DETECTOR MODELING USING CA-ZN-TE SOLID SOLUTION FOR RADIATION MONITORING SYSTEMS

Abstract

The article created a model of the primary converter - a gamma radiation sensor. It is based on the following properties of a semiconductor crystal: maximum quantum efficiency; maximum mobility of charge carriers; minimum density of structural defects; maximum values of resistivity and density. The combination of these properties provides a significant sensitivity of sensor with the minimum size of crystal. The inconsistency of such a combination must be eliminated both in the process of manufacturing a crystal (for example, a high-resistance crystal can be obtained by the simultaneous use of cleaning, components, and compensating doping) and subsequent processing by the methods proposed in this work (thermal field method, ionization annealing). Among the known materials for gamma radiation sensors, single crystals of Cdx-Zn1-xTe solid solutions have the optimal combination of the above properties and possibilities of their preparation. The advent of modern semiconductor sensors for the first time linked nuclear instrumentation and electronics into a single complex - a semiconductor detector. It combines a semiconductor primary converter of ionizing radiation (sensor), a secondary converter of information from the sensor (electronics) and software for processing this information, interconnected in terms of problem being solved and parameters. However, the development of nuclear energy and the spread of nuclear technologies have put forward new requirements for the control and metrology of ionizing radiation. The current level of nuclear instrumentation cannot fully satisfy them. The solution to this problem can be provided by the development of: methods for choosing the optimal type of semiconductor materials and controlling their properties to create uncooled detectors; sensors with higher resolution; electronics with lower noise level; computer methods and information processing programs with lower estimated costs; control systems for nuclear materials and the state of AES protective barriers that meet the requirements of the existing automatic control of radiation safety (ARS). This article is devoted to the solution of such problems, which ensures the relevance of its topic. The main principle of solving the named scientific problem was results of nuclear-physical studies of the interaction of ionizing radiation with semiconductors, the development and experimental verification of physical-mathematical models of technological processes dosimetry and control of nuclear materials.