Abstracts Brochure - CERN

TUPCH132
TUPCH133
TUPCH134
27-Jun-06 16:00 - 18:00 TUPCH — Poster Session
Higher Order Mode (HOM) Damper of 500MHz Damped Cavity for ASP Storage Ring
J. Watanabe, K. Nakayama, K. S. Sato, H. Suzuki (Toshiba) M. Izawa
(KEK) A. Jackson, G. LeBlanc, K. Zingre (ASP) T. Koseki (RIKEN/
RARF/CC) N. Nakamura, H. Sakai, H. Takaki (ISSP/SRL)
198
TOSHIBA has delivered the storage ring
RF system for the Australian Synchrotron
Project(ASP). Two pairs of the 500MHz
Higher Order Mode(HOM) damped cavities
were applied for this system. Two on-cen-
tered and one off-centered dampers were attached for damping the longitudinal HOM impedance down to less than
20kOhm/GHz. In order to reduce the coupling of off-center damper for accelerating mode and improve cooling
power of damper, New HOM damper was designed by optimizing SiC absorber structure and damper antenna length
using HFSS code. The design and manufacture of the new HOM damper and the test are described.
Comparison of Measured and Calculated Coupling between a Waveguide and an RF Cavity
Using CST Microwave Studio
J. Shi, H. Chen, S. Zheng (TUB) D. Li (LBNL) R.A. Rimmer, H.
Wang (Jefferson Lab)
Accurate predications of RF coupling between
an RF cavity and ports attached to
it have been an important study subject for
years for RF coupler and higher order modes
(HOM) damping design. We report recent progress and a method on the RF coupling simulations between waveguide
ports and RF cavities using CST Microwave Studio in time domain (Transit Solver). Comparisons of the measured
and calculated couplings are presented. The simulated couplings and frequencies agree within ∼ 10% and ∼ 0.1%
with the measurements, respectively. We have simulated couplings with external Qs ranging from ∼ 100 to ∼ 100,
000, and confirmed with measurements. The method should also work well for higher Qs, and can be easily applied
in RF power coupler designs and HOM damping for normal-conducting and superconducting cavities.
RF Characteristics of the PEFP DTL
A conventional 20 MeV Drift Tube Linac
H. S. Kim, Y.-S. Cho, H.-J. Kwon, K.T. Seol (KAERI)
(DTL) for the Proton Engineering Frontier
Project (PEFP) has been developed as a low
energy section of a 100 MeV accelerator. The 20 MeV DTL consists of 4 tanks with 152 cells. The machine has a
unique feature of driving the 4 tanks with a single klystron. Therefore it has several control knobs to compensate the
errors of each tank during operation. To develop the RF control scheme, the variations of the RF parameters of each
tank were measured under various environmental conditions such as wall temperature, cooling water temperature,
and cooling water pressure. In addition, the behaviors of the RF parameters among the tanks were also monitored
during high power operation. In this paper, the measurement results are discussed and the control scheme based on
the results are proposed.