I. Keshelashvili, F. Müller, D. Mchedlishvili, D. Shergelashvili
In all experiments involving polarized beams or/and targets, the determination of the degree of polarization by asymmetry measurements is of prime importance. Over the years, so-called analyzing powers were extracted, e.g., for various reactions for well-defined beam/target polarizations as a function of the reaction energy. Reciprocally, the polarization can be deduced precisely from measured asymmetries if the analyzing power is known. In practice, the task may become complicated by the required unambiguous identification of the reaction channel. In cases where the statistics are limited, such as, e.g., in the planned EDM (Electric Dipole Moment)-search for charged particles in storage rings, polarimetry becomes a real challenge. In this overview, different aspects of possible polarimetry concepts, the efficient reaction selection, and the quasi non-invasive scattering targets will be discussed. Also, the recent progress achieved by the JEDI collaboration using polarized deuteron beams of COSY-J"ulich will be presented.
{"title":"Polarimetry - from basics to precision","authors":"I. Keshelashvili, F. Müller, D. Mchedlishvili, D. Shergelashvili","doi":"10.22323/1.324.0025","DOIUrl":"https://doi.org/10.22323/1.324.0025","url":null,"abstract":"In all experiments involving polarized beams or/and targets, the determination of the degree of polarization by asymmetry measurements is of prime importance. Over the years, so-called analyzing powers were extracted, e.g., for various reactions for well-defined beam/target polarizations as a function of the reaction energy. Reciprocally, the polarization can be deduced precisely from measured asymmetries if the analyzing power is known. In practice, the task may become complicated by the required unambiguous identification of the reaction channel. In cases where the statistics are limited, such as, e.g., in the planned EDM (Electric Dipole Moment)-search for charged particles in storage rings, polarimetry becomes a real challenge. In this overview, different aspects of possible polarimetry concepts, the efficient reaction selection, and the quasi non-invasive scattering targets will be discussed. Also, the recent progress achieved by the JEDI collaboration using polarized deuteron beams of COSY-J\"ulich will be presented.","PeriodicalId":166894,"journal":{"name":"Proceedings of XVII International Workshop on Polarized Sources, Targets & Polarimetry — PoS(PSTP2017)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122267174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Yanai, H. Kohri, M. Yosoi, T. Hotta, H. Katsuragawa, T. Ohta, Shintarou Tanaka
A polarized solid HD (Hydrogen - Deuteride) has been developed for near future photoproduction experiment at SPring-8/LEPS. The solid HD target is polarized by the static method in a strong magnetic field of 17 T and low temperature of about 15 mK at RCNP Osaka university. The solid HD target is transported from RCNP to SPring-8, under the condition of a magnetic field larger than 0.1 T for holding the polarization and low temperature lower than 4 K, in which we use five cryostats. We have achieved a polarization degree of 44 % and a relaxation time of 8 months for H. We have recently succeeded in the connection among three cryostats used at SPring-8. After succeeding all the target transportations, we will start the physics experiment at SPring-8.
{"title":"Development of polarized HD target for SPring-8/LEPS experiment.","authors":"Y. Yanai, H. Kohri, M. Yosoi, T. Hotta, H. Katsuragawa, T. Ohta, Shintarou Tanaka","doi":"10.22323/1.324.0003","DOIUrl":"https://doi.org/10.22323/1.324.0003","url":null,"abstract":"A polarized solid HD (Hydrogen - Deuteride) has been developed for near future photoproduction experiment at SPring-8/LEPS. The solid HD target is polarized by the static method in a strong magnetic field of 17 T and low temperature of about 15 mK at RCNP Osaka university. The solid HD target is transported from RCNP to SPring-8, under the condition of a magnetic field larger than 0.1 T for holding the polarization and low temperature lower than 4 K, in which we use five cryostats. We have achieved a polarization degree of 44 % and a relaxation time of 8 months for H. We have recently succeeded in the connection among three cryostats used at SPring-8. After succeeding all the target transportations, we will start the physics experiment at SPring-8.","PeriodicalId":166894,"journal":{"name":"Proceedings of XVII International Workshop on Polarized Sources, Targets & Polarimetry — PoS(PSTP2017)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132254897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Musgrave, R. Milner, G. Atoian, E. Beebe, S. Kondrashev, A. Pikin, D. Raparia, J. Ritter, A. Zelenski, J. Maxwell
The capability of accelerating a polarized $^3$He ion beam in RHIC would demonstrate an effective polarized neutron beam for the study of new high-energy QCD studies of nucleon structure. This development would be particularly beneficial for the future plans of an Electron Ion Collider (EIC), which could use a polarized $^3$He ion beam to probe the spin structure of the neutron. The proposed polarized $^3$He ion source is based on the Electron Beam Ion Source (EBIS) currently in operation at Brookhaven National Laboratory (BNL). $^3$He gas would be polarized within the 5 T field of the EBIS solenoid via Metastability Exchange Optical Pumping (MEOP) and then pulsed into the EBIS vacuum and drift tube system where the $^3$He will be ionized by the 10 Amp electron beam. The goal of the polarized $^3$He ion source is to achieve $2.5 times 10^{11}$ $^3$He$^{++}$/pulse at 70% polarization. An upgrade of the EBIS is currently underway at BNL. The EBIS capability to produce polarized $^{3}$He$^{++}$ is being developed through a collaboration between BNL and MIT.
{"title":"Polarized 3He++ Ion Source for RHIC and an EIC","authors":"M. Musgrave, R. Milner, G. Atoian, E. Beebe, S. Kondrashev, A. Pikin, D. Raparia, J. Ritter, A. Zelenski, J. Maxwell","doi":"10.22323/1.324.0020","DOIUrl":"https://doi.org/10.22323/1.324.0020","url":null,"abstract":"The capability of accelerating a polarized $^3$He ion beam in RHIC would demonstrate an effective polarized neutron beam for the study of new high-energy QCD studies of nucleon structure. This development would be particularly beneficial for the future plans of an Electron Ion Collider (EIC), which could use a polarized $^3$He ion beam to probe the spin structure of the neutron. The proposed polarized $^3$He ion source is based on the Electron Beam Ion Source (EBIS) currently in operation at Brookhaven National Laboratory (BNL). $^3$He gas would be polarized within the 5 T field of the EBIS solenoid via Metastability Exchange Optical Pumping (MEOP) and then pulsed into the EBIS vacuum and drift tube system where the $^3$He will be ionized by the 10 Amp electron beam. The goal of the polarized $^3$He ion source is to achieve $2.5 times 10^{11}$ $^3$He$^{++}$/pulse at 70% polarization. An upgrade of the EBIS is currently underway at BNL. The EBIS capability to produce polarized $^{3}$He$^{++}$ is being developed through a collaboration between BNL and MIT.","PeriodicalId":166894,"journal":{"name":"Proceedings of XVII International Workshop on Polarized Sources, Targets & Polarimetry — PoS(PSTP2017)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123514531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For absolute calibration of the vertically polarized unit{200}{MeV} proton beam at BNL Linac, we detect in left/right symmetric scintillator detectors the elastic protons from the beam scattering on the Carbon target. The detectors are located at angles $theta_text{Lab}=pm16.2^circ$, at which analyzing power of the elastic scattering has local maximum of 99.35%. Variable length copper absorbers of $sim$unit{40}{mm} thickness are installed in both arms of the polarimeter to suppress the inelastic protons. During RHIC Run 2017 we upgraded the polarimeter DAQ with a unit{250}{MHz}12 bit WFD. The detailed analysis of all detected events allowed us to properly isolate scattered proton signals and to control in-situ the efficiency of inelastic proton suppression. The systematic error in absolute polarization measurement was confirmed to be $sigma_P^text{syst}/Psim0.5%$.
为了对BNL直线加速器的垂直极化unit{200}{MeV}质子束进行绝对校准，我们在左/右对称闪烁体探测器中检测到碳靶上的质子束散射产生的弹性质子。探测器位于$theta_text{Lab}=pm16.2^circ$角度处，弹性散射分析功率局部最大值为99.35％。可变长度的$sim$unit{40}{mm}厚度的铜吸收器安装在极化计的双臂，以抑制非弹性质子。在RHIC Run 2017期间，我们用unit{250}{MHz} 12位WFD升级了偏振仪DAQ。对所有检测到的事件的详细分析使我们能够正确地分离散射质子信号并控制非弹性质子抑制的现场效率。确定了绝对偏振测量的系统误差为$sigma_P^text{syst}/Psim0.5%$。
{"title":"Absolute polarization measurement of the 200 MeV proton beam at BNL Linac.","authors":"A. Poblaguev, G. Atoian, A. Zelenski","doi":"10.22323/1.324.0024","DOIUrl":"https://doi.org/10.22323/1.324.0024","url":null,"abstract":"For absolute calibration of the vertically polarized unit{200}{MeV} proton beam at BNL Linac, we detect in left/right symmetric scintillator detectors the elastic protons from the beam scattering on the Carbon target. The detectors are located at angles $theta_text{Lab}=pm16.2^circ$, at which analyzing power of the elastic scattering has local maximum of 99.35%. Variable length copper absorbers of $sim$unit{40}{mm} thickness are installed in both arms of the polarimeter to suppress the inelastic protons. During RHIC Run 2017 we upgraded the polarimeter DAQ with a unit{250}{MHz}12 bit WFD. The detailed analysis of all detected events allowed us to properly isolate scattered proton signals and to control in-situ the efficiency of inelastic proton suppression. The systematic error in absolute polarization measurement was confirmed to be $sigma_P^text{syst}/Psim0.5%$.","PeriodicalId":166894,"journal":{"name":"Proceedings of XVII International Workshop on Polarized Sources, Targets & Polarimetry — PoS(PSTP2017)","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126233221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Skaritka, E. Wang, F. Willeke, R. Lambiase, W. Lui, V. Ptitsyn, O. Rahman
To facilitate the SAC 2015 Long Range Plan for Nuclear Science: a high-energy high-luminosity polarized Electron-Ion Collider (EIC) as the highest priority for new facility construction following the completion of FRIB. Brookhaven National Laboratory (BNL) is proposing to build a high luminosity electron-hadron collider called e-RHIC which incorporates a new electron synchrotron with the existing Relativistic Heavy Ion Collider (RHIC). A low risk conventional technology based design is being adopted for the majority of the accelerator components. The e-RHIC electron source will produce a highly polarized beam current of up to 50 mA with > 80% polarization at an energy of up to 18 GeV with a luminosity > 1034 cm-2s-1. The prototype e-RHIC beam source is currently under development at BNL and Stony Brook University. This paper presents a conceptual design of the e-RHIC machine, how polarized beam will enhance the physics program and plans to address the remaining challenges associated with the construction of e-RHIC. In order to construct a future electron ion collider with high luminosity, a high average current and high bunch charge polarized electron source is under development at Brookhaven National Laboratory. We present the R&D plan for achieving the required charge and current in the polarized eRHIC gun.. The plan involves developing a large single cathode gun to generate 5.3 nC and 6 mA polarized electrons beam. We report the progress of large cathode prototype gun development, the beam line design and plan for measuring gun charge lifetime for high bunch charge, high current operation.
{"title":"Conceptual design of a Polarized Electron Ion Collider at Brookhaven National Laboratory","authors":"J. Skaritka, E. Wang, F. Willeke, R. Lambiase, W. Lui, V. Ptitsyn, O. Rahman","doi":"10.22323/1.324.0015","DOIUrl":"https://doi.org/10.22323/1.324.0015","url":null,"abstract":"To facilitate the SAC 2015 Long Range Plan for Nuclear Science: a high-energy high-luminosity polarized Electron-Ion Collider (EIC) as the highest priority for new facility construction following the completion of FRIB. Brookhaven National Laboratory (BNL) is proposing to build a high luminosity electron-hadron collider called e-RHIC which incorporates a new electron synchrotron with the existing Relativistic Heavy Ion Collider (RHIC). A low risk conventional technology based design is being adopted for the majority of the accelerator components. The e-RHIC electron source will produce a highly polarized beam current of up to 50 mA with > 80% polarization at an energy of up to 18 GeV with a luminosity > 1034 cm-2s-1. The prototype e-RHIC beam source is currently under development at BNL and Stony Brook University. This paper presents a conceptual design of the e-RHIC machine, how polarized beam will enhance the physics program and plans to address the remaining challenges associated with the construction of e-RHIC. In order to construct a future electron ion collider with high luminosity, a high average current and high bunch charge polarized electron source is under development at Brookhaven National Laboratory. We present the R&D plan for achieving the required charge and current in the polarized eRHIC gun.. The plan involves developing a large single cathode gun to generate 5.3 nC and 6 mA polarized electrons beam. We report the progress of large cathode prototype gun development, the beam line design and plan for measuring gun charge lifetime for high bunch charge, high current operation.","PeriodicalId":166894,"journal":{"name":"Proceedings of XVII International Workshop on Polarized Sources, Targets & Polarimetry — PoS(PSTP2017)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125167612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The P2 Experiment at the new Mainz Energy-recovering Superconducting Accelerator (MESA) aims at measuring the weak mixing angle $sin^2 theta_text{W}$ at low Q$^2$ with high precision. Therefore the polarization of the incident electron beam has to be known with a very high accuracy (< 0.5 %). A conventional Mott-polarimeter requires a lot of effort in calibration to be able to acieve this goal. A Double Scattering Polarimeter (DSP) promises to meet these requirements with less effort.
在新的美因茨能量回收超导加速器(MESA)上进行的P2实验旨在高精度地测量低Q $^2$下的弱混合角$sin^2 theta_text{W}$。因此，入射电子束的极化必须以非常高的精度(< 0.5 %). A conventional Mott-polarimeter requires a lot of effort in calibration to be able to acieve this goal. A Double Scattering Polarimeter (DSP) promises to meet these requirements with less effort.
{"title":"A Double scattering polarimeter for the P2 experiment at MESA","authors":"M. Molitor, K. Aulenbacher","doi":"10.22323/1.243.0030","DOIUrl":"https://doi.org/10.22323/1.243.0030","url":null,"abstract":"The P2 Experiment at the new Mainz Energy-recovering Superconducting Accelerator (MESA) aims at measuring the weak mixing angle $sin^2 theta_text{W}$ at low Q$^2$ with high precision. Therefore the polarization of the incident electron beam has to be known with a very high accuracy (< 0.5 %). A conventional Mott-polarimeter requires a lot of effort in calibration to be able to acieve this goal. \u0000 \u0000A Double Scattering Polarimeter (DSP) promises to meet these requirements with less effort.","PeriodicalId":166894,"journal":{"name":"Proceedings of XVII International Workshop on Polarized Sources, Targets & Polarimetry — PoS(PSTP2017)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128761428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The A2 Collaboration at the Mainz Microtron MAMI measures photon absorption cross sections using circularly and linearly polarized 'Bremsstrahlung' photons up to an energy of ~1.5GeV and a polarized Frozen Spin Target. We use a 4 π detection system with the 'Crystal Ball' as central part. Our Frozen Spin Target provides both longitudinally and transversely polarized protons and deuterons. In this paper the apparatus will be described. Double polarized experiments for the investigation of the nucleons excitation spectrum via meson production and our Compton program to measure the proton polarizabilities will be briefly discussed.
{"title":"Double polarized measurements with frozen spin target at MAMI","authors":"Andreas Thomas","doi":"10.22323/1.182.0006","DOIUrl":"https://doi.org/10.22323/1.182.0006","url":null,"abstract":"The A2 Collaboration at the Mainz Microtron MAMI measures photon absorption cross sections using circularly and linearly polarized 'Bremsstrahlung' photons up to an energy of ~1.5GeV and a polarized Frozen Spin Target. We use a 4 π detection system with the 'Crystal Ball' as central part. Our Frozen Spin Target provides both longitudinally and transversely polarized protons and deuterons. \u0000In this paper the apparatus will be described. Double polarized experiments for the investigation of the nucleons excitation spectrum via meson production and our Compton program to measure the proton polarizabilities will be briefly discussed.","PeriodicalId":166894,"journal":{"name":"Proceedings of XVII International Workshop on Polarized Sources, Targets & Polarimetry — PoS(PSTP2017)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127942771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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