Solid dielectric detectors with breakdown phenomena and their applications in radioprotection

Abstract

Microscopic chemically etched nuclear tracks require the use of the optical microscope for detection. Applications of solid dielectric track detectors are hampered because the track counting is troublesome and time-consuming. Spark counting of etched- through holes is useful only for the counting of highly ionizing particles like fission fragments, Electrochemical etching facilitates track visualization and counting by enlarging tracks up to macroscopic sizes so that they are visible to the unaided eye. With this type of etching the registration of alpha particles and neutron-induced recoil tracks is greatly simplified. The characteristics of these electrochemical etched detectors are useful for applications in personnel neutron dosimetry, radon dosimetry, analysis of low concentrations of fissile impurities in biological and environmental samples. Finally the thin-film-capacitor counter provides real-time detection of fission fragments, which induce breakdowns at fields lower than the dielectric strength of the insulating film. These detectors are useful for real-time read-out and alarm dosimetry. The trait common to the different techniques described here is the use of electrical breakdown phenomena which results is simplified charged-particle and neutron detection.