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One of the most important diagnostics in the DDT experiment is the profile of the tube wall after the DDT event. Maximum expansion points, color changes, and texture of the walls all help to tell the story of what is happening during the DDT event. All of our exploded tubes have been cut exactly in half, and analyzed for shape, and other qualitative properties. An index of digitized profiles can be vied at:

The graph above shows the distance to detonation in granular HMX at various densities. (100% TMD= 1.903g/cc). The detonation was assumed to be at the point along the tube where it's profile reached a maximum rate of deflection, and theoretically a maximum rate of change in pressure. The profiles were scanned at high resolution and digitized. (see the link above) The maximum rate of deflection was calculated by taking the derivative of a 9th order polynomial fit, and finding the extremum.