Iwashita, Y.

Paper	Title	Page
TUP81	Superstrong Adjustable Permanent Magnet for a Linear Collider Final Focus	462
	Y. Iwashita, T. Mihara Kyoto ICR, Kyoto A. Evgeny, M. Kumada NIRS, Chiba-shi C. M. Spencer SLAC, Menlo Park, California E. Sugiyama NEOMAX, Osaka
	Super-strong permanent magnets are being considered as one of the candidates for the final focus quadrupole magnets in a linear collider. A short prototype with temperature compensation included and variable strength capability has been designed and fabricated. Fabrication details and some magnetic measurement results will be presented.
	Transparencies
TUP95	Evaluation of Magnetic Field Enhancement Along a Boundary	501
	Y. Iwashita Kyoto ICR, Kyoto T. Higo KEK, Ibaraki
	Generally, a cavity has convex corners on its inner surface, where the surface field becomes higher than the average accelerating gradient. This effect has been paid attention not to exceed a criterion only on surfaces that have high electric field gradient. A high magnetic field area, however, sometimes seems harmful on a stable operation too. Such enhancement factors are evaluated in a 2D model to show a feasible crossing angle limit on a convex angle of two surfaces.
THP43	Reduction of RF Power Loss Caused by Skin Effect	700
	Y. Iwashita Kyoto ICR, Kyoto
	RF current flows only on a metal surface with very thin skin depth, which decreases with RF frequency. Thus the surface resistance increases with the frequency. Because the skin depth also decreases when the metal conductivity increases, the improvement of the conductivity does not contribute much; it is only an inverse proportion to the square root of the conductivity. Recently, it is shown that such a power loss can be reduced on a dielectric cavity with thin conductor layers on the surface, where the layers are thinner than the skin depth. Some possibilities to implement the idea and to extend the application to general cavities and transmission lines will be discussed.
THP74	Laser Produced Ions as an Injection Beam for Cancer Therapy Facility	782
	A. Noda, M. Hashida, Y. Iwashita, S. Nakamura, S. Sakabe, S. Shimizu, T. Shirai, H. Tongu Kyoto ICR, Kyoto H. Daido JAERI APRC, Ibaraki-ken A. Fukumi, Z. Li, K. Matsukado NIRS, Chiba-shi T. Hosokai, H. Iijima, K. Kinoshita, M. Uesaka, T. Watanabe, K. Yoshii UTNL, Ibaraki T. Takeuchi DOP Nagoya, Nagoya
	Ion production from a solid target by a high-power short pulse laser has been investigated to replace the injector linac of the synchrotron dedicated for cancer therapy. As the high power laser, the laser with the peak power of 100 TW and minimum pulse duration of 20 fs which has been developed at JAERI Kansai Research Establishment, is assumed. Laser produced ions with 100% energy spread is energy selected within ±5% and then phase rotated with use of the RF electric field synchronized to the pulse laser, which further reduces the energy spread to ±1%. The scheme of the phase rotation is presented together with the experimental results of laser production from the thin foil target.