Physics design, fabrication, RF measurement and beam commissioning of a dual beam drift tube linac

Abstract

A novel type dual-beam drift tube linac (DB-DTL) prototype was firstly designed to prove the feasibility of the multi-beam type DTL at the institute of modern physics. The physics design, cavity fabrication, low-power RF measurement, RF conditioning and beam commissioning of the DB-DTL cavity were completed and presented in this paper. Operating at 81.25 MHz, the DB-DTL was designed to accelerate 10 mA proton from 0.56 MeV to 2.5 MeV. The field distribution of the DB-DTL cavity were measured at low RF power level and particle tracing using measured field were done, which both agree well with the physics design. The measured Q 0 value and the shunt impedance are 11606 and 172 MΩ/m, respectively. The RF conditioning and the first beam commissioning of the DB-DTL cavity were completed. The beam experiment platform was built at the Lanzhou university due to the academy research cooperation between the institute of modern physics, Sun Yat-sen university and Lanzhou university. Based on the existing experiment condition, 2.5 MeV proton acceleration and measurement were successfully achieved at 42 kW (0.85*Q 0)) RF power of the DB-DTL cavity, which match the physics design very well.