Bremsstrahlung reflex triode modeling and optimization

Summary form only given, as follows. A nuclear effect testing requires a large-area flash X-ray sources with specific X-ray endpoint energy to properly simulate responses in a wide variety of materials present in the test object. Improvements in radiation hardness have led to requirements for higher dose and fluence. In response, a 300-keV pinch reflex triode was recently developed on the DTRA PITHON simulator. Although the pinch reflex triode has good reproducibility at > 500 keV endpoint, the standard deviation in dose and fluence degrades to about 40% at the 300-keV endpoint. To improve the reproducibility, an experimental parametrical study was carried out where different configurations were tested and parameters such as the A-K gap were optimized. Simulations were performed in order to reproduce the trends observed experimentally and to evaluate the validity of our reflex triode model This paper describes the modeling work performed to understand the electron and ion dynamics in the diode. To simulate the relativistic planar diode, we use the electromagnetic particle-in-cell code LSP2 coupled with the Integrated Tiger Series3 electron/photon transport code. Experimental and simulation results are compared and discussed.