High power RF technology for JLC

In the high gradient experiment, the dark current of the clean structure is an order of magnitude lower than the normal and electroplated structure, and the three structures have almost the same microscopic β value. An HIP diffusion bond of OFHC and Titanium was achieved at temperature ranging 700 to 800degC and a pressure of 1,200 kgf/cm2 for 2 hours. The micropores in the OFHC disappeared with HIP processing. The minimum tear strength and the vacuum leak rate of the reaction zone is 4.9 kgf/mm2 and less than 10-7 Pa·1/sec, respectively. The klystron (E3712) can be operated with the repetition rate of 50 pps at the output power of 85 MW with 4.5 μsec pulse duration, and 100 MW with the pulse duration of 4 μsec. The stability of the E3712 was very excellent. The electric field strength at the coupling iris will can be reduce by 34 % the two sidewall coupling irises compared with the standard SLED cavity by using a MAFIA. (author)