Abstracts Brochure - CERN

WEPCH064
WEPCH065
WEPCH066
28-Jun-06 16:00 - 18:00 WEPCH — Poster Session
to negate the effect of the induced eddy currents. In this report results from measurements of these effects will be
presented. Results from modeling and comparisons to the measurements will also be presented.
Fast Compensation of Global Linear Coupling in RHIC Using AC Dipoles
Global linear coupling has been extensively
F. Franchi (GSI) R. Calaga (BNL) R. Tomas (CERN)
studied in accelerators and several methods
have been developed to compensate the coupling
vector C using skew quadrupole families scans. However, scanning techniques can become very time consuming
especially during the commissioning of an energy ramp. In this paper we illustrate a new technique to measure and
compensate, in a single machine cycle, global linear coupling from turn-by-turn BPM data without the need of a
skew quadrupole scan. The algorithm is applied to RHIC BPM data using AC dipoles and compared with traditional
methods.
Lattices for High-power Proton Beam Acceleration and Secondary Beam Collection, Cooling,
and Deceleration
S. Wang (IHEP Beijing) K.A. Brown, C.J. Gardner, Y.Y. Lee, D.I.
Lowenstein, S. Peggs, N. Simos, J. Wei (BNL)
290
Rapid-cycling synchrotrons are used to accelerate
high-intensity proton beams to energies
of tens of GeV for secondary beam production.
After primary beam collision with a
target, the secondary beam can be collected, cooled, accelerated or decelerated by ancillary synchrotrons for various
applications. In this paper, we first present a lattice for the main synchrotron. This lattice has: a) flexible momentum
compaction to avoid transition and to facilitate RF gymnastics b) long straight sections for low-loss injection,
extraction, and high-efficiency collimation c) dispersion-free straights to avoid longitudinal-transverse coupling, and
d) momentum cleaning at locations of large dispersion with missing dipoles. Then, we present a lattice for a cooler
ring for the secondary beam. The momentum compaction across half of this ring is near zero, while for the other half
it is normal. Thus, bad mixing is minimized while good mixing is maintained for stochastic beam cooling.
Space Charge Tune Shift and Quantum Lifetime
D.K. Kalantaryan (YSU) Y.L. Martirosyan, V.M. Tsakanov (CAN-
DLE)
The impact of the nonlinear resonance to
electron beam distribution is conditioned by
the proximity to the resonance and resonance
strength. The space charge caused tune shift
modifies the beam distribution. In this paper the equilibrium distribution of the electron beam near the nonlinear
resonance is evaluated, taking into account the space charge caused betatron tune shift. The reduction of the beam
quantum lifetime is calculated. The numerical example for the CANDLE synchrotron light source project is given.