Remote Detection of Fissile Material using Cherenkov Detectors

Anna Nikiforova, Massachusetts Institute of Technology

This research explores the applicability of water-based Cherenkov detectors to signature gamma and neutron radiation from photofission of special nuclear materials (SNM). Such detectors are facing a dual challenge: being able to detect radiation remotely (50 meters or more away) and to reconstruct the information such radiation might be carrying. At high energies and in large (kiloton to multi-kiloton scale) water detectors, Cherenkov imaging is a well proven technique. We are adapting this approach to the form factor we need at the lower energies encountered in SNM detection . In addition the direction and intensity of the Cherenkov cone arising from MeV-scale particle interactions may allow additional rejection of background gamma-rays.

Cherenkov radiation is visible light produced when a charged particle passes through an optical material with a particle velocity greater than the local velocity of light. Cherenkov radiation possesses a threshold nature which depends on both the particle’s velocity and the refractive index of the medium which allows rejection of low-energy radiation. This presentation summarizes the progress made in Cherenkov radiation characterization.

Abstract Author(s): Anna Nikiforova, Adam Bernstein, Michael Hynes, Richard Lanza