Dual-waveform ringing gain analysis and its application to pre-pulse reduction on Blumlein-based X-ray machines

Abstract

Pulsed-power machines at AWE are routinely used for flash X-ray radiographic applications in the 1–10 MV range to drive high- and low-impedance electron-beam diodes. During the pulse-forming line (PFL) charging phase, certain diode types are sensitive to pre-pulse voltages as low as a few tens of kilovolts due to small anode-cathode gaps and geometries that enhance electric fields. This results in electron emission before the main pulse is applied which can alter the conditions within the anode cathode gap, preventing the diode from operating properly. It is therefore crucial to limit the pre-pulse appearing at the diode to below the emission level.