US 5,308,987 AGranted

Microgap x-ray detector

AssigneeThe United States of America as represented by the United States Department of Energy

InventorsCraig R. Wuest, Richard M. Bionta, Elden Ables

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Abstract

An x-ray detector which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope.

Claims27

Dependent claims

A microgap photon detector comprising:

a coplanar anode and cathode, said anode and said cathode being separated to form a gap therebetween, said gap having a width of 5-1000 microns, said cathode being composed of a layer of low atomic number material forming a window and a layer of high atomic number material which emits electrons when photons are incident upon it;
said layer of high atomic number material being in contact with said layer of low atomic number material;
a gas filling said gap between said anode and said cathode;
means for applying an electric potential between said anode and said cathode to produce a single electric field in said gap;
and
means connected directly to said anode for converting charge pulses on said anode to output pulses, whereby photons incident upon said cathode cause electrons to be emitted therefrom into said gas-filled gaps which are accelerated in the single electric field towards said anode causing collisions with other electrons in gas atoms of said gas to create an electron avalanche which results in charged pulses collected by said anode, with said charged pulses being converted to output pulses.

3 more elements

Dependencies are inferred from the claim text.