Abstracts Brochure - CERN

TUPCH184
TUPCH185
TUPCH186
TUPCH187
27-Jun-06 16:00 - 18:00 TUPCH — Poster Session
to different particle loss rates and times between NEG regenerations. The results are presented in this paper and
discussed.
Development of a Novel HOM Absorber
N. Kurita, M. Kosovsky, A. Novokhatski, J. Seeman, S.P. Weathersby
(SLAC)
214
A novel HOM absorber module is being developed
for the PEP-II B-factory to help mitigate
HOM’s that are trapped in the vacuum
system. The PEP-II B-factory has achieved
the highest stored ring currents of 3A and at small bunch lengths. These high currents have created a new generation
of problems with HOM heating of machine components. The HOM absorber is planned to be installed early this year
in PEP-II. The mechanical design, fabrication and operational experience will be presented.
Performance and Design of an RF Shielded Bellows with HOM Absorber
The PEP-II RF shielded bellows have been
N. Kurita, M. Kosovsky, A. Novokhatski, S.P. Weathersby (SLAC) operating successfully at high current for 10
years. The bellows module has successfully
maintained RF continuity between mating chambers while allowing for thermal expansion of chambers and manufacturing
tolerances. However, the higher bunch currents and shorter bunch lengths, coupled with chamber aperture
perturbations have led to excessive TE mode power leaking past the shield and heating up the thin welded convolutions.
A new bellows design incorporates absorbing tiles behind the RF shield to absorb this power and keeps the
convolutions from overheating.
Low Level RF System Development for SOLEIL
P. Marchand, M.D. Diop, F. Ribeiro, R.S. Sreedharan (SOLEIL) M.
Luong, O. Piquet (CEA)
The Low Level RF system that is used in the
SOLEIL storage ring consists in fully analog
"slow" amplitude, phase and frequency
loops, complemented with a direct RF feed-
back. A fast digital FPGA-based I/Q feedback, currently under development, will be implemented later on. The
performance of both systems has been evaluated using a Matlab-Simulink-based simulation tool. The computed and
first experimental results are reported.
DSP-based Low Level RF Control as an Integrated Part of DOOCS Control System
V. Ayvazyan, A. Brandt, O. Hensler, G.M. Petrosyan, L.M. Petrosyan,
K. Rehlich, S. Simrock, P. Vetrov (DESY)
The Distributed Object Oriented Control System
(DOOCS) has been developed at DESY
as a control system for TTF/VUV-FEL. The
DSP based low level RF control system is one
of the main subsystems of the linac. Several DOOCS device servers and client applications have been developed to
integrate low level RF control into the TTF/VUV-FEL control system. The DOOCS approach defines each hardware
device as a separate object and this object is represented in a network by a device server, which handles all device