Performance of the HL-2A Bonner sphere spectrometer in monoenergetic neutron fields from 100 keV to 1 MeV

The Bonner sphere spectrometer (BSS) designed for the neutron spectrum measurement at HL-2A Tokamak was calibrated by using monoenergetic neutrons on the electrostatic accelerator. The electronic system of the spectrometer was developed based on FPGA and PXI bus communication. The BSS response function generated with the Monte Carlo tool Geant4 was validated and corrected by the calibration experiment. The performance of the BSS in monoenergetic neutron fields from 100 keV to 1 MeV proved that the difference between the simulated and measured response function was under 15%, and the monoenergetic neutron spectrums were unfolded successfully by using the calibrated BSS system.