Sakumi, A.

Paper	Title	Page
WEOALH02	Multiturn Extraction Based on Trapping in Stable Islands at CERN PS: Recent Measurement Advances	173
	M. Giovannozzi, R. Cappi, S.G. Gilardoni, M. Martini, E. Métral, A. Sakumi, R.R. Steerenberg CERN, Geneva A.-S. Müller FZK-ISS-ANKA, Karlsruhe
	Recently a novel approach to perform multi-turn extraction was proposed based on beam splitting in the transverse phase space by means of trapping inside stable islands. During the year 2002 run, preliminary measurements at the CERN Proton Synchrotron with a low-intensity, single-bunch, proton beam, confirmed the possibility of generating various beamlets starting from a single Gaussian beam. The experimental campaign continued also in the year 2003 run to assess a number of key issues, such as feasibility of trapping with high-intensity beam, capture efficiency, and multi-turn extraction proper. The experimental results are presented and discussed in detail in this paper.
	Video of talk
	Transparencies
TUPLT024	A Comparison of High Current Ion Beam Matching from an Ion Source to a RFQ by Electrostatic and by Magnetic Lenses	1192
	R. Becker, R.A. Jameson, A. Schempp IAP, Frankfurt-am-Main T. Hata, N. Hayashizaki, H. Kashiwagi, K. Yamamoto RLNR, Tokyo T. Hattori, M. Okamura, A. Sakumi RIKEN, Saitama
	In order to improve the ?direct? injection scheme of the Riken Nd-YAK-laser driven ion source into a RFQ rf-accelerator, several basic methods have been investigated and compared, in order to transform the initially divergent ion beam into a convergent one, needed for matching the high current (100 mA C6+) ion beam at an energy of 100 keV to a RFQ. From the point of power supplies and break down characteristics, the simplest solution is a decelerating electrostatic lens, with the decelerating electrode operated on ion source potential. Due to the strong divergence of the ions beam after acceleration, this lens will be filled to an aperture, which causes strong aberrations. Therefore, we also investigated to use an accelerating potential on the lens electrode. This reduces significantly the filling of the lens and the emittance growth is only a factor of 3, as compared to the decelerating lens with a factor of 30! Finally we have been looking also into a magnetic matching system, which can match the ion beam to the RFQ with virtually no emittance growth.