System For Active Long Range Detection And Identification Of Special Nuclear Materials Using A High Intensity Particle Beam

摘要

A long-range method and a system for reliably detecting and identifying special nuclear materials is provided that relies on the emission of delayed neutrons present in the decay of fission products (delayed neutron precursors) as a unique signature for the special nuclear materials, such as highly enriched uranium (235/238U). The method relies on a time-of-flight measurement in the first 1 μs after the inducing radiation pulse, and pulse height data analysis for both neutrons and gamma rays that can be done at a much higher data rate than in traditional pulse processing systems. The thermal neutron fission within the time regime of 100-500 μs provides a unique signature of special nuclear materials such as the highly enriched uranium.

主权项

1. A method for detecting and identifying special nuclear materials, the method comprising:
(i) exposing a target to a high intensity particle or photon beam pulse to induce fission; (ii) detecting emission of prompt and delayed radiation from the target using a detection system, wherein the radiation comprises fast and thermal neutrons; (iii) recording fast neutrons induced by thermal neutron fission and gamma-rays from thermal neutron induced fission; (iv) analyzing a die away in the fast neutron yield induced by thermal neutron fission of the target; and (iv) comparing the fast neutron yield from the target to the fast neutron yield characteristic for a special nuclear material; wherein a lose correlation of the fast neutron die away indicates the presence of the special nuclear material within the target.