“…These IPEB accelerators with compact designs, producing pulsed electron beams with energy of 6-200 J per pulse, electron energy in the range from 100 to 500 keV, beam current in kA scale, sub-microsecond (75-250 ns) pulse duration, and repetition up to 50 pulses per second (pps) [16,17], have been widely studied in material synthesis and processing [18], wastewater [19] and gas [20] purification, agricultural irradiation [21], and medical material preparation [22]. When used for X-rays, these IPEB sources also exhibit virtues such as compact design, high mobility, and flexibility in deployment [17]. Most IPEB sources extract electrons from plasma formed by explosive emissions induced by applying pulsed negative high voltages on cold solid cathodes made of graphite, metals, or composited metal-dielectric materials.…”