Abstracts Brochure - CERN

WEPCH — Poster Session 28-Jun-06 16:00 - 18:00
Beam Test of Thermionic Cathode X-band RF-gun and Linac for Monochromatic Hard Xray
Source
A compact hard X-ray source based on laserelectron
collision is proposed. The X-band
linac is introduced to realize a very compact
system. 2MeV electron beam with average
current 2µampere at 10 pps, 200 ns of RF
K. Dobashi, A. Fukasawa, M. D. Meng, T. Natsui, F. Sakamoto, M.
Uesaka, T. Yamamoto (UTNL) M. Akemoto, H. Hayano, T. Higo,
J.U. Urakawa (KEK)
pulse is generated by a thermionic cathode X-band RF-gun. Beam acceleration and X-ray generation experiment by
the X-band beam line are under way.
Study of Scatterer Method to Compensate Asymmetric Distribution of Slowly Extracted
Beam at HIMAC Synchrotron
In the medical use of the ion beam, the following
characteristics of the beam are preferred:
1) Symmetric Gaussian beam profile
is convenient for the scanning irradiation. 2)
T. Furukawa, K. Noda, S. Sato, S. Shibuya, E. Takada, M. Torikoshi,
T.H. Uesugi, S. Yamada (NIRS)
In the rotating gantry system, the symmetric beam condition can realize no-correlation between the beam profiles
and the rotation angles of the gantry. However, the slowly extracted beam has asymmetric distribution in the phasespace
and a difference between the horizontal emittance and vertical one. Thus, we have proposed the thin scatterer
method to compensate the phase-space distribution of the slowly extracted beam, although the emittance is enlarged
by scattering. As a result of particle tracking and experiment, it was verified that the asymmetric distribution was
compensated by very small scattering angle. It was also simulated that this scatterer method can realize the symmetric
beam condition for the rotating gantry. In this paper, these results of asymmetry compensation for the slow-extraction
at HIMAC is presented.
Development toward Turn-key Beam Delivery for Therapeutic Operation at HIMAC
Since 1994, more than 2500 cancer patients
have been treated by carbon ion beam at HI-
MAC. To increase the number of patients per
day, we have studied the reproducibility of
T. Furukawa, T. Kanai, K. Noda, S. Sato, E. Takada, M. Torikoshi, S.
Yamada (NIRS) M. Katsumata, T. Shimojyu, T. Shiraishi (AEC)
the beam quality, such as the position, profile and intensity, during the operation. For this purpose, the accelerator
needs high reproducibility to minimize the beam tuning time with more flexible scheme. Further, the irradiation
system and the accelerator need to ensure dose uniformity. As a result of this study, it was found that a slight
change of the magnetic field in the transport line would not affect the beam quality. However, a slight change of the
horizontal tune strongly affects the beam quality because of a resonant slow-extraction. In this paper, we report about
our investigation and present result of the development.
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