Study On The Method Of On-line Measuring Coal Components By PGNAA

The theme of the paper is supported by "Research and Application of the technology about on-line measuring coal components by Neutron Activation Analysis" of the Key Technologies R&D Program of Ministry of Science and Technology of China. The work of this paper includes three subprojects:1 .Optimization design of the moderating and shielding system. In this part, the moderating and shielding system of D-T neutron source on on-line PGNAA for measuring coal components is firstly studied by using Monte Carlo N-particle transport code system (MCNP code). An optimal design has been presented.2. Study on the performance of BGO scintillant crystal detector. The energy calibration function has been obtained in wide energy region by the method of detecting characteristic gamma rays from the thermal neutron capture reaction. And using MCNP code has simulated the response function of BGO detector system for Co-60 source. The results show that simulating response function can better meet with the experimental data in the Gamma energy greater than 1MeV.3.Research on the experimental standard spectrum of the single element. The neutron field distributions of the coal formed by the D-T neutron source have been simulated for a sort of coal sample with different element contents by MCNP code. According to the numerical simulation, an experimental measuring method on standard spectrum of element is given, and the standard spectra of Fe, Si, Al, Ti and S have been measured. The quantitative analysis for Fe and S have shown that the counts in the characteristic peak region have better linearity, namely, the least squares spectrum analysis method is reasonable by using standard library.Probing research work of PGNAA is done in this paper from aspects of physical theory. Method of analysis spectrum and experimental technology. The gained result set up the base for the realization of online measuring element in coal.