A compact low jitter high power repetitive long-pulse relativistic electron beam source

A compact low jitter high power repetitive long-pulse relativistic electron beam source with novel circuit structure and mechanical structure is presented. Based on Marx type circuit and direct-drive idea, the key technologies such as high energy density pulse forming network, repetitive high voltage pulse generator and low jitter electrical trigger technology are developed. The volume and weight of the pulsed electron beam source are reduced remarkably by using two-capacitor pulse forming modules, alternating superposition structure on both sides and high electric field shielding technology. The key technical parameters of the electron beam source design include a peak output voltage 1 MV with peak current 20 kA. The impulse is 180 ns and has a repetition frequency 1 similar to 50 Hz, however, the output power and repetition frequency are able to be adjusted within a certain operating range. The machine has a total volume of 2.5 m(3) and weighs 2.2 tons, making it much more compact than conventional electron beam sources. The experimental results show that when the e-beam source is operated under a single pulse condition, the output voltage, current, and power are 0.98 MV, 19.6 kA, and 19.2 GW, respectively. When the e-beam source has a continuous operating time of 10 s at a repetition frequency of 30 Hz and an output power of 16.7 GW, the voltage fluctuation range is limited to within +/- 1.5%, and the current fluctuation range is limited to within +/- 2%. The delay time jitter between the trigger pulse and the output pulse is limited less than 6.5 ns standard mean deviation. Statistical distributions of the delay time jitter and current amplitude variation of the 300 pulses are approximately Gaussian. When the cooling system is working, the electron beam source can work continuously for 100 s under the conditions of an output power of 16.7 GW and repetition frequency of 30 Hz, and the system operation is stable and reliable.