Proto II triaxial electron beam diode research

In this paper, the authors discuss research on the Proto II triaxiale electron beam diode research. The Proto II accelerator has been modified to provide electron beams diode loads for bremsstrahlung radiation production. Stable, reproducible operation has been established over a voltage range of 0.5 to 1.5 MV with diode power up to 5 TW. The electron beam diode consists of two nested triaxial diodes which operate independently due to transit time isolation of the power flow. Both current balance and prepulse levels have been found to be critical to the operation of the diodes. Water switching spreads between the 8 modules of up to 15 ns do not impair diode performance. Ion currents due to popular flow have been measured and are relatively low, consistent with triaxial diode models. Radiation output has been measured and compared with radiation transport code calculations. At the highest operating voltage, peak dose rates of > 1.2 x 1012 rad(SI)/s over > 250 cm2 (2:1 uniformity) are routinely obtained in radiation pulses with a full-width, half maximum (FWHM) of 22 ns