Mitsuhashi, T.

Paper	Title	Page
MOPC061	Progress in R&D Efforts on the Energy Recovery Linac in Japan	205
	S. Sakanaka, T. A. Agoh, A. Enomoto, S. Fukuda, K. Furukawa, T. Furuya, K. Haga, K. Harada, S. Hiramatsu, T. Honda, Y. Honda, K. Hosoyama, M. Izawa, E. Kako, T. Kasuga, H. Kawata, M. Kikuchi, H. Kobayakawa, Y. Kobayashi, T. Matsumoto, S. Michizono, T. Mitsuhashi, T. Miura, T. Miyajima, T. Muto, S. Nagahashi, T. Naito, T. Nogami, S. Noguchi, T. Obina, S. Ohsawa, T. Ozaki, H. Sasaki, S. Sasaki, K. Satoh, M. Satoh, M. Shimada, T. Shioya, T. Shishido, T. Suwada, T. Takahashi, Y. Tanimoto, M. Tawada, M. Tobiyama, K. Tsuchiya, T. Uchiyama, K. Umemori, S. Yamamoto KEK, Ibaraki R. Hajima, H. Iijima, N. Kikuzawa, E. J. Minehara, R. Nagai, N. Nishimori, M. Sawamura JAEA/ERL, Ibaraki H. Hanaki JASRI/SPring-8, Hyogo-ken A. Ishii, I. Ito, T. Kawasaki, H. Kudo, N. Nakamura, H. Sakai, S. Shibuya, K. Shinoe, T. Shiraga, H. Takaki ISSP/SRL, Chiba M. Katoh UVSOR, Okazaki Y. Kobayashi, K. Torizuka, D. Yoshitomi AIST, Tsukuba M. Kuriki HU/AdSM, Higashi-Hiroshima
	The future synchrotron light sources, based on the energy recovery linacs (ERL), are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. The ERL-based light sources are under development at such institutes as the Cornell University, the Daresbury Laboratory, the Advanced Photon Source, and KEK/JAEA. The Japanese collaboration team, including KEK, JAEA, ISSP, and UVSOR, is working to realize the key technologies for the ERLs. Our R&D program includes the developments of ultra-low-emittance photocathode DC guns and of superconducting cavities, as well as proofs of accelerator-physics issues at a small test ERL (the Compact ERL). A 250-kV, 50-mA photo-cathode DC gun is under construction at JAEA. Two single-cell niobium cavities have been tested under high electric fields at KEK. The conceptual design of the Compact ERL has been carried out. We report recent progress in our R&D efforts.
TUOCM02	X-ray Monitor Based on Coded-aperture Imaging for KEKB Upgrade and ILC Damping Ring	1029
	J. W. Flanagan, H. Fukuma, S. Hiramatsu, H. Ikeda, K.-I. Kanazawa, T. Mitsuhashi, J. Urakawa KEK, Ibaraki J. P. Alexander CLASSE, Ithaca M. A. Palmer Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York G. S. Varner UH, Honolulu, HI
	We present here design considerations for an x-ray monitor for high-resolution (a few um) and fast response (sub-nanosecond) for beam profile measurements to be used at an upgraded KEKB and/or ILC damping ring. The optics for the monitor are based on a technique borrowed from x-ray astronomy, coded-aperture imaging, which should permit broad-spectrum, low-distortion measurements to maximize the observable photon flux per bunch. Coupled with a high-speed digitizer system, the goal is to make sub-bunch-length, turn-by-turn measurements of beam profile and position.
	Slides
TUPC091	Measurement of Quadrupolar Tune Shifts under Multibunch Operations of the Photon Factory Storage Ring	1269
	S. Sakanaka, T. Mitsuhashi, T. Obina KEK, Ibaraki
	The quadrupolar tune shifts were observed under a single-bunch operation of the Photon Factory storage ring at KEK, which indicated that a quadrupolar component of wakefields affected the motion of an electron bunch. We recently measured the quadrupolar tune shifts under a multibunch operation of the Photon Factory storage ring. To detect the transverse quadrupole-mode oscillations of electron bunches, we used an avalanche photo diode (APD) which can detect visible synchrotron light with short rise-time of less than 1 ns. As a result, we observed that the quadrupolar tunes depended on the total beam current by 0.0082 1/A (in horizontal) and -0.0082 1/A (in vertical), respectively. These tune shifts can be caused by a quadrupolar component of long-range wakefield.
WEPC035	Present Status of PF-ring and PF-AR in KEK	2064
	Y. Kobayashi, S. Asaoka, K. Ebihara, K. Haga, K. Harada, T. Honda, T. Ieiri, M. Izawa, T. Kageyama, T. Kasuga, M. Kikuchi, K. Kudo, H. Maezawa, K. Marutsuka, A. Mishina, T. Mitsuhashi, T. Miyajima, H. Miyauchi, S. Nagahashi, T. T. Nakamura, T. Nogami, T. Obina, K. Oide, M. Ono, T. Ozaki, C. O. Pak, H. Sakai, Y. Sakamoto, S. Sakanaka, H. Sasaki, Y. Sato, M. Shimada, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, S. Takasaki, Y. Tanimoto, M. Tejima, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, S. Yamamoto, Ma. Yoshida, M. Yoshimoto KEK, Ibaraki
	In KEK, we have two synchrotron light sources which were constructed in the early 1980s. One is the Photon Factory storage ring (PF-ring) and the other is the Photon Factory advanced ring (PF-AR). The PF-ring is usually operated at 2.5 GeV and sometimes ramped up to 3.0 GeV to provide photons with the energy from VUV to hard X-ray region. The PF-AR is mostly operated in a single-bunch mode of 6.5GeV to provide pulsed hard X-rays. Operational performances of them have been upgraded through several reinforcements. After the reconstruction of the straight section of the PF-ring in 2005, two short-period-gap undulators have been stably operated. They allow us to produce higher brilliant hard X-rays even at the energy of 2.5 GeV. In March 2008, the circular polarized undulator will be installed in the long straight section of 8.9 m. In the PF-AR, new tandem undulators have been operated since September 2006 to generate much stronger pulsed hard X-rays for the sub-ns resolved X-ray diffraction experiments. In this conference, we report present status of the PF-ring and the PF-AR.