D-t Neutron Detection System Performance Studies

The neutron generator is a kind of neutron source that has widely applied, it mainly produces 2.5 MeV (D-D) or 14 MeV (D-T) neutron. The quality of the neutron generator is established on detection of neutron. As we know, the neutron detector obtains signal by the neutron and the material interaction, so its efficiency is low and uncertainty is higher. So it's important to do some research on the neutron detector, in this paper a neutron yield measurement system is established by long counter, scintillation detector and silver activation neutron detector.The chief aim of present work is calibration the neutron detector. As long counter, because of equal efficiency vs. energy responses, ²⁴¹Am-Be isotope neutron source is used to it and efficiency vs. 14MeV is calculated by the coefficient of energy- transition. In the meantime Long counter has good n-γdiscriminate characteristic and is used to sub-standard instruments in the neutron experiment, so scintillation detector is calibrated by it. This method reduced the fluctuation caused by the small counting value with long counter, overcame the defect that the scintillation detector would be strongly influenced byγbackground, and could also take advantage of the long counter's smooth energy responses and the scintillation detector's high efficiency.At the same time, this paper used Monte-Carlo method to calculate detector's efficiency. For Long counter's efficiency, using MCNP software can get a precision efficiency by neutron-photo transport mode, this result and experiment accord well, so using MCNP to calculate the BF₃-array detector. Scintillation detector's efficiency is calculated by neutron's energy deposition in scintillation matter.In addition, this paper do some research with the neutron yield measurement system and analyze uncertainty of experiment data. Detectors in system give an accordant result which present fluctuate of the neutron yield. In the meantime, MCNP software is used to calculate the detector's efficiency uncertainty. According to the data, a lot of information is got to the platform of neutron flux test and give some valuable reference to improve detector.