Experimental Study on Sound-Speed of Overdriven-Detonation Product and the Thermodynamic CJ State

Sound-speed data of overdriven-detonation product are fundamental to model EOS, and CJ data are important to manifest detonation properties of explosive. Using rarefaction wave chasing technique, the sound-speeds in overdriven detonation product at different pressures are measured with optic-fiber probes, which are used to monitor the process of rarefaction wave chasing shock wave in the trichloromethane behind explosive. The thermodynamic CJ state is determined by the intersection point of the steady detonation velocity and the sound-speed line Lc. The thermodynamic CJ pressure is evaluated 28.8 GPa by this method. There is only a slight difference of 0.3 GPa between the thermodynamic CJ pressure and the ordinarily measured value 28.5 GPa. The method to measure velocity and planarity of detonation driving flyer with optic-fiber probes is also introduced. The velocity and planarity of the flyer are obtained using this method, which possesses good precision of measurement.