Downscaling the Methodology for Determining Detonation Velocities Applied to small sample Quantities of Explosives

The detonation velocity is a key parameter for characterizing the performance of explosives. The standard method at ICT, which is also used in literature, is the use of short-circuit contacts along the charge axis to detect the detonation wave propagation at distinct positions in dependence of time to derive the detonation velocity from a regression. To ensure a high accuracy, the diameter of the pins has to be negligible in relation to their distance and the total number of pins must be sufficient to ensure a high regression quality. This requires a comparatively large charge and corresponding mass of explosive. At ICT, one focus of research is the reduction of mass required to characterize energetic materials, concerning performance and safety parameters. The objective of the research is to provide a comprehensive characterization of small samples of new energetic materials produced on a laboratory scale, as well as the characterization of small energetic components such as detonators. Therefore, a new miniaturized method to measure detonation velocities is the result of the development presented in this work. The method is based on printed circuit boards, using the same principle as the short-circuit pins within the large-scale method. Through this approach, a downscaling of the method by a factor of 50 was realized. The validation of the method shows a high agreement with the results obtained by the large-scale method for HWC, as well as for HNS-pellets e.g. used in EFI applications.