2011 Particle Accelerator Conference - Classification: Sources and Medium Energy Accelerators / Accel/Storage Rings 11: e-coolers and Cooling Techniques

Paper	Title	Page
WEP113	Low-Energy Run of Fermilab Electron Cooler's Beam Generation System	1695
	L.R. Prost, A.V. Shemyakin Fermilab, Batavia, USA A.V. Fedotov, J. Kewisch BNL, Upton, Long Island, New York, USA
	Funding: FNAL is operated by FRA, LLC under Contract No.DE-AC02-07CH11359 with US DoE. BNL is operated by BSA, LLC under Contract No.DE-AC02-98CH10886 with US DoE. In the context of the evaluation of possibly using the Fermilab Electron Cooler for the proposed low-energy RHIC run at BNL, operating the cooler at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main conclusion of this feasibility study is that the cooler's beam generation system is suitable for BNL needs. The beam recirculation was stable for all tested parameters. In particular, a beam current of 0.38 A was achieved with the cathode magnetic field up to the maximum value presently available of 250 G. The energy ripple was measured to be 40 eV. A striking difference with running the 4.3 MeV beam (nominal for operation at FNAL) is that no unprovoked beam recirculation interruptions were observed.

WEP228	Effect of Transverse Electron Velocities on the Longitudinal Cooling Force in the Fermilab Electron Cooler	1915
	A. Khilkevich BSU, Minsk, Belarus L.R. Prost, A.V. Shemyakin Fermilab, Batavia, USA
	Funding: FNAL is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. In Fermilab’s electron cooler, a 0.1A, 4.3MeV DC electron beam propagates through the 20 m cooling section, which is immersed in a weak longitudinal magnetic field. A proper adjustment of 200 dipole coils, installed in the cooling section for correction of the magnetic field imperfections, can create a helix-like trajectory with the wavelength of 1-10 m. The longitudinal cooling force is measured in the presence of such helices at different wavelengths and amplitudes. The results are compared with a model calculating the cooling force as a sum of collisions with small impact parameters, where the helical nature of the coherent angle is ignored, and far collisions, where the effect of the coherent motion is neglected. A qualitative agreement is found.

WEP229	Status of 2 MeV Electron Cooler for COSY-Julich/HESR	1918
	J. Dietrich, V. Kamerdzhiev FZJ, Jülich, Germany M.I. Bryzgunov, A.D. Goncharov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva, D.N. Skorobogatov BINP SB RAS, Novosibirsk, Russia
	The 2 MeV electron cooling system for COSY-Jülich was proposed to further boost the luminosity even in presence of strong heating effects of high-density internal targets. The 2 MeV cooler is also well suited in the start up phase of the High Energy Storage Ring (HESR) at FAIR in Darmstadt. It can be used for beam cooling at injection energy and is intended to test new features of the high energy electron cooler for HESR. The project is funded since mid 2009. The design and construction of the cooler is accomplished in cooperation with the Budker Institute of Nuclear Physics in Novosibirsk, Russia. The technical layout of the 2 MeV electron cooler is described. The infrastructure necessary for the operation of the cooler in the COSY ring (radiation shielding, cabling, water cooling etc.) is established. The electron beam commissioning at BINP Novosibirsk is scheduled to start at the end of 2010. First results are reported.

Paper

Title

Page

Low-Energy Run of Fermilab Electron Cooler's Beam Generation System

1695

L.R. Prost, A.V. Shemyakin
Fermilab, Batavia, USA
A.V. Fedotov, J. Kewisch
BNL, Upton, Long Island, New York, USA

Funding: FNAL is operated by FRA, LLC under Contract No.DE-AC02-07CH11359 with US DoE. BNL is operated by BSA, LLC under Contract No.DE-AC02-98CH10886 with US DoE.
In the context of the evaluation of possibly using the Fermilab Electron Cooler for the proposed low-energy RHIC run at BNL, operating the cooler at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main conclusion of this feasibility study is that the cooler's beam generation system is suitable for BNL needs. The beam recirculation was stable for all tested parameters. In particular, a beam current of 0.38 A was achieved with the cathode magnetic field up to the maximum value presently available of 250 G. The energy ripple was measured to be 40 eV. A striking difference with running the 4.3 MeV beam (nominal for operation at FNAL) is that no unprovoked beam recirculation interruptions were observed.

WEP228

Effect of Transverse Electron Velocities on the Longitudinal Cooling Force in the Fermilab Electron Cooler

1915

A. Khilkevich
BSU, Minsk, Belarus
L.R. Prost, A.V. Shemyakin
Fermilab, Batavia, USA

Funding: FNAL is operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
In Fermilab’s electron cooler, a 0.1A, 4.3MeV DC electron beam propagates through the 20 m cooling section, which is immersed in a weak longitudinal magnetic field. A proper adjustment of 200 dipole coils, installed in the cooling section for correction of the magnetic field imperfections, can create a helix-like trajectory with the wavelength of 1-10 m. The longitudinal cooling force is measured in the presence of such helices at different wavelengths and amplitudes. The results are compared with a model calculating the cooling force as a sum of collisions with small impact parameters, where the helical nature of the coherent angle is ignored, and far collisions, where the effect of the coherent motion is neglected. A qualitative agreement is found.

WEP229

Status of 2 MeV Electron Cooler for COSY-Julich/HESR

1918

J. Dietrich, V. Kamerdzhiev
FZJ, Jülich, Germany
M.I. Bryzgunov, A.D. Goncharov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva, D.N. Skorobogatov
BINP SB RAS, Novosibirsk, Russia

The 2 MeV electron cooling system for COSY-Jülich was proposed to further boost the luminosity even in presence of strong heating effects of high-density internal targets. The 2 MeV cooler is also well suited in the start up phase of the High Energy Storage Ring (HESR) at FAIR in Darmstadt. It can be used for beam cooling at injection energy and is intended to test new features of the high energy electron cooler for HESR. The project is funded since mid 2009. The design and construction of the cooler is accomplished in cooperation with the Budker Institute of Nuclear Physics in Novosibirsk, Russia. The technical layout of the 2 MeV electron cooler is described. The infrastructure necessary for the operation of the cooler in the COSY ring (radiation shielding, cabling, water cooling etc.) is established. The electron beam commissioning at BINP Novosibirsk is scheduled to start at the end of 2010. First results are reported.