Repetitive Operation of an $S$-Band 1-GW Relativistic Klystron Amplifier

This paper reports on the operation of a repetitively pulsed relativistic klystron amplifier at 100 pps. The electron beam was reproducibly modulated to $>$ 74%. Using a 700-kV, 6.5-kA, 25-ns electron beam and a 600-kW Magnetron as inputs, a 1.2-GW radiated power in 20-ns full-width at half-maximum pulses at 2.95 GHz is extracted. The average power is 2.4 kW. The efficiency is 27%, and the gain is about 33 dB.