The Design And Implementation Of Portable Multi-channel Gamma-ray Spectrometer Based On Embedded Linux

Portable gamma-ray spectrometer is one of the most important tools for determining radioactive contamination. With the development of technology and the knowledge of nuclear technique, gamma-ray spectrometer develops towards the direction of high-performance, high integration and high-intelligent, thus a convenient, fast and portable gamma-ray becomes more and more people's needs. The portable multi-channel gamma-ray spectrometer aboard mostly has higher performance and more fully features, but the price is relatively more expensive, so at present, it is difficult to be widely used for most domestic users. In China, people are trying to introduce embedded systems into the development of radiological equipment.In this paper, a multi-channel gamma-ray spectrometer based on embedded Linux system was designed. The gamma-ray system consists of the NaI (Tl) detector with high voltage power, the main amplify circuit and embedded board. Besides the traditional peak-hold circuit and noise discriminator unit, there are also some new features in the main amplify board: a cathode and anode switch,a magnification-chosen circuit,over-voltage protection and power filter. Considering from embedded microprocessor unit, embedded operating system and embedded memory, an appropriate cost-effective embedded board was chosen. In accordance with the embedded development process, the cross-compiler environment was built, Boot Loader was written, and Linux kernel was transplanted. Based on a comprehensive analysis on the communication of the multi-channel gamma-ray spectrometer system, the core code about data acquisition and data storage has been finished.Through the overall test of the gamma-ray spectrometer system, the conclusion is that: the cathode and anode switch increases the adaptability of different detectors; different magnification can be controlled flexibly by software; the over-voltage protection circuit can protect the embedded when the signal amplitude is too large; the power filter reduces the impact on the gamma-ray spectrometer when power change. The main amplify circuit board and embedded system can communicate easily, and the whole multi-channel gamma-ray spectrometer can get the input signals of detector and store them for display.This research finished the prototype of muli-channel gamma-ray spectrometer based on embedded system. Because of its low power comsumption, small size, low cost and high integration, it can be widely used in field measurements and also it has great significance in geological research, searching for mineral resources, and finding solution to engineering and technology such as hydro-geological and engineering geology.