Radiation Measurements Based On The Charge Sensitive Amplifier Circuit Design And Simulation

In the measurement of nuclear radiation, the fluorescence spectrum of the CsI (TI) crystal matches well with the absorption spectrum of the photo-sensitive diodes, and oftentimes shows greater photoyield. Therefore, the combination of the scintillation crystal and the photo detector is beneficial for the measurement of gamma ray energy spectrum. In the measurement of gamma ray spectrum, the nuclear information detection system is often comprised of two parts:nuclear radiation detector and nuclear electronic measurement system. The first part, the nuclear radiation detector coupled by both the scintillator and the photo-sensitive diodes, is often used to absorb gamma rays, which illuminate directly upon the CsI (TI)-based scintillator. The scintillator then transfers the fluorescence light, obtained from the stimulated emissive gamma rays, to the photo-sensitive diodes, which is coupled with the scintillator by silicone oil. The scintillator, however, is often wrapped up in a membrane in order to raise the efficiency of the photo energy collection process. This process is how high energy gamma photon transforms into low energy fluorescence, or visible light, that can be detected and absorbed by the photo-sensitive diodes.This paper introduces a gamma rays detector module comprised of both the silicon PIN photo-sensitive diodes and the charge-sensitive preamplifier. With detailed introduction to the design principles of nuclear radiation detection module serving as a basis, this paper lays great emphasis on the analysis and introduction of the design principles of the charge-sensitive amplifier. Also, this paper provides detailed analysis on the structural design of electronic circuits and the selection of microprocessors. In addition, through reasonable selection of simulation parameters of the circuits, the electronic circuit simulation software, Multisim, is used to run the simulation tests on the charge-sensitive preamplifier and the main amplifier. The result demonstrates that the charge-sensitive preamplifier and the main amplifier introduced in this paper are capable of running nuclear radiation detection tasks. Furthermore, this paper presents the nuclear radiation detection control circuits based on the low-power-consumption 16 bit microprocessor MSP430F169 from the TI company, including functions like key control, pulse count, amplitude detect, LCD display and data transmission. Finally, this paper presents a complete circuit with functions like nuclear radiation detection, data processing, data display and transmission. And the circuit is capable of practical nuclear radiation detection. Compared with the traditional nuclear radiation detection circuits, the circuit module based on the charge-sensitive preamplifier introduced in this paper has simpler circuit structure, lower production cost, higher dependable performance, and in the meantime exhibits great advantages as relatively low noise and better measurement precision.