HIGHLY SENSITIVE DOSIMETERS BASED ON FIELD-EFFECT AND UNIJUNCTION TRANSISTORS

Abstract

The possibility of making of the data unit of radiation on the basis of the bridge from four field-effect transistors has been observationally investigated. Use as sensory units of field-effect transistors allows to increase sensitivity of the detector, and the bridge-type of their connection decreases a noise level to a minimum. The combination of four field-effect transistors, two of which have a positive sign of radiation susceptibility, but others two have a negative sign, allows to obtain by order of magnitude greater the dependence of an output potential in a diagonal of a bridge of the detector from intensity of radiation. For improving of noise immunity of a desired signal at its further amplification and elimination of the intermediate analogue-digital converters at matching of the detector with numeral data reduction systems, the relaxation generator on the base of the unijunction transistor with the field-effect transistor in an emitter circuit has been used as sensitive element. The exit parameter of such detector is frequency of a variable signal depending on intensity of radiation.