Publications Details

The inverse triax x-ray diode---an alternate reduced-endpoint-energy bremsstrahlung source

Harper-Slaboszewicz, V.J.; Poukey, J.W.; Stygar, W.A.; Fowler, W.E.; Peyton, B.

The inverse triax diode is a high power, low impedance electron diode which offers significant advantages over conventional electron diodes on short-pulse (<30 ns FWHM) high power x-ray simulators. Parametric calculations show that the radiation efficiency of the inverse triax is competitive with standard diodes fro mean photon energies below about 120 keV, and sometimes up to 150 keV. Particle-in-cell code simulations show the impedance behavior and flow pattern in the inverse triax with and without the presence of an anode plasma. The simulation results are used to suggest design rules for inverse triax diodes. Experimental results show good agreement with calculations of the impedance behavior and electron beam dynamics. Using inverse triax diodes, we have produced peak doses of 1.4 {times} 10{sup 11} rad(TLD)/s over 840 cm{sup 2} with a mean photon energy of 120 keV on SPEED and 3.1 {times} 10{sup 11} rad(TLD)/s over 3700 cm{sup 2} with a mean photon energy of 140 keV on Saturn. 20 refs., 16 figs.