Tiede, R.

Paper	Title	Page
MOP06	A Dedicated 70 MeV Proton Linac for the Antiproton Physics Program of the Future Facility for Antiproton and Ion Research (FAIR) at Darmstadt	42
	L. Groening, W. Barth, L. Dahl, R. Hollinger, P. Spädtke, W. Vinzenz, S. Yaramishev GSI, Darmstadt B. Hofmann, Z. Li, U. Ratzinger, A. Schempp, R. Tiede IAP, Frankfurt-am-Main
	The antiproton physics program of the future International Accelerator Facility at Darmstadt is based on a rate of 7·1010 cooled antiprotons per hour. To provide the primary proton intensities a proton linac is planned, which will be operated independently from the existing UNILAC for heavy ions. The proposed linac comprises a proton source, a RFQ, and a DTL. Its operation frequency of 352 MHz allows for an efficient acceleration to up to 70 MeV using normal conducting Crossed-bar H-cavities. These CH-cavities show high shunt impedances as known from IH-structures, but allow for much higher relative particle velocities of up to 40%. The beam pulses with a length of 25 μs, a current of 70 mA, and total transverse emittances of 7 μm will allow to fill the existing synchrotron SIS within one multi-turn-injection up to its space charge limit of 7·1012 protons. The maximum SIS ramping rate limits the applied proton linac repetition rate to 5 Hz. This paper gives an overview of the proposed proton linac. The status of the design including beam dynamic studies will be reported.
	Transparencies
MOP11	The Compact 20 MV IH-DTL for the Heidelberg Cancer Therapy Facility	57
	Y.R. Lu, Y.R. Lu, B. Schlitt GSI, Darmstadt S. Minaev ITEP, Moscow U. Ratzinger, R. Tiede IAP, Frankfurt-am-Main
	A clinical synchrotron facility for cancer therapy using energetic proton and ion beams (C, He and O) is under construction and will be installed at the Radiologische Universitätsklinik in Heidelberg, Germany, starting in 2005. The different rf tuning concepts and tuning results for an 1:2 scaled IH-DTL model cavity are presented. Microwave Studio simulations have been carried out for the model and for the real power cavity. Results from the model measurements and the field simulations agree very well also for the higher order modes. The beam matching from the RFQ to the IH-DTL was optimised. Beam dynamics simulations using the LORASR code and starting with a particle distribution at the RFQ exit as calculated with PARMTEQ are presented. The IH drift tube array was matched with the gap voltage distribution resulting from rf model measurements.
MOP12	KONUS Beam Dynamics Design of a 70 mA, 70 MeV Proton CH-DTL for GSI-SIS12	60
	R. Tiede, G. Clemente, H. Podlech, U. Ratzinger IAP, Frankfurt-am-Main W. Barth, L. Groening GSI, Darmstadt Z. Li IMP, Lanzhou S. Minaev ITEP, Moscow
	The future scientific program at GSI needs a dedicated proton injector into the synchrotron SIS, in order to increase the proton intensity of the existing UNILAC/SIS12 combination by a factor of 70, resulting in 7· 1012 protons in the synchrotron. A compact and efficient 352 MHz RFQ - CH-DTL combination based on novel structure developments for RFQ and DTL was worked out. For DTLs operated in an H-mode like CH-cavities (H210-mode), the shunt impedance is optimized by use of the KONUS beam dynamics. Beam dynamics simulation results of the CH-DTL section, covering the energy range from 3 to 70 MeV, with emphasis on the low energy front end are presented. Optimization aims are the reduction of emittance growth, of beam losses and of capital costs, by making use of the high acceleration gradients and shunt impedance values provided by the Crossbar H-Type (CH) structure. In addition, the beam dynamics design of the overall DTL layout has to be matched to the power limits of the available 352 MHz power klystrons. The aim is to power each cavity by one klystron with a peak rf power of around 1 MW.
MOP20	Design of the R.T. CH-Cavity and Perspectives for a New GSI Proton Linac	81
	Z. Li IMP, Lanzhou W. Barth, K. Dermati, L. Groening GSI, Darmstadt G. Clemente, H. Podlech, U. Ratzinger, R. Tiede IAP, Frankfurt-am-Main
	The CH-Structure has been studied at the IAP Frankfurt and at GSI for several years. Compared with the IH structure (H110-mode), the CH structure (H210-mode) can work at higher frequency (700 MHz) and can accelerate ions to higher energy (up to 150 AMeV). Detailed Microwave Studio (MWS) simulations were performed for this structure. Since a multi-gap cavity can be approximated as a quasi-periodic structure, it is possible to analyze one βλ/2-cell at an energy corresponding to the cavity center. Additionally, a reduced copper conductivity of 85% was assumed. Geometry variations with respect to rf frequency and shunt impedance can be performed rapidly by that method in the first stage of optimization. Effective shunt impedances from 100 MΩ/m down to 25 MΩ/m were obtained for the energy range from 5 AMeV to 150 AMeV by this method. The rf frequency was 350 MHz up to 70 MeV and 700 MHz above. A systematic analysis of the influence of the cell number in long CH cavities on the effective shunt impedance is presented. The possibility to apply this structure to a 70 mA, 70 MeV, 352 MHz proton linac for GSI is discussed.