Physical description of nuclear materials identification system (NMIS) signatures

Active Neutron Interrogation of Non-Radiological Materials with NMIS

“…This paper demonstrates applications of the following four measurement methods that are useful in material identification with NMIS-type measurements. DT transmission, DT scattering, and californium transmission have been demonstrated in previous papers (Grogan et al, 2008;Mihalczo et al, 2000). Active gamma spectroscopy has been proposed for NMIS and has been used for explosive (Hurley and Tinsley, 2007).…”

Evaluating laser-driven Bremsstrahlung radiation sources for imaging and analysis of nuclear waste packages

“…Neutrons are highly sensitive to hydrogen based compounds, thus neutron imaging will be able to efficiently identify their location and relative quantity [33]. Neutrons have also previously been utilized for criticality testing, for example by the nuclear materials identification system (NMIS) [34]. In this method, a time resolved analysis is achieved; neutrons that pass through active material induces fission, generating additional particles that are detected later than directly transmitted neutrons.…”

Radiation Detection from Fission

“…The time dependence of fission chain multiplication processes has been measured by a variety of methods. 2,3 The number of delayed neutrons and gamma rays is proportional to the number of prompt neutrons. The ratio of delayed neutron emissions to prompt emissions is fixed and does not depend on the multiplication, although the total number does.…”