Particle-in-cell simulations of the electra KrF electron-beam diode

Semi-analytic methods and particle-in-cell simulations are used to model large-area electron beam diodes that are used to pump KrF laser cells. The simulations include models for following the energy loss and scattering of beam particles in foils, gas and support structures. Estimates of energy deposition to the various components of the diode system are obtained allowing optimization studies to be carried out. Losses to the pressure foil separating the diode vacuum region from the laser cell are found to be of order 10% due to back-scattering from the foil and gas for 1-mil Ti foils and 500 keV operation. An upper limit on the energy deposition fraction into the gas of nearly 80% is found for the design considered here.