Abstracts Brochure - CERN

WEPCH169
WEPCH170
WEPCH172
28-Jun-06 16:00 - 18:00 WEPCH — Poster Session
Alternating Phase Focused IH-DTL for Heavy-ion Medical Accelerators
Y. Iwata, T. Fujisawa, T. Furukawa, S. H. Hojo, M. Kanazawa, N.
M. Miyahara, T. Murakami, M. Muramatsu, K. Noda, H. Ogawa,
Y. S. Sakamoto, M. Torikoshi, S. Yamada, K. Yamamoto (NIRS) T.
Fujimoto, T. Takeuchi (AEC) T. Mitsumoto, H. Tsutsui (SHI)
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Tumor therapy using HIMAC has been performed
at NIRS since June 1994. With the
successful clinical results over more than
ten years, a number of projects to construct
these complexes have been proposed over the
world. Since existing heavy-ion linacs are
large in size, the development of compact linacs would play a key role in designing compact and cost-effective complexes.
Therefore, we developed an injector system consisting of RFQ and Interdigital H-mode (IH) DTL having
the frequency of 200 MHz. The injector system can accelerate carbon ions up to 4.0 AMeV. For the beam focusing
of IH-DTL, the method of Alternating Phase Focusing (APF) was employed. With the IH structure and rather
high frequency, the cavity size is compact; the radius is 0.4 m, and lengths of RFQ and IH-DTL are 2.5m and 3.5m
respectively. The fabrication of RFQ was completed, and we succeeded to accelerate carbon ions with satisfactory
performances. For IH-DTL, the full-scale model was first fabricated. With the encouraging result* of its electric field
measurement, we constructed IH-DTL and beam acceleration tests will be performed in March 2006. We will present
the performances of the entire injector system.
*Y. Iwata et al., Nucl Instr. & Meth in Phys. Res. A (submitted).
Development of Intensity Control System with RF-knockout Extraction at the HIMAC
Synchrotron
We have developed a dynamic intensity con-
S. Sato, T. Furukawa, K. Noda (NIRS)
trol system toward scanning irradiation at
the HIMAC Synchrotron. In this system, for
controlling the spill structure and intensities of the beams extracted from the synchrotron, the amplitude of the RFknockout
is controlled with the response of 10 kHz. Its amplitude modulation (AM) function is generated based on
an analytical one-dimensional model of the RF-knockout slow-extraction. In this paper, we describe the system for
controlling amplitude modulation including feedback and the experimental result.
Electron Beam Pulse Processing toward the Intensity Modified Radiation Therapy (IMRT)
Radiation therapy attracts attention as one
T. Kondoh, S. Tagawa, J. Yang, Y. Yoshida (ISIR)
of the cancer therapies nowadays. Toward
the next generation of the intensity modified
radiation therapy (IMRT), the processing of electron beam pulse is studied using a photo cathode RF gun linac.
Accelerated electron pulses will be converted to x-ray pulses by a metal target bremsstrahlung method or by a laser
inverse Compton scattering method. Recently, the radiation therapy of cancer is developing to un-uniform irradiation
as IMRT. A photo cathode RF gun is able to generate a low emittance electron beam pulse using a laser light pulse.
We thought that a photo cathode RF gun can generate intensity and shape modified electron beam by processing of
incident laser light. Because of a low emittance, an electron pulse is able to accelerate keeping shape. Electron beam
processing by photo masks in incident optical system and generated beams are reported here. Images on photo masks
were transported to a cathode surface by optical relay imaging. Beams were monitored by Desmarquest (Cr:Al2O3)
luminescence. Spatially separation of a spot to a spot is about 0.3mm. Modified electron beam has fine spatial
resolution.