Design of a post linac for an energy upgrade of a heavy-ion injector

摘要

A post linac is being designed for an energy upgrade of a heavy-ion injector. This post linac is to be installed downstream of the formerly developed compact injector, consisting of an Electron-Cyclotron-Resonance Ion-Source (ECRIS), the Radio-Frequency-Quadrupole (RFQ) linac and the Alternating-Phase-Focused Interdigital H-mode Drift-Tube-Linac (APF IH-DTL). It is aimed to increase the output energy of a heavy-ion injector. Carbon ions are initially accelerated with the compact injector to 4 MeV/u, and further accelerated with the post linac up to 8 MeV/u. The three linacs have the same operating frequency of 200 MHz. For beam focusing of the post linac, the APF method is used. Iterative simulations of beam dynamics were performed to determine the optimum array of synchronous phases in each gap. The results of the simulations provided that the calculated efficiency of beam transmission through the post linac is as high as 98.4%. The total length of this APF post linac is estimated to be approximately 3 m. A design overview of the injector system including the post linac is presented.