B. SCHLITT, U. RATZINGER (GSI, Darmstadt, Germany), A. BECHTOLD, A. SCHEMPP (IAP, Frankfurt, Germany)
A dedicated clinical synchrotron facility for cancer therapy using energetic proton and ion beams (carbon, helium and oxygen) is designed at present at GSI for the Radiologische Universittsklinik at Heidelberg, Germany. The LEBT allows for switching between two ion sources as well as for beam chopping and for controlled beam current variation. A short RFQ accelerates the ions from 8 keV/u to 400 keV/u. It is followed by a very compact beam matching section and an IH-type drift tube linac for the acceleration to 7 MeV/u. Both the RFQ and the IH-DTL are designed for a resonance frequency of 216.816 MHz and for ion mass-to-charge ratios A/q up to 3 (12C4+). The IH tank with an expected rf power consumption around 1 MW has a length of about 3.8 m. It consists of three integrated magnetic quadrupole triplets and 56 accelerating gaps grouped in four KONUS [1] sections. The maximum effective gap voltage is about 480 kV resulting in an on-axis electric field of 18 MV/m. An overview of the complete injector is given and the design of the IH-DTL including the matching between the RFQ and the DTL are discussed.
[1] U. Ratzinger and R. Tiede, Nucl. Instr. and Meth. in Phys. Res. A 415 (1998) 229.
Comments or Questions to
linac2000@slac.stanford.edu