Gamma-insensitive optical sensor
AssigneeThe United States of America as represented by the United States Department of Energy
InventorHans W. Kruger
Life of this patent
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Abstract
An ultra-violet/visible/infra-red gamma-insensitive gas avalanche focal plane array comprising a planar photocathode and a planar anode pad array separated by a gas-filled gap and across which is applied an electric potential. Electrons ejected from the photocathode are accelerated sufficiently between collisions with the gas molecules to ionize them, forming an electron avalanche. The gap acts like a proportional counter. The array of anode pad are mounted on the front of an anode plate and are connected to matching contact pads on the back of the anode via feed through wires. Connection of the anode to signal processing electronics is made from the contact pads using standard indium bump techniques, for example.
Claims22
A gamma-insensitive sensor comprising:
- a cathode;
- an anode;
- said cathode and said anode being separated to form a gap there between;
- said anode including a plurality of anode pads defining a pattern;
- said gap containing a gas;
- means for applying an electric potential between the anode and the cathode for producing an electric field in said gap;
- and
- means for detecting electron avalanche charges on said anode pads.
An optical focal plane array, comprising:
- a planar monolithic quartz cathode plate;
- a semi-transparent photocathode layer coveringly disposed over a planar surface of the quartz plate;
- a planar monolithic anode plate, positioned parallel to the photocathode layer and separated therefrom by a narrow gap, with a first planar surface of the anode plate being closer to the photocathode layer than a second planar surface of the anode plate;
- a regular pixel array of anode pads disposed upon the first planar surface of the anode plate;
- a regular pixel array of contact pads, similar to the anode pad array, disposed upon the second planar surface of the anode plate;
- means for electrically connecting each anode pad to its corresponding contact pad;
- a gas, positioned within the narrow gap;
- and
- means for impressing a voltage across the narrow gap;
- whereby, when a photon strikes the photocathode layer, electrons are ejected therefrom and form an electron avalanche within the gas and across the narrow gap, with the diameter of the electron avalanche being sufficiently narrow so that the electron avalanche can impinge at most on four anode pads.
An optical focal plane array, comprising:
- a fiber optic planar cathode plate, in which the fibers are comprised of a material selected from the group consisting of quartz, scintillating glass, and scintillating plastic;
- a semi-transparent photocathode layer coveringly disposed over a planar surface of the cathode plate;
- a fiber optic planar anode plate, in which the fibers are comprised of a material selected from the group consisting of quartz, scintillating glass, and scintillating plastic, positioned parallel to the photocathode layer and separated therefrom by a narrow gap, with a first planar surface of the anode plate being closer to the photocathode layer than a second planar surface of the anode plate;
- a regular pixel array of anode pads disposed upon the first planar surface of the anode plate;
- a regular pixel array of contact pads, similar to the anode pad array, disposed upon the second planar surface of the anode plate;
- means for electrically connecting each anode pad to its corresponding contact pad;
- a gas, positioned within the narrow gap;
- and
- means for impressing a voltage across the narrow gap;
- whereby, when a photon strikes the photocathode layer, electrons are ejected therefrom and form an electron avalanche within the gas and across the narrow gap, with the diameter of the electron avalanche being sufficiently narrow so that the electron avalanche can impinge at most on four anode pads.
Dependencies are inferred from the claim text.