers a possibility to describe the latter contribution for light intermediate mass fragments by coalescence of the emitted nucleons. The qualitative agreement of the model predictions with the data was observed but the high-energy tails of the spectra were significantly overestimated. The shape of the isotropic part of the spectra was reproduced by all four models. The GEM2 model strongly underestimated the value of the cross-sections for heavier IMF whereas the SMM and ABLA07 models generally overestimated the data. The best quantitative description of the data was offered by GEMINI++, however, a discrepancy between the data and the model cross-sections still remained for almost all reaction products, especially at forward angles. It indicates that non-equilibrium processes are present which cannot be reproduced by the applied models. The goodness of the data description was judged quantitatively using two statistical deviation factors, the H-factor and the M-factor, as a tool for ranking and validation of the theoretical models.

  19. A Polarized Universe

    NASA Technical Reports Server (NTRS)

    Wanjek, Christopher

    2003-01-01

    The CMB polarization was produced as light scattered off a primordial cloud of protons and electrons nearly 14 billion years ago, about 400,000 years after the Big Bang. This marks the moment of recombination, when the universe finally cooled enough to allow electrons to join protons. The CMB is the light that broke through the fog.

  20. Effects of “excessive” exciton interactions in polarized IR spectra of the hydrogen bond in 2-butynoic acid crystals: Proton transfer induced by dynamical co-operative interactions involving hydrogen bonds

    NASA Astrophysics Data System (ADS)

    Flakus, Henryk T.; Hachuła, Barbara

    2008-04-01

    In this article, we present the results of our study of polarized IR spectra of the hydrogen bond in crystals of 2-butynoic acid (CH 3C tbnd CCOOH) as well as in crystals of its deuterium derivative (CH 3C tbnd CCOOD). 2-Butynoic acid can exist in two polymorphous crystalline forms: in the "α" form, based on a classic dimer motif and in the "β" form, based on the catamer pattern of the hydrogen bond arrangement. By cooling the melted substance crystals of the "β" phase were obtained selectively. The polarized IR spectra of the hydrogen bond in the "β" form of 2-butynoic acid crystals were measured at room temperature and at the temperature of liquid nitrogen in the νO-H and νO-D band frequency ranges. In terms of the "strong-coupling" theory the fine structure patterns of the νO-H and νO-D polarized bands were quantitatively explained along with the dichroic and the H/D isotopic effects in the spectra. To interpret the main properties of the spectra the existence of a non-conventional effect concerning a self-stimulated concerted proton position rearrangements in the neighboring cells in the lattice had to be assumed. On the basis of the spectra of isotopically diluted crystalline samples of 2-butynoic acid it was suggested that a random distribution of protons and deuterons occurred in the open chains of the hydrogen bonded molecules. However, coordination in the mutual arrangement of protons and deuterons in the neighboring hydrogen bonds from the closely spaced molecular chains was found to be non-random. This fact was ascribed to dynamical co-operative interactions, most strongly involving hydrogen bonds from different chains in the modified lattice. These non-conventional interactions were responsible for appearance of the so-called H/D "self-organization" isotopic effects in the spectra.

  1. Planning and Prototyping for a Storage Ring Measurement of the Proton Electric Dipole Moment

    SciTech Connect

    Talman, Richard

    2015-07-01

    Electron and proton EDM's can be measured in "frozen spin" (with the beam polarization always parallel to the orbit, for example) storage rings. For electrons the "magic" kinetic energy at which the beam can be frozen is 14.5 MeV. For protons the magic kinetic energy is 230 MeV. The currently measured upper limit for the electron EDM is much smaller than the proton EDM upper limit, which is very poorly known. Nevertheless, because the storage ring will be an order of magnitude cheaper, a sensible plan is to first build an all-electric electron storage ring as a prototype. Such an electron ring was successfully built at Brookhaven, in 1954, as a prototype for their AGS ring. This leaves little uncertainty concerning the cost and performance of such a ring. (This is documentedin one of the Physical Review papers mentioned above.)

  2. The axisymmetric stellar wind of AG Carinae

    NASA Technical Reports Server (NTRS)

    Schulte-Ladbeck, Regina E.; Clayton, Geoffrey C.; Hillier, D. John; Harries, Tim J.; Howarth, Ian D.

    1994-01-01

    We present optical linear spectropolarimetry of the Luminous Blue Variable AG Carinae obtained after a recent visual brightness increase. The absence of He II lambda 4686 emission, together with the weakening of the He I spectrum and the appearance of Fe lines in the region around 5300 A, confirm that AG Car has started a new excursion across the HR diagram. The H alpha line profile exhibits very extended line wings that are polarized differently in both amount and position angle from either the continuum or the line core. The polarization changes across H alpha, together with variable continuum polarization, indicate the presence of intrinsic polarization. Coexistence of the line-wing polarization with extended flux-line wings evidences that both are formed by electron scattering in a dense wind. The position angle rotates across the line profiles, in a way that presently available models suggest is due to rotation and expansion of the scattering material. AG Car displays very large variations of its linear polarization with time, Delta P approximately 1.2%, indicating significant variations in envelope opacity. We find that the polarization varies along a preferred position angle of approximately 145 deg (with a scatter of +/- 10 deg) which we interpret as a symmetry axis of the stellar wind (with an ambiguity of 90 deg). This position angle is co-aligned with the major axis of the AG Car ring nebula and perpendicular to the AG Car jet. Our observations thus suggest that the axisymmetric geometry seen in the resolved circumstellar environment at various distances already exists within a few stellar radii of AG Car. From the H alpha polarization profile we deduce an interstellar polarization of Q = 0.31%, U = -1.15% at H alpha. The inferred interstellar polarization implies that the intrinsic polarization is not always of the same sign. This indicates either significant temporal changes in the envelope geometry, or it may arise from effects of multiple scattering

  3. Gluon polarization in the proton: Constraints at low x from the measurement of the double longitudinal spin asymmetry for forward-rapidity hadrons with the PHENIX detector at RHIC

    NASA Astrophysics Data System (ADS)

    McKinney, Cameron Palmer

    In the 1980s, polarized deep inelastic lepton-nucleon scattering experiments revealed that only about a third of the proton's spin of ½ h is carried by the quarks and antiquarks, leaving physicists with the puzzle of how to account for the remaining spin. As gluons carry roughly 50% of the proton's momentum, it seemed most logical to look to the gluon spin as another significant contributor. However, lepton-nucleon scattering experiments only access the gluon helicity distribution, Delta g, through effects on the quark distributions via scaling violations. Constraining Deltag through scaling violations requires experiments that together cover a large range of Q 2. Such experiments had been carried out with unpolarized beams, leaving g(x) (the unpolarized gluon distribution) relatively well-known, but the polarized experiments have only thus far provided weak constraints on Deltag in a limited momentum fraction range. With the commissioning in 2000 of the Relativistic Heavy Ion Collider, the first polarized proton-proton (pp) collider, and the first polarized pp running in 2002, the gluon distributions could be accessed directly by studying quark-gluon and gluon-gluon interactions. In 2009, data from measurements of double longitudinal spin asymmetries, ALL, at the STAR and PHENIX experiments through 2006 were included in a QCD global analysis performed by Daniel de Florian, Rodolfo Sassot, Marco Stratmann, and Werner Vogelsang (DSSV), yielding the first direct constraints on the gluon helicity. The DSSV group found that the contribution of the gluon spin to the proton spin was consistent with zero, but the data provided by PHENIX and STAR was all at mid-rapidity, meaning Delta g was constrained by data only a range in x from 0.05 to 0.2, leaving out helicity contributions from the huge number of low- x gluons. A more recent analysis by DSSV from 2014 including RHIC data through 2009 for the first time points to significant gluon polarization at intermediate

  4. Polarized nuclear target based on parahydrogen induced polarization

    SciTech Connect

    D. Budker, M.P. Ledbetter, S. Appelt, L.S. Bouchard, B. Wojtsekhowski

    2012-12-01

    We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast ({approx}100 HZ) polarization oscillation (akin to polarization reversal), and operation with large intensity of an electron beam.

  5. Polarized nuclear target based on parahydrogen induced polarization

    NASA Astrophysics Data System (ADS)

    Budker, D.; Ledbetter, M. P.; Appelt, S.; Bouchard, L. S.; Wojtsekhowski, B.

    2012-12-01

    We discuss a novel concept of a polarized nuclear target for accelerator fixed-target scattering experiments, which is based on parahydrogen induced polarization (PHIP). One may be able to reach a 33% free-proton polarization in the ethane molecule. The potential advantages of such a target include operation at zero magnetic field, fast (˜100 Hz) polarization oscillation (akin to polarization reversal), and operation with large intensity of an electron beam.

  6. Transverse impedance measurement in RHIC and the AGS

    SciTech Connect

    Biancacci, Nicolo; Blaskiewicz, M.; Dutheil, Y.; Liu, C.; Mernick, M.; Minty, M.; White, S. M.

    2014-05-12

    The RHIC luminosity upgrade program aims for an increase of the polarized proton luminosity by a factor 2. To achieve this goal a significant increase in the beam intensity is foreseen. The beam coupling impedance could therefore represent a source of detrimental effects for beam quality and stability at high bunch intensities. For this reason it is essential to quantify the accelerator impedance budget and the major impedance sources, and possibly cure them. In this MD note we summarize the results of the 2013 transverse impedance measurements in the AGS and RHIC. The studies have been performed measuring the tune shift as a function of bunch intensity and deriving the total accelerator machine transverse impedance. For RHIC, we could obtain first promising results of impedance localization measurements as well.

  7. Precision measurement of the longitudinal double-spin asymmetry for inclusive jet production in polarized proton collisions at √s = 200 GeV

    DOE PAGESBeta

    Adamczyk, L.

    2015-08-26

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √s = 200 GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. Lastly, the measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x > 0.05 .

  8. Precision measurement of the longitudinal double-spin asymmetry for inclusive jet production in polarized proton collisions at √s = 200 GeV

    SciTech Connect

    Adamczyk, L.

    2015-08-26

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √s = 200 GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. Lastly, the measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x > 0.05 .

  9. Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at √{s }=200 GeV

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, AL L, in polarized p p collisions at center-of-mass energy √{s }=200 GeV . The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC p p data. The measured asymmetries provide evidence at the 3 σ level for positive gluon polarization in the Bjorken-x region x >0.05 .

  10. Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s]=200  GeV.

    PubMed

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

    2015-08-28

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05. PMID:26371644

  11. Towards Polarized Antiprotons at FAIR

    SciTech Connect

    Rathmann, Frank

    2007-06-13

    Understanding the interplay of the nuclear interaction with polarized protons and the electromagnetic interaction with polarized electrons in polarized atoms is crucial to progress towards the PAX goal to eventually produce stored polarized antiproton beams at FAIR. Presently, there exist two competing theoretical scenarios: one with substantial spin filtering of (anti)protons by atomic electrons, and a second one suggesting a self-cancellation of the electron contribution to spin filtering. After a brief review of the PAX physics case for polarized antiprotons at FAIR, a detailed discussion of future investigations, including spin-filtering experiments at COSY-Juelich and at the AD of CERN is presented.

  12. 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.

  13. Siberian Snake solenoid for the AGS

    SciTech Connect

    Ratner, L. G.

    1991-01-01

    Recent experiments at the Indiana University Cyclotron Facility (IUCF) have demonstrated that Siberian Snakes'' can be used to preserve the polarization of an accelerated polarized beam in a circular accelerator. Retrofitting full snakes into accelerators such as the Alternating Gradient Synchrotron (AGS) at Brookhaven is almost impossible due to space limitations, but a partial snake that can correct depolarization due to imperfection resonances with 1/20 to 1/30 of a full strength snake seems to present a viable option. We describe such a device for the AGS and give the design criteria in terms of simplicity of accelerator operation and level of achievable polarization. 2 refs., 5 figs., 1 tab.

  14. Pulsed power supply system for the fast quadrupoles in the AGS

    SciTech Connect

    Nawrocky, R.J.; Lambiase, R.F.

    1983-01-01

    In the acceleration of polarized protons in the AGS, a number of depolarizing resonances will be encountered. Depolarization due to the so-called intrinsic resonances will be minimized by crossing each resonance in less than one beam revolution period (approx. 2 ..mu..s). This will be accomplished with a set of twelve fast tune-shifting quadrupoles distributed symmetrically around the ring. During a typical acceleration cycle, the fast quads will be energized with a burst of alternating polarity, fast rise/slow fall triangular current pulses. The amplitude of these pulses will vary from 160 A to about 2700 A peak. This paper describes the development of the pulsed power supply for the fast quads, the construction of a prototype modulator, and some of the initial test results obtained with the prototype.

  15. Features of possible polarized photon beams at high energy and corresponding physics programme or the proton structure function using real photons

    SciTech Connect

    Tannenbaum, M.J.

    1980-01-01

    In the range of electron energies available at Fermilab, 100 GeV less than or equal to E less than or equal to 500 GeV, coherent Bremsstrahlung in crystals, particularly diamond, gives a huge enhancement to the equivalent photon spectrum at large values of x where x = k/E. The photons in this enhancement are polarized. Requirements on electron beam energy spread, angular divergence and spot size imposed by the use of a diamond as a radiator are discussed. The physics program emphasizes hard processes and tests of QCD using polarization.

  16. ENGINEERING OF THE AGS SNAKE COIL ASSEMBLY.

    SciTech Connect

    ANERELLA,M.GUPTA,R.KOVACH,P.MARONE,A.PLATE,S.POWER,K.SCHMALZLE,J.WILLEN,E.

    2003-05-12

    A 30% Snake superconducting magnet is proposed to maintain polarization in the AGS proton beam, the magnetic design of which is described elsewhere. The required helical coils for this magnet push the limits of the technology developed for the RHIC Snake coils. First, fields must be provided with differing pitch along the length of the magnet. To accomplish this, a new 3-D CAD system (''Pro/Engineer'' from PTC), which uses parametric techniques to enable fast iterations, has been employed. Revised magnetic field calculations are then based on the output of the mechanical model. Changes are made in turn to the model on the basis of those field calculations. To ensure that accuracy is maintained, the final solid model is imported directly into the CNC machine programming software, rather than by the use of graphics translating software. Next, due to the large coil size and magnetic field, there was concern whether the structure could contain the coil forces. A finite element analysis was performed, using the 3-D model, to ensure that the stresses and deflections were acceptable. Finally, a method was developed using ultrasonic energy to improve conductor placement during coil winding, in an effort to minimize electrical shorts due to conductor misplacement, a problem that occurred in the RHIC helical coil program. Each of these activities represents a significant improvement in technology over that which was used previously for the RHIC snake coils.

  17. Commissioning of the new AGS MMPS transformers

    SciTech Connect

    Bajon,E.; Badea, V. S.; Bannon, M.; Bonati, R.; Marneris, I. M.; Porqueddu, r.; Roser, T.; Sandberg, J.; Savatteri, S.

    2009-05-04

    The Brookhaven AGS Main Magnet Power Supply (MMPS) is a thyristor control supply rated at 5500 Amps. +/-9000 Volts. The peak magnet power is 50 MWatts. The power supply is fed from a motor/generator manufactured by Siemens. During rectify and invert operation the P Bank power supplies are used. During the flattops the F Bank power supplies are used. The P Bank power supplies are fed from two 23 MVA transformers and the F Bank power supplies are fed from two 5.3 MYA transformers. The fundamental frequency of the F Bank power supplies is 1440 Hz, however the fundamental frequency of the P banks was 720 Hz. It was very important to reduce the ripple during rectify to improve polarized proton operations. For this reason and also because the original transformers were 45 years old we replaced these transformers with new ones and we made the fundamental frequency of both P and F banks 1440 Hz. This paper will highlight the major hurdles that were involved during the installation of the new transformers. It will present waveforms while running at different power levels up to 6MW full load. It will show the transition from the F-Bank power supplies to the P-Banks and also show the improvements in ripple made on the P-Bank power supplies.

  18. Effect of dynamical polarization potentials on fusion radial potential barriers and on fusion cross sections for the proton-halo system 8B+58Ni

    NASA Astrophysics Data System (ADS)

    Gómez Camacho, A.

    2013-03-01

    Fusion radial potential (l = 0) barriers of 8B+58Ni are determined from a simultaneous optical model analysis of elastic scattering angular distributions and fusion data at energies around the Coulomb energy. Dynamical energy dependent Woods-Saxon polarization potentials, UF (volume) and UDR (surface) are used in the calculation of the barriers, where UF is a potential that accounts for polarization effects emerging from couplings to the fusion channel and UDR for effects due to direct reaction absorption couplings. Each of these potentials, UF and UDR are in turn, split into real and imaginary potentials VF, WF and VDR, WDR, which are related via the dispersion relation. The parameters of these potentials are determined during the simultaneous fitting process. The effect on fusion cross section from the competitive barrier lowering and rising produced respectively by VF and VDR, is investigated. Also, the net effect of breakup couplings on the fusion cross section is studied by analyzing the particular effect from both direct reaction polarization potentials VDR and WDR. Finally, it is shown that energy dependence of the total polarization potential U(E) = UF(E) + UDR(E) at the strong absorption radius Rsa is consistent with the Breakup Threshold Anomaly as expected for weakly bound nuclei.

  19. Measurement of the polarization parameter in proton-neutron elastic scattering at 1. 30, 1. 39, 1. 59, and 1. 82 GeV/c

    SciTech Connect

    Sakuda, M.; Isagawa, S.; Ishimoto, S.; Kabe, S.; Masaike, A.; Morimoto, K.; Ogawa, K.; Suetake, M.; Takasaki, F.; Watase, Y.; Kim, N.; Kobayashidouble-dagger, S.; Murakami, A.; de Lesguen, A.; Nakajima, K.; Nakada, S.; Wada, T.; Yamachi, I.

    1982-04-01

    The polarization parameters of the pn elastic scattering were measured at beam momenta between 1.30 and 1.82 GeV/c. The results are discussed in comparison with the partial-wave analysis of Hashimoto and Hoshizaki.

  20. New versions of sources for nuclear polarized negative ion production

    SciTech Connect

    Dudnikov, V.G.; Shabalin, A.L. ); Wojtsekhowski, B.B. ); Belov, A.S.; Kuzik, V.E.; Plohinsky, Y.V.; Yakushev, V.P. )

    1992-10-05

    Several variants of sources for nuclear polarized negative ion production have been proposed and tested. The simple adaptation of a high intensity polarized proton source for nuclear polarized H[sup [minus

  1. Intramolecular, Exciplex-Mediated, Proton-Coupled, Charge-Transfer Processes in N,N-Dimethyl-3-(1-pyrenyl)propan-1-ammonium Cations: Influence of Anion, Solvent Polarity, and Temperature.

    PubMed

    Safko, Trevor M; Faleiros, Marcelo M; Atvars, Teresa D Z; Weiss, Richard G

    2016-06-16

    An intramolecular exciplex-mediated, proton-coupled, charge-transfer (PCCT) process has been investigated for a series of N,N-dimethyl-3-(1-pyrenyl)propan-1-ammonium cations with different anions (PyS) in solvents of low to intermediate polarity over a wide temperature range. Solvent mediates both the equilibrium between conformations of the cation that place the pyrenyl and ammonium groups in proximity (conformation C) or far from each other (conformation O) and the ability of the ammonium group to transfer a proton adiabatically in the PyS excited singlet state. Thus, exciplex emission, concurrent with the PCCT process, was observed only in hydrogen-bond accepting solvents of relatively low polarity (tetrahydrofuran, ethyl acetate, and 1,4-dioxane) and not in dichloromethane. From the exciplex emission and other spectroscopic and thermodynamic data, the acidity of the ammonium group in conformation C of the excited singlet state of PyS (pKa*) has been estimated to be ca. -3.4 in tetrahydrofuran. The ratios between the intensities of emission from the exciplex and the locally excited state (IEx/ILE) appear to be much more dependent on the nature of the anion than are the rates of exciplex formation and decay, although the excited state data do not provide a quantitative measure of the anion effect on the C-O equilibrium. The activation energies associated with exciplex formation in THF are calculated to be 0.08 to 0.15 eV lower than for the neutral amine, N,N-dimethyl-3-(1-pyrenyl)propan-1-amine. Decay of the exciplexes formed from the deprotonation of PyS is hypothesized to occur through charge-recombination processes. To our knowledge, this is the first example in which photoacidity and intramolecular exciplex formation (i.e., a PCCT reaction) are coupled. PMID:27268751

  2. Spin models of the proton

    SciTech Connect

    Ramsey, G.P.

    1988-10-20

    We have constructed a model of the proton spin based on a broken SU(6) parameterization for the spin-weighted valence quark distributions in a longitudinally polarized proton. The polarized sea and gluon distributions are assumed to have simple relations to the corresponding unpolarized structure functions. The sum rules, which involve the non-singlet components of the structure function xg/sub 1/, imply that the valence quarks carry about 78% of the proton spin, while the spin carried by sea quarks is negative. Recent EMC data suggest a model in which the sea quarks carry a large negative polarization, whereas certain theoretical arguments favor a model with a smaller negatively polarized sea. These models are discussed with reference to the sum rules. Experiments are suggested which will discriminate between these models. 24 refs., 4 figs.

  3. TOWARDS 100% POLARIZATION IN THE OPTICALLY-PUMPED POLARIZED ION SOURCE.

    SciTech Connect

    ZELENSKI,A.; ALESSI, J.; KOKHANOVSKI, S.; KPONOU, A.; RITTER, B.J.; ZUBETS, V.

    2007-06-25

    The depolarization factors in the multi-step spin-transfer polarization technique and basic limitations on maximum polarization in the OPPIS (Optically-Pumped Polarized H{sup -} Ion Source) are discussed. Detailed studies of polarization losses in the RHIC OPPIS and the source parameters optimization resulted in the OPPIS polarization increase to 86-90%. This contributed to increasing polarization in the AGS and RHIC to 65-70%.

  4. Large NMR signals and polarization asymmetries.

    SciTech Connect

    Penttila, S. I.

    1998-11-25

    A large modulation in the series Q-meter can lead to nonlinear NMR signals and asymmetric polarization values. With a careful circuit analysis the nonlinearity can be estimated and corrections to polarization can be determined as a function of the strength of the modulation. We describe the recent LAMPF polarized proton target experiment, its NMR measurement and corrections to the measured polarizations.

  5. Physics with Polarized Antiprotons

    SciTech Connect

    Lenisa, Paolo

    2008-04-30

    Polarized antiprotons will provide access to a wealth of double- (and single-) spin observables, thereby opening a window to physics uniquely accessible with the HESR at FAIR. This include a first direct measurement of the transversity distribution of the valence quarks in the proton and a first measurement of the moduli and phase of the time-like electric and magnetic form factors G{sub E,M} of the proton. Additional applications of a polarized antiproton beam can be forseen in hadron spectroscopy, and nucleon-antinucleon scattering.

  6. Time purified/separated antiproton beam at the AGS

    SciTech Connect

    Bachman, M.; Barlett, M.L.; Bonner, B.; Borenstein, S.; Bridges, D.; Brown, H.; Buchanan, J.; Clement, J.C.; Daftari, I.; Debbe, R.

    1984-01-01

    A 1 km antiproton beam has been designed for construction at the AGS. The momentum band can be varied between +-0.3% to +-1.0%, and the resolution for tagged particles will be deltap/p approx. 10/sup -4/ at beam rates as high as 10/sup 6/ anti p/s. Separation by decay purification will be on the order of 1 anti p/10(..pi../sup -/+..mu../sup -/). This beam will be used in a detailed investigation of Charmonium including a measurement of the chi widths. We will also search for expected but as yet unseen states, and search for possible I=1 events which would imply the existence of four quark states. This facility will also lend itself to a wide variety of exciting physics such as the proton form factor including both e/sup +/e/sup -/ and ..gamma gamma.. final states, two-body hadron final states, anti-nucleus yields, and possibly tagged hadron beams (i.e., Lambda, E, etc.). When heavy ions become available at the AGS, one can measure various long lived particle yields. Finally, with as many as 10/sup 7/ polarized muons in the beam, one has the possibility to use them for nuclear structure studies.

  7. PHYSICS OF POLARITY AT RHIC-VOLUME 10.

    SciTech Connect

    IMAI,K.; FIELDS,D.

    1998-08-04

    The RBRC Workshop on Physics of Polarimetry at RHIC was held from Aug 4 to 7, 1998 at BNL. The primary motive of the workshop is (1) to discuss the RHIC polarimeter using the elastic proton-carbon scattering at Coulomb-nuclear interference region (p-C CNI polarimeter) in detail and write a proposal for the test experiment a t the AGS, (2) to discuss the related physics, (3) and to discuss other options for the RHIC polarimetry. The idea of the p-C CNI polarimeter was proposed last year as a simple, inexpensive and efficient polarimeter for RHIC. In order to establish this polarimeter, we have decided to carry out a test experiment by using a polarized beam at the AGS. We have made a draft of the proposal during the workshop. For the p-C CNI polarimeter, a telescope detector using both the micro-channel plate (MCP) and the SSD was proposed to detect low energy recoil carbon ions, based on the test measurements at IUCF and Kyoto, where the carbon ions as low as 200 keV were successfully detected. The kinetic energy of carbon ion is measured with the SSD, and the velocity is measured by TOF between the two detectors and between the accelerator rf pulse and the two detectors. Counting rates for the background and true events were estimated. With the proposed polarimeter, one can expect to measure the beam polarization at the AGS and RHIC at an accuracy of 10% within a reasonable time period. We will test this detector system at Kyoto as soon as possible and install it in the AGS ring for the test measurement of A{sub N} during E880 which is scheduled early in the next year.

  8. A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantum-classical approximation. II. Proton transfer reaction in non-polar solvent.

    PubMed

    Kojima, H; Yamada, A; Okazaki, S

    2015-05-01

    The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantum-classical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solute-solvent interactions. PMID:25956108

  9. A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantum-classical approximation. II. Proton transfer reaction in non-polar solvent

    NASA Astrophysics Data System (ADS)

    Kojima, H.; Yamada, A.; Okazaki, S.

    2015-05-01

    The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantum-classical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solute-solvent interactions.

  10. A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantum–classical approximation. II. Proton transfer reaction in non-polar solvent

    SciTech Connect

    Kojima, H.; Yamada, A.; Okazaki, S.

    2015-05-07

    The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantum–classical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solute–solvent interactions.

  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. Polarized antiproton beam at U-70 accelerator of IHEP

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    The polarized proton and antiproton beam channel is currently under development at the U-70 accelerator of IHEP, Protvino, Russia. An availability of the both, polarized protons and antiprotons provides an exciting opportunity for the comparative studies of spin effects induced by polarized protons and antiprotons in a variety of hadronic reactions. While the proton and antiproton beams are formed by essentially the same method, there is the specific in the antiproton beam shaping and properties compared to protons. In this report, we address some technical details of forming the polarized antiproton beam and describe its main properties.

  13. Experimental tests of proton spin models

    SciTech Connect

    Ramsey, G.P. . Dept. of Physics Argonne National Lab., IL . High Energy Physics Div.)

    1989-11-03

    We have developed models for the spin-weighted quark and gluon distribution in a longitudinally polarized proton. The model parameters are determined from current algebra sum rules and polarized deep-inelastic scattering data. A number of different scenarios are presented for the fraction of spin carried the constituent parton distributions. A possible long-range experimental program is suggested for measuring various hard scattering processes using polarized lepton and proton beams. With the knowledge gained from these experiments, we can begin to understand the parton contributions to the proton spin. 28 refs., 5 figs.

  14. Measurements of Polarization Transfers in Real Compton Scattering by a proton target at JLAB. A new source of information on the 3D shape of the nucleon

    SciTech Connect

    Fanelli, Cristiano V.

    2015-03-01

    In this thesis work, results of the analysis of the polarization transfers measured in real Compton scattering (RCS) by the Collaboration E07-002 at the Je fferson Lab Hall-C are presented. The data were collected at large scattering angle (theta_cm = 70deg) and with a polarized incident photon beam at an average energy of 3.8 GeV. Such a kind of experiments allows one to understand more deeply the reaction mechanism, that involves a real photon, by extracting both Compton form factors and Generalized Parton Distributions (GPDs) (also relevant for possibly shedding light on the total angular momentum of the nucleon). The obtained results for the longitudinal and transverse polarization transfers K_LL and K_LT, are of crucial importance, since they confirm unambiguously the disagreement between experimental data and pQCD prediction, as it was found in E99-114 experiment, and favor the Handbag mechanism. The E99-114 and E07-002 results can contribute to attract new interest on the great yield of the Compton scattering by a nucleon target, as demonstrated by the recent approval of an experimental proposal submitted to the Jefferson Lab PAC 42 for a Wide-angle Compton Scattering experiment, at 8 and 10 GeV Photon Energies. The new experiments approved to run with the updated 12 GeV electron beam at JLab, are characterized by much higher luminosities, and a new GEM tracker is under development to tackle the challenging backgrounds. Within this context, we present a new multistep tracking algorithm, based on (i) a Neural Network (NN) designed for a fast and efficient association of the hits measured by the GEM detector which allows the track identification, and (ii) the application of both a Kalman filter and Rauch-Tung-Striebel smoother to further improve the track reconstruction. The full procedure, i.e. NN and filtering, appears very promising, with high performances in terms of both association effciency and reconstruction accuracy, and these preliminary results will

  15. 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.

  16. Progress with the AGS Booster

    SciTech Connect

    Weng, W.T.

    1988-01-01

    Rare K-decay, neutrino and heavy ion physics demands that a rapid- cycling high vacuum and high intensity Booster be built for the AGS at Brookhaven. For each mode of operation there are corresponding accelerator physics and design issues needing special attention. Problems pertinent to any single mode of operation have been encountered and solved before, but putting high intensity proton requirements and high vacuum heavy ion requirements into one machine demands careful design considerations and decisions. The lattice design and magnet characteristics will be briefly reviewed. Major design issues will be discussed and design choices explained. Finally, the construction status and schedule will be presented. 6 refs., 6 figs.

  17. Measurement of the left-right asymmetry in pion-proton radiative exchange and charge exchange scattering from 301 to 625 MeV/c on a transversely polarized target

    SciTech Connect

    Kim, George Jung-Kwang

    1988-05-01

    The left-right asymmetry A/sub N/ in ..pi../sup /minus//p ..-->.. ..gamma..n has been measured at p/sub ..pi.. = 301, 316, 427, 471, 547, 586, and 625 MeV/c using a transversely polarized target. The final-state neutron and gamma were detected in coincidence by two states of matching neutron and gamma detectors at gamma angles centered around 90/degree and 110/degree/ c.m. A gamma detector consisted of an array of 15 counters, each was 15/times/15/times/25 cm/sup 3/ block of lead-glass. A neutron detector consisted of 15 counters also, each one was a cylindrical plastic scintillator 7.6 cm in diameter and 45.7 cm long. The A/sub N/ results are compared with the predictions from the most recent single-pion photoproduction partial-wave analysis by Arai and Fujii. The agreement is poor, casting doubt on the correctness of the value for the radiative-decay amplitude of the neutral Roper resonance now in use. A comparison is made with the 90/degree/recoil proton polarization data of the inverse reaction derived from ..gamma..d scattering, there are substantial discrepencies. Charge exchange (..pi../sup /minus/p/ ..-->.. ..gamma../degree/n) events were the major yield in this experiment. Very precise values of the charge exchange analyzing power were obtained with an error of typically 3%. The charge exchange results are compared with the predictions from recent ..gamma..n partial wave analyses. At the lower incident energies little difference is seen between the VPI, Karlsruhe-Helsinki, and CMU-LBL analyses, and there is excellent agreement with our experiment. From the onset of the Roper resonance the VPI solution is strongly favored.

  18. DESIGN OF A THIN QUADRUPOLE TO BE USED IN THE AGS SYNCHROTRON

    SciTech Connect

    TSOUPAS,N.; AHRENS, L.; ALFORQUE, R.; BAI, M.; BROWN, K.; COURANT, E.; ET AL.

    2007-06-25

    The Alternating Gradient Synchrotron (AGS) employs two partial helical snakes[l] to preserve the polarization of the proton beam during acceleration. In order to compensate for the focusing effect of the partial helical snakes on the beam optics in the AGS during acceleration of the beam, we introduced eight quadrupoles in straight sections of the AGS at the proximity of the partial snakes. At injection energies, the strength of each quad is set at a high value, and is ramped down to zero as the effect of the snakes diminishes by the square of beam's rigidity. Four of the eight compensation quadrupoles had to be placed in very short straight sections -30 cm in length, therefore the quadruples had be thin with an overall length of less than 30 cm. In this paper we will discus: (a) the mechanical and magnetic specifications of the ''thin'' quadrupole. (b) the method to minimize the strength of the dodecapole harmonic, (c) the method to optimize the thickness of the laminations that the magnet iron is made, (d) mechanical tolerances of the magnet, (e) comparison of the measured and calculated magnetic multipoles of the quadrupole.

  19. 1.5-GEV FFAG ACCELERATOR AS INJECTOR TO THE BNL-AGS.

    SciTech Connect

    RUGGIERO,A.G.BLASKIEWICZ,M.TRBOJEVIC,D.ET AL.

    2004-07-05

    A 1.5-GeV Fixed-Field Alternating-Gradient (FFAG) proton Accelerator is being studied as a new injector to the Alternating-Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). The major benefit is that it would considerably shorten the overall AGS acceleration cycle, and, consequently, may yield to an improvement of beam stability, intensity and size. The AGS-FFAG will also facilitate the proposed upgrade of the AGS facility toward a 1-MW average proton beam power at the top energy of 28 GeV. This paper describes the FFAG design for acceleration of protons from 400 MeV to 1.5 GeV, with the same circumference of the AGS, and entirely housed in the AGS tunnel.

  20. Gluon-spin contribution to the proton spin from the double-helicity asymmetry in inclusive pi0 production in polarized p+p collisions at [sqrt]s=200 GeV.

    PubMed

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aphecetche, L; Asai, J; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chand, P; Chang, B S; Chang, W C; Charvet, J-L; Chernichenko, S; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Chujo, T; Chung, P; Churyn, A; Cianciolo, V; Citron, Z; Cole, B A; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Dairaku, S; Das, K; David, G; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durum, A; Dutta, D; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Gunji, T; Gustafsson, H-A; Henni, A Hadj; Haggerty, J S; Hamagaki, H; Han, R; Hartouni, E P; Haruna, K; Haslum, E; Hayano, R; Heffner, M; Hemmick, T K; Hester, T; He, X; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kang, J H; Kapustinsky, J; Kawall, D; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, B I; Kim, D H; Kim, D J; Kim, E; Kim, S H; Kinney, E; Kiriluk, K; Kiss, A; Kistenev, E; Klay, J; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, K B; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Liebing, P; Liska, T; Litvinenko, A; Liu, H; Liu, M X; Li, X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mikes, P; Miki, K; Milov, A; Mishra, M; Mitchell, J T; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Niita, T; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Okada, H; Okada, K; Oka, M; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ruzicka, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Samsonov, V; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Seto, R; Sharma, D; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunecka, M; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Togawa, M; Toia, A; Tomásek, L; Tomita, Y; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Veicht, A; Velkovska, J; Vertesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Walker, D; Wang, X R; Watanabe, Y; Wei, F; Wessels, J; White, S N; Williamson, S; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zhou, S; Zolin, L

    2009-07-01

    The double helicity asymmetry in neutral pion production for pT=1 to 12 GeV/c was measured with the PHENIX experiment to access the gluon-spin contribution, DeltaG, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of micro2=4 GeV2 a next to leading order QCD analysis gives DeltaG[0.02,0.3]=0.2, with a constraint of -0.7polarized deep inelastic scattering data. We also consider the dependence of the DeltaG constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions. PMID:19659137

  1. Gluon-Spin Contribution to the Proton Spin from the Double-Helicity Asymmetry in Inclusive pi(0) Production in Polarized p plus p Collisions at s = 200 GeV

    SciTech Connect

    Adare, A.; Awes, Terry C; Cianciolo, Vince; Enokizono, Akitomo; Read Jr, Kenneth F; Silvermyr, David O; Sorensen, Soren P; Stankus, Paul W; Young, Glenn R; PHENIX, Collaboration

    2009-01-01

    The double helicity asymmetry in neutral pion production for p{sub T} = 1 to 12 GeV/c was measured with the PHENIX experiment to access the gluon-spin contribution, {Delta}G, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of {mu}{sup 2} = 4 GeV{sup 2} a next to leading order QCD analysis gives {Delta}G{sup [0.02,0.3]} = 0.2, with a constraint of -0.7 < {Delta}G{sup [0.02,0.3]} < 0.5 at {Delta}{chi}{sup 2} = 9 (-3{sigma}) for the sampled gluon momentum fraction (x) range, 0.02 to 0.3. The results are obtained using predictions for the measured asymmetries generated from four representative fits to polarized deep inelastic scattering data. We also consider the dependence of the {Delta}G constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions.

  2. Gluon-Spin Contribution to the Proton Spin from the Double-Helicity Asymmetry in Inclusive pi{sup 0} Production in Polarized p+p Collisions at sq root(s)=200 GeV

    SciTech Connect

    Adare, A.; Bickley, A. A.; Ellinghaus, F.; Glenn, A.; Kinney, E.; Kiriluk, K.; Nagle, J. L.; Seele, J.; Wysocki, M.; Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L.; Aidala, C.; Ajitanand, N. N.; Alexander, J.; Chung, P.

    2009-07-03

    The double helicity asymmetry in neutral pion production for p{sub T}=1 to 12 GeV/c was measured with the PHENIX experiment to access the gluon-spin contribution, DELTAG, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of mu{sup 2}=4 GeV{sup 2} a next to leading order QCD analysis gives DELTAG{sup [0.02,0.3]}=0.2, with a constraint of -0.7polarized deep inelastic scattering data. We also consider the dependence of the DELTAG constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions.

  3. POLARIZED NEUTRONS IN RHIC

    SciTech Connect

    COURANT,E.D.

    1998-04-27

    There does not appear to be any obvious way to accelerate neutrons, polarized or otherwise, to high energies by themselves. To investigate the behavior of polarized neutrons the authors therefore have to obtain them by accelerating them as components of heavier nuclei, and then sorting out the contribution of the neutrons in the analysis of the reactions produced by the heavy ion beams. The best neutron carriers for this purpose are probably {sup 3}He nuclei and deuterons. A polarized deuteron is primarily a combination of a proton and a neutron with their spins pointing in the same direction; in the {sup 3}He nucleus the spins of the two protons are opposite and the net spin (and magnetic moment) is almost the same as that of a free neutron. Polarized ions other than protons may be accelerated, stored and collided in a ring such as RHIC provided the techniques proposed for polarized proton operation can be adapted (or replaced by other strategies) for these ions. To accelerate polarized particles in a ring, one must make provisions for overcoming the depolarizing resonances that occur at certain energies. These resonances arise when the spin tune (ratio of spin precession frequency to orbit frequency) resonates with a component present in the horizontal field. The horizontal field oscillates with the vertical motion of the particles (due to vertical focusing); its frequency spectrum is dominated by the vertical oscillation frequency and its modulation by the periodic structure of the accelerator ring. In addition, the magnet imperfections that distort the closed orbit vertically contain all integral Fourier harmonics of the orbit frequency.

  4. Preparation, characterization, and photocatalytic activity of porous AgBr@Ag and AgBrI@Ag plasmonic photocatalysts

    NASA Astrophysics Data System (ADS)

    Yang, Fan; Tian, Baozhu; Zhang, Jinlong; Xiong, Tianqing; Wang, Tingting

    2014-02-01

    Porous AgBr@Ag and AgBrI@Ag plasmonic photocatalysts were synthesized by a multistep route, including a dealloying method to prepare porous Ag, a transformation from Ag to AgBr and AgBrI, and a photo-reduction process to form Ag nanoparticles on the surface of AgBr and AgBrI. It was found that the porous structure kept unchanged during Ag was transferred into AgBr, AgBrI, AgBr@Ag, and AgBrI@Ag. Both porous AgBr@Ag and porous AgBrI@Ag showed much higher visible-light photocatalytic activity than cubic AgBr@Ag for the degradation of methyl orange, which is because the interconnected pore channels not only provide more reactive sites but also favor the transportation of photo-generated electrons and holes. For AgBrI@Ag, AgBrI solid solution formed at the interface of AgBr and AgI, and the phase junction can effectively separate the photo-generated electrons and holes, favorable to the improvement of photocatalytic activity. The optimal I content for obtaining the highest activity is ∼10 at.%.

  5. COMMISSIONING CNI PROTON POLARIMETERS IN RHIC.

    SciTech Connect

    HUANG,H.; BRAVAR,A.; LI,Z.; MACKAY,W.W.; MAKDISI,Y.; RESCIA,S.; ROSER,T.; SURROW,B.; BUNCE,G.; DESHPANDE,A.; GOTO,Y.; ET AL

    2002-06-02

    Two polarimeters based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region have been installed and commissioned in the Blue and Yellow rings of RHIC during the first RHIC polarized proton collider run. Each polarimeter consists of ultra-thin carbon targets and six silicon detectors. With newly developed wave form digitizers, they provide fast and reliable polarization information for both rings.

  6. The upgrade project for the RF system for the Brookhaven AGS

    SciTech Connect

    Brennan, J.M.; Ciardullo, D.J.; Hayes, T.; Meth, M.; McNerney, A.J.; Otis, A.; Pirkl, W.; Sanders, R.; Spitz, R.; Toldo, F.; Zaltsman, A.

    1993-06-01

    The AGS operates a varied program of proton, heavy ion, and polarized proton acceleration for fixed-target experiments and will soon serve as the injector of these beams into the Relativistic Heavy Ion Collider, RHIC. The new Booster synchrotron extends the range of intensities and masses that can be accelerated. The 1.5 GeV injection energy increases the space charge limit by a factor of four to more than 6 {times} 10{sup 13} protons per pulse. To accommodate the increased beam current the rf system will be upgraded to provide more power and lower impedance to the beam. The flexibility of the rf system will also be enhanced by virtue of a new rf beam control system and installation of individual tuning servos for the ten rf cavities. The fundamental necessity for upgrading the rf system is to deliver more power to the accelerating beam. Three key ingredients of the upgrade project addressing this problem is (1) new power amplifiers provide the necessary power, and are closely coupled to the cavities, (2) wideband rf feedback reduces the effective impedance by a factor of 10, and (3) the capacitors loading the acceleration gaps (four per cavity) are increased from 275 pF to 600 pF.

  7. The upgrade project for the RF system for the Brookhaven AGS

    SciTech Connect

    Brennan, J.M.; Ciardullo, D.J.; Hayes, T.; Meth, M.; McNerney, A.J.; Otis, A.; Pirkl, W.; Sanders, R.; Spitz, R.; Toldo, F.; Zaltsman, A.

    1993-01-01

    The AGS operates a varied program of proton, heavy ion, and polarized proton acceleration for fixed-target experiments and will soon serve as the injector of these beams into the Relativistic Heavy Ion Collider, RHIC. The new Booster synchrotron extends the range of intensities and masses that can be accelerated. The 1.5 GeV injection energy increases the space charge limit by a factor of four to more than 6 [times] 10[sup 13] protons per pulse. To accommodate the increased beam current the rf system will be upgraded to provide more power and lower impedance to the beam. The flexibility of the rf system will also be enhanced by virtue of a new rf beam control system and installation of individual tuning servos for the ten rf cavities. The fundamental necessity for upgrading the rf system is to deliver more power to the accelerating beam. Three key ingredients of the upgrade project addressing this problem is (1) new power amplifiers provide the necessary power, and are closely coupled to the cavities, (2) wideband rf feedback reduces the effective impedance by a factor of 10, and (3) the capacitors loading the acceleration gaps (four per cavity) are increased from 275 pF to 600 pF.

  8. 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.

  9. Proton polarimetry by undulator radiation

    SciTech Connect

    Luccio, A.U.; Conte, M.

    1998-12-31

    The authors show how spin light from an undulator can be used to measure the spin polarization of a proton beam in a high energy circular collider. They propose to perform left-right asymmetry measurements, employing lock-in amplification techniques.

  10. PROTON POLARIMETRY BY UNDULATOR RADIATION.

    SciTech Connect

    LUCCIO,A.U.

    1998-10-20

    We show how spin light from an undulator can be used to measure the spin polarization of a proton beam in a high energy circular collider. We propose to perform left-right asymmetry measurements, employing lock-in amplification techniques.

  11. Invariant Spin in the Proton

    SciTech Connect

    Thomas, Anthony

    2008-11-01

    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.

  12. 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

  13. A Stretcher for the Brookhaven AGS

    SciTech Connect

    Foelsche, H.W.J.

    1989-01-01

    Brookhaven National Laboratory is proposing to add a Stretcher ring to increase the capacity and the quality of the experimental physics program at the AGS. At the present time a typical AGS cycle is about equally divided between the task of accelerating the beam to full energy and the task of distributing it on a 30 GeV flattop. The Stretcher, a 30 GeV dc storage ring, will take over from the AGS the distribution of the high energy beam with a continuous slow spill, and the AGS can then provide beam for the program at more than twice the present repetition rate. In this manner the average current delivered to the experimenters will be more than doubled, and the duty cycle of the spill will increase from the present optimum of about 40% to nearly 100%. The Stretcher proposal continues the gradual evolution of the AGS toward a high intensity hadron factory. At the present time the AGS provides about 1 ..mu..A average proton current. With the booster alone, now under construction, this is expected to increase to above 4 ..mu..A, and with the Stretcher to about 8-10 ..mu..A, an order of magnitude higher than now. 5 refs., 9 figs.

  14. Proton interrogation

    SciTech Connect

    Morris, Christopher L

    2008-01-01

    Energetic proton beams may provide an attractive alternative when compared to electromagnetic and neutron beams for active interrogation of nuclear threats because: they have large fission cross sections, long mean free paths and high penetration, and proton beams can be manipulated with magnetic optics. We have measured time-dependent cross sections for delayed neutrons and gamma-rays using the 800 MeV proton beam from the Los Alamos Neutron Science Center for a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Results will be presented.

  15. Results from the AGS Booster transverse damper

    SciTech Connect

    Russo, D.; Brennan, M.; Meth, M.; Roser, T.

    1993-01-01

    To reach the design intensity of 1.5 [times] 10[sup 13] protons per pulse in the AGS Booster, transverse coupled bunch instabilities with an estimated growth rate of 1500s[sup [minus]1] have to be dampened. A prototype transverse damper has been tested successfully using a one turn digital delay and closed orbit suppression implemented in a programmable gate array. An updated damper, which includes an algorithm to optimize damping for a changing betatron rune, will also be presented.

  16. Results from the AGS Booster transverse damper

    SciTech Connect

    Russo, D.; Brennan, M.; Meth, M.; Roser, T.

    1993-06-01

    To reach the design intensity of 1.5 {times} 10{sup 13} protons per pulse in the AGS Booster, transverse coupled bunch instabilities with an estimated growth rate of 1500s{sup {minus}1} have to be dampened. A prototype transverse damper has been tested successfully using a one turn digital delay and closed orbit suppression implemented in a programmable gate array. An updated damper, which includes an algorithm to optimize damping for a changing betatron rune, will also be presented.

  17. Parity Violation in Proton-Proton Scattering at 47 Mev.

    NASA Astrophysics Data System (ADS)

    Tanner, Danelle Mary

    A measurement of parity-violation in proton-proton scattering at 47 MeV has been completed by observing the longitudinal analyzing power. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI). where (sigma)('+)((sigma)('-)) is the scattering cross section for positive (negative) helicity. Polarized protons from an atomic beam ion source were accelerated by the 224-cm Texas A&M University cyclotron to an energy of 50 MeV, producing a vertically polarized beam. A superconducting solenoid magnet precessed the beam polarization into the horizontal plane after which a 47.6(DEGREES) bending magnet precessed the polarization into the longtitudinal direction (p(,z) = 0.69 (+OR-) 0.02). RF transitions reversed the polarization direction every 21 msec. Protons scattered from the high pressure ((DBLTURN)37 atm), 42-cm long H(,2) gas target were detected by four plastic scintillators located in the target chamber. Photomultiplier tubes amplified the light from the scintillators, providing a signal proportional to the scattered beam intensity. A lock-in amplifier (LIA) synchronized to the spin-flip frequency compared the scattered intensity to the total beam intensity, measured with a Faraday cup. The output of the LIA was integrated for one second and then read by an ADC. Polarimeters were used to monitor both beam intensity and polarization profiles. A series of tests were performed to determine the role of spurious asymmetries due to changes in beam position and angle, and due to beam intensity modulations correlated with the spin reversal. The result after correction for beam intensity modulation was A(,z) = -(4.6 (+OR-) 2.6) x 10('-7). A more conservative result, taking into account all of the possible spurious asymmetries was A(,z) = -(4.6 (+OR-) 4.2) x 10('-7).

  18. The Booster to AGS beam transfer fast kicker systems

    SciTech Connect

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

    1992-01-01

    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.

  19. 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.

  20. Polarized Sources, Targets and Polarimetry

    NASA Astrophysics Data System (ADS)

    Ciullo, Guiseppe; Contalbrigo, Marco; Lenisa, P.

    2011-01-01

    Remarks on the history of workshops on "spin tools" / E. Steffens -- Polarized proton beams in RHIC / A. Zelenski -- The COSY/Julich polarized H[symbol] and D[symbol] ion source / O. Felden -- The new source of polarized ions for the JINR accelerator complex / V. V. Fimushkin -- Resonance effects in nuclear dichroism - an inexpensive source of tensor-polarized deuterons / H. Seyfarth -- Polarized electrons and positrons at the MESA accelerator / K. Aulenbacher -- Status report of the Darmstadt polarized electron injector / Y. Poltoratska -- The Mott polarimeter at MAMI / V. Tioukine -- Proton polarimetry at the relativistic heavy ion collider / Y. Makdisi -- Polarisation and polarimetry at HERA / B. Sobloher -- Polarisation measurement at the ILC with a Compton polarimeter / C. Bartels -- Time evolution of ground motion-dependent depolarisation at linear colliders / A. Hartin -- Electron beam polarimetry at low energies and its applications / R. Barday -- Polarized solid targets: recent progress and future prospects / C. D. Keith -- HD gas distillation and analysis for HD frozen spin targets / A. D'Angelo -- Electron spin resonance study of hydrogen and alkyl free radicals trapped in solid hydrogen aimed for dynamic nuclear polarization of solid HD / T. Kumada -- Change of ultrafast nuclear-spin polarization upon photoionization by a short laser pulse / T. Nakajima -- Radiation damage and recovery in polarized [symbol]NH[symbol] ammonia targets at Jefferson lab / J. D. Maxwell.Polarized solid proton target in low magnetic field and at high temperature / T. Uesaka -- Pulse structure dependence of the proton spin polarization rate / T. Kawahara -- Proton NMR in the large COMPASS [symbol]NH[symbol] target / J. Koivuniemi -- DNP with TEMPO and trityl radicals in deuterated polystyrene / L. Wang -- The CLIC electron and positron polarized sources / L. Rinolfi -- Status of high intensity polarized electron gun at MIT-Bates / E. Tsentalovich -- Target section for spin

  1. Proton spin in the valon model

    NASA Astrophysics Data System (ADS)

    Arash, Firooz

    1994-08-01

    The valon model description of the proton is used to calculate contributions of the constituents of the proton to its spin. It is shown that the results of the model calculation agree rather well with the EMC results. It is conjectured that in probing the nucleon with high Q2 one actually probes its valon structure. It is further conjectured that the valence quark contribution to the proton spin cancels out the sea contribution, and gluons almost exclusively carry the spin of the proton. Our results satisfy various theoretical constraints on the sea polarization.

  2. Resonance Structure with Polarization Experiments at MAMI

    SciTech Connect

    Arends, Hans-Juergen

    2011-10-21

    The Mainz Microtron MAMI is an ideal facility to study the hadron structure with the electromagnetic probe. With the new accelerator stage, the Harmonic Double-Sided Microtron (HDSM), which is in operation since 2007, high-intensity polarized electron and photon beams with energies up to 1.6 GeV are delivered to the experiments. Polarized proton, deuteron, {sup 3}He targets, and recoil proton polarimeters are available to allow a broad range of polarization observables for low-mass nucleon resonances to be measured. In this talk, an overview over selected recent double polarization experiments at MAMI is given.

  3. Asymmetry-induced resistive switching in Ag-Ag2S-Ag memristors enabling a simplified atomic-scale memory design

    PubMed Central

    Gubicza, Agnes; Manrique, Dávid Zs.; Pósa, László; Lambert, Colin J.; Mihály, György; Csontos, Miklós; Halbritter, András

    2016-01-01

    Prevailing models of resistive switching arising from electrochemical formation of conducting filaments across solid state ionic conductors commonly attribute the observed polarity of the voltage-biased switching to the sequence of the active and inert electrodes confining the resistive switching memory cell. Here we demonstrate stable switching behaviour in metallic Ag-Ag2S-Ag nanojunctions at room temperature exhibiting similar characteristics. Our experimental results and numerical simulations reveal that the polarity of the switchings is solely determined by the geometrical asymmetry of the electrode surfaces. By the lithographical design of a proof of principle device we demonstrate the merits of simplified fabrication of atomic-scale, robust planar Ag2S memory cells. PMID:27488426

  4. Asymmetry-induced resistive switching in Ag-Ag2S-Ag memristors enabling a simplified atomic-scale memory design

    NASA Astrophysics Data System (ADS)

    Gubicza, Agnes; Manrique, Dávid Zs.; Pósa, László; Lambert, Colin J.; Mihály, György; Csontos, Miklós; Halbritter, András

    2016-08-01

    Prevailing models of resistive switching arising from electrochemical formation of conducting filaments across solid state ionic conductors commonly attribute the observed polarity of the voltage-biased switching to the sequence of the active and inert electrodes confining the resistive switching memory cell. Here we demonstrate stable switching behaviour in metallic Ag-Ag2S-Ag nanojunctions at room temperature exhibiting similar characteristics. Our experimental results and numerical simulations reveal that the polarity of the switchings is solely determined by the geometrical asymmetry of the electrode surfaces. By the lithographical design of a proof of principle device we demonstrate the merits of simplified fabrication of atomic-scale, robust planar Ag2S memory cells.

  5. Asymmetry-induced resistive switching in Ag-Ag2S-Ag memristors enabling a simplified atomic-scale memory design.

    PubMed

    Gubicza, Agnes; Manrique, Dávid Zs; Pósa, László; Lambert, Colin J; Mihály, György; Csontos, Miklós; Halbritter, András

    2016-01-01

    Prevailing models of resistive switching arising from electrochemical formation of conducting filaments across solid state ionic conductors commonly attribute the observed polarity of the voltage-biased switching to the sequence of the active and inert electrodes confining the resistive switching memory cell. Here we demonstrate stable switching behaviour in metallic Ag-Ag2S-Ag nanojunctions at room temperature exhibiting similar characteristics. Our experimental results and numerical simulations reveal that the polarity of the switchings is solely determined by the geometrical asymmetry of the electrode surfaces. By the lithographical design of a proof of principle device we demonstrate the merits of simplified fabrication of atomic-scale, robust planar Ag2S memory cells. PMID:27488426

  6. High intensity proton synchrotrons

    NASA Astrophysics Data System (ADS)

    Craddock, M. K.

    1986-10-01

    Strong initiatives are being pursued in a number of countries for the construction of ``kaon factory'' synchrotrons capable of producing 100 times more intense proton beams than those available now from machines such as the Brookhaven AGS and CERN PS. Such machines would yield equivalent increases in the fluxes of secondary particles (kaons, pions, muons, antiprotons, hyperons and neutrinos of all varieties)—or cleaner beams for a smaller increase in flux—opening new avenues to various fundamental questions in both particle and nuclear physics. Major areas of investigation would be rare decay modes, CP violation, meson and hadron spectroscopy, antinucleon interactions, neutrino scattering and oscillations, and hypernuclear properties. Experience with the pion factories has already shown how high beam intensities make it possible to explore the ``precision frontier'' with results complementary to those achievable at the ``energy frontier''. This paper will describe proposals for upgrading and AGS and for building kaon factories in Canada, Europe, Japan and the United States, emphasizing the novel aspects of accelerator design required to achieve the desired performance (typically 100 μA at 30 GeV).

  7. Personal History of Nucleon Polarization Experiments

    DOE R&D Accomplishments Database

    Chamberlain, O.

    1984-09-01

    The history of nucleon scattering experiments is reviewed, starting with the observation of large proton polarizations in scattering from light elements such as carbon, and ending with the acceleration of polarized proton beams in high-energy synchrotrons. Special mention is made about significant contributions made by C.L. Oxley, L. Wolfenstein, R.D. Tripp, T. Ypsilantis, A. Abragam, M. Borghini, T. Niinikoski, Froissart, Stora, A.D. Krisch, and L.G. Ratner.

  8. AGS experiments - 1994, 1995, 1996

    SciTech Connect

    Depken, J.C.

    1997-01-01

    This report contains the following information on the Brookhaven AGS Accelerator complex: FY 1996 AGS schedule as run; FY 1997 AGS schedule (working copy); AGS beams 1997; AGS experimental area FY 1994 physics program; AGS experimental area FY 1995 physics program; AGS experimental area FY 1996 physics program; AGS experimental area FY 1997 physics program (in progress); a listing of experiments by number; two-phage summaries of each experiment begin here, also ordered by number; listing of publications of AGS experiments begins here; and listing of AGS experimenters begins here.

  9. A stretcher for the Brookhaven AGS

    SciTech Connect

    Foelsche, H.W.J.

    1989-01-01

    This paper summarizes the conceptual design of a 30 GeV Stretcher ring, which is designed to increase the capacity and the quality of the experimental physics program at the AGS. In a typical 3 second operating cycle the AGS now accomplishes two functions: accelerating the beam to full energy and then providing a slow spill on a 30 GeV flattop. These tasks consume approximately equal time. The proposed Stretcher, a dc storage ring, will take up the task of distributing the high energy beam with a continuous slow spill, making it possible for the AGS to provide beam for the program at more than twice the present repetition rate. Thus the average current delivered to the experimenters will be more than doubled, and the duty cycle of the spill will increase from the present optimum of about 40% to nearly 100%. The Stretcher will continue the gradual evolution of the AGS toward a kaon factory. At present, the AGS provides about 1 {mu}A average proton current. A Booster, now under construction, is expected to increase the current to above 4 {mu}a, and the Stretcher to about 8-10 {mu}A, an order of magnitude higher than now. 5 refs., 6 figs., 1 tab.

  10. Micro-PIXE study of Ag in digestive glands of a nano-Ag fed arthropod ( Porcellio scaber, Isopoda, Crustacea)

    NASA Astrophysics Data System (ADS)

    Tkalec, Živa Pipan; Drobne, Damjana; Vogel-Mikuš, Katarina; Pongrac, Paula; Regvar, Marjana; Štrus, Jasna; Pelicon, Primož; Vavpetič, Primož; Grlj, Nataša; Remškar, Maja

    2011-10-01

    Micro-proton induced X-ray emission (micro-PIXE) method was applied to study the micro-localization of silver (Ag) in digestive glands of a terrestrial arthropod (Porcellio scaber) after feeding on silver nanoparticles (nano-Ag) dosed food. The aim of our work was to assess whether feeding on nano-Ag results in the assimilation of silver (Ag) in digestive gland cells. To study micro-localization and elemental distribution of Ag, the animals were fed on food dosed with nanoparticles for 14 days under controlled laboratory conditions. At the end of the feeding exposure, the animals were dissected and digestive glands prepared for micro-PIXE analyses and TEM investigation. The results obtained by micro-PIXE documented high amounts of Ag inside S-cells of the digestive gland epithelium; however, TEM investigation did not show particle aggregates inside digestive gland cells. Also no adverse effect on feeding behavior was recorded what is a measure of toxic effects. We explain the presence of Ag inside the cells as a result of the assimilation of dissoluted Ag ions from ingested nano-Ag particles. Assimilation of excessive amounts of ingested metal ions in S-cells is a well known metal detoxification mechanism in isopods. We discuss the advantages of using micro-PIXE for the micro-localization of elements in biological tissue in studies of interactions between nanoparticles and biological systems.

  11. Ionospherically reflected proton whistlers

    NASA Astrophysics Data System (ADS)

    Vavilov, D. I.; Shklyar, D. R.

    2014-12-01

    We present experimental observations and detailed investigation of the variety of proton whistlers that includes transequatorial and ionospherically reflected proton whistlers. The latter have previously been indicated from numerical modeling of spectrograms. The study is based on six-component ELF wave data from the Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite which permits to obtain not only spectrograms displaying the power spectral density but also such wave properties as the polarization, wave normal angle, wave refractive index, and normalized parallel component of the Poynting vector. The explanation of various types of proton whistlers is based on the properties of ion cyclotron wave propagation in a multicomponent magnetoplasma, with special consideration of the effect of ion hybrid resonance reflection. Analysis of experimental data is supplemented by numerical modeling of spectrograms that reproduces the main features of experimental ones. As a self-contained result, we provide conclusive experimental evidences that the region illuminated by a lightning stroke in the Earth-ionosphere waveguide may spread over a distance of 4000 km in both hemispheres.

  12. Distribution of computer functionality for accelerator control at the Brookhaven AGS

    SciTech Connect

    Stevens, A.; Clifford, T.; Frankel, R.

    1985-01-01

    A set of physical and functional system components and their interconnection protocols have been established for all controls work at the AGS. Portions of these designs were tested as part of enhanced operation of the AGS as a source of polarized protons and additional segments will be implemented during the continuing construction efforts which are adding heavy ion capability to our facility. Included in our efforts are the following computer and control system elements: a broad band local area network, which embodies MODEMS; transmission systems and branch interface units; a hierarchical layer, which performs certain data base and watchdog/alarm functions; a group of work station processors (Apollo's) which perform the function of traditional minicomputer host(s) and a layer, which provides both real time control and standardization functions for accelerator devices and instrumentation. Data base and other accelerator functionality is assigned to the most correct level within our network for both real time performance, long-term utility, and orderly growth.

  13. Distribution of computer functionality for accelerator control at the Brookhaven AGS

    SciTech Connect

    Stevens, A.; Clifford, T.; Frankel, R.

    1985-10-01

    A set of physical and functional system components and their interconnection protocols have been established for all controls work at the AGS. Portions of these designs were tested as part of enhanced operation of the AGS as a source of polarized protons and additional segments will be implemented during the continuing construction efforts which are adding heavy ion capability to our facility. Included in our efforts are the following computer and control system elements: a broad band local area network, which embodies MODEMS; transmission systems and branch interface units; a hierarchical layer, which performs certain data base and watchdog/alarm functions; a group of work station processors (Apollo's) which perform the function of traditional minicomputer host(s) and a layer, which provides both real time control and standardization functions for accelerator devices and instrumentation. Data base and other accelerator functionality is assigned to the most correct level within our network for both real time performance, long-term utility, and orderly growth.

  14. Proton therapy

    MedlinePlus

    ... skin redness in the radiation area, and temporary hair loss. AFTER THE PROCEDURE Following proton therapy, you should be able to resume your normal activities. You will likely see your doctor every 3 to 4 months for a follow-up exam.

  15. Polarization buildup in stored p and p-bar beams interacting with a polarized target

    SciTech Connect

    Strakhovenko, V.

    2008-04-30

    The kinetics of the polarization buildup in the interaction of stored protons or antiprotons with a polarized target is considered. It is demonstrated that for events where a projectile remains in the beam the polarization buildup is completely due to the spin-flip transitions. However, the corresponding effect turns out to be negligibly small for a hydrogen gas target as well as for a pure electron target. For the latter, the filtering mechanism also does not provide a noticeable beam polarization.

  16. Polarization Transfer by Solution in Laser-Polarized Liquid Xenon

    NASA Astrophysics Data System (ADS)

    Fitzgerald, R. J.; Sauer, K. L.; Happer, W.

    1998-05-01

    We have dissolved compounds in hyperpolarized liquid Xe, in which the ^129Xe polarization was ~ 20%, and have observed the transfer of polarization through cross-relaxation from ^129Xe to other spins in solution. We have measured enhanced NMR signals for ^1H that are more than a factor of 45 larger than thermal polarization signals at 200 K and 1.4 T. For ^13C, we have seen signal enhancements of over 70. The lifetimes of the enhancements were ~ 20 min. In dissolved toluene, we have further observed different enhancements of the ring and the methyl proton signals.

  17. 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.

  18. AGS RESONANT EXTRACTION WITH HIGH INTENSITY BEAMS.

    SciTech Connect

    AHRENS,L.; BROWN,K.; GLENN,J.W.; ROSER,T.; TSOUPAS,N.; VANASSELT,W.

    1999-03-29

    The Brookhaven AGS third integer resonant extraction system allows the AGS to provide high quality, high intensity 25.5 GeV/c proton beams simultaneously to four target stations and as many as 8 experiments. With the increasing intensities (over 7 x 10{sup 13} protons/pulse) and associated longer spill periods (2.4 to 3 seconds long), we continue to run with low losses and high quality low modulation continuous current beams.[1] Learning to extract and transport these higher intensity beams has required a process of careful modeling and experimentation. We have had to learn how to correct for various instabilities and how to better match extraction and the transport lines to the higher emittance beams being accelerated in the AGS. Techniques employed include ''RF'' methods to smooth out momentum distributions and fine structure. We will present results of detailed multi-particle tracking modeling studies which enabled us to develop a clear understanding of beam loss mechanisms in the transport and extraction process. We will report on our status, experiences, and the present understanding of the intensity limitations imposed by resonant extraction and transport to fixed target stations.

  19. High energy polarized beams from hyperon decays

    SciTech Connect

    Underwood, D.G.

    1986-01-01

    The use of various ways to utilize lambda decays to obtain polarized beams of protons and antiprotons is emphasized. Examples described are the Fermilab polarized beam, now under construction, and the use of similar techniques at other energies. Beam transport, spin precession and reversal systems, and polarimeters are also discussed. 8 refs., 4 figs.

  20. Ferromagnetic resonance of ultrathin Co /Ag superlattices on Si(111)

    NASA Astrophysics Data System (ADS)

    Kakazei, G. N.; Martin, P. P.; Ruiz, A.; Varela, M.; Alonso, M.; Paz, E.; Palomares, F. J.; Cebollada, F.; Rubinger, R. M.; Carmo, M. C.; Sobolev, N. A.

    2008-04-01

    Ferromagnetic resonance (FMR) is used to probe the magnetic properties of Co /Ag superlattices (SLs) with ultrathin Co layers (2-6Å). Different series of 5×[Ag/Co] multilayers have been grown by molecular beam epitaxy on Si(111) substrates, monitoring the growth by reflection high energy electron diffraction. Cross-section transmission electron microscopy confirms the growth of local areas with the designed SL periodicity, a sharp compositional modulation, well defined Ag-Co interfaces, and a perfect fcc (111) stacking. FMR spectra have been recorded at various polar angles in the 0°-90° range. A single and extremely broad resonance peak is observed in all cases. While SLs with Ag layers thinner than 10Å exhibit similar values of the perpendicular anisotropy, a clear reduction is observed for samples with Ag layers about 14Å thick. Possible causes for this change are discussed.

  1. Propagating and localized surface plasmons in Ag nanostructures

    NASA Astrophysics Data System (ADS)

    Dabrowski, Maciej; Dai, Yanan; Petek, Hrvoje

    Plasmonic excitations strongly depend on the size, geometry and dielectric environment of nanoscale metals. Here, we study an epitaxially grown Ag nanostructures on Si(001) and Si(111) surfaces by Low Energy Electron Microscopy/Photoemission Electron Microscopy (LEEM/PEEM). Using the combination of LEEM and broadly tunable femtosecond laser excited multiphoton PEEM we image how single crystalline metallic nanostructures form and how plasmon excitations depend on the particle structure and laser excitation parameters. For Ag pyramids with the dimensions of few hundreds nanometers, dipolar and quadrupolar localized surface plasmons are observed. For Ag wires with several micrometer lengths, both localized and propagating surface plasmons can be excited, depending on the polarization, particle orientation and energy of the excitation. Finally, in larger Ag islands, several micrometers in size, the interference patterns are created by plasmon waves excited at the island edges. In addition to plasmonic response, light diffraction patterns around the Ag nanostrutures are discussed.

  2. Opportunities with polarized beam & target

    NASA Astrophysics Data System (ADS)

    Miyachi, Yoshiyuki

    2014-09-01

    Single spin asymmetries in Drell-Yan (DY) scattering, which are going to be measured in the present and planned polarized DY experiments, gain further insight into the internal structure of the nucleon. For the novel Sivers distribution function, the possible sign change in DY and Semi-Inclusive Deep-Inelastic-Scattering (SIDIS) may be confirmed for the first time, which is a critical test of the transverse momentum dependent (TMD) factorization in QCD, and precise information on the sea quarks, which are less sensitive in DIS, will be obtained. Since DY is one of the cleanest hard scattering processes, where no hadron fragmentation involved, it does not require information on hadron fragmentation functions (FF) to extract TMD PDF from the observed azimuthal amplitudes, where TMD PDF appears along with a corresponding FF in the case of SIDIS. Various azimuthal amplitudes of un-polarized cross section and singly-polarized or doubly-polarized cross section asymmetries in SIDIS have been measured. Double spin asymmetry in DY where beam and target are polarized is another unique tool to study TMD PDFs directly and it is a complementary measurement to SIDIS toward the complete description of the nucleon. Single spin asymmetries of the W-production cross section in the polarized proton-proton collision, recently measured at the RHIC/spin program, indicate the possible quark flavor symmetry violation in the polarized light-sea. Similar flavor asymmetry in the un-polarized light-sea, known as violation of the Gottfried sum rule, is currently studied at the on-going DY experiment SeaQuest at Fermilab. The observed flavor asymmetries can be a key to understand non-perturbative structure of the nucleon. With double spin asymmetry measurements in longitudinally polarized DY the flavor asymmetry in the polarized sea can be confirmed. In the presentation, physics cases which can be studied in doubly polarized DY and related topics will be discussed.

  3. Cysteine-Ag Cluster Hydrogel Confirmed by Experimental and Numerical Studies.

    PubMed

    Cui, Yanyan; Wang, Yaling; Zhao, Lina

    2015-10-01

    The native cysteine (Cys)-Ag3 cluster hydrogel is approved for the first time by both experimental and theoretical studies. From the detailed molecular structure and energy information, three factors are found to ensure the self-assembly of Cys and Ag3 , and result in the hydrogel. First, the Ag-S bonds make Cys and Ag3 form Cys-Ag3 -Cys monomer. Second, intermolecular hydrogen bonds between carboxyl groups of adjacent monomer push them self-assembled. Third, more monomer precisely self-assemble to produce the -[Cys-Ag3 -Cys]n multimer, e.g., a single molecular chain with the left-handed helix conformation, via a benign thermodynamic process. These multimers entangle together to form micro-network to trap water and produce hydorgel in situ. The hydrogen bonds of hydrogel are sensitive to thermal and proton stimuli, and the hydrogel presents lysosome targeting properties via fluorescent imaging with biocompatibility. PMID:26248576

  4. SCATTERING POLARIZATION IN SOLAR FLARES

    SciTech Connect

    Štěpán, Jiří; Heinzel, Petr

    2013-11-20

    There is ongoing debate about the origin and even the very existence of a high degree of linear polarization of some chromospheric spectral lines observed in solar flares. The standard explanation of these measurements is in terms of the impact polarization caused by non-thermal proton and/or electron beams. In this work, we study the possible role of resonance line polarization due to radiation anisotropy in the inhomogeneous medium of the flare ribbons. We consider a simple two-dimensional model of the flaring chromosphere and we self-consistently solve the non-LTE problem taking into account the role of resonant scattering polarization and of the Hanle effect. Our calculations show that the horizontal plasma inhomogeneities at the boundary of the flare ribbons can lead to a significant radiation anisotropy in the line formation region and, consequently, to a fractional linear polarization of the emergent radiation of the order of several percent. Neglecting the effects of impact polarization, our model can provide a clue for resolving some of the common observational findings, namely: (1) why a high degree of polarization appears mainly at the edges of the flare ribbons; (2) why polarization can also be observed during the gradual phase of a flare; and (3) why polarization is mostly radial or tangential. We conclude that radiation transfer in realistic multi-dimensional models of solar flares needs to be considered as an essential ingredient for understanding the observed spectral line polarization.

  5. Historical Review on Solid Polarized Targets

    NASA Astrophysics Data System (ADS)

    Masaike, Akira

    2007-04-01

    Protons in the crystal of La2Mg3(NO3)1224H2O were found to be polarized dynamically by means of the solid effect at the beginning of 1960's. Organic materials were polarized up to 80 % in 3He cryostats in 1969. It can be interpreted as the equal spin temperature model. The spin frozen targets with dilution refrigerators were constructed in 1974. Such targets have been used for experiments which require wide access angles. The NH3, LiH and LiD were polarized in 1980's. Static polarization of HD has been tried and proton polarization higher than 60 % was obtained with small amount of ortho H2 in 2000. We mention also the dynamic polarization of aromatic molecules in high temperature.

  6. Pion content of the nucleon in polarized semi-inclusive DIS

    SciTech Connect

    Melnitchouk, W.; Thomas, A.W.

    1994-04-01

    An explicit pionic component of the nucleon may be identified by measuring polarized {Delta}{sup ++} fragments produced in deep-inelastic scattering (DIS) off polarized protons. The pion-exchange model predicts highly correlated polarizations of the {Delta}{sup ++} and target proton, in marked contrast with the competing diquark fragmentation process.

  7. Direct observation of Ag filament growth and unconventional SET-RESET operation in GeTe amorphous films

    NASA Astrophysics Data System (ADS)

    Imanishi, Yusuke; Kida, Shimon; Nakaoka, Toshihiro

    2016-07-01

    We report on the direct observation of Ag filament growth and a peculiar resistance switching in amorphous GeTe films with a lateral electrode geometry. The Ag filament growth was monitored by in-situ optical microscopy. The resistance switching was studied in three electrode pairs, Ag-Ag, Pt-Ag, and Pt-Ag/Pt (Ag electrode covered with Pt). In all the three electrode pairs, similar dendritic Ag filaments were clearly observed growing along both directions from one electrode to the other, according to the applied bias polarity. However, the SET and RESET processes are quite different. The Ag-Ag pair produces a unipolar clockwise switching. The Pt-Ag pair shows a bipolar counter-clockwise switching, as predicted in the basic electrochemical metallization theory, but the observed switching polarity is exactly opposite to the basic theory prediction. The Pt-Ag/Pt pair produces a unipolar counter-clockwise switching. The peculiar SET/RESET processes are explained on the basis of strong Ag diffusion into GeTe matrix resulting in an asymmetric effective electrode pair. The findings suggest that the SET/RESET processes are controlled by the amount of Ag and the electrode geometry.

  8. 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.

  9. Ion polarization in the MEIC figure-8 ion collider ring

    SciTech Connect

    V.S. Morozov, Ya.S. Derbenev, Y. Zhang, P. Chevtsov, A.M. Kondratenko, M.A. Kondratenko, Yu.N. Filatov

    2012-07-01

    The nuclear physics program envisaged at the Medium-energy Electron-Ion Collider (MEIC) currently being developed at the Jefferson Lab calls for collisions of 3-11 GeV/c longitudinally polarized electrons and 20-100 GeV/c, in equivalent proton momentum, longitudinally/ transversely polarized protons/ deuterons/ light ions. We present a scheme that provides the required ion polarization arrangement in the MEIC's ion collider ring.

  10. Possible Sources of Polar Volatiles

    NASA Astrophysics Data System (ADS)

    Schultz, P. H.

    2011-12-01

    Extensive analyses of returned Apollo samples demonstrated that the Moon is extremely volatile poor. While this conclusion remains true, various measurements since the late 90's implicated the presence of water: e.g., enhanced reflection of circularly polarized radar signals and suppression of epithermal neutrons near the poles. More recently, traces of H2O have been discovered inside volcanic glass, along with more significant amounts residing in hydrous minerals (apatite) returned from both highland and mare landing sites. Three recent lunar missions (DIXI, M3, Cassini) identified hydrous phases on/near the lunar surface, whereas the LCROSS probe detected significant quantities of volatiles (OH, H2O and other volatiles) excavated by the Centaur impact. These new mission results and sample studies, however, now allow testing different hypotheses for the generation, trapping, and replenishment of these volatiles. Solar-proton implantation must contribute to the hydrous phases in the lunar regolith in order to account for the observed time-varying abundances and occurrence near the lunar equator. This also cannot be the entire story. The relatively low speed LCROSS-Centaur impact (2.5km/s) could not vaporize such hydrous minerals, yet emissions lines of OH (from the thermal disassociation of H2O), along with other compounds (CO2, NH2) were detected within the first second, before ejecta could reach sunlight. Telescopic observations by Potter and Morgan (1985) discovered a tenuous lunar atmosphere of Na, but the LCROSS UV/Vis spectrometer did not detect the Na-D line until after the ejecta reached sunlight (along with a line pair attributed to Ag). With time, other volatile species emerged (OH, CO). The LAMP instrument on the Lunar Reconnaissance Orbiter had a different viewpoint from the side (rather than from above) and detected many other atomic species release by the LCROSS-Centaur impact. Consequently, it appears that there is a stratigraphy for trapped species

  11. Global QCD Analysis of Polarized Parton Densities

    SciTech Connect

    Stratmann, Marco

    2009-08-04

    We focus on some highlights of a recent, first global Quantum Chromodynamics (QCD) analysis of the helicity parton distributions of the nucleon, mainly the evidence for a rather small gluon polarization over a limited region of momentum fraction and for interesting flavor patterns in the polarized sea. It is examined how the various sets of data obtained in inclusive and semi-inclusive deep inelastic scattering and polarized proton-proton collisions help to constrain different aspects of the quark, antiquark, and gluon helicity distributions. Uncertainty estimates are performed using both the robust Lagrange multiplier technique and the standard Hessian approach.

  12. Baryon Spectroscopy with Polarization Observables from CLAS

    NASA Astrophysics Data System (ADS)

    Strauch, Steffen

    2016-06-01

    The spectrum of nucleon excitations is dominated by broad and overlapping resonances. Polarization observables in photoproduction reactions are key in the study of these excitations. They give indispensable constraints to partial-wave analyses and help clarify the spectrum. A series of polarized photoproduction experiments have been performed at the Thomas Jefferson National Accelerator Facility with the CEBAF Large Acceptance Spectrometer. These measurements include data with linearly and circularly polarized tagged-photon beams, longitudinally and transversely polarized proton and deuterium targets, and recoil polarizations through the observation of the weak decay of hyperons. An overview of these studies and recent results will be given.

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

    SciTech Connect

    Nikolaev, Nikolai; Pavlov, Fyodor

    2008-04-30

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

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

    SciTech Connect

    Nikolaev, Nikolai; Pavlov, Fyodor

    2007-06-13

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

  15. The AgNORs.

    PubMed

    Derenzini, M

    2000-04-01

    The structure and the function of interphase AgNORs and the importance of the "AgNOR" parameter in tumor pathology have been reviewed. Interphase AgNORs are structural-functional units of the nucleolus in which all the components necessary for ribosomal RNA synthesis are located. Two argyrophilic proteins involved in rRNA transcription and processing, nucleolin and nucleophosmin, are associated with interphase AgNORs and are responsible for their stainability with silver methods, thus allowing interphase AgNORs to be visulaized at light microscopic level, also in routine cyto-histopathological preparations. The number of interphase AgNORs is strictly related to rRNA transcriptional activity and, in continuously proliferating cells, to the rapidity of cell proliferation. Evaluation of the quantitative distribution of interphase AgNORs has been applied in tumor pathology both for diagnostic and prognostic purposes. The "AgNOR" parameter has been proved to represent a reliable tool for defining the clinical outcome of cancer disease, being an independent prognostic factor in many types of tumors. PMID:10588056

  16. AgRISTARS

    NASA Technical Reports Server (NTRS)

    1984-01-01

    An introduction to the overall AgRISTARS program, a general statement on progress, and separate summaries of the activities of each project, with emphasis on the technical highlights are presented. Organizational and management information on AgRISTARS is included in the appendices, as is a complete bibliography of publication and reports.

  17. Explore the possibility of accelerating polarized He-3 beam in RHIC

    SciTech Connect

    Bai M.; Courant, E.; Fischer, W.; Ptitsyn, V.; Roser, T.

    2012-05-20

    As the world's first high energy polarized proton collider, RHIC has made significant progresses in measuring the proton spin structure in the past decade. In order to have better understanding of the contribution of up quarks and down quarks to the proton spin structure, collisions of high energy polarized neutron beams are required. Polarized He-3 beams offer an effectiveway to provide polarized neutron beams. In this paper, we present studies of accelerating polarized He-3 in RHIC with the current dual snake configuration. Possibilities of adding two more pairs of snakes for accelerating polarized He-3 were explored. Results of six snake configuration in RHIC are also reported in the paper.

  18. Gluon Polarization and Jet Production at STAR

    SciTech Connect

    Djawotho, Pibero

    2009-12-17

    I will discuss the most recent measurements of the inclusive jet longitudinal spin asymmetry A{sub LL} in polarized proton-proton collisions. STAR collected its largest data sample thus far, 4.7 pb{sup -1} of integrated luminosity at an average beam polarization of {approx}57%, during the 2006 run at a center-of-mass energy of 200 GeV. I will also present previous STAR inclusive jet A{sub LL} and cross section measurements. The results are compared with theoretical calculations of A{sub LL} based on polarized distribution functions in the nucleon with a range of different contributions from the gluon polarization, {delta}G. The STAR data place significant constraints on {delta}G for 0.02proton.

  19. AGS experiments: 1993 - 1994 - 1995

    SciTech Connect

    Depken, J.C.

    1996-04-01

    This report contains: FY 1995 AGS Schedule as Run; FY 1996-97 AGE Schedule (working copy); AGS Beams 1995; AGS Experimental Area FY 1993 Physics Program; AGS Experimental Area FY 1994 Physics Program; AGS Experimental Area FY 1995 Physics Program; AGS Experimental Area FY 1996 Physics Program (In progress); A listing of experiments by number; Two-page summaries of each experiment begin here, also ordered by number; Listing of publications of AGS experiments begins here; and Listing of AGS experimenters begins here. This is the twelfth edition.

  20. [Interaction of Ag+ ions with DNA and its monomers].

    PubMed

    Sorokin, V A; Valeev, V A; Gladchenko, G O; Sysa, I V; Volchok, I V; Blagoĭ, Iu P

    2000-01-01

    Differential UV spectra of DNA and its monomers that were induced by Ag+ ions were measured, and the effect of ions on the parameters of the helix-coil transition was studied. The data obtained confirm the existence of "strong" and "weak" modes of binding of Ag+ to DNA. The earlier proposed proton transfer from N1G to N3C, which is determined by the interaction of Ag+ with N7G (a "strong" complex), follows immediately from the shape of the differential UV spectra. The positive cooperativity of the binding of Ag+ to DNA upon the formation of a "weak" complex is due to the cooperativity of the transition of DNA to a new double-helical conformation. A model of this conformation is proposed which suggests the formation of Hougsteen GC and AT pairs. PMID:11040965

  1. PERFORMANCE OF THE AGS TRANSITION JUMP SYSTEM.

    SciTech Connect

    AHRENS,L.A.; BRENNAN,J.M.; GLENN,J.W.; ROSER,T.; VAN ASSELT,W.K.

    1999-03-29

    The transition jump system has been indispensable to the high intensity proton operation of the AGS complex. Nevertheless, transition crossing remains one of the major hurdles as the accelerator complex intensity is pushed upward. To enhance the performance of the system ''quadrupole pumping'' in the Booster is used to minimize the necessary longitudinal dilution of the beam on the AGS injection porch. During the transition jump sextupole correctors at strategic locations are pulsed to minimize the effects of the chromatic non-linearity of the jump system. The available instrumentation for diagnosing the performance of the system will be described, along with installed hardware to counter the non-linear effects of the transition jump system.

  2. Simulations of proton beam characteristics for ELIMED Beamline

    NASA Astrophysics Data System (ADS)

    Psikal, Jan; Limpouch, Jiri; Klimo, Ondrej; Vyskocil, Jiri; Margarone, Daniele; Korn, Georg

    2016-03-01

    ELIMED Beamline should demonstrate the capability of laser-based particle accelerators for medical applications, mainly for proton radiotherapy of tumours which requires a sufficient number of accelerated protons with energy about 60 MeV at least. In this contribution, we study the acceleration of protons by laser pulse with parameters accessible for ELIMED Beamline (intensity ∼ 1022 W/cm2, pulse length ∼ 30 fs). In our two-dimensional particle-incell simulations, we observed higher energies of protons for linear than for circular polarization. Oblique incidence of the laser pulse on target does not seem to be favourable for proton acceleration at such high intensities as the accelerated protons are deflected from target normal axis and their energy and numbers are slightly decreased. The expected numbers of accelerated protons in the energy interval 60 MeV ± 5% are calculated between 109 and 1010 per laser shot with estimated proton beam divergence about 20° (FWHM).

  3. Ion-proton pulsars

    NASA Astrophysics Data System (ADS)

    Jones, P. B.

    2016-07-01

    Evidence derived with minimal assumptions from existing published observations is presented to show that an ion-proton plasma is the source of radio-frequency emission in millisecond and in normal isolated pulsars. There is no primary involvement of electron-positron pairs. This conclusion has also been reached by studies of the plasma composition based on well-established particle-physics processes in neutron stars with positive polar-cap corotational charge density. This work has been published in a series of papers which are also summarized here. It is now confirmed by simple analyses of the observed radio-frequency characteristics, and its implications for the further study of neutron stars are outlined.

  4. Ion-proton pulsars

    NASA Astrophysics Data System (ADS)

    Jones, P. B.

    2016-04-01

    Evidence derived with minimal assumptions from existing published observations is presented to show that an ion-proton plasma is the source of radio-frequency emission in millisecond and in normal isolated pulsars. There is no primary involvement of electron-positron pairs. This conclusion has also been reached by studies of the plasma composition based on well-established particle-physics processes in neutron stars with positive polar-cap corotational charge density. This work has been published in a series of papers which are also summarized here. It is now confirmed by simple analyses of the observed radio-frequency characteristics, and its implications for the further study of neutron stars are outlined.

  5. Experimental effects of orbit on polarization loss in RHIC

    SciTech Connect

    Ranjbar V.; Bai, M.; Huang, H.; Marusic, A.; Ptitsyn, V.; Minty, M.

    2012-05-20

    We are performing several experiments during the RHIC ramp to better understand the impact of orbit errors on the polarization at our current working point. These will be conducted by exciting specified orbit harmonics during the final two large intrinsic resonance crossing in RHIC during the 250 GeV polarized proton ramp. The resultant polarization response will then be measured.

  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. The SH3/PH domain protein AgBoi1/2 collaborates with the Rho-type GTPase AgRho3 to prevent nonpolar growth at hyphal tips of Ashbya gossypii.

    PubMed

    Knechtle, Philipp; Wendland, Jürgen; Philippsen, Peter

    2006-10-01

    Unlike most other cells, hyphae of filamentous fungi permanently elongate and lack nonpolar growth phases. We identified AgBoi1/2p in the filamentous ascomycete Ashbya gossypii as a component required to prevent nonpolar growth at hyphal tips. Strains lacking AgBoi1/2p frequently show spherical enlargement at hyphal tips with concomitant depolarization of actin patches and loss of tip-located actin cables. These enlarged tips can repolarize and resume hyphal tip extension in the previous polarity axis. AgBoi1/2p permanently localizes to hyphal tips and transiently to sites of septation. Only the tip localization is important for sustained elongation of hyphae. In a yeast two-hybrid experiment, we identified the Rho-type GTPase AgRho3p as an interactor of AgBoi1/2p. AgRho3p is also required to prevent nonpolar growth at hyphal tips, and strains deleted for both AgBOI1/2 and AgRHO3 phenocopied the respective single-deletion strains, demonstrating that AgBoi1/2p and AgRho3p function in a common pathway. Monitoring the polarisome of growing hyphae using AgSpa2p fused to the green fluorescent protein as a marker, we found that polarisome disassembly precedes the onset of nonpolar growth in strains lacking AgBoi1/2p or AgRho3p. AgRho3p locked in its GTP-bound form interacts with the Rho-binding domain of the polarisome-associated formin AgBni1p, implying that AgRho3p has the capacity to directly activate formin-driven actin cable nucleation. We conclude that AgBoi1/2p and AgRho3p support polarisome-mediated actin cable formation at hyphal tips, thereby ensuring permanent polar tip growth. PMID:16950929

  8. Self-similarity of proton spin and z-scaling

    NASA Astrophysics Data System (ADS)

    Tokarev, M.; Zborovský, I.

    2016-02-01

    The concept of z-scaling previously developed for analysis of inclusive reactions in proton-proton collisions is applied for description of processes with polarized particles. Hypothesis of self-similarity of the proton spin structure is discussed. The possibility of extracting information on spin-dependent fractal dimensions of hadrons and fragmentation process from the cross sections and asymmetries is justified. The double longitudinal spin asymmetry ALL of jet and π0-meson production and the coefficient of polarization transfer DLL measured in proton-proton collisions at √s = 200 GeV at RHIC are analyzed in the framework of z-scaling. The spin-dependent fractal dimension of proton is estimated.

  9. Polarization phenomena in quantum chromodynamics

    SciTech Connect

    Brodsky, S.J.

    1994-03-01

    The author discusses a number of interrelated hadronic spin effects which test fundamental features of perturbative and non-perturbative QCD. For example, the anomalous magnetic moment of the proton and the axial coupling g{sub A} on the nucleon are shown to be related to each other for fixed proton radius, independent of the form of the underlying three-quark relativistic quark wavefunction. The renormalization scale and scheme ambiguities for the radiative corrections to the Bjorken sum rule for the polarized structure functions can be eliminated by using commensurate scale relations with other observables. Other examples include (a) new constraints on the shape and normalization of the polarized quark and gluon structure functions of the proton at large and small x{sub bj}; (b) consequences of the principle of hadron helicity retention in high x{sub F} inclusive reactions; (c) applications of hadron helicity conservation to high momentum transfer exclusive reactions; and (d) the dependence of nuclear structure functions and shadowing on virtual photon polarization. He also discusses the implications of a number of measurements which are in striking conflict with leading-twist perturbative QCD predictions, such as the extraordinarily large spin correlation A{sub NN} observed in large angle proton-proton scattering, the anomalously large {rho}{pi} branching ratio of the J/{psi}, and the rapidly changing polarization dependence of both J/{psi} and continuum lepton pair hadroproduction observed at large x{sub F}. The azimuthal angular dependence of the Drell-Yan process is shown to be highly sensitive to the projectile distribution amplitude, the fundamental valence light-cone wavefunction of the hadron.

  10. Femtochemistry of Intramolecular Charge and Proton Transfer Reactions in Solution

    SciTech Connect

    Douhal, Abderrazzak; Sanz, Mikel; Carranza, Maria Angeles; Organero, Juan Angel; Tormo, Laura

    2005-03-17

    We report on the first observation of ultrafast intramolecular charge- and proton-transfer reactions in 4'-dimethylaminoflavonol (DAMF) in solution. Upon femtosecond excitation of a non-planar structure of DMAF in apolar medium, the intramolecular charge transfer (ICT) does not occur, and a slow (2 ps) proton motion takes place. However, in polar solvents, the ICT is very fast (100-200 fs) and the produced structure is stabilized that proton motion takes place in few or tens of ps.

  11. Two-photon exchange and elastic electron-proton scattering

    SciTech Connect

    Peter Blunden; Wally Melnitchouk; John Tjon

    2003-06-01

    Two-photon exchange contributions to elastic electron-proton scattering cross sections are evaluated in a simple hadronic model including the finite size of the proton. The corrections are found to be small, but with a strong angular dependence at fixed Q{sup 2}. This is significant for the Rosenbluth technique for determining the ratio of electric and magnetic form factors of the proton, and partly reconciles the apparent discrepancy with the results of the polarization transfer technique.

  12. Polarization of a stored beam by spin-filtering

    NASA Astrophysics Data System (ADS)

    Augustyniak, W.; Barion, L.; Barsov, S.; Bechstedt, U.; Benati, P.; Bertelli, S.; Carassiti, V.; Chiladze, D.; Ciullo, G.; Contalbrigo, M.; Dalpiaz, P. F.; Dymov, S.; Engels, R.; Erwen, W.; Fiorini, M.; Gaisser, M.; Gebel, R.; Goslaswski, P.; Grigoriev, K.; Guidoboni, G.; Kacharava, A.; Khoukaz, A.; Kulikov, A.; Kleines, H.; Langenberg, G.; Lehrach, A.; Lenisa, P.; Lomidze, N.; Lorentz, B.; Macharashvili, G.; Maier, R.; Marianski, B.; Martin, S.; Mchedlishvili, D.; Merzliakov, S.; Meshkov, I. N.; Meyer, H. O.; Mielke, M.; Mikirtychiants, M.; Mikirtychiants, S.; Nass, A.; Nekipelov, M.; Nikolaev, N.; Nioradze, M.; Oellers, D.; Papenbrock, M.; Pappalardo, L.; Pesce, A.; Polyanskiy, A.; Prasuhn, D.; Rathmann, F.; Sarkadi, J.; Smirnov, A.; Seyfarth, H.; Shmakova, V.; Statera, M.; Steffens, E.; Stein, H. J.; Stockhorst, H.; Straatman, H.; Ströher, H.; Tabidze, M.; Tagliente, G.; Thörngren-Engblom, P.; Trusov, S.; Trzcinski, A.; Valdau, Yu.; Vasiliev, A.; von Würtemberg, K. M.; Weidemann, Chr.; Wüstner, P.; Zupranski, P.

    2012-11-01

    The PAX Collaboration has successfully performed a spin-filtering experiment with protons at the COSY-ring. The measurement allowed the determination of the spin-dependent polarizing cross section, that compares well with the theoretical prediction from the nucleon-nucleon potential. The test confirms that spin-filtering can be adopted as a method to polarize a stored beam and that the present interpretation of the mechanism in terms of the proton-proton interaction is correct. The outcome of the experiment is of utmost importance in view of the possible application of the method to polarize a beam of stored antiprotons.

  13. Polarization developments

    SciTech Connect

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist.

  14. Neuronal polarization.

    PubMed

    Takano, Tetsuya; Xu, Chundi; Funahashi, Yasuhiro; Namba, Takashi; Kaibuchi, Kozo

    2015-06-15

    Neurons are highly polarized cells with structurally and functionally distinct processes called axons and dendrites. This polarization underlies the directional flow of information in the central nervous system, so the establishment and maintenance of neuronal polarization is crucial for correct development and function. Great progress in our understanding of how neurons establish their polarity has been made through the use of cultured hippocampal neurons, while recent technological advances have enabled in vivo analysis of axon specification and elongation. This short review and accompanying poster highlight recent advances in this fascinating field, with an emphasis on the signaling mechanisms underlying axon and dendrite specification in vitro and in vivo. PMID:26081570

  15. Polarization Aberrations

    NASA Technical Reports Server (NTRS)

    Mcguire, James P., Jr.; Chipman, Russell A.

    1990-01-01

    The analysis of the polarization characteristics displayed by optical systems can be divided into two categories: geometrical and physical. Geometrical analysis calculates the change in polarization of a wavefront between pupils in an optical instrument. Physical analysis propagates the polarized fields wherever the geometrical analysis is not valid, i.e., near the edges of stops, near images, in anisotropic media, etc. Polarization aberration theory provides a starting point for geometrical design and facilitates subsequent optimization. The polarization aberrations described arise from differences in the transmitted (or reflected) amplitudes and phases at interfaces. The polarization aberration matrix (PAM) is calculated for isotropic rotationally symmetric systems through fourth order and includes the interface phase, amplitude, linear diattenuation, and linear retardance aberrations. The exponential form of Jones matrices used are discussed. The PAM in Jones matrix is introduced. The exact calculation of polarization aberrations through polarization ray tracing is described. The report is divided into three sections: I. Rotationally Symmetric Optical Systems; II. Tilted and Decentered Optical Systems; and Polarization Analysis of LIDARs.

  16. Low-temperature cross polarization in view of enhancing dissolution Dynamic Nuclear Polarization in NMR

    NASA Astrophysics Data System (ADS)

    Jannin, Sami; Bornet, Aurélien; Colombo, Sonia; Bodenhausen, Geoffrey

    2011-12-01

    Dynamic Nuclear Polarization (DNP) induced by saturation of ESR transitions of TEMPO at 1.2 K and 3.35 T is characterized by build-up rates that are typically 5 times faster for protons than for the carboxylic carbon-13 in acetate. We show that cross polarization from protons to carbon-13 allows one to achieve a polarization P( 13C) >20% in less than 10 min, twice as much as has been previously reported, in one-fifth of the time. This should open the way to an unprecedented improvement in the efficiency of dissolution DNP.

  17. Effect of Ag nanoparticle concentration on the electrical and ferroelectric properties of Ag/P(VDF-TrFE) composite films

    DOE PAGESBeta

    Paik, Haemin; Choi, Yoon -Young; Hong, Seungbum; No, Kwangsoo

    2015-09-04

    We investigated the effect of the Ag nanoparticles on the ferroelectric and piezoelectric properties of Ag/poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) composite films. We found that the remanent polarization and direct piezoelectric coefficient increased up to 12.14 μC/cm2 and 20.23 pC/N when the Ag concentration increased up to 0.005 volume percent (v%) and decreased down to 9.38 μC/cm2 and 13.45 pC/N when it increased up to 0.01 v%. Further increase in Ag concentration resulted in precipitation of Ag phase and significant leakage current that hindered any meaningful measurement of the ferroelectric and piezoelectric properties. 46% increase of the remanent polarization value and 27% increasemore » of the direct piezoelectric coefficient were observed in the film with the 0.005 v% of the Ag nanoparticles added without significant changes to the crystalline structure confirmed by both X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) experiments. The enhancements of both the ferroelectric and piezoelectric properties are attributed to the increase in the effective electric field induced by the reduction in the effective volume of P(VDF-TrFE) that results in more aligned dipoles.« less

  18. Effect of Ag nanoparticle concentration on the electrical and ferroelectric properties of Ag/P(VDF-TrFE) composite films

    SciTech Connect

    Paik, Haemin; Choi, Yoon -Young; Hong, Seungbum; No, Kwangsoo

    2015-09-04

    We investigated the effect of the Ag nanoparticles on the ferroelectric and piezoelectric properties of Ag/poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) composite films. We found that the remanent polarization and direct piezoelectric coefficient increased up to 12.14 μC/cm2 and 20.23 pC/N when the Ag concentration increased up to 0.005 volume percent (v%) and decreased down to 9.38 μC/cm2 and 13.45 pC/N when it increased up to 0.01 v%. Further increase in Ag concentration resulted in precipitation of Ag phase and significant leakage current that hindered any meaningful measurement of the ferroelectric and piezoelectric properties. 46% increase of the remanent polarization value and 27% increase of the direct piezoelectric coefficient were observed in the film with the 0.005 v% of the Ag nanoparticles added without significant changes to the crystalline structure confirmed by both X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) experiments. The enhancements of both the ferroelectric and piezoelectric properties are attributed to the increase in the effective electric field induced by the reduction in the effective volume of P(VDF-TrFE) that results in more aligned dipoles.

  19. Effect of Ag nanoparticle concentration on the electrical and ferroelectric properties of Ag/P(VDF-TrFE) composite films

    PubMed Central

    Paik, Haemin; Choi, Yoon-Young; Hong, Seungbum; No, Kwangsoo

    2015-01-01

    We investigated the effect of the Ag nanoparticles on the ferroelectric and piezoelectric properties of Ag/poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) composite films. We found that the remanent polarization and direct piezoelectric coefficient increased up to 12.14 μC/cm2 and 20.23 pC/N when the Ag concentration increased up to 0.005 volume percent (v%) and decreased down to 9.38 μC/cm2 and 13.45 pC/N when it increased up to 0.01 v%. Further increase in Ag concentration resulted in precipitation of Ag phase and significant leakage current that hindered any meaningful measurement of the ferroelectric and piezoelectric properties. 46% increase of the remanent polarization value and 27% increase of the direct piezoelectric coefficient were observed in the film with the 0.005 v% of the Ag nanoparticles added without significant changes to the crystalline structure confirmed by both X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) experiments. These enhancements of both the ferroelectric and piezoelectric properties are attributed to the increase in the effective electric field induced by the reduction in the effective volume of P(VDF-TrFE) that results in more aligned dipoles. PMID:26336795

  20. Self-Depolarization Studies on Some Fast Ag+ Ion Conducting Glasses

    NASA Astrophysics Data System (ADS)

    Agrawal, R. C.; Verma, M. L.; Bhatt, A.

    2002-12-01

    A novel technique based on the dc polarization method is being reported to study polarization/self-depolarization phenomenon in some fast Ag+ ion conducting glass systems viz.: 0.8[0.75AgI: 0.25AgCl]: 0.2[Ag2O: MoO3] & 0.7[0.75AgI: 0.25AgCl]: 0.3[Ag2O: WO3]. These superionic glasses were prepared recently in the present laboratory using an alternate host: "a quenched [0.75AgI: 0.25AgCl] mixed system/solid solution" in place of the traditional host AgI. An extensive investigation on ion transport behavior of these systems has been done which appeared elsewhere in the literature. In the present study, the sample pallet, placed in between two blocking (graphite) electrodes, was initially polarized with the help of an external d. c. potential (~ 0.5 V) for sufficient long time ensuring that the system attained the state of complete polarization. This resulted into a build up of a potential gradient across the two faces of the sample pallet, which can be measured instantly on removal of the external dc potential. This has been be referred to as an 'Instant Peak Potential (Vp)'. The magnitude of 'Vp' gives the quantitative information regarding the number of mobile Ag+ ions present in the system at a given temperature. 'Vp' measurements were carried out extensively on the sample pallets of different thickness as a function of time and temperature. The log Vp - 1/T variations for these systems were found to be almost analogous to log n - 1/T plots, reported earlier.

  1. Heteronuclear proton assisted recoupling

    NASA Astrophysics Data System (ADS)

    De Paëpe, Gaël; Lewandowski, Józef R.; Loquet, Antoine; Eddy, Matt; Megy, Simon; Böckmann, Anja; Griffin, Robert G.

    2011-03-01

    We describe a theoretical framework for understanding the heteronuclear version of the third spin assisted recoupling polarization transfer mechanism and demonstrate its potential for detecting long-distance intramolecular and intermolecular 15N-13C contacts in biomolecular systems. The pulse sequence, proton assisted insensitive nuclei cross polarization (PAIN-CP) relies on a cross term between 1H-15N and 1H-13C dipolar couplings to mediate zero- and/or double-quantum 15N-13C recoupling. In particular, using average Hamiltonian theory we derive effective Hamiltonians for PAIN-CP and show that the transfer is mediated by trilinear terms of the form N±C∓Hz (ZQ) or N±C±Hz (DQ) depending on the rf field strengths employed. We use analytical and numerical simulations to explain the structure of the PAIN-CP optimization maps and to delineate the appropriate matching conditions. We also detail the dependence of the PAIN-CP polarization transfer with respect to local molecular geometry and explain the observed reduction in dipolar truncation. In addition, we demonstrate the utility of PAIN-CP in structural studies with 15N-13C spectra of two uniformly 13C,15N labeled model microcrystalline proteins—GB1, a 56 amino acid peptide, and Crh, a 85 amino acid domain swapped dimer (MW = 2 × 10.4 kDa). The spectra acquired at high magic angle spinning frequencies (ωr/2π > 20 kHz) and magnetic fields (ω0H/2π = 700-900 MHz) using moderate rf fields, yield multiple long-distance intramonomer and intermonomer 15N-13C contacts. We use these distance restraints, in combination with the available x-ray structure as a homology model, to perform a calculation of the monomer subunit of the Crh protein.

  2. Preliminary results for the helicity asymmetry E for eta photoproduction on the proton

    SciTech Connect

    B. T. Morrison, M. Dugger, B. G. Ritchie, CLAS Collaboration

    2012-04-01

    Polarization observables are an important tool for clarifying the nucleon resonance spectrum. No previous measurements for double polarization asymmetries have been published for eta photoproduction. Double polarization measurements have been made at Jefferson Lab using a polarized photon beam and protons in a polarized frozen spin target (FROST). Data were taken during the first running period of FROST using the CLAS detector with photon energies from 0.33 to 2.35 GeV. Preliminary results for the E polarization observable for eta meson photoproduction from the proton at threshold and above, along with comparisons to several theoretical predictions are presented.

  3. Physics results with polarized electrons at SLAC

    SciTech Connect

    Prescott, C.Y.

    1996-03-01

    Polarized electron beams can play an important role in the dynamics of interactions at high energies. Polarized electron beams at SLAC have been an important part of the physics program since 1970, when they were first proposed for use in testing the spin structure of the proton. Since 1992, the SLAC linear accelerator and the SLC have operated solely with polarized electrons, providing data for tests of QCD in studies of the spin structure of the nucleon and tests of the electroweak sector of the Standard Model. In the following sections, the performance of the source is summarized, and some of the recent results using the polarized beams are discussed.

  4. Measurement of the transverse polarization of Λ and Λ¯ hyperons produced in proton-proton collisions at s=7TeV using the ATLAS detector

    SciTech Connect

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, B.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baas, A. E.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bassalat, A.; Basye, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J. -B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boddy, C. R.; Boehler, M.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.; Buchholz, P.; Buckley, A. G.; Buda, S. I.

    2015-02-10

    We measure the transverse polarization of Λ and Λ¯ hyperons produced in proton-proton collisions at a center-of mass energy of 7 TeV is measured. The analysis uses 760 μb₋1 of minimum bias data collected by the ATLAS detector at the LHC in the year 2010. The measured transverse polarization averaged over Feynman xF from 5 × 10₋5 to 0.01 and transverse momentum pT from 0.8 to 15 GeV is ₋0.010 ± 0.005(stat) ± 0.004(syst) for Λ and 0.002 ± 0.006(stat) ± 0.004(syst) for Λ¯ . It is also measured as a function of xF and pT, but we observed no significant dependence on these variables. Prior to this measurement, the polarization was measured at fixed-target experiments with center-of-mass energies up to about 40 GeV. The ATLAS results are compatible with the extrapolation of a fit from previous measurements to the xF range covered by this measurement.

  5. Polar Bear

    USGS Publications Warehouse

    Amstrup, S.D.; DeMaster

    1988-01-01

    Polar bears are long-lived, late-maturing carnivores that have relatively low rates of reproduction and natural mortality. Their populations are susceptible to disturbance from human activities, such as the exploration and development of mineral resources or hunting. Polar bear populations have been an important renewable resource available to coastal communities throughout the Arctic for thousands of years.

  6. Opportunities with Polarized Hadron Beams

    NASA Astrophysics Data System (ADS)

    Lorenzon, Wolfgang

    2016-02-01

    Spin physics at future hadron facilities provide unique opportunities for the study of QCD well beyond those available at existing facilities. Opportunities with polarized protons in the Fermilab Main Injector are discussed that encompass polarized Drell-Yan scattering of unprecedented precision and also enable measurements of transversity, helicty and other transverse momentum dependent distributions. Forthcoming measurements at COMPASS-II that aim to test fundamental predictions of non-perturbative QCD, and complementary studies at RHIC-Spin that address, among others, open puzzles such as the sharing of the nucleon spin among its constituents are also discussed.

  7. 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.

  8. Polarized rainbow.

    PubMed

    Können, G P; de Boer, J H

    1979-06-15

    The Airy theory of the rainbow is extended to polarized light. For both polarization directions a simple analytic expression is obtained for the intensity distribution as a function of the scattering angle in terms of the Airy function and its derivative. This approach is valid at least down to droplet diameters of 0.3 mm in visible light. The degree of polarization of the rainbow is less than expected from geometrical optics; it increases with droplet size. For a droplet diameter >1 mm the locations of the supernumerary rainbows are equal for both polarization directions, but for a diameter <1 mm the supernumerary rainbows of the weaker polarization component are located between those in the strong component. PMID:20212586

  9. Cation Hydration Constants by Proton NMR: A Physical Chemistry Experiment.

    ERIC Educational Resources Information Center

    Smith, Robert L.; And Others

    1988-01-01

    Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

  10. Energetic solar proton vs terrestrially trapped proton fluxes. [geocentric space missions shielding requirements

    NASA Technical Reports Server (NTRS)

    King, J. H.; Stassinopoulos, E. G.

    1975-01-01

    The relative importance of solar and trapped proton fluxes in the consideration of shielding requirements for geocentric space missions is analyzed. Using models of these particles, their fluences encountered by spacecraft in circular orbits are computed as functions of orbital altitude and inclination, mission duration, threshold energy (10 to 100 MeV), and risk factor (for solar protons only), and ratios of solar-to-trapped fluences are derived. It is shown that solar protons predominate for low-altitude polar and very high-altitude missions, while trapped protons predominate for missions at low and medium altitudes and low inclinations. It is recommended that if the ratio of solar-to-trapped protons falls between 0.1 and 10, both fluences should be considered in planning shielding systems.

  11. 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.

  12. New approach to polarized deep inelastic scattering

    NASA Astrophysics Data System (ADS)

    Buccella, Franco; Soffer, Jacques

    1993-12-01

    We show, in a simple way, that the flavor asymmetry in the light-quark sea of the proton discovered by the New Muon Collaboration suggests also a large flavor asymmetry for the corresponding polarized distributions. This accounts for the violation of the Ellis-Jaffe proton sum rule reported by the European Muon Collaboration, but it implies no violation of the Ellis-Jaffe neutron sum rule, which seems confirmed from the very recent SLAC data.

  13. Protonated water clusters in TPC's

    NASA Astrophysics Data System (ADS)

    Kaya, Yunus; Kalkan, Yalçın; Veenhof, Rob

    2016-07-01

    Water vapour is added to the ALICE TPC gas to enhance its stability. These polar molecules create large protonated water clusters around a H+ core. In this context, the reactions H3O+(H2O)n-1 +H2 O →H3O+(H2O)n (n=1-9) were studied in the gas phase. Structures for these clusters are suggested and the most stable structures for each cluster size are shown. The thermodynamic parameters Δ Hn-1,n0,Δ Gn-1,n0,Δ Sn-1,n0 and equilibrium constants Kn-1,n for the reaction were calculated to determine the size of the water clusters. The results are close to experimental data found in the literature. Protonated water clusters at stp have a size of 6-9 which corresponds to a mass of 127.1 - 181.2 g / mole.

  14. Experimental cross sections for charged particle production of the therapeutic radionuclide 111Ag and its PET imaging analogue 104m,gAg

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Takács, S.; Tárkányi, F.; Bolbos, R.

    2004-04-01

    Proton and deuteron particle induced nuclear reactions for generation of selected Ag radionuclides used in therapeutic or diagnostic nuclear medicine were investigated with the stacked foil activation technique on natural palladium targets up to Ep=43 MeV and Ed=22 MeV, respectively. Excitation functions are reported for the first time for the reactions natPd(d, xn) 111Ag, natPd(d, xn) 110mAg, natPd(d, xn) 104m,gAg, natPd(p, xn) 104m,gAg. Optimal production pathways with minimal contamination, cross sections, thick target yields and activation functions have been deduced and compared with available experimental data.

  15. The polarization sensitivity of GRETINA

    NASA Astrophysics Data System (ADS)

    Wiens, Andreas; Gretina Collaboration

    2014-09-01

    The new tracking array GRETINA provides position information of the individual interactions of γ rays within the active Ge detector material. The position knowledge of the first two interaction points enables the calculation of the Compton scattering angle, which is sensitive to the linear polarization. Measuring the angular distribution and the linear polarization can help determine the electromagnetic character of a transition and its parity. Inelastic proton scattering on Mg (24 Mg (p , p ' γ)) provides highly polarized γ rays which we used to characterize the polarization sensitivity of GRETINA. We have studied the angular distribution and the azimuthal Compton scattering angle of the 1368 keV gamma transition after signal-decomposition and tracking, which were normalized with the unpolarized results derived from 60 Co . The a2 and a4 coefficients from the Legendre Polynomial fit of the angular distribution confirmed the high degree of polarization. We will report on the asymmetry in the azimuthal Compton scattering angle distribution which is in good agreement with a cos (2 φ) fit. We will discuss the energy dependance of the polarization sensitivity and compare the results with a GEANT4 simulation. The new tracking array GRETINA provides position information of the individual interactions of γ rays within the active Ge detector material. The position knowledge of the first two interaction points enables the calculation of the Compton scattering angle, which is sensitive to the linear polarization. Measuring the angular distribution and the linear polarization can help determine the electromagnetic character of a transition and its parity. Inelastic proton scattering on Mg (24 Mg (p , p ' γ)) provides highly polarized γ rays which we used to characterize the polarization sensitivity of GRETINA. We have studied the angular distribution and the azimuthal Compton scattering angle of the 1368 keV gamma transition after signal-decomposition and tracking

  16. Proton decay theory

    SciTech Connect

    Marciano, W.J.

    1983-01-01

    Topics include minimal SU(5) predictions, gauge boson mediated proton decay, uncertainties in tau/sub p/, Higgs scalar effects, proton decay via Higgs scalars, supersymmetric SU(5), dimension 5 operators and proton decay, and Higgs scalars and proton decay. (WHK)

  17. Polar Glaciology

    NASA Technical Reports Server (NTRS)

    Robin, G. D.

    1984-01-01

    Two fields of research on polar ice sheets are likely to be of dominant interest during the 1990s. These are: the role of polar ice sheets in the hydrological cycle ocean-atmosphere-ice sheets-oceans, especially in relation to climate change; and the study and interpretation of material in deep ice cores to provide improved knowledge of past climates and of the varying levels of atmospheric constituents such as CO2, NOx, SO2, aerosols, etc., over the past 200,000 years. Both topics require a better knowledge of ice dynamics. Many of the studies that should be undertaken in polar regions by Earth Observing System require similar instruments and techniques to those used elsewhere over oceans and inland surfaces. However to study polar regions two special requirements need to be met: Earth Observing System satellite(s) need to be in a sufficiently high inclination orbit to cover most of the polar regions. Instruments must also be adapted, often by relatively limited changes, to give satisfactory data over polar ice. The observational requirements for polar ice sheets in the 1990s are summarized.

  18. Modelling of the AGS using Zgoubi - Status

    SciTech Connect

    Meot F.; Ahrens, L.; Dutheil, Y.; Glenn, J.; Huang, H.; Roser, T.; Schoefer, V.; Tsoupas, N.

    2012-05-20

    This paper summarizes the progress achieved so far, and discusses various outcomes, regarding the development of a model of the Alternating Gradient Synchrotron at the RHIC collider. The model, based on stepwise ray-tracing methods, includes beam and polarization dynamics. This is an on-going work, and a follow-on of code developments and particle and spin dynamics simulations that have been subject to earlier publications at IPAC and PAC [1, 2, 3]. A companion paper [4] gives additional informations, regarding the use of the measured magnetic field maps of the AGS main magnets.

  19. 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.

  20. Mass Measurements and Implications for the Energy of the High-Spin Isomer in {sup 94}Ag

    SciTech Connect

    Kankainen, A.; Elomaa, V.-V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Moore, I. D.; Penttilae, H.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Saastamoinen, A.; Sonoda, T.; Weber, C.; Aeystoe, J.; Batist, L.; Popov, A.; Seliverstov, D. M.; Eliseev, S.; Novikov, Yu. N.

    2008-10-03

    Nuclides in the vicinity of {sup 94}Ag have been studied with the Penning trap mass spectrometer JYFLTRAP at the Ion-Guide Isotope Separator On-Line. The masses of the two-proton-decay daughter {sup 92}Rh and the beta-decay daughter {sup 94}Pd of the high-spin isomer in {sup 94}Ag have been measured, and the masses of {sup 93}Pd and {sup 94}Ag have been deduced. When combined with the data from the one-proton- or two-proton-decay experiments, the results lead to contradictory mass excess values for the high-spin isomer in {sup 94}Ag, -46 370(170) or -44 970(100) keV, corresponding to excitation energies of 6960(400) or 8360(370) keV, respectively.

  1. Intermediate-range chemical ordering of cations in molten RbCl-AgCl.

    PubMed

    Tahara, S; Kawakita, Y; Shimakura, H; Ohara, K; Fukami, T; Takeda, S

    2015-07-28

    A first sharp diffraction peak (FSDP) is observed in the X-ray total structure factor of a molten mixture of RbCl-AgCl, while both pure melts of RbCl and AgCl do not exhibit FSDP individually. Molecular dynamics simulations were performed to investigate the origin of the FSDP with the polarizable ion model (PIM). Coexistence of covalent Ag-Cl and ionic Rb-Cl bonds leads the system to evolve intermediate range ordering, which is simulated by introducing the induced polarization in different ways between Ag-Cl with fully polarizable treatment based on Vashishta-Raman potential and Rb-Cl with suppression over-polarization in the nearest neighbor contribution based on Born-Meyer potential. The partial structure factors for both the Ag-Ag and Rb-Rb correlations, SAgAg(Q) and SRbRb(Q), show a positive contribution to the FSDP, while SAgRb(Q) for the Ag-Rb correlation exhibits a negative contribution, indicating that Ag and Rb ions are distributed in an alternating manner within the intermediate-range length scale. The origin of the intermediate-range chemical ordering of cations can be ascribed to the preferred direction of the dipole moments of anions in the PIM. PMID:26233147

  2. Construction and early commissioning results of the AGS Booster

    SciTech Connect

    Weng, W.T.; Ahrens, L.; Damm, R.; McNerney, A.J.

    1991-01-01

    The AGS Booster synchrotron has been designed to accelerate protons from 200 MeV to 1.5 GeV and heavy ions from several MeV per nucleon to several hundred MeV per nucleon for all the nuclei up to gold. The design requirements and measurements results of major accelerator components and systems are presented. The early commissioning results of the injection is also presented. 12 refs., 9 figs., 2 tabs.

  3. 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.

  4. Polarization Preservation and Control in a Figure-8 Ring

    NASA Astrophysics Data System (ADS)

    Derbenev, Ya. S.; Morozov, V. S.; Lin, F.; Zhang, Y.; Kondratenko, A. M.; Kondratenko, M. A.; Filatov, Yu. N.

    2016-02-01

    We present a complete scheme for managing the polarization of ion beams in Jefferson Lab’s proposed Medium-energy Electron-Ion Collider (MEIC). It provides preservation of the ion polarization during all stages of beam acceleration and polarization control in the collider’s experimental straights. We discuss characteristic features of the spin motion in accelerators with Siberian snakes and in accelerators of figure-8 shape. We propose 3D spin rotators for polarization control in the MEIC ion collider ring. We provide polarization calculations in the collider with the 3D rotator for deuteron and proton beams. The main polarization control features of the figure-8 design are summarized.

  5. Polarizing cues.

    PubMed

    Nicholson, Stephen P

    2012-01-01

    People categorize themselves and others, creating ingroup and outgroup distinctions. In American politics, parties constitute the in- and outgroups, and party leaders hold sway in articulating party positions. A party leader's endorsement of a policy can be persuasive, inducing co-partisans to take the same position. In contrast, a party leader's endorsement may polarize opinion, inducing out-party identifiers to take a contrary position. Using survey experiments from the 2008 presidential election, I examine whether in- and out-party candidate cues—John McCain and Barack Obama—affected partisan opinion. The results indicate that in-party leader cues do not persuade but that out-party leader cues polarize. This finding holds in an experiment featuring President Bush in which his endorsement did not persuade Republicans but it polarized Democrats. Lastly, I compare the effect of party leader cues to party label cues. The results suggest that politicians, not parties, function as polarizing cues. PMID:22400143

  6. Polar motion

    NASA Technical Reports Server (NTRS)

    Kolenkiewicz, R.

    1973-01-01

    Tracking of the Beacon Explorer-C satellite by a precision laser system was used to measure the polar motion and solid earth tide. The tidal perturbation of satellite latitude is plotted as variation in maximum latitude in seconds of arc on earth's surface as a function of the date, and polar motion is shown by plotting the variation in latitude of the laser in seconds of arc along the earth's surface as a function of date

  7. A H+/Ag+ dual-target responsive label-free light-up probe based on a DNA triplex.

    PubMed

    Xu, Lijun; Guo, Yahui; Wang, Jine; Zhou, Lu; Zhang, Yuanyuan; Hong, Shanni; Wang, Zhili; Zhang, Jianye; Pei, Renjun

    2015-05-01

    We developed a dual-target responsive sensor for label-free light-up fluorescent detection of protons (H(+)) and silver ions (Ag(+)) using an "OR'' logic gate. Berberine, a cost-effective and non-toxic indicator, partially intercalates the formed triplex DNA in the presence of H(+) or Ag(+), generating enhanced fluorescence. The designed Ag(+) probe has high selectivity and desirable sensitivity, which is necessary for practical use. The robust "OR" logic gate is capable of a rapid and reversible response to the H(+) and/or Ag(+) inputs. PMID:25663002

  8. Accelerating and storing polarized hadron beams

    SciTech Connect

    Teng, L.C.

    1990-10-01

    Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power in pp elastic scattering remains high, why hyperons are produced with high polarizations etc. It is, therefore, interesting to investigate the possibilities of accelerating and storing polarized beams in high energy colliders. On the technical side the recent understanding and confirmation of the actions of partial and multiple Siberian snakes made it possible to contemplate accelerating and storing polarized hadron beams to multi-TeV energies. In this paper, we will examine the equipment, the operation and the procedure required to obtain colliding beams of polarized protons at TeV energies.

  9. Spin and structural features of oxygen dissociation on tetrahedral Ag20 and Ag19Au clusters.

    PubMed

    Pichugina, D A; Polynskaya, Y G; Kuz'menko, N E

    2016-07-21

    The spin-crossing mechanism of oxygen dissociation on Ag20 and monodoped Ag19Au clusters was investigated via spin-polarized scalar-relativistic DFT calculations using the PBE, TPSSh, M06L, mPBE, BLYP, OLYP, and B3LYP functionals. In particular, the singlet and triplet O-O bond rupture pathways at vertex-edge and facet-edge sites on the tetrahedral clusters were studied. The calculations reveal that for the Ag20O2 and Ag19AuO2 complexes, the spin inversion from the triplet to singlet state occurs during the last step, which involves O-O bond rupture through a singlet transition state (TS). When spin crossing during oxygen dissociation on the clusters is considered, the activation energies decrease by 10-29 kJ mol(-1); however, they are still high due to the magic nature of the clusters and high vertical spin excitation energies. For these silver clusters, size effects based on the relationship between the TS structure and oxidation activation energy were predicted. PMID:27327106

  10. Polarizing mechanisms for stored and beams interacting with a polarized target.

    PubMed

    Milstein, A I; Strakhovenko, V M

    2005-12-01

    The kinetics of the polarization buildup during the interaction of stored protons (antiprotons) with a polarized target is considered. It is demonstrated that for small scattering angles, when a projectile remains in the beam, the polarization buildup is completely due to the spin-flip transitions. The corresponding cross sections turn out to be negligibly small for a hydrogen gas target as well as for a pure electron target. For the latter, the filtering mechanism also does not provide a noticeable beam polarization. PMID:16486071

  11. Morphological and electrochemical characterization of electrodeposited Zn–Ag nanoparticle composite coatings

    SciTech Connect

    Punith Kumar, M.K.; Srivastava, Chandan

    2013-11-15

    Silver nanoparticles with an average size of 23 nm were chemically synthesized and used to fabricate Zn–Ag composite coatings. The Zn–Ag composite coatings were generated by electrodeposition method using a simple sulfate plating bath dispersed with 0.5, 1 and 1.5 g/l of Ag nanoparticles. Scanning electron microscopy, X-ray diffraction and texture co-efficient calculations revealed that Ag nanoparticles appreciably influenced the morphology, micro-structure and texture of the deposit. It was also noticed that agglomerates of Ag nanoparticles, in the case of high bath load conditions, produced defects and dislocations on the deposit surface. Ag nanoparticles altered the corrosion resistance property of Zn–Ag composite coatings as observed from Tafel polarization, electrochemical impedance analysis and an immersion test. Reduction in corrosion rate with increased charge transfer resistance was observed for Zn–Ag composite coatings when compared to a pure Zn coating. However, the particle concentration in the plating bath and their agglomeration state directly influenced the surface morphology and the subsequent corrosion behavior of the deposits. - Highlights: • Synthesis of Ag nanoparticles with an average size of 23 nm • Fabrication of Zn/nano Ag composite coating on mild steel • Composite coatings showed better corrosion resistance. • Optimization of particle concentration is necessary.

  12. Freeze-dried PVP-Ag+ precursors to novel AgBr/AgCl-Ag hybrid nanocrystals for visible-light-driven photodegradation of organic pollutants

    NASA Astrophysics Data System (ADS)

    Chen, Deliang; Chen, Qianqian; Zhang, Wenjie; Ge, Lianfang; Shao, Gang; Fan, Bingbing; Lu, Hongxia; Zhang, Rui; Yang, Daoyuan; Shao, Guosheng

    2015-04-01

    AgBr/AgCl-Ag nanocrystals with various molar Br-to-Ag ratios (RBr/Ag = 0, 1/3, 1/2, 2/3, 1) and different photoreduction times (0-20 min) were synthesized via stepwise liquid-solid reactions using the freeze-dried PVP-Ag+ hybrid as the Ag source, followed by a photoreduction reaction. The AgBr/AgCl-Ag7.5(1:2) nanocrystals obtained take on a spherical morphology with a particle-size range of 58 ± 15 nm. The photocatalytic performance of AgBr/AgCl-Ag nanocrystals was evaluated by photodegrading organic dyes, 4-chlorophenol and isopropanol under artificial visible light (λ ⩾ 420 nm, 100 mW cm-2). For the decomposition of rhodamine B, the AgBr/AgCl-Ag7.5(1:2) nanocrystals has a photodegradation rate of ∼0.87 min-1, ∼159 times higher than that (∼0.0054 min-1) of TiO2 (P25), whereas the AgCl-Ag and AgBr-Ag nanocrystals have photodegradation rates of 0.35 min-1 and 0.45 min-1, respectively. The efficient separation of photogenerated electron-hole pairs in the ternary system consisting of AgBr, AgCl and Ag species plays a key role in the enhancement of photocatalytic performance.

  13. Ag K- and L3-edge XAFS study on Ag species in Ag/Ga2O3 photocatalysts

    NASA Astrophysics Data System (ADS)

    Yamamoto, M.; Yoshida, T.; Yamamoto, N.; Nomoto, T.; Yamamoto, A.; Yoshida, H.; Yagi, S.

    2016-05-01

    Ag loaded Ga2O3 (Ag/Ga2O3) shows photocatalytic activity for reduction of CO2 with water. Ag L3-edge XANES and K-edge EXAFS spectra were measured for various Ag/Ga2O3 samples, which suggested that structural and chemical states of Ag species varied with the loading amount of Ag and the preparation method. The Ag species were metallic Ag particles with an AgGaO2-like interface structure in the sample with high loading amount of Ag while predominantly Ag metal clusters in the sample with low loading amount of Ag. The XANES feature just above the edge represented the interaction between the Ag species and the Ga2O3 surface, showing that the Ag metal clusters had more electrons in the d-orbitals by interacting with the Ga2O3 surface, which would contribute the high photocatalytic activity.

  14. 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.

  15. AGS experiments -- 1995, 1996 and 1997

    SciTech Connect

    Depken, J.C.; Presti, P.L.

    1997-12-01

    This report contains (1) FY 1995 AGS schedule as run; (2) FY 1996 AGS schedule as run; (3) FY 1997 AGS schedule as run; (4) FY 1998--1999 AGS schedule (proposed); (5) AGS beams 1997; (6) AGS experimental area FY 1995 physics program; (7) AGS experimental area FY 1996 physics program; (8) AGS experimental area FY 1997 physics program; (9) AGS experimental area FY 1998--1999 physics program (proposed); (10) a listing of experiments by number; (11) two-page summaries of each experiment, in order by number; and (12) listing of publications of AGS experiments.

  16. AGS experiments -- 1991, 1992, 1993. Tenth edition

    SciTech Connect

    Depken, J.C.

    1994-04-01

    This report contains: (1) FY 1993 AGS schedule as run; (2) FY 1994--95 AGS schedule; (3) AGS experiments {ge} FY 1993 (as of 30 March 1994); (4) AGS beams 1993; (5) AGS experimental area FY 1991 physics program; (6) AGS experimental area FY 1992 physics program; (7) AGS experimental area FY 1993 physics program; (8) AGS experimental area FY 1994 physics program (planned); (9) a listing of experiments by number; (10) two-page summaries of each experiment; (11) listing of publications of AGS experiments; and (12) listing of AGS experiments.

  17. OPPIS UPGRADE FOR 2003 POLARIZED RUN IN RHIC.

    SciTech Connect

    ZELENSKI,A.ALESSI,J.BRISCOE,B.KPONOU,A.KOKHANOVSKI,S.KLENOV,V.LODESTRO,V.RITTER,J.ZUBETS,V.

    2002-11-06

    The polarization dilution by molecular ions which are produced in the ECR primary proton source is discussed. The molecular component can be reduced to about 5% by ECR source-operation optimization. It is further suppressed by optimization of the extraction electrode optics and by the decelerating einzel lens in the 35 keV LEBT line. As a result, the proton polarization of the accelerated beam was increased to over 80%. as measured in the 200 MeV proton-deuterium polarimeter. The OPPIS upgrade for 6 2/3 Hz repetition rate operation is also discussed.

  18. A new movable polarized target at Dubna

    SciTech Connect

    Anischenko, N.G.; Bazhanov, N.A.; Benda, B.; Borisov, N.S.; Borzunov, Y.T.; Burinov, V.F.; Durand, G.; Dzyubak, A.P.; Gevchuk, A.V.; Golovanov, L.B.; Gurevich, G.M.; Kovalev, A.I.; Lazarev, A.B.; Leconte, P.; Lehar, F.; de Lesquen, A.; Lukhanin, A.A.; Matafonov, V.N.; Matyushevsky, E.A.; Mironov, S.; Neganov, A.B.; Piskunov, N.M.; Plis, Y.A.; Shilov, S.N.; Shishov, Y.A.; Sorokin, P.V.; Teterin, V.V.; Topalov, S.

    1995-09-01

    A description of the recently installed mouable Polarized Proton Targe (MPT) at the JINR in Dubna is described. This target was acquired from Fermilab. The physics program based on the MPT at Dbna is outlined. (AIP) {copyright} {ital 1995 American Institute of Physics.}

  19. Review of polarized internal gas targets

    NASA Astrophysics Data System (ADS)

    Rathmann, Frank

    2002-03-01

    Experiments utilizing polarized internal gas targets are discussed. Since a few years these targets are used at electron and proton machines and considerable progress has been made in operating them on a routinely basis. This paper will focus on experimental aspects, such as the design and construction of storage cells and different methods employed for polarimetry.

  20. Review of polarized internal gas targets

    NASA Astrophysics Data System (ADS)

    Rathmann, Frank

    2000-06-01

    Experiments utilizing polarized internal gas targets will be reviewed. Since a few years these targets are being used at electron and proton machines and the progress made in operating these targets on a routinely basis has been pronounced. This paper will focus on experimental aspects, such as the design and construction of storage cells and different methods employed for polarimetry.

  1. What's In a Proton?

    ScienceCinema

    Brookhaven Lab

    2010-01-08

    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

  2. Proton pump inhibitors

    MedlinePlus

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

  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. Destabilization of Ag nanoislands on Ag(100) by adsorbed sulfur

    SciTech Connect

    Shen, Mingmin; Russell, Selena M.; Liu, Da-Jiang; Thiel, Patricia A.

    2011-10-17

    Sulfur accelerates coarsening of Ag nanoislands on Ag(100) at 300 K, and this effect is enhanced with increasing sulfur coverage over a range spanning a few hundredths of a monolayer, to nearly 0.25 monolayers. We propose that acceleration of coarsening in this system is tied to the formation of AgS{sub 2} clusters primarily at step edges. These clusters can transport Ag more efficiently than can Ag adatoms (due to a lower diffusion barrier and comparable formation energy). The mobility of isolated sulfur on Ag(100) is very low so that formation of the complex is kinetically limited at low sulfur coverages, and thus enhancement is minimal. However, higher sulfur coverages force the population of sites adjacent to step edges, so that formation of the cluster is no longer limited by diffusion of sulfur across terraces. Sulfur exerts a much weaker effect on the rate of coarsening on Ag(100) than it does on Ag(111). This is consistent with theory, which shows that the difference between the total energy barrier for coarsening with and without sulfur is also much smaller on Ag(100) than on Ag(111).

  5. Central Exclusive Production in Proton-Proton Collisions with the STAR Experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Guryn, Włodek

    2016-07-01

    We shall describe the physics program with tagged forward protons, focusing on Central Exclusive Production in polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC), with the STAR detector at √s = 200 GeV. Preliminary results in CEP of two oppositely charged pions and kaons produced in the processes pp → ppπ+π- and pp → ppK+K- shall be presented. Those Double Pomeron Exchange (DPE) processes, allow the final states to be dominated by gluonic exchanges. Silicon strip detectors placed in Roman Pots were used for measuring forward protons. The preliminary results are based on the measurement of the recoil system of charged particles in the STAR experiment's Time Projection Chamber (TPC). Ionization energy loss, dE/dx, of charged particles was used for particle identification (PID).

  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. PMID:24074929

  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. Proton-driven electromagnetic instabilities in high-speed solar wind streams

    NASA Technical Reports Server (NTRS)

    Abraham-Shrauner, B.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.

    1979-01-01

    Electromagnetic instabilities of the field-aligned, right-hand circularly polarized magnetosonic wave and the left-hand circularly polarized Alfven wave driven by two drifted proton components are analyzed for model parameters determined from Imp 7 solar wind proton data measured during high-speed flow conditions. Growth rates calculated using bi-Lorentzian forms for the main and beam proton as well as core and halo electron velocity distributions do not differ significantly from those calculated using bi-Maxwellian forms. Using distribution parameters determined from 17 measured proton spectra, we show that considering the uncertainties the magnetosonic wave may be linearly stable and the Alfven wave is linearly unstable. Because proton velocity distribution function shapes are observed to persist for times long compared to the proton gyroperiod, the latter result suggests that linear stability theory fails for proton-driven ion cyclotron waves in the high-speed solar wind.

  9. Polar Stratigraphy

    NASA Technical Reports Server (NTRS)

    1999-01-01

    These three images were taken on three different orbits over the north polar cap in April 1999. Each shows a different part of the same ice-free trough. The left and right images are separated by a distance of more than 100 kilometers (62 miles). Note the similar layers in each image.

  10. Political polarization

    PubMed Central

    Dixit, Avinash K.; Weibull, Jörgen W.

    2007-01-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality. PMID:17452633

  11. The AGS Booster beam loss monitor system

    SciTech Connect

    Beadle, E.R.; Bennett, G.W.; Witkover, R.L.

    1991-01-01

    A beam loss monitor system has been developed for the Brookhaven National Laboratory Booster accelerator, and is designed for use with intensities of up to 1.5 {times} 10{sup 13} protons and carbon to gold ions at 50-3 {times} 10{sup 9} ions per pulse. This system is a significant advance over the present AGS system by improving the sensitivity, dynamic range, and data acquisition. In addition to the large dynamic range achievable, it is adaptively shifted when high losses are detected. The system uses up to 80 argon filled ion chambers as detectors, as well as newly designed electronics for processing and digitizing detector outputs. The hardware simultaneously integrates each detector output, interfaces to the beam interrupt systems, and digitizes all 80 channels to 21 bits at 170 KHz. This paper discuses the design, construction, and operation of the system. 4 refs., 2 figs.

  12. New AGS slow external beam switchyard

    SciTech Connect

    Brown, H; Brown, R; Chimienti, L

    1981-01-01

    The original switchyard for the Slow External Proton Beam at the AGS of Brookhaven National Laboratory incorporated two current carrying, copper septa to split the beam into three parts. These septa were each .05 mm thick and intercepted a substantial amount of beam when, as often occurs, it was necessary to split the beam across its densest region. To adjust splitting ratios and optimize losses, a complex time consuming pattern of steering adjustments using various magnets was necessary. When the question of providing a fourth beam to a new target station arose, it was clear that adding a third copper septum in the very constrained space available would lead to unacceptable increases in the radiation and control problems. In order to circumvent these difficulties, it was decided to rebuild the switchyard using much thinner electrostatic septa as splitters and to provide a greater degree of independence of the various beam segments.

  13. The AGS Booster Beam Position Monitor system

    SciTech Connect

    Ciardullo, D.J.; Abola, A.; Beadle, E.R.; Smith, G.A.; Thomas, R.; Van Zwienen, W.; Warkentien, R.; Witkover, R.L.

    1991-01-01

    To accelerate both protons and heavy ions, the AGS Booster requires a broadband (multi-octave) beam position monitoring system with a dynamic range spanning several orders of magnitude (2 {times} 10{sup 10} to 1.5 {times} 10{sup 13} particles per pulse). System requirements include the ability to acquire single turn trajectory and average orbit information with {plus minus} 0.1 mm resolution. The design goal of {plus minus} 0.5 mm corrected accuracy requires that the detectors have repeatable linear performance after periodic bakeout at 300 {degree}C. The system design and capabilities of the Booster Beam Position Monitor will be described, and initial results presented. 7 refs., 5 figs.

  14. Determination of solar proton fluxes and energies at high solar latitudes by UV radiation measurements

    NASA Technical Reports Server (NTRS)

    Witt, N.; Blum, P. W.; Ajello, J. M.

    1981-01-01

    The latitudinal variation of the solar proton flux and energy causes a density increase at high solar latitudes of the neutral gas penetrating the heliosphere. Measurements of the neutral density by UV resonance radiation observations from interplanetary spacecraft thus permit deductions on the dependence of the solar proton flux on heliographic latitude. Using both the results of Mariner 10 measurements and of other off-ecliptic solar wind observations, the values of the solar proton fluxes and energies at polar heliographic latitudes are determined for several cases of interest. The Mariner 10 analysis, together with IPS results, indicate a significant decrease of the solar proton flux at polar latitudes.

  15. Photoemission from Shockley surface state on Ag(111)

    NASA Astrophysics Data System (ADS)

    Karkare, Siddharth; Wan, Weishi; Feng, Jun; Padmore, Howard

    We present measurements of quantum yield and transverse momentum distributions of electrons emitted from the Shockley surface state on Ag(111) surface using near threshold photons. Our measurements shed light on the validity of the conservation of transverse momentum during photoemission when the kinetic energy of electrons is less than 0.1 eV. We also develop a one-step photoemission model that quantitatively explains photoemission from single crystal metal surfaces. This model accurately calculates the dependence of the electron yield on the angle of incidence and the polarization of incident light (vectorial photoelectric effect). We show excellent agreement between the measured and calculated photoemission properties of the Ag(111) surface. Our measurements show that Ag(111) surface can act as an excellent electron source for several applications like Free Electron Lasers and Ultra-fast Electron Diffraction.

  16. What's the matter in the Proton?

    NASA Astrophysics Data System (ADS)

    Beise, Elizabeth

    2007-10-01

    It has been over 70 years since the Nobel Prize was awarded to Otto Stern for the discovery that the proton has an anomalously large magnetic moment, nearly three times what one expects from a spin-1/2 object with no internal structure. This was one of the first hints of the spatial extent of protons and neutrons that make up nearly all of the visible matter in the universe. Not long after this discovery, this interior landscape began to be explored in detail through the use of electron scattering, a precision microscope with which one can peer deep inside the nucleon. Recent experiments, using polarized beams, light polarized targets, recoil detection and complementary views via the weak interaction are now changing our traditional textbook view of the nucleon and its lowest-lying excited states. This talk will be a review of the recent experimental results and a summary of near future opportunities.

  17. Squeezing at entrance of proton transport pathway in proton-translocating pyrophosphatase upon substrate binding.

    PubMed

    Huang, Yun-Tzu; Liu, Tseng-Huang; Lin, Shih-Ming; Chen, Yen-Wei; Pan, Yih-Jiuan; Lee, Ching-Hung; Sun, Yuh-Ju; Tseng, Fan-Gang; Pan, Rong-Long

    2013-07-01

    Homodimeric proton-translocating pyrophosphatase (H(+)-PPase; EC 3.6.1.1) is indispensable for many organisms in maintaining organellar pH homeostasis. This unique proton pump couples the hydrolysis of PPi to proton translocation across the membrane. H(+)-PPase consists of 14-16 relatively hydrophobic transmembrane domains presumably for proton translocation and hydrophilic loops primarily embedding a catalytic site. Several highly conserved polar residues located at or near the entrance of the transport pathway in H(+)-PPase are essential for proton pumping activity. In this investigation single molecule FRET was employed to dissect the action at the pathway entrance in homodimeric Clostridium tetani H(+)-PPase upon ligand binding. The presence of the substrate analog, imidodiphosphate mediated two sites at the pathway entrance moving toward each other. Moreover, single molecule FRET analyses after the mutation at the first proton-carrying residue (Arg-169) demonstrated that conformational changes at the entrance are conceivably essential for the initial step of H(+)-PPase proton translocation. A working model is accordingly proposed to illustrate the squeeze at the entrance of the transport pathway in H(+)-PPase upon substrate binding. PMID:23720778

  18. Electron correlation and relativistic effects in the coinage metal compounds. II. Heteronuclear dimers: CuAg, CuAu, and AgAu

    NASA Astrophysics Data System (ADS)

    Kellö, Vladimir; Sadlej, Andrzej J.

    1995-08-01

    Electric properties of heteronuclear dimers of the coinage metals are calculated at the level of the CCSD(T) approximation applied to 38 electrons of the valence and next-to-valence atomic shells. The relativistic effects are accounted for by using the scalar approximation to the Pauli hamiltonian. Both the pure relativistic and mixed relativistic-correlation contributions to energies and electric properties are computed. All calculations have been carried out by using the recently developed first-order polarized basis sets of the coinage metal atoms. In the non-relativistic approximation all studied dimers show only a moderate degree of polarity; the non-relativistic CuAg turns out to be the most polar dimer with the Cu(-)Ag(+) polarity. The relativistic effects considerably reduce the negative value of the CuAg dipole moment, change the sign of the CuAu dipole moment, and make the AgAu molecule the most polar species in the series. Simultaneously, the parallel component of the dipole polarizability shows only a small relativistic contraction. The calculated quasirelativistic interaction potentials have a correct behavior in the vicinity of their minima and give the Re and ωe values in complete agreement with experiment. Much less satisfactory are the dissociation energy data which seem to suffer from the single reference configuration approximation.

  19. Organic pollutant photodecomposition by Ag/KNbO3 nanocomposites: A combined experimental and theoretical study

    DOE PAGESBeta

    Zhang, Tingting; Liu, Ping; Lei, Wanying; Rodriguez, J. A.; Yu, Jiaguo; Qi, Yang; Liu, Gang; Liu, Minghua

    2016-01-12

    In this study, Ag nanoparticles supported on well-defined perovskite orthorhombic KNbO3 nanowires are synthesized via facile photoreduction and systematically characterized by XRD, Raman, DRUV–vis, XPS, PL, TEM, HRTEM, and HAADF-STEM. The photoreactivity of Ag/KNbO3 nanocomposites as a function of Ag contents (0.4–2.8 wt %) is assessed toward aqueous rhodamine B degradation under UV- and visible-light, respectively. It is found that the UV-induced photoreactivity initially increases and then decreases with increasing Ag contents. At an optimal Ag content (ca. 1.7 wt %), the greatest photoreactivity is achieved under UV light, with the photocatalytic reaction rate of 1.7 wt % Ag/KNbO3 exceedingmore » that of pristine KNbO3 by a factor of ca. 13. In contrast, visible light-induced photoreactivity monotonically increases with increasing Ag contents in the range of 0.4–2.8 wt %. On the basis of the detected active species and intermediate products in the photocatalytic processes, conjugated structure cleavage and N-deethylation are revealed to be the respective predominant pathway under UV and visible-light illumination. To gain an insight into the observed photoreactivity, the electronic properties of Ag/KNbO3 have been investigated using spin-polarized DFT calculations. Herein, Ag extended adlayers (1–4 ML) on the slab models of KNbO3 (101) are employed to mimic large supported Ag nanoparticles. A Bader analysis of the electron density shows a small net charge transfer (ca. 0.1 e) from KNbO3 to Ag. The electron localization function of Ag/KNbO3 (101) illustrates that Ag adlayers with thickness larger than 2 ML are essentially metallic, and weak polarization occurs at the interface. In addition, the metallic Ag adlayers generate a continuum of Ag bandgap states, which play a key role in determining different Ag content-dependent behavior between UV and visible-light illumination.« less

  20. Polarized Solid Targets - Present and Future

    SciTech Connect

    Meyer, W.

    2009-08-04

    The development, in the early 1960s, of the dynamic nuclear polarization scheme in solid diamagnetic materials, doped with paramagnetic radicals, led to the use of solid polarized H and D targets in numerous nuclear and particle physics experiments. Since then steady progress has been made in all contributing sub-systems so that proton polarization values around 90% and deuteron polarization values between 40% and 80% have been achieved in various set-ups. These polarization values have been measured with a relative accuracy of {+-}5% or better using nuclear magnetic resonance techniques. Many experiments with reasonably high luminosities have taken advantage of these developments and many more are being planned, especially with electromagnetic probes. Latest developments open up the possibility to use DNP hyperpolarized substances for medical applications.

  1. FY2014 Parameters for Helions and Gold Ions in Booster, AGS, and RHIC

    SciTech Connect

    Gardner, C. J.

    2014-08-15

    The nominal parameters for helions (helion is the bound state of two protons and one neutron, the nucleus of a helium-3 atom) and gold ions in Booster, AGS, and RHIC are given for the FY2014 running period. The parameters are found using various formulas to derive mass, helion anomalous g-factor, kinetic parameters, RF parameters, ring parameters, etc..

  2. Results from polarized experiments at LEGS and GRAAL

    NASA Astrophysics Data System (ADS)

    D'Angelo, A.; Ardashev, K.; Bade, C.; Bartalini, O.; Bellini, V.; Blecher, M.; Bocqueti, J.-P.; Capogni, M.; Caracappa, A.; Casano, L. E.; Castoldi, M.; Di Salvo, R.; Fantini, A.; Franco, D.; Gervino, G.; Ghio, F.; Giardina, G.; Gibson, C.; Girolami, B.; Giusa, A.; Glükler, H.; Hicks, K.; Hoblit, S.; Honig, A.; Kageya, T.; Khandaker, M.; Kistner, O. C.; Kizilgul, S.; Kucuker, S.; Lapik, A.; Lehmann, A.; Sandri, P. Levi; Lleres, A.; Lowry, M.; Lucas, M.; Mahon, J.; Mammoliti, F.; Mandaglio, G.; Manganaro, M.; Miceli, L.; Moricciani, D.; Mushkarenkov, A.; Nedorezov, V.; Norum, B.; Pap, M.; Preedom, B.; Seyfarth, H.; Randieri, C.; Rebreyend, D.; Rudnev, N.; Russo, G.; Sandorfi, A.; Schaerf, C.; Sperduto, M.-L.; Ströher, H.; Sutera, M.-C.; Thorn, C. E.; Turinge, A.; Vegna, V.; Whisnant, C. S.; Wang, K.; Wei, X.

    2012-04-01

    Compton backscattering gamma ray beams are characterized by a high degree of linear and circular polarization with low unpolarized backgrounds and have proven to provide very precise measurements of polarization observables. Latest results from LEGS and GRAAL experiments on proton and deuteron targets are presented. The Σ beam asymmetry for ω photoproduction has been measured by the GRAAL collaboration for both the ω→π0γ and the ω→π+π-π0 decay channels on the proton target; single and double polarization asymmetries have been provided also for the K photoproduction channel. E and G double polarization asymmetries for single pion photoproduction on the proton and deuteron have been measured at LEGS using a frozen spin HD target.

  3. Conceptual design of a polarized 3He neutron spin filter for polarized neutron spectrometer POLANO at J-PARC

    NASA Astrophysics Data System (ADS)

    Ino, T.; Ohoyama, K.; Yokoo, T.; Itoh, S.; Ohkawara, M.; Kira, H.; Hayashida, H.; Sakai, K.; Hiroi, K.; Oku, T.; Kakurai, K.; Chang, L. J.

    2016-04-01

    A 3He neutron spin filter (NSF) has been designed for a new polarized neutron chopper spectrometer called the Polarization Analysis Neutron Spectrometer with Correlation Method (POLANO) at the Materials and Life Science Experimental Facility of the Japan Proton Accelerator Research Complex. It is designed to fit in a limited space on the spectrometer as an initial neutron beam polarizer and is polarized in situ by spin exchange optical pumping. This will be the first generation 3He NSF on POLANO, and a polarized neutron beam up to 100 meV with a diameter of 50 mm will be available for research on magnetism, hydrogen materials, and strongly correlated electron systems.

  4. Pulsars as cosmic ray particle accelerators: Proton orbits

    NASA Technical Reports Server (NTRS)

    Thielheim, K. O.

    1985-01-01

    Proton orbits are calculated in the electromagnetic vacuum field of a magnetic point dipole rotating with its angular velocity omega perpendicular to its dipole moment mu by numerical integration of the Lorentz-Dirac equation. Trajectories are shown and discussed for various initial conditions. A critical surface is shown separating initial positions of protons which finally hit the pulsar in the polar region from those which finally recede to infinity.

  5. 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.

  6. Cell polarity

    PubMed Central

    Romereim, Sarah M

    2011-01-01

    Despite extensive genetic analysis of the dynamic multi-phase process that transforms a small population of lateral plate mesoderm into the mature limb skeleton, the mechanisms by which signaling pathways regulate cellular behaviors to generate morphogenetic forces are not known. Recently, a series of papers have offered the intriguing possibility that regulated cell polarity fine-tunes the morphogenetic process via orienting cell axes, division planes and cell movements. Wnt5a-mediated non-canonical signaling, which may include planar cell polarity, has emerged as a common thread in the otherwise distinct signaling networks that regulate morphogenesis in each phase of limb development. These findings position the limb as a key model to elucidate how global tissue patterning pathways direct local differences in cell behavior that, in turn, generate growth and form. PMID:22064549

  7. Polar Textures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03646 Polar Textures

    This VIS image shows part of the south polar region. The ejecta from the relatively young crater covers the rougher textured polar surface.

    Image information: VIS instrument. Latitude 81S, Longitude 54.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  8. The proton form factor ratio results from Jefferson Lab

    SciTech Connect

    Vina Punjabi

    2012-09-01

    The ratio of the proton form factors, GE p/GMp, has been measured extensively, from Q2 of 0.5 GeV2 to 8.5 GeV2, 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 polarization transfer results are of unprecedented high precision and accuracy, due in large part to the small systematic uncertainties associated with the experimental technique. There is an approved experiment at JLab, GEP(5), to continue the ratio measurements to 12 GeV2. 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.

  9. Preparation and antibacterial activities of Ag/Ag+/Ag3+ nanoparticle composites made by pomegranate (Punica granatum) rind extract

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Ren, Yan-yu; Wang, Tao; Wang, Chuang

    Nano-silver and its composite materials are widely used in medicine, food and other industries due to their strong conductivity, size effect and other special performances. So far, more microbial researches have been applied, but a plant method is rarely reported. In order to open up a new way to prepare AgNP composites, pomegranate peel extract was used in this work to reduce Ag+ to prepare Ag/Ag+/Ag3+ nanoparticle composites. UV-Vis was employed to detect and track the reduction of Ag+ and the forming process of AgNPs. The composition, structure and size of the crystal were analyzed by XRD and TEM. Results showed that, under mild conditions, pomegranate peel extract reacted with dilute AgNO3 solution to produce Ag/Ag+/Ag3+ nanoparticle composites. At pH = 8 and 10 mmol/L of AgNO3 concentration, the size of the achieved composites ranged between 15 and 35 nm with spherical shapes and good crystallinity. The bactericidal experiment indicated that the prepared Ag/Ag+/Ag3+ nanoparticles had strong antibacterial activity against gram positive bacteria and gram negative bacteria. FTIR analysis revealed that biological macromolecules with groups of sbnd NH2, sbnd OH, and others were distributed on the surface of the newly synthesized Ag/Ag+/Ag3+ nanoparticles. This provided a useful clue to further study the AgNP biosynthesis mechanism.

  10. Nanoantioxidant-driven plasmon enhanced proton-coupled electron transfer

    NASA Astrophysics Data System (ADS)

    Sotiriou, Georgios A.; Blattmann, Christoph O.; Deligiannakis, Yiannis

    2015-12-01

    Proton-coupled electron transfer (PCET) reactions involve the transfer of a proton and an electron and play an important role in a number of chemical and biological processes. Here, we describe a novel phenomenon, plasmon-enhanced PCET, which is manifested using SiO2-coated Ag nanoparticles functionalized with gallic acid (GA), a natural antioxidant molecule that can perform PCET. These GA-functionalized nanoparticles show enhanced plasmonic response at near-IR wavelengths, due to particle agglomeration caused by the GA molecules. Near-IR laser irradiation induces strong local hot-spots on the SiO2-coated Ag nanoparticles, as evidenced by surface enhanced Raman scattering (SERS). This leads to plasmon energy transfer to the grafted GA molecules that lowers the GA-OH bond dissociation enthalpy by at least 2 kcal mol-1 and therefore facilitates PCET. The nanoparticle-driven plasmon-enhancement of PCET brings together the so far unrelated research domains of nanoplasmonics and electron/proton translocation with significant impact on applications based on interfacial electron/proton transfer.Proton-coupled electron transfer (PCET) reactions involve the transfer of a proton and an electron and play an important role in a number of chemical and biological processes. Here, we describe a novel phenomenon, plasmon-enhanced PCET, which is manifested using SiO2-coated Ag nanoparticles functionalized with gallic acid (GA), a natural antioxidant molecule that can perform PCET. These GA-functionalized nanoparticles show enhanced plasmonic response at near-IR wavelengths, due to particle agglomeration caused by the GA molecules. Near-IR laser irradiation induces strong local hot-spots on the SiO2-coated Ag nanoparticles, as evidenced by surface enhanced Raman scattering (SERS). This leads to plasmon energy transfer to the grafted GA molecules that lowers the GA-OH bond dissociation enthalpy by at least 2 kcal mol-1 and therefore facilitates PCET. The nanoparticle-driven plasmon

  11. Ag-Air Service

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Econ, Inc.'s agricultural aerial application, "ag-air," involves more than 10,000 aircraft spreading insecticides, herbicides, fertilizer, seed and other materials over millions of acres of farmland. Difficult for an operator to estimate costs accurately and decide what to charge or which airplane can handle which assignment most efficiently. Computerized service was designed to improve business efficiency in choice of aircraft and determination of charge rates based on realistic operating cost data. Each subscriber fills out a detailed form which pertains to his needs and then receives a custom-tailored computer printout best suited to his particular business mix.

  12. Polarization Measurements in High-Energy Deuteron Photodisintegration

    SciTech Connect

    Adam Sarty; Andrei Afanasev; Arunava Saha; Bogdan Wojtsekhowski; Brendan Fox; C. Chang; Cathleen Jones; Charles Glashausser; Charles Perdrisat; Cornelis De Jager; Cornelis de Jager; D. Crovelli; Daniel Simon; David Meekins; Demetrius Margaziotis; Dipangkar Dutta; Edgar Kooijman; Edward Brash; Edward Kinney; Elaine Schulte; Eugene Chudakov; Feng Xiong; Franco Garibaldi; Garth Huber; Gerfried Kumbartzki; Guido Urciuoli; Haiyan Gao; James Kelly; Javier Gomez; Jens-Ole Hansen; Jian-Ping Chen; John Calarco; John LeRose; Jordan Hovdebo; Joseph Mitchell; Juncai Gao; Kamal Benslama; Kathy McCormick; Kevin Fissum; Konrad Aniol; Krishni Wijesooriya; Louis Bimbot; Ludyvine Morand; Luminita Todor; Marat Rvachev; Mark Jones; Martin Epstein; Meihua Liang; Michael Kuss; Moskov Amarian; Nilanga Liyanage; Oleksandr Glamazdin; Olivier Gayou; Paul Ulmer; Pete Markowitz; Peter Bosted; R. Holt; Riad Suleiman; Richard Lindgren; Rikki Roche; Robert Michaels; Roman Pomatsalyuk; Ronald Gilman; Ronald Ransome; Salvatore Frullani; Scott Dumalski; Seonho Choi; Sergey Malov; Sonja Dieterich; Steffen Strauch; Stephen Becher; Steve Churchwell; Ting Chang; Viktor Gorbenko; Vina Punjabi; Xiaodong Jiang; Zein-Eddine Meziani; Zhengwei Chai; Wang Xu

    2001-04-01

    We present measurements of the recoil proton polarization for the d(polarized y, polarized p)n reaction at thetac.m. = 90 degrees for photon energies up to 2.4 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. The induced polarization py vanishes above 1 GeV, contrary to meson-baryon model expectations, in which resonances lead to large polarizations. However, the polarization transfer Cx does not vanish above 1 GeV, inconsistent with hadron helicity conservation. Thus, we show that the scaling behavior observed in the d(y,p)n cross sections is not a result of perturbative QCD. These data should provide important tests of new nonperturbative calculations in the intermediate energy regime.

  13. The Heliospheric Transport of Protons and Anti-Protons a Stochastic Modelling Approach to Pamela Observations

    NASA Astrophysics Data System (ADS)

    Strauss, R. D.; Potgieter, M. S.; Boezio, M.; de Simone, N.; di Felice, V.; Kopp, A.; Büsching, I.

    2012-08-01

    Using a newly developed 5D comic ray modulation model, we study the modulation of galactic protons and anti-protons inside the heliosphere. This is done for different heliospheric magnetic field polarity cycles, which, in combination with drifts, lead to charge-sign dependent cosmic ray transport. Computed energy spectra and intensity ratios for the different cosmic ray populations are shown and discussed. Modelling results are extensively compared to recent observations made by the PAMELA space borne particle detector. Using a stochastic transport approach, we also show pseudo-particle traces, illustrating the principle behind charge-sign dependent modulation.

  14. A P + DEUTERON PROTON POLARIMETER AT 200 MEV.

    SciTech Connect

    HUANG,H.; ROSER,T.; ZELENSKI,A.; KURITA,K.; STEPHENSON,E.; TOOLE,R.

    2002-06-02

    There has been concern about the analyzing power of the p-Carbon polarimeter at the end of 200 MeV LINAC of BNL. A new polarimeter based on proton-deuteron scattering was installed and we have repeated the calibration of proton-Carbon scattering at 12 degrees and 200 MeV against proton-deuteron scattering. The result is consistent with the value of A=0.62 now used to measure the beam polarization at the end of the LINAC.

  15. Intermediate-range chemical ordering of cations in molten RbCl-AgCl

    SciTech Connect

    Tahara, S.; Kawakita, Y.; Shimakura, H.; Ohara, K.; Fukami, T.; Takeda, S.

    2015-07-28

    A first sharp diffraction peak (FSDP) is observed in the X-ray total structure factor of a molten mixture of RbCl-AgCl, while both pure melts of RbCl and AgCl do not exhibit FSDP individually. Molecular dynamics simulations were performed to investigate the origin of the FSDP with the polarizable ion model (PIM). Coexistence of covalent Ag–Cl and ionic Rb–Cl bonds leads the system to evolve intermediate range ordering, which is simulated by introducing the induced polarization in different ways between Ag–Cl with fully polarizable treatment based on Vashishta-Raman potential and Rb–Cl with suppression over-polarization in the nearest neighbor contribution based on Born-Meyer potential. The partial structure factors for both the Ag–Ag and Rb–Rb correlations, S{sub AgAg}(Q) and S{sub RbRb}(Q), show a positive contribution to the FSDP, while S{sub AgRb}(Q) for the Ag–Rb correlation exhibits a negative contribution, indicating that Ag and Rb ions are distributed in an alternating manner within the intermediate-range length scale. The origin of the intermediate-range chemical ordering of cations can be ascribed to the preferred direction of the dipole moments of anions in the PIM.

  16. Morphology and electrochemical behavior of Ag-Cu nanoparticle-doped amalgams.

    PubMed

    Chung, Kwok-Hung; Hsiao, Li-Yin; Lin, Yu-Sheng; Duh, Jenq-Gong

    2008-05-01

    The aim of this study was to introduce Ag-Cu phase nanopowder as an additive to improve the corrosion behavior of dental amalgams. A novel Ag-Cu nanopowder was synthesized by the precipitation method. An amalgam alloy powder (World-Cap) was added and mixed with 5 wt.% and 10 wt.% of Ag-Cu nanopowders, respectively, to form experimental amalgam alloy powders. The original alloy powder was used as a control. Alloy powders were examined using X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy and electron probe microanalysis. Amalgam disk specimens of metallurgically prepared were tested in 0.9% NaCl solution using electrochemical methods. The changes in the corrosion potential and anodic polarization characteristics were determined. Corrosion potential data were analyzed statistically (n=3, analysis of variance, Tukey's test, p<0.05). The diameters of lamellar structure Ag-Cu nanoparticles were measured to be approximately 30 nm. The composition of the Ag-Cu nanoparticles determined by TEM-energy-dispersive spectroscopy was 56.28 at.% Ag-43.72 at.% Cu. A light-shaded phase was found mixing with dark Cu-Sn reaction particles in the reaction zones of Ag-Cu nanoparticle-doped amalgams. The Ag-Cu nanoparticle-doped amalgams exhibited zero current potentials more positive than the control (p<0.05) and no current peak was observed at -325mV that related to Ag-Hg phase and Cu6Sn5 phase in anodic polarization curves. The results indicated that the corrosion resistance of high-copper single-composition amalgam could be improved by Ag-Cu nanoparticle-doping. PMID:18321799

  17. The H1 very forward proton spectrometer at HERA

    NASA Astrophysics Data System (ADS)

    Astvatsatourov, A.; Cerny, K.; Delvax, J.; Favart, L.; Hreus, T.; Janssen, X.; Roosen, R.; Sykora, T.; Van Mechelen, P.

    2014-02-01

    The very forward proton spectrometer, VFPS, is a component of the H1 detector at the HERA collider. Scattered protons emitted with a polar angle less than 1 mrad and carrying a fractional energy 1 -xP, 0.008 proton beam energy can be detected by scintillating fiber detectors which are read out by position sensitive photo-multipliers. These detectors are contained in Roman pot stations which are moved close to the circulating proton beam. The structure, operation and performance of the two Roman pot stations located at about 220 m from the H1 interaction point in the cryogenic section of the proton ring are described.

  18. Bimetallic Pt-Ag and Pd-Ag nanoparticles

    SciTech Connect

    Lahiri, Debdutta; Bunker, Bruce; Mishra, Bhoopesh; Zhang, Zhenyuan; Meisel, Dan; Doudna, C. M.; Bertino, M. F.; Blum, Frank D.; Tokuhiro, A. T.; Chattopadhyay, Soma; Shibata, Tomohiro; Terry, Jeff

    2005-04-19

    We report studies of bimetallic nanoparticles with 15%–16% atomic crystal parameters size mismatch. The degree of alloying was also probed in a 2-nm Pt core ssmallest attainable core sized of Pt–Ag nanoparticles scompletely immiscible in bulkd and 20-nm-diameter Pd–Ag nanowires scompletely miscible in bulkd. Particles were synthesized radiolytically, and depending on the initial parameters, they assume spherical or cylindrical snanowired morphologies. In all cases, the metals are seen to follow their bulk alloying characteristics. Also, Pt and Ag segregate in both spherical and wire forms, which indicates that strain due to crystallographic mismatch overcomes the excess surface free energy in the small particles. The Pd–Ag nanowires alloy similar to previously reported spherical Pd–Ag particles of similar diameter and composition

  19. Bimetallic Pt-Ag and Pd-Ag nanoparticles

    SciTech Connect

    Lahiri, Debdutta; Bunker, Bruce; Mishra, Bhoopesh; Zhang, Zhenyuan; Meisel, Dan; Doudna, C.M.; Bertino, M. F.; Blum, Frank D.; Tokuhiro, A.T.; Chattopadhyay, Soma; Shibata, Tomohiro; Terry, Jeff

    2005-05-01

    We report studies of bimetallic nanoparticles with 15%-16% atomic crystal parameters size mismatch. The degree of alloying was probed in a 2-nm Pt core (smallest attainable core size) of Pt-Ag nanoparticles (completely immiscible in bulk) and 20-nm-diameter Pd-Ag nanowires (completely miscible in bulk). Particles were synthesized radiolytically, and depending on the initial parameters, they assume spherical or cylindrical (nanowire) morphologies. In all cases, the metals are seen to follow their bulk alloying characteristics. Pt and Ag segregate in both spherical and wire forms, which indicates that strain due to crystallographic mismatch overcomes the excess surface free energy in the small particles. The Pd-Ag nanowires alloy similar to previously reported spherical Pd-Ag particles of similar diameter and composition.

  20. Simulation study of proton transport in ionomers

    NASA Astrophysics Data System (ADS)

    Taylor, Philip; Allahyarov, Elshad

    2008-03-01

    Coarse-grained molecular-dynamics simulations were used to study the morphological changes induced in a Nafion-like ionomer by the imposition of a strong electric field. We observe that proton transport through this polymer electrolyte membrane is accompanied by morphological changes that include the formation of structures aligned along the direction of the applied field. The polar head groups of the ionomer side chains assemble into clusters, which then form rod-like formations, and these cylindrical structures then assemble into a hexagonally ordered array aligned with the direction of current flow. For dry ionomers, at current densities in excess of 1 A/cm^2 these rod-like clusters undergo an inner micro-phase separation, in which distinct wire-like lines of sulfonate head groups are accompanied by similar wire-like alignments of bound protons. The clusters appear to be of two types. If there are two, four, or five lines of sulfonates then there is an equal number of lines of protons, but if there are three lines of sulfonates then they are accompanied by four lines of protons. Occasionally these lines of sulfonates and protons form a helical structure. Upon removal of the electric field, the hexagonal array of rod-like structures remains, but the microphase separation disappears below the threshold current of 1 A/cm^2.

  1. Polar Landforms

    NASA Technical Reports Server (NTRS)

    2005-01-01

    10 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows eroded remnants of carbon dioxide ice in the south polar residual cap of Mars. The scarps that outline each small mesa have retreated about 3 meters (10 feet) per Mars year since MGS began orbiting the red planet in 1997.

    Location near: 87.0oS, 31.9oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  2. Proton and Ion Beams Generated with Picosecond CO{sub 2} Laser Pulses

    SciTech Connect

    Pogorelsky, Igor; Yakimenko, Vitaly; Stolyarov, Daniil; Shkolnikov, Peter; Chen Min; Pukhov, Alexander; McKenna, Paul; Carroll, David; Neely, David; Najmudin, Zulfikar; Willingale, Louise; Stolyarova, Elena; Flynn, George

    2009-01-22

    1-TW, 6-ps, circularly polarized CO{sub 2} laser pulses focused onto thin Al foils are used to drive ion acceleration. The spectra of ions and protons generated in the direction normal to the rear surface, detected with a compact magnet spectrometer with CR39, reveals a broad proton high-energy peak at {approx}1 MeV. This observation conforms to the theoretical predictions that circularly polarized laser pulses are less efficient than linearly polarized pulses in driving ion acceleration via the Target Normal Sheath Acceleration (TNSA) mechanism. Instead, there is evidence that the circularly polarized laser may provide direct ponderomotive acceleration of ions and protons. We report also the first application of the BNL proton source in nano-science. Irradiation of graphite and graphene films produced local defects and membranes for variety of applications.

  3. Estimation of p-bar beam polarization due to spin filtering by a polarized hydrogen target

    SciTech Connect

    Strakhovenko, V.

    2008-04-30

    The polarization buildup in a p-bar beam due to the interaction of stored antiprotons with polarized protons of a hydrogen target is considered. The corresponding cross section is calculated in the energy interval 20polarization in a time comparable with the beam lifetime.

  4. Transverse Spin Asymmetries in the CNI Region of Elastic Proton-Proton Scattering at s=200 GeV

    NASA Astrophysics Data System (ADS)

    Svirida, Dmitry

    2016-02-01

    Precise measurements of transverse spin asymmetries in proton-proton elastic scattering at very small values of four-momentum transfer squared, t, have been performed using the Relativistic Heavy Ion Collider (RHIC) polarized proton beams. The measurements of both single and double spin asymmetries were made at the center-of-mass energy s = 200 GeV and in the region 0.003 ≤|t|≤ 0.035 (GeV/c)2, which was accessed using Roman Pot devices incorporated into the STAR experimental setup. The obtained set of asymmetries is sensitive to the poorly known hadronic contribution to the spin-flip amplitudes and provide significant constraints for the theoretical descriptions of the reaction mechanism of proton-proton elastic scattering at high energies.

  5. 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.

  6. What Is Ag-Ed?

    ERIC Educational Resources Information Center

    Lindley, Judy

    Ag-Ed is an agricultural education project aimed at upper primary students, held in conjunction with the Toowoomba Show (similar to a county fair) in Queensland, Australia. The program achieves its purpose of helping children understand the impact and relevance that agriculture has on their everyday lives through two components, an Ag-Ed day and a…

  7. AGS Experiments: 1989, 1990, 1991

    SciTech Connect

    Depken, J.C.

    1992-02-01

    This report contains: Experimental areas layout; table of beam parameters and fluxes; experiment schedule ``as run``; proposed 1992 schedule; a listing of experiments by number; two-page summaries of each experiment begin here, also ordered by number; publications of AGS Experiments begin here; and list of AGS Experimenters begins here.

  8. AGS Experiments: 1989, 1990, 1991

    SciTech Connect

    Depken, J.C.

    1992-02-01

    This report contains: Experimental areas layout; table of beam parameters and fluxes; experiment schedule as run''; proposed 1992 schedule; a listing of experiments by number; two-page summaries of each experiment begin here, also ordered by number; publications of AGS Experiments begin here; and list of AGS Experimenters begins here.

  9. Heavy ion acceleration at the AGS: Present and future plans

    SciTech Connect

    Lee, Y.Y.

    1989-01-01

    The Brookhaven AGS is alternating gradient synchrotron, 807 meters in circumference, which was originally designed for only protons. Using the 15 MV Brookhaven Tandem Van de Graaff as an injector, the AGS started to accelerate heavy ions of mass lighter than sulfur. Because of the relatively poor vacuum (/approximately/10/sup /minus/8/ Torr), the AGS is not able to accelerate heavier ions which could not be fully stripped of electrons at the Tandem energy. When the AGS Booster, which is under construction, is completed the operation will be extended to all species of heavy ions including gold and uranium. Because ultra-high vacuum (/approximately/10/sup /minus/11/ Torr) is planned, the Booster can accelerate partially stripped elements. The operational experience, the parameters, and scheme of heavy ion acceleration will be presented in detail from injection to extraction, as well as future injection into the new Relativistic Heavy Ion Collider (RHIC). A future plan to improve intensity of the accelerator will also be presented. 5 figs., 4 tabs.

  10. Anomalous polarization dependence of Raman scattering and crystallographic orientation of black phosphorus.

    PubMed

    Kim, Jungcheol; Lee, Jae-Ung; Lee, Jinhwan; Park, Hyo Ju; Lee, Zonghoon; Lee, Changgu; Cheong, Hyeonsik

    2015-11-28

    We investigated polarization dependence of the Raman modes in black phosphorus (BP) using five different excitation wavelengths. The crystallographic orientation was determined by comparing polarized optical microscopy with high-resolution transmission electron microscopy analysis. In polarized Raman spectroscopy, the B2g mode shows the same polarization dependence regardless of the excitation wavelength or the sample thickness. On the other hand, the Ag(1) and Ag(2) modes show a peculiar polarization behavior that depends on the excitation wavelength and the sample thickness. The thickness dependence can be explained by considering the anisotropic interference effect due to the birefringence and dichroism of the BP crystal, but the wavelength dependence cannot be explained. We propose a simple and fail-proof procedure to determine the orientation of a BP crystal by combining polarized Raman scattering with polarized optical microscopy. PMID:26503032

  11. Polar ozone

    NASA Technical Reports Server (NTRS)

    Solomon, S.; Grose, W. L.; Jones, R. L.; Mccormick, M. P.; Molina, Mario J.; Oneill, A.; Poole, L. R.; Shine, K. P.; Plumb, R. A.; Pope, V.

    1990-01-01

    The observation and interpretation of a large, unexpected ozone depletion over Antarctica has changed the international scientific view of stratospheric chemistry. The observations which show the veracity, seasonal nature, and vertical structure of the Antarctic ozone hole are presented. Evidence for Arctic and midlatitude ozone loss is also discussed. The chemical theory for Antarctic ozone depletion centers around the occurrence of polar stratospheric clouds (PSCs) in Antarctic winter and spring; the climatology and radiative properties of these clouds are presented. Lab studies of the physical properties of PSCs and the chemical processes that subsequently influence ozone depletion are discussed. Observations and interpretation of the chemical composition of the Antarctic stratosphere are described. It is shown that the observed, greatly enhanced abundances of chlorine monoxide in the lower stratosphere are sufficient to explain much if not all of the ozone decrease. The dynamic meteorology of both polar regions is given, interannual and interhemispheric variations in dynamical processes are outlined, and their likely roles in ozone loss are discussed.

  12. Polar Markings

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02155 Polar Markings

    These bright and dark markings occurred near the end of summer in the south polar region. The dark material is likely dust that has been freed of frost cover.

    Image information: VIS instrument. Latitude -76.3N, Longitude 84.9E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  13. Polar Layers

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA02153 Polar Layers

    This image of the south polar region shows layered material. It is not known if the layers are formed yearly or if they form over the period of 10s to 100s of years or more.

    Image information: VIS instrument. Latitude -80.3N, Longitude 296.2E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. Polar Ridges

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03662 Polar Ridges

    This ridge system is located in the south polar region.

    Image information: VIS instrument. Latitude -81.7N, Longitude 296.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  15. Polar Textures

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03638 Polar Textures

    This image illustrates the variety of textures that appear in the south polar region during late summer.

    Image information: VIS instrument. Latitude 80.5S, Longitude 57.9E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. Polar Terrains

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03577 Polar Terrains

    The region surrounding the South Polar Cap contains many different terrain types. This image shows both etched terrain and a region of 'mounds'.

    Image information: VIS instrument. Latitude 75S, Longitude 286.5E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  17. Effects of slow clinorotation on lipid contents and proton permeability of thylakoid membranes of pea chloroplasts

    NASA Astrophysics Data System (ADS)

    Mikhaylenko, N. F.; Sytnik, S. K.; Zolotareva, E. K.

    Photochemical characteristics and lipid composition of thylakoid membranes from 12 day-old pea leaves that were exposed to slow clino-rotation were examined and compared with a vertical control. Proton permeability of thylakoid membranes was estimated from light-induced proton uptake (ΔH+) and post-illumination proton efflux in chloroplast suspensions. The ΔpH magnitude was calculated from the level of light-induced quenching of 9-aminoacridine fluorescence. Proton permeability of thylakoid membranes increased during exposure to clino-rotation. When subsequently transferred to darkness, proton efflux increased almost 2-fold in clinorotated leaves. The results were compared with data on pigment and polar lipid composition of photosynthetic membranes in clino-rotated and control plants. It was concluded that both the increase of proton permeability and the decrease of polar lipid content in chloroplasts were induced by clino-rotation.

  18. Effect of 3D Polarization profiles on polarization measurements and colliding beam experiments

    SciTech Connect

    Fischer, W.; Bazilevsky, A.

    2011-08-18

    The development of polarization profiles are the primary reason for the loss of average polarization. Polarization profiles have been parametrized with a Gaussian distribution. We derive the effect of 3-dimensional polarization profiles on the measured polarization in polarimeters, as well as the observed polarization and the figure of merit in single and double spin experiments. Examples from RHIC are provided. The Relativistic Heavy Ion Collider (RHIC) is the only collider of spin polarized protons. During beam acceleration and storage profiles of the polarization P develop, which affect the polarization measured in a polarimeter, and the polarization and figure of merit (FOM) in colliding beam experiments. We calculate these for profiles in all dimensions, and give examples for RHIC. Like in RHIC we call the two colliding beams Blue and Yellow. We use the overbar to designate intensity-weighted averages in polarimeters (e.g. {bar P}), and angle brackets to designate luminosity-weighted averages in colliding beam experiments (e.g.

    ).

  19. Preliminary study of AC power feeders for AGS booster

    SciTech Connect

    Meth, M.

    1992-07-17

    It has been proposed that the AGS Heavy Ion/Proton Booster be excited directly from the electric power distribution system without intervening an energy storage buffer such as an MG set or a magnetic energy buffer. The average power requirement of the AGS Booster is less than many single-loads presently housed on the lab site. However, the power swing will be the largest single pulsating load on the lab site. The large power swings will impact on the power grid producing utility-line disturbances such as voltage fluctuations and harmonic generation. Thus, it is necessary to carefully evaluate the quality of the electric power system resulting from the interconnection, such that the utility system is not degraded either on the lab site or at LILCO`s substation.

  20. Preliminary study of AC power feeders for AGS booster

    SciTech Connect

    Meth, M.

    1992-07-17

    It has been proposed that the AGS Heavy Ion/Proton Booster be excited directly from the electric power distribution system without intervening an energy storage buffer such as an MG set or a magnetic energy buffer. The average power requirement of the AGS Booster is less than many single-loads presently housed on the lab site. However, the power swing will be the largest single pulsating load on the lab site. The large power swings will impact on the power grid producing utility-line disturbances such as voltage fluctuations and harmonic generation. Thus, it is necessary to carefully evaluate the quality of the electric power system resulting from the interconnection, such that the utility system is not degraded either on the lab site or at LILCO's substation.