Microwave Interferometry Diagnostic Applications for Measurements of Explosives

Abstract

Microwave interferometry (MI) is a Doppler based diagnostic tool used to measure the detonation velocity of explosives, which has applications to explosive safety. The geometry used in existing MI experiments is cylindrical explosives pellets layered in a cylindrical case. It is of interest to Lawrence Livermore National Labs to measure additional geometries that may be overmoded, meaning that the geometries propagate higher-order transverse electromagnetic waves. The goal of my project is to measure and analyze the input reflection from a novel structure and to find a good frequency to use in an experiment using this structure. Two methods of determining a good frequency are applied to the phase of the input reflection. The first method is R 2 , used to measure the linearity of input reflection phase. The second is a zerocrossing method that measures how periodic the input reflection phase is. Frequencies with R 2 values higher than 0.995 may be usable for an experiment in the novel structure.