Nomura, M.

Paper	Title	Page
TUPLT072	Dual Harmonic Acceleration with Broadband MA Cavities in J-PARC RCS	1318
	M. Yamamoto JAERI, Chiba-ken S. Anami, E. Ezura, K. Hara, Y. Hashimoto, C. Ohmori, A. Takagi, M. Yoshii KEK, Ibaraki M. Nomura, A. Schnase, F. Tamura JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	In the J-PARC RCS rf system, since the fundamental rf acceleration voltage and the 2nd higher harmonic one are applied to each cavity, the impedance of hte cavity has a broadband characteristic. The Q-value of the cavity is chosen to make the higher harmonic beam loading effect as small as possible. The analysis of the amplifier and the beam loading effect on the dual harmonic rf system is described.
WEOACH01	High Field Gradient Cavity for J-PARC 3 GeV RCS	123
	C. Ohmori, S. Anami, E. Ezura, K. Hara, Y. Hashimoto, A. Takagi, M. Toda, M. Yoshii KEK, Ibaraki M. Nomura, A. Schnase, F. Tamura, M. Yamamoto JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	A new type of rf cavity will be used for J-PARC project. To minimize the beam loading effects, the quality factor of the core stack is increased by a cut core configuration. High power test of the rf system has been performed. Temperature rise around the cut surface of the cores were observed. It is minimized by improving the cooling efficiency.
	Video of talk
	Transparencies
THPKF039	Study of Photo-cathode RF Gun for a High Brightness Electron Beam	2359
	Y. Yamazaki JNC/OEC, Ibaraki-ken S. Araki, H. Hayano, M. Kuriki, T. Muto, N. Terunuma, J. Urakawa KEK, Ibaraki M.K. Fukuda, K. Hirano, M. Nomura, M. Takano NIRS, Chiba-shi
	We are going to develop a compact high-brightness electron beam system to adopt industrial and medical applications. A multi-bunch photo-cathode RF gun has been developed to generate 100 bunches beam with 2.8ns spacing and 5nC charge per bunch. We will report details of the development, especially photo-cathode production and emission characteristics from cathode by the laser.
THPLT061	Development of a Multibunch Photo-cathode RF Gun System	2625
	J. Urakawa, M. Akemoto, S. Araki, H. Hayano, M. Kuriki, T. Muto, N. Terunuma, Y. Yamazaki KEK, Ibaraki M.K. Fukuda, K. Hirano, M. Nomura, M. Takano NIRS, Chiba-shi
	A multibunch photo-cathode RF gun system has been developed as a electron source for the production of quasi-monoenergetic X-rays based on inverse Compton scattering. This system consists of a photocathode rf gun, a cathode system, a laser system, beam diagnostic sections, and beam dump line. The gun produces 100 bunches with a 2.8ns bunch spacing and 5nC bunch charge. We will report on the RF gun system with 4 bending dipoles of a chicane which makes the laser injection to the cathode with perpendicular angle possible.
THPLT064	Enhancement of Laser Power from a Mode Lock Laser with an Optical Cavity	2634
	M. Nomura, K. Hirano, M. Takano NIRS, Chiba-shi S. Araki, Y. Higashi, T. Taniguchi, J. Urakawa, Y. Yamazaki KEK, Ibaraki Y. Honda, N. Sasao, K. Takezawa Kyoto University, Kyoto H. Sakai ISSP/SRL, Chiba
	We have developed a laser-wire beam monitor to measure a beam profile in the KEK/ATF damping ring. This monitor is based on the inverse Compton scattering with a thin wire of the laser. The laser-wire is produced with a Fabry-Perot optical cavity in which laser power from a CW laser is stored and enhanced up to 1000 times. We have a plan to increase a gamma ray flux by using a pulsed laser instead of the CW laser. There are many applications for such a high flux gamma ray, e.g. medical use, transmutation and so on. We have done a test experiment of laser pulse stacking with a mode lock laser where wavelength is 1064 nm, repetition rate 357MHz, pulse width 7psec(FWHM) and a 42 cm long Fabry-Perot optical cavity. The experimental results show that laser power in the optical cavity can be enhanced by laser pulse stacking.