COOL2013 - List of Authors (Kamerdzhiev, V.)

Paper

Title

Page

Stochastic Cooling of a Polarized Proton Beam at COSY

44

H. Stockhorst, R. Gebel, V. Kamerdzhiev, A. Lehrach, B. Lorentz, R. Maier, D. Prasuhn, R. Stassen
FZJ, Jülich, Germany
T. Katayama
GSI, Darmstadt, Germany

Stochastic cooling can increase the spin coherence time in storage ring experiments dedicated to the search of electric dipole moments of protons or deuterons. Since radial magnetic fields may lead to depolarizing spin resonances a first test with a vertical polarized beam at COSY subject to vertical stochastic cooling has been investigated. The polarization was measured at the beginning and the end of flat top momentum with the result that no polarization loss could be observed within five minutes. The spin motion under the influence of stochastic cooling was also studied with the Thomas-BMT equation including the estimated electromagnetic fields for a quarter wave length kicker structure. It is found that the resonance strength in the cooling bandwidth of 1-2 GHz is much smaller than the typical imperfection or intrinsic resonance strengths. The resonance condition of the spin rotation is not fulfilled as the harmonics of cooling RF kicker fields are not in phase with the spin rotation angle per turn. In conclusion it is expected that stochastic cooling will not lead to depolarization even when stochastic cooling is applied for a longer time as in the present experiment.

Slides TUAM1HA02 [2.324 MB]

TUPM2HA02

Commissioning of the 2 MeV COSY Electron Cooler in Jülich

V. Kamerdzhiev, L.J. Mao
FZJ, Jülich, Germany
J. Dietrich
DELTA, Dortmund, Germany
J. Dietrich
HIM, Mainz, Germany
L.J. Mao
IMP, Lanzhou, People's Republic of China
V.V. Parkhomchuk, V.B. Reva
BINP SB RAS, Novosibirsk, Russia

The construction of the 2 MeV electron cooler at BINP has been completed. After initial testing, the cooler was shipped to Jülich. The installation in COSY is scheduled to begin in April 2013. The report covers the installation and commissioning progress in Jülich. The history of the project is briefly touched on.

Slides TUPM2HA02 [4.490 MB]

WEPPO12

Compass for Measuring the Magnetic Lines Straightness at the Cooling Section in Vacuum

121

A.V. Bubley, M.I. Bryzgunov, V.G. Cheskidov, M.G. Fedotov, V.K. Gosteev, O.I. Meshkov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva
BINP SB RAS, Novosibirsk, Russia
V. Kamerdzhiev, G. Langenberg
FZJ, Jülich, Germany

The 2 MeV cooler is under construction at COSY synchrotron. Due to high energy it is very strict requirement for the magnetic field homogeneity at the cooling solenoid. Since the magnetic field has to be adjusted during the accelerator operation, the measurement system is installed inside vacuum chamber. The design and features of this system are described in the article, as well as preliminary results are discussed.

Paper	Title	Page
TUAM1HA02	Stochastic Cooling of a Polarized Proton Beam at COSY	44
	H. Stockhorst, R. Gebel, V. Kamerdzhiev, A. Lehrach, B. Lorentz, R. Maier, D. Prasuhn, R. Stassen FZJ, Jülich, Germany T. Katayama GSI, Darmstadt, Germany
	Stochastic cooling can increase the spin coherence time in storage ring experiments dedicated to the search of electric dipole moments of protons or deuterons. Since radial magnetic fields may lead to depolarizing spin resonances a first test with a vertical polarized beam at COSY subject to vertical stochastic cooling has been investigated. The polarization was measured at the beginning and the end of flat top momentum with the result that no polarization loss could be observed within five minutes. The spin motion under the influence of stochastic cooling was also studied with the Thomas-BMT equation including the estimated electromagnetic fields for a quarter wave length kicker structure. It is found that the resonance strength in the cooling bandwidth of 1-2 GHz is much smaller than the typical imperfection or intrinsic resonance strengths. The resonance condition of the spin rotation is not fulfilled as the harmonics of cooling RF kicker fields are not in phase with the spin rotation angle per turn. In conclusion it is expected that stochastic cooling will not lead to depolarization even when stochastic cooling is applied for a longer time as in the present experiment.
	Slides TUAM1HA02 [2.324 MB]

TUPM2HA02	Commissioning of the 2 MeV COSY Electron Cooler in Jülich
	V. Kamerdzhiev, L.J. Mao FZJ, Jülich, Germany J. Dietrich DELTA, Dortmund, Germany J. Dietrich HIM, Mainz, Germany L.J. Mao IMP, Lanzhou, People's Republic of China V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia
	The construction of the 2 MeV electron cooler at BINP has been completed. After initial testing, the cooler was shipped to Jülich. The installation in COSY is scheduled to begin in April 2013. The report covers the installation and commissioning progress in Jülich. The history of the project is briefly touched on.
	Slides TUPM2HA02 [4.490 MB]

WEPPO12	Compass for Measuring the Magnetic Lines Straightness at the Cooling Section in Vacuum	121
	A.V. Bubley, M.I. Bryzgunov, V.G. Cheskidov, M.G. Fedotov, V.K. Gosteev, O.I. Meshkov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia V. Kamerdzhiev, G. Langenberg FZJ, Jülich, Germany
	The 2 MeV cooler is under construction at COSY synchrotron. Due to high energy it is very strict requirement for the magnetic field homogeneity at the cooling solenoid. Since the magnetic field has to be adjusted during the accelerator operation, the measurement system is installed inside vacuum chamber. The design and features of this system are described in the article, as well as preliminary results are discussed.