DTL Construction Status of China Spallation Neutron Source

The 324 MHz alvarez-type drift tube linac (DTL) for China Spallation Neutron Source is used to accelerate the H^- ion beam. It can provide 15 mA peak current beam with energy gain from 3 MeV to 80 MeV. It consists of four independent tanks, of which the average length is about 9 m. Each tank is driven by a 3 MW klystron respectively. Each tank is divided into three short unit sections for ease of fabrication and assembly. The construction of DTL cavity and drift tube is the most critical technical in CSNS. In this paper, the fabrication process of DTL was introduced, including the first time to perform copper electroplating with high electrical conductivity in the domestic high intensity beam accelerator, the design study on the newly developed electro-magnet coil and the high accuracy magnetic field measurement. The measurement results can satisfy with the physical design.