RESULTS OF THE HIGH-POWER CONDITIONING AND THE FIRST BEAM ACCELERATION OF THE DTL-1 FOR J-PARC

The first tank of the DTL for Japan Proton Accelerator Research Complex (J-PARC) was installed in the test facil- ity at KEK. The DTL tank is 9.9 m in length and consists of 76 cells. The resonant frequency of the tank is 324 MHz. After the installation of the tank, the high-power condition- ing was carried out deliberately. Consequently a peak rf power of 1.2 MW (pulse repetition of 50Hz, pulse length of 600 µsec) was put into the tank stably. (The required power is about 1.1 MW for the designed accelerating field of 2.5 MV/m.) Following the conditioning, An H ion beam, ac- celerated by the RFQ linac up to 3 MeV, was injected into the DTL and accelerated up to its design value of 19.7 MeV. The peak current of 30 mA was achieved with almost 100 % transmission in November of 2003.