Electron multiplier and method of making same

Abstract

An electron multiplication apparatus uses a matrix of dielectric particles interspersed with conductive particles. Typically a porous layer of metal oxide and relatively inert metal, the material provides high electron count rates while maintaining good temperature stability. The layer is located between a cathode and an anode that together provide desired voltage differentials. A mesh is also used on a side of the matrix layer opposite the cathode to conduct surface charge away from the matrix, while providing an intermediate voltage potential between that of the anode and the cathode. A voltage source is used to generate the voltage potentials for each of the anode, cathode and mesh layer, and the resulting electric fields provide a device that may be used in the detection of high energy particles and photons, such as x-rays. A preferred method of fabricating the material involves the codeposition of a metal prone to oxidation and a relatively inert metal to form a porous layer. A subsequent oxidization step results in a metal oxide being intermingled with a conductive material. The resulting matrix has a high counting rate, but maintains a negative temperature coefficient.