Scanning Gamma Ray Densitometer System for Detonations
Abstract:
The subject of this report is the description of a gamma ray scanning densitometer for measurement of height and density of the explosive increments in loaded detonators and delays. The 317 KEV gamma rays from an Ir192 source were collimated into a beam of 0.002 by 0.100 inch. A scanning system moved the detonators through this beam while the intensity of the transmitted radiation was recorded. On M-55 detonators (0.146 inch dia x 0.142 inch high), heights of explosive increments were measured to an accuracy of plus or minus 0.002 inch, and densities of lead azide were measured to plus or minus 3%. With Ir192, density measurements on NOL-130 were reproduced to plus or minus 5%, and on RDX to plus or minus 16%. Based on gamma ray absorption theory, it is known that accuracy of RDX measurements will be improved by use of a lower energy gamma ray source.