University of Michigan uses neutrons at Notre Dame to interrogate materials for nuclear nonproliferation studies

Author: Janet Weikel

Jovanovic Group Photo 1

The University of Michigan's Applied Nuclear Science Group, led by Professor Igor Jovanovic, visited the University of Notre Dame last week to perform a series of experiments using the FN Tandem accelerator. The experiments centered around the acceleration of deuterons into a boron-11 target, which produces unique high-energy neutrons and gamma-rays. This reaction was in turn used as a mixed-particle interrogation source in conjunction with a variety of detection systems, including organic, inorganic, and semi-conductor detectors. Neutron and photon spectroscopic transmission measurements were used identify various metals based on their effective atomic number. A contraband detection method was tested that utilized gamma-ray signatures from inelastic neutron interactions to characterize material composition. Further experiments investigated delayed neutron production by oxygen-17, which is an important component of the background signature for some detection schemes searching for concealed special nuclear material. Each of these measurements explores fundamental physics concepts in an effort to continue advancing nuclear security and nonproliferation applications.

Pic 1Bismuth metal interacting with neutrons


Pic 3New shielded target position in East target room


Pic 2Students changing targets in the new shielded target position in East target room


Pic 4Scintillator array with borated polyethylene shielding


Pic 5Scintillator spectrum showing separation of neutrons and gammas from 4 MeV d + natB:


Pic 6HPGe spectrum showing gammas from 4 MeV d+nat^B