A programmable multichannel correlation module for analyzing neutron multiplicities

Abstract

We have developed a CAMAC module for analyzing neutron multiplicities. Reduction in dead time over previous methods has been made possible by providing independent detector channels. We have achieved a considerable reduction in circuitry by utilizing RAM and PROM integrated circuits in a nonstandard fashion. Along with specially developed algorithms, the module has been able to successfully unfold overlapping multiplicity chains for count rates varying over three orders of magnitude.

Fissile material detection using neutron time-correlations from photofission

“…The idea for using the time-correlation for non-destructive inspection of objects containing fissile material has been pursued for "passive" interrogation schemes [21,22,24,[26][27][28][29][30][49][50][51][52] (where the natural background initiates the fission chains) and for "active" interrogation schemes [19,20,23,25,53] (where a beam of particles induces the fission chains).…”

“…All of these methods use single-particle signals. Multi-particle schemes, usually two-and three-neutron signals have also been pursued, with photon [19,20] and neutron [21][22][23][24][25] beams as well as in passive interrogation [26][27][28][29][30][31][32], where ambient radiations are used to induce the signals. Here we report on an active interrogation method using 9 MeV Bremsstrahlung photons to induce the emission of time-correlated, prompt neutrons measured within the Prompt Neutrons from Photofission (PNPF) system developed at Passport Systems Inc. (PSI) [33][34][35].…”