Atomic Energy, Vol. 94, No. 1, 2003
1063-4258/03/9401-0024$25.00
©
2003 Plenum Publishing Corporation
24
COSY electronic cooling is used after charge-exchange injection of H
–
or D
–
to produce the required
emittance and momentum spread in the beam after the beam is accelerated. The cooled and accelerated
beam is then used for experimental applications, such as, fast or slow extraction for experiments onto an
external target. Methods for setting up the electronic-cooling system and limiting the ion-beam intensity are
discussed.
The purpose of the COSY accelerator-accumulator is to obtain unpolarized and polarized proton or deuteron beams
for experiments on internal and external targets in the momentum range of accelerated electrons from 300 MeV/sec up to
3.7 GeV/sec [1]. The accumulator is equipped with electronic and stochastic cooling systems and its basic parameters are
as follows:
Injection type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Charge-exchange injection H
–
,D
–
;
target – 20–25 µg/cm
2
thick carbon film
Injection energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 MeV for protons, 76 MeV for deuterons
Accumulator form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Two rectilinear and two bending sections
Nominal orbit perimeter, m . . . . . . . . . . . . . . . . . . . . . . . 183.473
Vacuum chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . In rectilinear sections 0.15 m in diameter circular
section, in bending sections 0.15 m horizontal
size and 0.06 m vertical size
Betatron oscillation frequency . . . . . . . . . . . . . . . . . . . . . Tuned from 3.55 to 3.7 in both planes
Structure functions in the electronic cooling sections . . . β
x
= 8 m, β
y
= 16 m, D = –6 m
The stochastic cooling system, covering the beam momentum range from 1.5 GeV/sec up to the maximum value, is
used to compensate the beam energy losses in experiments on an internal target, for example, COSY 11.
The electronic cooling system, developed and built simultaneously with the accumulator from 1988 to 1993 and
put into operation in May 1993, is now most actively used for physical experiments. Its basic design parameters are as
follows:
CURRENT STATUS OF THE COSY ELECTRON
COOLER (JÜLICH, GERMANY)
H. Stein,
1
D. Prasuhn,
1
H. Stockhorst,
1
J. Dietrich,
1
K. Phan,
1
V. Kamerdzhiev,
1
R. Maier,
1
I. N. Meshkov,
2
A. O. Sidorin,
2
and V. V. Parkhomchuk
3
UDC 621.384.6
Translated from Atomnaya Énergiya, Vol. 94, No. 1, pp. 57–59, January, 2003.
1
Research Center, Jülich, Germany.
2
Joint Institute of Nuclear Research.
3
G. I. Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences.