Design and operation of inductive acceleration modules for FEL with controlled voltage ramp

A new pulse compression system is fabricated for grading up the induction accelerator LAX-1, which is currently used for Raman FEL research at JAERI. It is designed so that the capacitance of PFL can be varied partly, and the output voltage ramp be controlled within /spl plusmn/20%. The system consists of a series of PFLs and magnetic switches for pulse compression from 2 /spl mu/s and 30 kV to 130 ns and 250 kV. The final output is supplied with to 2/spl times/4 units of accelerating cavity. The design, circuit parameters, mechanism of varying the PFL parameters and the results compared with those of the numerical simulation are presented. Relation to the beam dynamics and FEL performance is also considered. >