Neutron energy spectra and dose equivalent rates from heavy-ion reactions below 20 MeV/u using the PHITS code

Iwamoto, Yosuke; Ronningen, R. M.*; Niita, Koji*

Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.1683 - 1685, 2009/05

The reliability of PHITS at low energies has not been investigated. In this work, neutron energy spectra from 10 MeV/u C and O ions incidence have been calculated using the QMD model coupled to the GEM model in PHITS. In particular, the influence of the "switching time", defined as the time when the QMD calculation is stopped and the calculation switches to the GEM model, was studied. The calculated neutron energy spectra obtained using a value of 100 fm/c for the switching time agree well with the experimental data. We have also used PHITS to simulate an experimental study by Ohnesorge et al., by calculating neutron dose equivalent rates, for 3-16 MeV/u C, O and Ne beams incident on Fe, Ni and Cu targets. The calculated neutron dose equivalent rates agree well with the data.

Higher harmonic voltages in J-PARC RCS operation

Schnase, A.; Tamura, Fumihiko; Yamamoto, Masanobu; Nomura, Masahiro; Hasegawa, Katsushi; Shimada, Taihei; Suzuki, Hiromitsu; Omori, Chihiro*; Yoshii, Masahito*; Ezura, Eiji*; et al.

Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.1988 - 1990, 2009/05

Longitudinal painting studies in the J-PARC RCS

Tamura, Fumihiko; Yamamoto, Masanobu; Yoshii, Masahito*; Omori, Chihiro*; Nomura, Masahiro; Schnase, A.; Toda, Makoto*; Suzuki, Hiromitsu; Shimada, Taihei; Hara, Keigo*; et al.

Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.1445 - 1447, 2009/05

In the J-PARC RCS, we employ the longitudinal painting methods, the momentum offset injection method and applying the second harmonic RF voltages, to increase the bunching factor so that the space-charge tune shift is reduced. By the dual-harmonic operation with wide-band MA loaded cavities, in which each single cavity is driven by a superposition of the fundamental and the second harmonic RF signals, we can generate a large amplitude second harmonic RF voltage without extra cavities for the second harmonic RF. We present the results of the beam tests for the longitudinal painting in the J-PARC RCS. Also, we present the beam behavior at very high beam power.

Measurement results of the characteristic of the pulse power supply for the injection bump system in J-PARC 3-GeV RCS

Takayanagi, Tomohiro; Ueno, Tomoaki; Togashi, Tomohito; Kinsho, Michikazu; Kamiya, Junichiro; Watanabe, Masao; Yoshimoto, Masahiro; Irie, Yoshiro*

Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.1742 - 1744, 2009/05

The main circuit of the switching power supplies for the injection bump system is composed of multiple-connection of the IGBT assemblies. The element of the IGBT assembly of the shift bump magnet is a type of 3300V-1200A and 6 kHz in elementary frequency. The synthetic frequency of the multiple-connection assemblies is over 48 kHz and the tracking error less than 1 % is proved. The beam commissioning test of long-term operation for about three-week was performed. The deviation of the exciting current from the programmed current pattern has been confirmed less than 1%. The peculiar characteristic of the pulse power supply has been obtained and the FFT analytical result of the magnetic field, the peaks of 48 kHz and its higher harmonics that are related to the switching frequency was observed.

Automatic frequency matching for cavity warming-up in J-PARC linac digital LLRF control

Kobayashi, Tetsuya; Suzuki, Hiroyuki; Anami, Shozo*; Yamaguchi, Seiya*; Michizono, Shinichiro*; Fang, Z.*

Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.2213 - 2215, 2009/05

In the J-PARC Linac LLRF, for the cavity start-up, the cavity resonance is automatically controlled to be the accelerating frequency (324 MHz and 972 MHz) with a mechanical tuner installed on the cavity. We are planning to introduce a new method of the cavity-input frequency matching into the digital LLRF control system instead of the tuner control for the cavity start-up. In order to match the frequency with the detuned cavity, the output RF frequency is modulated by way of phase rotation with the I/Q modulator, while the cavity tuner is fixed. The detuning of the cavity is obtained from phase gradient of the cavity field decay at the RF-pulse end and the phase rotation is automatically controlled by a FPGA and a DSP. No hardware modification is necessary for this frequency modulation method. The cost reduction or the high durability for the mechanical tuner production is expected in the future.

Designing integrated laser-driven ion accelerator systems for hadron therapy at PMRC (Photo Medical Research Center)

Sakaki, Hironao; Hori, Toshihiko; Nishiuchi, Mamiko; Bolton, P.; Daido, Hiroyuki; Kawanishi, Shunichi; Sutherland, K.*; Soda, Hikaru*; Noda, Akira*; Iseki, Yasushi*; et al.

Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.1309 - 1311, 2009/05

The concept of a compact ion particle accelerator has become attractive in view of recent progress in laser-driven hadrons acceleration. The Photo Medical Research Center (PMRC) of JAEA was recently established to address the challenge of laser-driven ion accelerator development for hadron beam cancer therapy. PMRC considers conceptual designs of such a therapeutic instrument based on the current state in the laser-driven acceleration. We describe a conceptual gantry device that is designed by the general-purpose ion accelerator design code, PARMILA.

Study of J-PARC linac beam position monitor as phase monitor

Sato, Susumu; Miura, Akihiko; Tomisawa, Tetsuo; Sako, Hiroyuki; Morishita, Takatoshi; Ueno, Akira; Hasegawa, Kazuo; Yoshikawa, Hiroshi; Igarashi, Zenei*; Ikegami, Masanori*

Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.3591 - 3593, 2009/05