Study on the thermal initiation of shelled PBXN-109 under laser irradiation

In order to investigate the thermal initiation mechanism of a warhead under laser irradiation, small scale experiments have been carried out with shelled PBXN-109 to obtain the initiation time and critical metal temperature. It was found that, as the laser power increases, the initiation time decreases exponentially; while the critical metal temperature increases linearly due to the effect of thermal conduct resistance. Based on theoretical analysis, a prediction model was built with a good accuracy for engineering application. In order to establish the relationship between the small-scale and the full-scale experiments, the scaling law of the thermal response process was approximated with that of the thermal conduct process, which was deduced through equation analysis to avoid the difficulty brought by the exponential nonlinearity from the equation of the thermal decomposition of the explosive. (paper)