PROTOTYPE PULSE MODULATOR FOR HIGH-POWER KLYSTRON IN PLS LINAC

2.8 Pohang Accelerator Laboratory (PAL) is constructing a 2 GeV electron linac. To achieve the final electron energy, it employs total eleven units of high power klystron (65 or 80 MW) and pulse modulator (>150 MW) as RF power source. PAL is now constructing 200 MW modulators (400 kV, 4.4 ps flat top, 800 0 load). A prototype 150 MW modulator (350 kV, 3.5 p s flat top, 840 fl load) is already constructed and under operation with a dummy load. Required parameters of modulators and construction of the prototype are presented.