Photon-induced charge transfer and surface emission

Experimental measurements have been made of photon-induced charge transfer between plane-parallel electrodes. X-rays from a pulsed X-ray source were directed at near-normal incidence onto plane-parallel electrodes, and the current which flowed between the electrodes during the X-ray pulse was measured. Quantities obtained include bulk charge transfer in several dielectric materials; forward and reverse electron emission from Al, Cu, and Au surfaces; and secondary electron emission coefficients for these metals and selected dielectrics. Measured values for charge transfer and surface emission are compared with calculations.