Design Studies of an RFQ-Injector for a Medicine-Synchrotron1

Work supported by the BMBF and GSI An accelerator facility for radiotherapy of cancer tumours with ions is proposed for the Radiologische Universitaetsklinik in Heidelberg. Design studies have been done for the injector-complex [1] in front of the Synchrotron with respect to the construction and operation costs as well as to a comfortable handling of the machine [2]. After the source section and a LEBT path the beam will be injected into the RFQ at an energy of 8 keV/u to be accelerated to 400 keV/u with an electrode voltage of 70 kV and an expected power consumption of 100 kW. The RFQ layout, featuring a special parameter design, has been investigated with an extended version of the PARMTEQ code. The length of the RFQ will be approximately 1.45 m, the operation frequency is 216.816 MHz, same value as in the following IH drift tube Linac. For beam matching reasons, the combination of drift tubes with the RFQ electrodes at the high energy end is examined in detail by beam dynamic simulations and model measurements.