High Security Laser Detonator Design And Development

Laser detonator belongs to the third generation of initiating explosive device,with the advantages of simple structure,high safety,and immunity to electromagnetic interference,which have attracted much attention in the field of aerospace and aviation in recent years.In this paper,the laser ignition agents are screened,and the factors influencing the laser detonator combustion to detonation are systematically studied under the condition of small size charge.In this paper,the DDT process is simulated by LSDYNA software.Based on the test results and theoretical simulation,the optimal condition of deflagration to detonation transition is determined,which provides a reference for the further study of laser detonator.The major research content of the paper is as follows:Under the conditions of outer diameter of 6mm,shell length of 20mm and shell material of S30408 stainless steel,the laser ignition delay time test was carried out on five kinds of potassium boronitrate（B/KNO3）with different proportions.According to the experimental results,the binder has a significant effect on reducing the laser delay time of BPN,and the effect of phenolic resin is better than that of fluororubber.The delay time of laser ignition decreases with the increase of boron content.B/KNO₃/PF（40/60/5）was determined as the ideal ignition agent,and the best density range was 1.25～1.35 g·cm^-3.Four kinds of explosives DDT performance tests were carried out in completely closed DDT tubes of different materials,among which HMX,RDX and TKX-50 explosives could all achieve deflagration to detonation transition.In the meantime,the deflagration to detonation transition law of laser detonator was studied under different experimental conditions such as charge density,explosive particle size,and constraint strength.Two types of explosives with more intense deflagration to detonation transition were selected for control variable experiments.The results find that:The effect of charge density on the transition from combustion to detonation of explosives follows a"U-shaped"pattern.The optimal ranges for HMX,RDX,and TKX-50 charge densities are 1.1 g·cm^-3～1.3 g·cm^-3,1.2g·cm^-3～1.4 g·cm^-3and 1 g·cm^-3,respectively;the medium particle explosive of about 100μm is more likely to turn from combustion to detonation.The binder can inhibit the conversion of HMX from combustion to detonation.LSDYNA was used to numerically simulate the DDT process of laser detonator.Based on the analysis of the reaction pressure cloud map and reactivity cloud map inside the tube,it can be concluded that the laser detonator forms stable detonation inside the tube,achieving the process of combustion deflagration to detonation transition.