Shock-Wave Diagnostics

Delayed measurements, such as photographs (Swift, 1990 Isbell, 1990) of debris clouds and even post-mortem examinations, contribute less directly to 

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Recently, we have turned to smaller scale experiments --both in the field and at laboratory scale--in which melt quantities varied from approximately 2 to 2000 g. In these experiments melt was released, either in free fall or by injection, or generated below the water. The interactions studied were either nontriggered (no external pressure pulse applied) or triggered with carefully characterized triggers (shock wave source). Careful attention was paid to diagnostics during the interactions and to the collection and measurement of the products, gaseous and solid, of the interactions. 

Fedele, F., Coleman, A.J., Leighton, T.G., et al. Development of a new diagnostic sensor for extra-corporeal shock-wave lithotripsy, in Advanced Metrology for Ultrasound in Medicine 2004 (ed. A. Shaw), J. Physics Conf. Series 1, Institute of Physics, London, 2004, 134-79. 

Unfortunately, the lack of any diagnostics within the transition section does not allow us to directly identify the process responsible for the successful detonation transition. Nevertheless, since for the current apparatus it was observed that the strength of a reflected shock off the shock-focusing cone is less than 10% of the strength of the incident shock, one can infer from the pressure trace recorded directly upstream from the transition section that a localized explosion has occurred in between this location and the exit of the transition section. Thus, it can be concluded that the overdriven state of the detonation is responsible for the successful transition of the detonation wave into the main thrust tube. 

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