Kirill Grigoryev | RWTH Aachen University (original) (raw)
Papers by Kirill Grigoryev
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2005
The occupation numbers of the individual hyperfine substates in a beam of hydrogen or deuterium a... more The occupation numbers of the individual hyperfine substates in a beam of hydrogen or deuterium atoms are measured with a Lamb-shift polarimeter. Therefore, the nuclear polarization of an atomic beam can be determined with high precision of about 0:5% within 20 s. The measurements are carried out with the atomic beam source for the internal polarized storage-cell gas target of ANKE (I $ 7 Â 10 16 atoms/s). The polarization of a slow (500-2000 eV) ion beam with currents higher than 1 nA can be measured as well. When the intensity of the atomic beam is reduced by a factor of 100, the Lamb-shift polarimeter still provides a precise measurement with an error of about 2% within 30 s. Thus, it is thought possible to determine the nuclear polarization of the atomic gas inside the storage cell, when a sample of these atoms effuse into the Lamb-shift polarimeter through a sample tube.
For future few-nucleon interaction studies with polarized beams and targets at COSY-Jülich, a pol... more For future few-nucleon interaction studies with polarized beams and targets at COSY-Jülich, a polarized internal storage-cell gas target was implemented at the magnet spectrometer ANKE in summer 2005. First commissioning of the polarized Atomic Beam Source (ABS) at ANKE was carried out and some improvements of the system have been done. Storage-cell tests to determine the COSY beam dimensions have
AIP Conference Proceedings
The vector P z and tensor P zz polarizations of a deuteron beam have been measured using elastic ... more The vector P z and tensor P zz polarizations of a deuteron beam have been measured using elastic deuteron-carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After acceleration to 1170 MeV inside the COSY storage ring, the polarizations of the deuterons were remeasured by studying the analyzing powers of a variety of nuclear reactions at the ANKE magnetic spetrometer. The overall precisions obtained were about 4% for both P z and P zz . One of the motivation for the experimental programme is the direct reconstruction of the spin-dependent amplitudes, including relative phases, of large angle neutron-proton elastic scattering, through the study of the p(d, 2p)n charge-exchange reaction up to the highest available deuteron energy at COSY (2.3 GeV).
In a collaboration between IKP, FZ Jülich, PNPI and ITMO, St. Petersburg, the influence of nuclea... more In a collaboration between IKP, FZ Jülich, PNPI and ITMO, St. Petersburg, the influence of nuclear polarized projectiles on the differential and total cross section will be investigated for the dd-fusion reactions at low ener-gies. For the 3 He(d, p) 4 He and the t(d, n) 4 He reaction it was expected and has been shown, that aligned spins will increase the fusion rate by a factor up to 1.5 [1] because both reactions have a J π = 3/2 + resonance at energies below 100 keV. For the d + d reactions no valid theoretical guidance exists [2]. The knowledge of the complete reaction matrix may allow to control the neutron rate in a fusion reactor and, therefore, to optimize the energy transport from the fusion plasma to the reactor walls. In addition, the lifetime of the reactor walls can be maximized, which will decrease the cost of investments for fusion energy.
In collaboration with Petersburg Nuclear Physics Institute and Institut für Kernphysik of Univers... more In collaboration with Petersburg Nuclear Physics Institute and Institut für Kernphysik of Universität zu Köln measurements of the nuclear polarization of H2 molecules maintained after the recombination of polarized hydrogen atoms will be performed.
With the use of a spinfilter as the most important component of a Lamb-shift polarimeter, a beam ... more With the use of a spinfilter as the most important component of a Lamb-shift polarimeter, a beam of metastable atoms in one hyperfine state (alpha1 or alpha2) can be produced. By induced transitions it seems possible to observe any transition between the 2S1/2 metastable hyperfine states or into the short-lived states 2P1/2 and 2P3/2 of the hydrogen (deuterium) atom separately
The production of tensor polarization in an unpolarized deuteron beam after passage through unpol... more The production of tensor polarization in an unpolarized deuteron beam after passage through unpolarized carbon targets, which includes the effect of deuteron spin dichroism, has been observed for the first time. Theoretical background, experimental setup, and results of the experiment are presented.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013
Polarized atomic beam source Polarized internal target Nuclear polarized hydrogen and deuterium a... more Polarized atomic beam source Polarized internal target Nuclear polarized hydrogen and deuterium a b s t r a c t A polarized atomic beam source was developed for the polarized internal storage-cell gas target at the magnet spectrometer ANKE of COSY-Jülich. The intensities of the beams injected into the storage cell, measured with a compression tube, are 7:5 Â 10 16 hydrogen atoms/s (two hyperfine states) and 3:9 Â 10 16 deuterium atoms/s (three hyperfine states). For the hydrogen beam the achieved vector polarizations are p z ≈ 7 0:92. For the deuterium beam, the obtained combinations of vector and tensor (p zz ) polarizations are p z ≈ 7 0:90 (with a constant p zz ≈ þ 0:86), and p zz ¼ þ 0:90 or p zz ¼ −1:71 (both with vanishing p z ). The paper includes a detailed technical description of the apparatus and of the investigations performed during the development. This source has been very successfully used for single and double polarization measurements at ANKE as well as for studies of the polarization of recombining hydrogen molecules.
Polarized Sources, Targets and Polarimetry - Proceedings of the 13th International Workshop, 2011
ABSTRACT The PAX (Polarized Antiproton eXperiment) collaboration aims to polarize a stored antipr... more ABSTRACT The PAX (Polarized Antiproton eXperiment) collaboration aims to polarize a stored antiproton beam by means of spin filtering. The setup requires a polarized internal gas target (PIT) surrounded by silicon detectors.1 An overview of the target configuration necessary for spin filtering is presented. The setup of the PIT is discussed with an emphasis on the working principle of the Breit-Rabi Polarimeter (BRP) including the calibration procedure. Furthermore, some preliminary results of the BRP signal and transitions tuning are presented.
International Journal of Modern Physics E, 2009
Proton beams were stored in COSY at 45 MeV and electron-cooled. Their lifetime was measured with ... more Proton beams were stored in COSY at 45 MeV and electron-cooled. Their lifetime was measured with gas target on and off and found to be 321.3 ± 0.4 s and 4639 ± 70 s, respectively. A model based on calculated machine parameters and the measured, interpolated residual gas distribution in COSY predicts lifetimes which are about 7 times longer. Possible
Polarized Sources and Targets - Proceedings of the 11th International Workshop, 2007
For future few-nucleon interaction studies with polarized beams and targets at COSY (Jülich, Germ... more For future few-nucleon interaction studies with polarized beams and targets at COSY (Jülich, Germany), a polarized internal storage-cell gas target has been developed. Polarization measurements are performed with a Lamb-shift polarimeter. For commissioning and first experimental studies, the polarized target has been installed at the magnet spectrometer ANKE. COSY-beam properties, achieved with stacking injection and electron cooling, have been investigated. The vertex distribution at the target is investigated by events from the pp → dπ + reaction. Results of these studies are presented.
Physics of Particles and Nuclei, 2014
Since more than 50 years it has been discussed to increase the gain of nuclear fusion reactors wi... more Since more than 50 years it has been discussed to increase the gain of nuclear fusion reactors with the use of polarized fuel. For example, the total cross sections of the fusion reactions d + t → 4 He + n or 3 He + d → 4 He + p are increased by a factor of about 1.5 if the spins of both incoming particles are aligned. But before polarized fuel can be used for energy production in the different types of reactors, a number of questions must be answered. In this contribution we give an overview on our various activities in this field of research.
International Journal of Modern Physics E, 2009
In the last decades different types of storage cells have been used to increase the target densit... more In the last decades different types of storage cells have been used to increase the target density of polarized internal targets in storage rings, fed with atoms from an atomic beam source. Most of these cells are optimized to avoid recombination of the polarized hydrogen or deuterium atoms into molecules and to preserve the nuclear polarization at a high level between 0.75 and 0.9. Independently, groups at AmPS[1], IUCF[2], and HERMES[3] have shown that nucleons of re-combined molecules can still be polarized. In a collaboration between the Petersburg Nuclear Physics Institute, the University of Cologne and the Forschungszentrum Jülich we have built a dedicated apparatus to measure the polarization of hydrogen(deuterium) atoms and molecules in cells of different surface materials for temperatures between 45 and 120 K, and in magnetic fields up to 1 T. In addition, the recombination probability of atoms and the number of wall collisions of molecules inside the cells have been measur...
Since 2005 the ANKE experiment at COSY/Jülich is equipped with a Polarized Internal gas Target (P... more Since 2005 the ANKE experiment at COSY/Jülich is equipped with a Polarized Internal gas Target (PIT) [1], which consists of an Atomic Beam Source (ABS) [2] feeding a storage cell (SC) and a Lamb-shift polarimeter (LSP) [3]. After several beamtimes were completed successfully we decided to upgrade the hardware of the ABS due to the following reasons: • the ANKE facility requires a luminosity upgrade; • the ANKE ABS should have a higher duty time. The first problem can be partly solved without big investment into the COSY machine by use of a storage cell with smaller cross section. But future experiments will require an openable storage cell. Moving the storage cell parts out of the beam during single or stacking injection and acceleration procedures will have the following advantages: • no losses on the cell walls during injection; • no need to use long stacking injection; • increasing of the target density by minimizing the cross section of the storage cell beam tube. All possible c...
When polarized hydrogen atoms recombine in a storage cell, the residual H2 molecules may still sh... more When polarized hydrogen atoms recombine in a storage cell, the residual H2 molecules may still show nuclear polarization [1]. In a collaboration between PNPI, University of Cologne and FZ Jülich a device was built in the framework of an ISTC project (No. 1861) and a DFG project (436 RUS 113/977/0-1) to measure the polarization of hydrogen (deuterium) atoms and hydrogen (deuterium) molecules after recombination of polarized atoms depending on different surface materials, temperatures and magnetic fields. When the polarized atomic beam source (ABS) of the ANKE experiment is not in use at COSY, investigations of the interaction of polarized atoms with the sur-face of a T-shaped storage cell inside a superconduct-ing solenoid were carried out. The polarization of both, atoms and molecules, was measured with a Lamb-shift polarimeter (LSP) [2]. After some improvements of the Wienfilter of the LSP, which was used here as a mass filter to separate the pro-tons and the H +
The polarized internal gas target of ANKE at COSY/Jülich requires a dedicated storage cell to inc... more The polarized internal gas target of ANKE at COSY/Jülich requires a dedicated storage cell to increase the target density. In the paper we present studies of the beam parameters at the ANKE target position. The optimization of the storage cell support mechanism and the beam tube cross section is described as well.
The Lamb-shift polarimeter [1] (LSP) constitutes an exellent instrument for the determination of ... more The Lamb-shift polarimeter [1] (LSP) constitutes an exellent instrument for the determination of the polarisation of an atomic beam produced, e.g. in a polarized atomic beam source ABS [2]. Within a few seconds, the beam polarization can be measured to a high degree of precision. The transition units of the ABS, necessary to provide the desired magnetic substate population for hydrogen and deuterium, could be tuned very efficiently.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2005
The occupation numbers of the individual hyperfine substates in a beam of hydrogen or deuterium a... more The occupation numbers of the individual hyperfine substates in a beam of hydrogen or deuterium atoms are measured with a Lamb-shift polarimeter. Therefore, the nuclear polarization of an atomic beam can be determined with high precision of about 0:5% within 20 s. The measurements are carried out with the atomic beam source for the internal polarized storage-cell gas target of ANKE (I $ 7 Â 10 16 atoms/s). The polarization of a slow (500-2000 eV) ion beam with currents higher than 1 nA can be measured as well. When the intensity of the atomic beam is reduced by a factor of 100, the Lamb-shift polarimeter still provides a precise measurement with an error of about 2% within 30 s. Thus, it is thought possible to determine the nuclear polarization of the atomic gas inside the storage cell, when a sample of these atoms effuse into the Lamb-shift polarimeter through a sample tube.
For future few-nucleon interaction studies with polarized beams and targets at COSY-Jülich, a pol... more For future few-nucleon interaction studies with polarized beams and targets at COSY-Jülich, a polarized internal storage-cell gas target was implemented at the magnet spectrometer ANKE in summer 2005. First commissioning of the polarized Atomic Beam Source (ABS) at ANKE was carried out and some improvements of the system have been done. Storage-cell tests to determine the COSY beam dimensions have
AIP Conference Proceedings
The vector P z and tensor P zz polarizations of a deuteron beam have been measured using elastic ... more The vector P z and tensor P zz polarizations of a deuteron beam have been measured using elastic deuteron-carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After acceleration to 1170 MeV inside the COSY storage ring, the polarizations of the deuterons were remeasured by studying the analyzing powers of a variety of nuclear reactions at the ANKE magnetic spetrometer. The overall precisions obtained were about 4% for both P z and P zz . One of the motivation for the experimental programme is the direct reconstruction of the spin-dependent amplitudes, including relative phases, of large angle neutron-proton elastic scattering, through the study of the p(d, 2p)n charge-exchange reaction up to the highest available deuteron energy at COSY (2.3 GeV).
In a collaboration between IKP, FZ Jülich, PNPI and ITMO, St. Petersburg, the influence of nuclea... more In a collaboration between IKP, FZ Jülich, PNPI and ITMO, St. Petersburg, the influence of nuclear polarized projectiles on the differential and total cross section will be investigated for the dd-fusion reactions at low ener-gies. For the 3 He(d, p) 4 He and the t(d, n) 4 He reaction it was expected and has been shown, that aligned spins will increase the fusion rate by a factor up to 1.5 [1] because both reactions have a J π = 3/2 + resonance at energies below 100 keV. For the d + d reactions no valid theoretical guidance exists [2]. The knowledge of the complete reaction matrix may allow to control the neutron rate in a fusion reactor and, therefore, to optimize the energy transport from the fusion plasma to the reactor walls. In addition, the lifetime of the reactor walls can be maximized, which will decrease the cost of investments for fusion energy.
In collaboration with Petersburg Nuclear Physics Institute and Institut für Kernphysik of Univers... more In collaboration with Petersburg Nuclear Physics Institute and Institut für Kernphysik of Universität zu Köln measurements of the nuclear polarization of H2 molecules maintained after the recombination of polarized hydrogen atoms will be performed.
With the use of a spinfilter as the most important component of a Lamb-shift polarimeter, a beam ... more With the use of a spinfilter as the most important component of a Lamb-shift polarimeter, a beam of metastable atoms in one hyperfine state (alpha1 or alpha2) can be produced. By induced transitions it seems possible to observe any transition between the 2S1/2 metastable hyperfine states or into the short-lived states 2P1/2 and 2P3/2 of the hydrogen (deuterium) atom separately
The production of tensor polarization in an unpolarized deuteron beam after passage through unpol... more The production of tensor polarization in an unpolarized deuteron beam after passage through unpolarized carbon targets, which includes the effect of deuteron spin dichroism, has been observed for the first time. Theoretical background, experimental setup, and results of the experiment are presented.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013
Polarized atomic beam source Polarized internal target Nuclear polarized hydrogen and deuterium a... more Polarized atomic beam source Polarized internal target Nuclear polarized hydrogen and deuterium a b s t r a c t A polarized atomic beam source was developed for the polarized internal storage-cell gas target at the magnet spectrometer ANKE of COSY-Jülich. The intensities of the beams injected into the storage cell, measured with a compression tube, are 7:5 Â 10 16 hydrogen atoms/s (two hyperfine states) and 3:9 Â 10 16 deuterium atoms/s (three hyperfine states). For the hydrogen beam the achieved vector polarizations are p z ≈ 7 0:92. For the deuterium beam, the obtained combinations of vector and tensor (p zz ) polarizations are p z ≈ 7 0:90 (with a constant p zz ≈ þ 0:86), and p zz ¼ þ 0:90 or p zz ¼ −1:71 (both with vanishing p z ). The paper includes a detailed technical description of the apparatus and of the investigations performed during the development. This source has been very successfully used for single and double polarization measurements at ANKE as well as for studies of the polarization of recombining hydrogen molecules.
Polarized Sources, Targets and Polarimetry - Proceedings of the 13th International Workshop, 2011
ABSTRACT The PAX (Polarized Antiproton eXperiment) collaboration aims to polarize a stored antipr... more ABSTRACT The PAX (Polarized Antiproton eXperiment) collaboration aims to polarize a stored antiproton beam by means of spin filtering. The setup requires a polarized internal gas target (PIT) surrounded by silicon detectors.1 An overview of the target configuration necessary for spin filtering is presented. The setup of the PIT is discussed with an emphasis on the working principle of the Breit-Rabi Polarimeter (BRP) including the calibration procedure. Furthermore, some preliminary results of the BRP signal and transitions tuning are presented.
International Journal of Modern Physics E, 2009
Proton beams were stored in COSY at 45 MeV and electron-cooled. Their lifetime was measured with ... more Proton beams were stored in COSY at 45 MeV and electron-cooled. Their lifetime was measured with gas target on and off and found to be 321.3 ± 0.4 s and 4639 ± 70 s, respectively. A model based on calculated machine parameters and the measured, interpolated residual gas distribution in COSY predicts lifetimes which are about 7 times longer. Possible
Polarized Sources and Targets - Proceedings of the 11th International Workshop, 2007
For future few-nucleon interaction studies with polarized beams and targets at COSY (Jülich, Germ... more For future few-nucleon interaction studies with polarized beams and targets at COSY (Jülich, Germany), a polarized internal storage-cell gas target has been developed. Polarization measurements are performed with a Lamb-shift polarimeter. For commissioning and first experimental studies, the polarized target has been installed at the magnet spectrometer ANKE. COSY-beam properties, achieved with stacking injection and electron cooling, have been investigated. The vertex distribution at the target is investigated by events from the pp → dπ + reaction. Results of these studies are presented.
Physics of Particles and Nuclei, 2014
Since more than 50 years it has been discussed to increase the gain of nuclear fusion reactors wi... more Since more than 50 years it has been discussed to increase the gain of nuclear fusion reactors with the use of polarized fuel. For example, the total cross sections of the fusion reactions d + t → 4 He + n or 3 He + d → 4 He + p are increased by a factor of about 1.5 if the spins of both incoming particles are aligned. But before polarized fuel can be used for energy production in the different types of reactors, a number of questions must be answered. In this contribution we give an overview on our various activities in this field of research.
International Journal of Modern Physics E, 2009
In the last decades different types of storage cells have been used to increase the target densit... more In the last decades different types of storage cells have been used to increase the target density of polarized internal targets in storage rings, fed with atoms from an atomic beam source. Most of these cells are optimized to avoid recombination of the polarized hydrogen or deuterium atoms into molecules and to preserve the nuclear polarization at a high level between 0.75 and 0.9. Independently, groups at AmPS[1], IUCF[2], and HERMES[3] have shown that nucleons of re-combined molecules can still be polarized. In a collaboration between the Petersburg Nuclear Physics Institute, the University of Cologne and the Forschungszentrum Jülich we have built a dedicated apparatus to measure the polarization of hydrogen(deuterium) atoms and molecules in cells of different surface materials for temperatures between 45 and 120 K, and in magnetic fields up to 1 T. In addition, the recombination probability of atoms and the number of wall collisions of molecules inside the cells have been measur...
Since 2005 the ANKE experiment at COSY/Jülich is equipped with a Polarized Internal gas Target (P... more Since 2005 the ANKE experiment at COSY/Jülich is equipped with a Polarized Internal gas Target (PIT) [1], which consists of an Atomic Beam Source (ABS) [2] feeding a storage cell (SC) and a Lamb-shift polarimeter (LSP) [3]. After several beamtimes were completed successfully we decided to upgrade the hardware of the ABS due to the following reasons: • the ANKE facility requires a luminosity upgrade; • the ANKE ABS should have a higher duty time. The first problem can be partly solved without big investment into the COSY machine by use of a storage cell with smaller cross section. But future experiments will require an openable storage cell. Moving the storage cell parts out of the beam during single or stacking injection and acceleration procedures will have the following advantages: • no losses on the cell walls during injection; • no need to use long stacking injection; • increasing of the target density by minimizing the cross section of the storage cell beam tube. All possible c...
When polarized hydrogen atoms recombine in a storage cell, the residual H2 molecules may still sh... more When polarized hydrogen atoms recombine in a storage cell, the residual H2 molecules may still show nuclear polarization [1]. In a collaboration between PNPI, University of Cologne and FZ Jülich a device was built in the framework of an ISTC project (No. 1861) and a DFG project (436 RUS 113/977/0-1) to measure the polarization of hydrogen (deuterium) atoms and hydrogen (deuterium) molecules after recombination of polarized atoms depending on different surface materials, temperatures and magnetic fields. When the polarized atomic beam source (ABS) of the ANKE experiment is not in use at COSY, investigations of the interaction of polarized atoms with the sur-face of a T-shaped storage cell inside a superconduct-ing solenoid were carried out. The polarization of both, atoms and molecules, was measured with a Lamb-shift polarimeter (LSP) [2]. After some improvements of the Wienfilter of the LSP, which was used here as a mass filter to separate the pro-tons and the H +
The polarized internal gas target of ANKE at COSY/Jülich requires a dedicated storage cell to inc... more The polarized internal gas target of ANKE at COSY/Jülich requires a dedicated storage cell to increase the target density. In the paper we present studies of the beam parameters at the ANKE target position. The optimization of the storage cell support mechanism and the beam tube cross section is described as well.
The Lamb-shift polarimeter [1] (LSP) constitutes an exellent instrument for the determination of ... more The Lamb-shift polarimeter [1] (LSP) constitutes an exellent instrument for the determination of the polarisation of an atomic beam produced, e.g. in a polarized atomic beam source ABS [2]. Within a few seconds, the beam polarization can be measured to a high degree of precision. The transition units of the ABS, necessary to provide the desired magnetic substate population for hydrogen and deuterium, could be tuned very efficiently.