APF方式IH型線形加速器の開発

A compact injector, designed for a heavy-ion medical accelerator complex, was developed. It consists of an Electron-Cyclotron-Resonance Ion-Source (ECRIS) and two linacs, which are a Radio-Frequency-Quadrupole (RFQ) linac and an Alternating-Phase-Focused Interdigital H-mode Drift-Tube-Linac (APF IH-DTL) having the same operating frequency of 200 MHz. The compact injector can accelerate carbon ions of 12C4+ up to 4.0 MeV/u. The APF IH-DTL uses the APF method for beam focusing and the IH structure for the cavity. Use of the APF IH-DTL enabled us to design the compact injector; the total length of the two linacs is approximately 6 m. The compact injector was constructed, beam acceleration tests were performed. We have succeeded to accelerate carbon ions with satisfactory performance. An overview of the APF IH-DTL as well as results of the beam acceleration tests is described