Iwashita, Y.

Paper	Title	Page
MOPC146	Development of Piezoelectric Pulse Gas Valve for Small ECR Ion Source	418
	M. Ichikawa, H. Fujisawa, Y. Iwashita, Y. Tajima, H. Tongu, M. Yamada Kyoto ICR, Uji, Kyoto
	In a conventional ion source, the source gas is continuously fed even in its pulse operation. This requires a high load to a vacuum pumping system. The situation is prominent when the gas load is relatively higher in such a high current ion source. In order to improve this situation, we try to supply gas only when it is needed by synchronizing the gas feed with the extraction of the ion beam. We have developed a small pulse-gas-valve using a commercially available disc-shape piezoelectric element. This valve is small enough to be mounted in our ECR ion source and is capable of very fast open-and-close operation of an order of kHz repetition. A small ECR ion source with this valve will be presented.
MOPP005	The 2 mrad Crossing Angle Scheme for the International Linear Collider	556
	R. Appleby UMAN, Manchester D. Angal-Kalinin STFC/DL/ASTeC, Daresbury, Warrington, Cheshire P. Bambade, S. Cavalier, G. Le Meur, F. Touze LAL, Orsay Y. Iwashita Kyoto ICR, Uji, Kyoto
	The present baseline configuration of the ILC has a 14 mrad crossing angle between the beams at the interaction point. This allows easier extraction of the beams after collisions, but imposes on the other hand more constraints on the control of the beams prior to colliding them. Moreover, some limitations to physics capabilities arise, in particular because of the degraded very forward electromagnetic detector hermeticity and because calibration procedures for (gaseous) tracking detectors become more complex. To mitigate these problems, alternative configurations with very small crossing angles are studied. A new version of the 2 mrad layout was designed last year, based on simpler concepts and assumptions. The emphasis of this new scheme was to satisfy specifications with as few and feasible magnets as possible, in order to reduce costs. Recent progress designing several of the magnets involved and the particular vacuum chamber needed in the shared part of the beam line is reported.
MOPP015	Continuously Adjustable Permanent Magnet Quadrupole for a Final Focus	583
	T. Sugimoto, M. Ichikawa, Y. Iwashita, M. Yamada Kyoto ICR, Uji, Kyoto M. Kumada NIRS, Chiba-shi S. Kuroda, T. Tauchi KEK, Ibaraki
	A permanent magnet quadrupole with continuous strength adjustability has been fabricated. It has a five-ring-singlet structure, which was proposed by R. L.Gluckstern. Its small overall diameter allows an outgoing beamline to pass closeby. Since the permanent magnet pieces do not have any vibration source in themselves, this magnet could be used as a quadrupole in a final focus doublet. Such a quadrupole system is described.
MOPP103	High Field Gradient RF System for Bunch Rotation in PRISM-FFAG	796
	C. Ohmori KEK, Ibaraki M. Aoki, Y. Arimoto, I. Itahashi, Y. Kuno, Y. Kuriyama, A. Sato, M. Y. Yoshida Osaka University, Osaka Y. Iwashita Kyoto ICR, Uji, Kyoto Y. Mori KURRI, Osaka
	The PRISM project aims to supply a high quality muon beam using a wide aperture FFAG for mu-e conversion experiment. The low energy muon which has a large momentum spread will be manipulated in the FFAG using a bunch rotation technique with a low frequency RF around 3.5 MHz. Because of a short lifetime of muon, the rotation should be end in 5-6 turns in the FFAG and more than 2 MV is needed. The low frequency RF system using a magnetic alloy is designed to achieve a very high field gradient of more than 200 kV/m. The whole system is designed for a very low duty pulse operation to minimize the cost. The system has been modified to operate at 2 MHz for the beam test using alpha particle. A field gradient of more than 100 kV/m has been obtained by the preliminary test.
WEOBM03	Development of a High Resolution Camera and Observations of Superconducting Cavities	1956
	Y. Iwashita, Y. Tajima Kyoto ICR, Uji, Kyoto H. Hayano KEK, Ibaraki
	An inspection system of the interior surface of superconducting RF cavities is developed in order to study the relation between the achievable field gradient and the defects of the interior surface. The achieved resolution is about 7 microns/pixel. So far there are good correlations between locations identified by a thermometry measurements and positions of defects found by this system. The heights or depths can be also estimated by measuring wall gradients for some well-conditioned defects. The detailed system and the data obtained from the system will be described.
	Slides
WEPC164	Development of Modulating Permanent Magnet Sextupole Lens for Focusing of Cold Neutrons	2392
	M. Yamada, M. Ichikawa, Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto T. Ino, S. Muto, H. M. Shimizu KEK, Ibaraki
	A modulating permanent magnet sextupole lens that can focus pulsed cold neutrons is under development. It is based on the extended Halbach configuration to generate stronger magnetic field. In order to adjust the strength, the magnet is divided into two co-axial nested rings, where the inner ring is fixed and the outer ring can be rotated. Synchronizing the period of the modulation with that of pulsed neutron beam suppress the chromatic aberration. We have fabricated a half-scale model and studied the strength, the torque and the temperature rise caused by eddy current. Now we are developing the full-scale model improving such problems. These two scale models of magnet are described.
THPP007	Six-sector FFAG Ring to Demonstrate Bunch Rotation for PRISM	3389
	A. Sato, M. Aoki, S. Araki, Y. Arimoto, Y. Eguchi, K. Hirota, I. Itahashi, Y. Kuno, Y. Kuriyama, Y. Nakanishi, M. Y. Yoshida Osaka University, Osaka Y. Iwashita Kyoto ICR, Uji, Kyoto A. Kurup Imperial College of Science and Technology, Department of Physics, London Y. Mori KURRI, Osaka C. Ohmori KEK, Ibaraki
	A monochromatic muon beam is one of the most important requirements to improve a sensitivity of mu-e conversion experiments. In the PRISM project, which searches for mu-e conversion at a sensitivity of BR~10-18, makes such muon beams by using a bunch rotation technique in an FFAG ring. To demonstrate the bunch rotation, a FFAG ring has been constructed in RCNP, Osaka. The ring has six FFAG magnets and one RF cavity. Alpha particles from a radioactive isotope 241Am will circulate in the ring for the demonstration of bunch rotation.
THPP071	Construction of Six-sector FFAG Ring for Muon Phase Rotation	3524
	Y. Arimoto, M. Aoki, S. Araki, Y. Eguchi, K. Hirota, I. Hossain, I. Itahashi, Y. Kuno, Y. Kuriyama, Y. Nakanishi, A. Sato, M. Y. Yoshida Osaka University, Osaka Y. Iwashita Kyoto ICR, Uji, Kyoto A. Kurup Imperial College of Science and Technology, Department of Physics, London Y. Mori KURRI, Osaka C. Ohmori KEK, Ibaraki T. Oki Tsukuba University, Ibaraki
	PRISM is a next-generation of muon source which provides high purity, high intense and high brightness beam. In PRISM, a PRISM-FFAG is one of key section which make a muon beam narrow energy width by using phase rotation technique. To demonstrate the phase rotation, a six-cell FFAG ring has been constructed; the ring consists of full size of scaling-FFAG magnets and a high gradient rf cavity. The experiment is achieved by injecting alpha particles from a radioisotope source as a beam. Construction of the ring has been started from September, 2007; beam duct has been designed and installed, the six FFAG magnets has been aligned, etc. In this paper, we will present the design of the ring and the construction (alignment, etc) from engineering point of view.