Simulation study of an ionization chamber detector with fast response time

Abstract

Gas ionization chambers were the first detector devices used for radiation detection, and they are widely used in the field of non-destructive testing because of their long service life and reliability. The time response characteristic is an important performance parameter of gas ionization chamber detectors, which has been studied for many years through experimental tests and simulations. In gas ionization chambers operating in the cumulative mode, the response time of the detector is determined by the drift rate of the ions. The existing parallel plate ionization chambers have low electric field strength in some areas, which prolongs the response time of the gas detector. In this paper, a detector with a fast response time is proposed and a variety of simulation tools are used to simulate the ionization chamber. A glass plate ionization chamber model was built using SolidWorks, and the detector inter-pole electric field distribution and detector output signal were simulated using the finite element analysis software MagNet and Garfield++. The results show that the interpolar electric field strength of the new electrode structure reaches 7.4 x 10⁵V/m, which is 48% higher than that of the parallel plate ionization chamber, and the response time of the glass plate detector is reduced to 0.15 to about 0.44 ms. Therefore, the development of the new electrode structure can effectively reduce the response time of the detector, which is important for the development and application of high-performance gas ionization chamber detectors. It is of great significance to promote the development and application of high-performance gas ionization chamber detectors.