20-MW-long-pulse klystron modulator

The main goal of the development at PPT is to optimize the existing modulator design towards a reliable and cost-effective design to allow for the production of about 750 modulators. The "long-pulse"-klystron modulator must generate a 1.7 ms output pulse with an output power up to 20 MW which is flat to within 1% during 1.5 ms. Based on the first design of FERMI Lab the main features of the redesigned new pulse modulator sub-assemblies are: (1) a 300-kW switched mode 12-kV power supply with a new regulating system to avoid the generation of powerful subharmonic disturbances back into the line. (2) a volume optimized 1.4-mF storage capacitor bank using high energy capacitors with self-healing segmented PP-foil technology; (3) a rugged, compact IGCT-switch stack with seven 4.5-kV IGCT\´s, integrated low inductive gate units and a current turn-off capability up to 4 kA.