Claims
- 1. A directional detector of gamma rays comprising:
- an electrically conductive collector having first and second surfaces;
- at least one emitter which emits electrons upon exposure to gamma rays;
- a first insulator of predetermined resistance disposed between said first surface of said collector and said emitter;
- a second insulator disposed between said second surface of said collector and said emitter, said second insulator having a resistance greater than the resistance of said first insulator;
- means for completing an electrical circuit between said emitter and said collector; and
- means for measuring the electric current in the circuit.
- 2. The apparatus of claim 1 wherein said collector includes confronting surfaces which contact said first and said second insulators, respectively.
- 3. The apparatus of claim 2 wherein said confronting surfaces of said collector are planar.
- 4. The apparatus of claim 1 wherein said first and said second insulators are formed of a homogeneous dielectric material.
- 5. The apparatus of claim 4 wherein said first insulator has a predetermined substantially uniform thickness and said second insulator has a substantially uniform thickness greater than the thickness of said first insulator.
- 6. The apparatus of claim 5 wherein said dielectric material is beryllia.
- 7. The apparatus of claim 6 wherein the thickness of said second insulator is in the range of three to six time the thickness of said first insulator.
- 8. The apparatus of claim 1 wherein said collector comprises nickel foil.
- 9. The apparatus of claim 1 wherein said emitter is a vacuum enclosure encasing said collector and said first and said second insulators.
- 10. The apparatus of claim 1 wherein:
- said collector comprises a sheet of nickel foil approximately 0.5 mil thick;
- said emitter is formed of stainless steel approximately 5/16 of an inch in thickness;
- said first insulator includes a sheet of beryllia approximately 0.05 inches thick; and
- said second insulator includes a sheet of beryllia approximately 0.2 inches in thickness.
CONTRACTUAL ORIGIN OF THE INVENTION
The invention described herein was made in the course of, or under, a contract with the U.S. DEPARTMENT OF ENERGY.
US Referenced Citations (5)