| Popis: |
Online composition analysis is a crucial method for energy-saving and environment-friendly cement industry. A prompt gamma neutron activation analysis (PGNAA) system, which is aimed to determine the elemental concentrations of cement sample, has been designed and optimized by the Monte Carlo approach. This system consists of a 2 × 2” Bismuth Germanate (BGO) scintillation detector, a portable D-D neutron generator, a multi-channel analyzer, the reflector, the moderator and the shield. Out of consideration for minimization of costs and maximization of the thermal neutron flux at the output surface, different models of reflectors and moderators were tested in the MCNP code. Meanwhile, lead shield was also designed to reduce gamma-ray background produced by the nature and the system itself. In addition, simulated spectra of a standard cement sample were obtained to test the performance of this system. For ensuring the safety of the system operators, the dose rate distribution around the system were evaluated. The results demonstrated the feasibility of adopting this optimized design for chemical composition analysis of cement sample, and provided data reference for similar research. Eventually, an in-situ system has been established for further study. |
