X-ray detection characteristics of gold photocathodes and microchannel plates using synchrotron radiation (10 eV–82.5 keV)

Abstract

Abstract X-ray detection characteristics of gold photocathodes, and microchannel plates (MCP) have been investigated using synchrotron radiation in the energy range from 12 eV to 82.5 keV. The quantum efficiency of gold is compared with the published data which were reported at some discrete energies, and we add several new data points in the 12–35.9 eV. The detection response of MCP has been represented for photons from the VUV regime of 12 eV to the hard X-ray region of 82.5 keV along with its incident angle dependence. This MCP response has demonstrated the following remarkable sensitivity in this wide energy range: The energy response of MCP remains within about one order of magnitude through this broad range. This comes from the contribution of the combination of various ingredients of MCP; namely, C, O, Si, Ba and Pb. For the energy response, these ingredients, in turn, make some jumps and humps at their edge energies. Another useful feature of the MCP response we obtained is a rapid decrease in the MCP response for the energies less than about ten eV; this is desirable for avoiding the effect of visible light on the X-ray data. Also, the MCP response is compared with the detection efficiency of a silicon surface barrier detector for the application to plasma X-ray diagnostics.