A real-time n/γ digital pulse shape discriminator based on FPGA

A FPGA-based real-time digital pulse shape discriminator has been employed to distinguish between neutrons (n) and gammas (γ) in the Neutron Flux Monitor (NFM) for International Thermonuclear Experimental Reactor (ITER). The discriminator takes advantages of the Field Programmable Gate Array (FPGA) parallel and pipeline process capabilities to carry out the real-time sifting of neutrons in n/γ mixed radiation fields, and uses the rise time and amplitude inspection techniques simultaneously as the discrimination algorithm to observe good n/γ separation. Some experimental results have been presented which show that this discriminator can realize the anticipated goals of NFM perfectly with its excellent discrimination quality and zero dead time.

► Discriminator has excellent n/γ resolution capability for fission chamber detection.
► It is real-time, so the neutron flux measured by it can be used for real-time feedback or control.
► Use of the pipeline architecture in this discriminator facilitates a zero dead time.
► It is flexible, and users can set different thresholds according to different detection methods.