IPAC2015 - List of Authors (Lehrach, A.)

Paper	Title	Page
MOPWA044	Quasi-frozen Spin Method for EDM Deuteron Search	213
	Y. Senichev, A. Lehrach, B. Lorentz, R. Maier FZJ, Jülich, Germany S.N. Andrianov, A.N. Ivanov St. Petersburg State University, St. Petersburg, Russia M. Berz, E. Valetov MSU, East Lansing, Michigan, USA S. Chekmenev RWTH, Aachen, Germany
	To search for EDM using proton storage ring with purely electrostatic elements the concept of frozen spin method has been proposed by BNL. This method is based on two facts: in the equation of the spin precession the magnetic field dependence is entirely eliminated and at “magic” energy the spin precession frequency coincides with the precession frequency of the momentum. In case of deuteron the anomalous magnetic moment is negative (G=-0.142), therefore we have to use the electrical and magnetic field simultaneously keeping the frozen spin direction along the momentum as in the pure electrostatic ring. In this article we suggest the concept of the quasi-frozen spin when the spin oscillates around the momentum direction within the half value of the advanced spin phase each time returning back by special optics. Due to the low value of the anomalous magnetic moment of deuteron an effective contribution to the expected EDM effect is reduced only by a few percent.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA044
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WEAB2	Beam and Spin Dynamics for Storage Ring Based EDM Search	2454
	A. Lehrach FZJ, Jülich, Germany
	Funding: On behalf of the JEDI collaboration and JARA-FAME (Jülich Aachen Research Alliance) Permanent EDMs (electric dipole moment) of fundamental particles violate both time invariance T and parity P. Assuming the CPT theorem this implies CP violation. The Standard Model (SM) predicts non-vanishing EDMs, their magnitudes, however, are expected to be unobservably small with current techniques. Hence, the discovery of a non-zero EDM would be a signal for “new physics”. As a first step towards EDM searches of charged particles in storage rings, R&D work at the Cooler Synchrotron COSY is pursued. On a longer time scale, the design and construction of a dedicated storage ring will be carried out. Spin-tracking simulations are absolutely crucial to explore the feasibility of the planned storage ring EDM experiments and to investigate systematic limitations. For a detailed study during the storage and buildup of the EDM signal, one needs to track a large sample of particles for billions of turns. Benchmarking experiments are performed at the Cooler Synchrotron COSY to check and to further improve the simulation tools and prototype accelerator components are tested. Finally, the layout of a dedicated storage ring has to be optimized by a full simulation of spin motion.
	Slides WEAB2 [1.459 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEAB2
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THPF030	Antiproton Acceleration and Deceleration in the HESR	3758
	B. Lorentz, T. Katayama, A. Lehrach, R. Maier, D. Prasuhn, R. Stassen, H. Stockhorst, R. Tölle FZJ, Jülich, Germany
	The High Energy Storage Ring (HESR) is a part of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The ring is used for hadron physics experiments with a pellet target and the PANDA detector, and will supply antiprotons of momenta from 1.5 GeV/c to 15 GeV/c. To cover the whole energy range a flexible adjustment of transition energy and the corresponding gamma-t value is foreseen. For Injection and Accumulation of Antiprotons delivered from the CR at a momentum of 3.8 GeV/c (gamma=4.2), the HESR optics will be tuned to gamma-t=6.2. For deceleration down to a momentum of 1.5 GeV/c this optic is suitable as well. Stochastic cooling at an intermediate energy is required to avoid beam losses caused by adiabatic growth of the beam during deceleration. For acceleration to 8 GeV/c (gamma=8.6) the optics will be changed after accumulation of the antiproton beam to gamma-t=14.6. For momenta higher than 8 GeV/c the beam will be debunched at 8 GeV/c, optics will be changed to gamma-t=6.2, and after adiabatic rebunching the beam will be accelerated to 15 GeV/c (gamma=16). Simulations show the feasibility of the described procedures with practically no beam losses.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF030
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THPF032	Spin Tracking Simulations Towards Electric Dipole Moment Measurements at COSY	3764
	M. Rosenthal, A. Lehrach FZJ, Jülich, Germany A. Lehrach, M. Rosenthal RWTH, Aachen, Germany
	A strong hint for physics beyond the Standard Model would be achieved by direct measurements of charged particles' Electric Dipole Moments (EDMs). Measurements in magnetic storage rings using a resonant spin interaction of a radiofrequency Wien filter are proposed and needs to be scrutinized. Therefore, the calculation of phase space transfer maps for time-varying fields has been implemented into an extensions for the software framework COSY INFINITY. Benchmarking with measured data and analytical estimates for rf solenoid induced spin resonances are in good agreement. The dependence of polarization oscillation damping on the solenoid frequency could be confirmed. First studies of the rf Wien filter method reveal systematic limitations: Uncorrected Gaussian distributed misalignments of the COSY lattice quadrupoles with a standard deviation of 0.1 mm generate a similar buildup as an EDM of 5·10^-19 e cm using this method.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF032
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Paper

Title

Page

Quasi-frozen Spin Method for EDM Deuteron Search

213

Y. Senichev, A. Lehrach, B. Lorentz, R. Maier
FZJ, Jülich, Germany
S.N. Andrianov, A.N. Ivanov
St. Petersburg State University, St. Petersburg, Russia
M. Berz, E. Valetov
MSU, East Lansing, Michigan, USA
S. Chekmenev
RWTH, Aachen, Germany

To search for EDM using proton storage ring with purely electrostatic elements the concept of frozen spin method has been proposed by BNL. This method is based on two facts: in the equation of the spin precession the magnetic field dependence is entirely eliminated and at “magic” energy the spin precession frequency coincides with the precession frequency of the momentum. In case of deuteron the anomalous magnetic moment is negative (G=-0.142), therefore we have to use the electrical and magnetic field simultaneously keeping the frozen spin direction along the momentum as in the pure electrostatic ring. In this article we suggest the concept of the quasi-frozen spin when the spin oscillates around the momentum direction within the half value of the advanced spin phase each time returning back by special optics. Due to the low value of the anomalous magnetic moment of deuteron an effective contribution to the expected EDM effect is reduced only by a few percent.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPWA044

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEAB2

Beam and Spin Dynamics for Storage Ring Based EDM Search

2454

A. Lehrach
FZJ, Jülich, Germany

Funding: On behalf of the JEDI collaboration and JARA-FAME (Jülich Aachen Research Alliance)
Permanent EDMs (electric dipole moment) of fundamental particles violate both time invariance T and parity P. Assuming the CPT theorem this implies CP violation. The Standard Model (SM) predicts non-vanishing EDMs, their magnitudes, however, are expected to be unobservably small with current techniques. Hence, the discovery of a non-zero EDM would be a signal for “new physics”. As a first step towards EDM searches of charged particles in storage rings, R&D work at the Cooler Synchrotron COSY is pursued. On a longer time scale, the design and construction of a dedicated storage ring will be carried out. Spin-tracking simulations are absolutely crucial to explore the feasibility of the planned storage ring EDM experiments and to investigate systematic limitations. For a detailed study during the storage and buildup of the EDM signal, one needs to track a large sample of particles for billions of turns. Benchmarking experiments are performed at the Cooler Synchrotron COSY to check and to further improve the simulation tools and prototype accelerator components are tested. Finally, the layout of a dedicated storage ring has to be optimized by a full simulation of spin motion.

Slides WEAB2 [1.459 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-WEAB2

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF030

Antiproton Acceleration and Deceleration in the HESR

3758

B. Lorentz, T. Katayama, A. Lehrach, R. Maier, D. Prasuhn, R. Stassen, H. Stockhorst, R. Tölle
FZJ, Jülich, Germany

The High Energy Storage Ring (HESR) is a part of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The ring is used for hadron physics experiments with a pellet target and the PANDA detector, and will supply antiprotons of momenta from 1.5 GeV/c to 15 GeV/c. To cover the whole energy range a flexible adjustment of transition energy and the corresponding gamma-t value is foreseen. For Injection and Accumulation of Antiprotons delivered from the CR at a momentum of 3.8 GeV/c (gamma=4.2), the HESR optics will be tuned to gamma-t=6.2. For deceleration down to a momentum of 1.5 GeV/c this optic is suitable as well. Stochastic cooling at an intermediate energy is required to avoid beam losses caused by adiabatic growth of the beam during deceleration. For acceleration to 8 GeV/c (gamma=8.6) the optics will be changed after accumulation of the antiproton beam to gamma-t=14.6. For momenta higher than 8 GeV/c the beam will be debunched at 8 GeV/c, optics will be changed to gamma-t=6.2, and after adiabatic rebunching the beam will be accelerated to 15 GeV/c (gamma=16). Simulations show the feasibility of the described procedures with practically no beam losses.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF030

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPF032

Spin Tracking Simulations Towards Electric Dipole Moment Measurements at COSY

3764

M. Rosenthal, A. Lehrach
FZJ, Jülich, Germany
A. Lehrach, M. Rosenthal
RWTH, Aachen, Germany

A strong hint for physics beyond the Standard Model would be achieved by direct measurements of charged particles' Electric Dipole Moments (EDMs). Measurements in magnetic storage rings using a resonant spin interaction of a radiofrequency Wien filter are proposed and needs to be scrutinized. Therefore, the calculation of phase space transfer maps for time-varying fields has been implemented into an extensions for the software framework COSY INFINITY. Benchmarking with measured data and analytical estimates for rf solenoid induced spin resonances are in good agreement. The dependence of polarization oscillation damping on the solenoid frequency could be confirmed. First studies of the rf Wien filter method reveal systematic limitations: Uncorrected Gaussian distributed misalignments of the COSY lattice quadrupoles with a standard deviation of 0.1 mm generate a similar buildup as an EDM of 5·10^-19 e cm using this method.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF032

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)