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About
BEPCII
As a
natural extention of the Beijing Electron Positron Collider
(BEPC), the BEPCII will operate in the beam energy region of
1.0-2.1 GeV so that its physical potential in the whole t
and charm range is preserved. As the physics is concentrated
at the J/y (3097), y(3686), and y(3770), the collider is
optimized at 1.89 GeV. In order to obtain a high duty factor
of the collision, the injection time should be shorter than
half an hour. The injector should be capable of the
full-energy topoff injection up to 1.89 GeV, and the
positron injection rate should be higher than 50 mA/min. As
the machine will also be operated as a SR source, the
upgrade of the collider should also provide an improved SR
operation performance with higher beam energy and intensity,
i.e. 250 mA at E = 2.5 GeV. Layout of the BEPCII is shown in
the following figure and its design goals are listed in the
table below.
Design goals
of the BEPCII
|
Beam
energy range
|
1-2.1
GeV
|
|
Optimized
beam energy region
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1.89
GeV
|
|
Current
of each beam in collision
|
0.93
A
|
|
Design
luminosity
|
1
´10
33 cm-2s-1 @189
GeV
|
|
Beam
lifetime
|
2.7
hrs.
|
|
Injection
from linac
|
Full
energy injection: Einj = 1.55-1.89GeV
Positron
injection rate >50 mA/min
|
|
Dedicated
SR operation
|
250
mA @ 2.5 GeV
|
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