Abstract:

In order to detect radioactive materials, the pulse detection of radioactive materials and energy calibration, are designed based on the photomultiplier. The system includes photomultiplier detector, the radioactive pulse conditioning circuit and the circuit of MCU MSP430F1612, which has 12bit A/D inside, to sample the peak of radioactive pulse and so on. The data through the Single chip microcomputer dealing will be transmitted to PC through the RS232 serial port. The PC uses the Visual Basic 6.0 software to filter and fit the data in order to search the peak. Analyzed the building materials  have which radioactive element contained and it is energy range by the obtained energy.This system is much more accurate to achieve the energy scale,automatic and manual peak search,which could accurately determine the energy between 0.01 to 2.97 MeV.The system has realized the detection of radioactive materials on the scene.

Key words: photomultiplier, peak sampling, filter fitting, energy calibration.