The Gain Characteristics of Microchannel Plates for X-Ray Photon Counting

A theoretical and experimental study is report-ed of the gain of microchannel plate (MCP) electron multipliers under conditions of output charge satur-ation. Theoretical calculations, assuming a wall charge saturation mechanism, are used to interpret peak gain and pulse height distribution FWHM data obtained with a number of chevron MCP multipliers. A curved surface MCP intended for use with grazing incidence X-ray optics is described. The effects of an inter-plate voltage are described. Limiting pulse height FWHMs around 30% have been obtained. The properties of straight channel chevrons and single curved channel MCPs are briefly compared.