MULTI-ANODE DEEP WELL RADIATION DETECTOR

摘要

An inner cylindrical cathode (112) and outer cylindrical cathode (106C) are concentrically positioned about a vertical center axis. Vertical anode electrodes (130) extend parallel to the center axis and are symmetrically arranged around the inter-cylinder space (126I) between the cathodes. The ends of the anode wires are supported by a pair of insulator rings (132T) and (132B) mounted near the top and bottom of the cathode cylinders. A collection voltage applied to each anode wire (130) for establishing an inward radial E field to the inner cathode cylinder (112) and an outward radial E field to the outer cathode cylinder (106). The anode-cathode assembly is mounted within a housing (106) containing a conversion gas. A radioactive sample (116) is inserted into the inner cathode (112) which functions as a tubular, deep well radiation window between the sample environment and the conversion gas environment. A portion of the gamma radiations passing through the inter-cylinder region (126I) interact with the conversion gas to produce free electrons which are accelerated by the E fields and collected on the anode wires (130). The extremely small diameter of the anode wires intensifies the electric fields proximate each wire causing avalanche multiplication of the free electrons resulting in a detectable charge pulse.