L-264 Effects of Electromagnetic Radiation on Munitions Part 2: X-Ray, Gamma and Neutron Radiation

This document is to serve as a background resource for the array of interactions that X-ray, gamma and neutron radiation may have with a munition system during the course of a non-destructive examination.  The discussion of X-rays and gamma rays (energetic photons) is limited to the range of 100 keV to 5 MeV as non-destructive imaging systems use X-rays that are within this range.  The nature of the interactions of energetic photons and neutrons with matter are reviewed along with the mechanisms of energy absorption.  Neutron interactions with matter are also reviewed, including some effects of neutron capture.

The effects of photon and neutron radiation on electronics is relatively well studied.  Military electronics employ materials technologies that are relatively robust in a high radiation environment.  Unless they have been specifically tested, the susceptibility of the electronic components is the potential issue. It is apparent that much experimental work on energetic materials was conducted from the late 1940’s through to the 1960’s and subsequently published. Generally, those energetic materials that are thermally stable are the materials that best survive in a radiation environment. The environments in these tests were much more severe than would be expected during an NDT examination.  It is recommended that the radiation resistance of the electronic components in munition items be confirmed prior to any extended NDT examination.