Modeling of Gas Filled Vacuum Photodiode Operation

Summary form only given. Gas amplification of the photoemission current in the gas filled discharge gap was investigated with influence of space charge on the electric field in the gap. This process models measurements of soft X-ray from MAGO camera hydrogen plasma with quanta energy -0.1-2 keV with gas filled photodiodes containing hydrogen. Gaseous media in the photodiode volume is kept due to technical difficulties of volume isolation from the chamber and necessity of additional pumping system. Physical model used is operational in the wide range of discharge currents while the discharge takes all photodiode volume. 1D program was developed to calculate photodiode current with given current of photoemission that depends on flux and spectra of incoming X-ray radiation. Dependence was investigated of the photodiode current on a number of parameters influencing discharge development substantially. 2D-modeling of device operation was made for inhomogeneous distribution of incandescent radiation flux on the photocathode surface in flat photodiode geometry.