关键词: 电爆炸驱动飞片, HNS炸药, 爆轰反应区, 冲击起爆, 爆轰反应速率方程

Abstract: Exploding foil initiator (EFI) represents a promising initiation technology for meeting the high requirements of miniaturized and intelligent weapon systems for initiation capability. To gain an in-depth understanding of the initiation and detonation output characteristics of an exploding foil initiator system, a synchronized observation system for the electrical explosion-driven flyer characteristics of metal bridge foils was established, along with a particle velocity measurement system at the explosive-window interface for flyer-impact-initiated small-scale explosive detonation. The study investigated the flyer velocity, morphological characteristics, and the initiation and detonation reaction behavior of small-scale HNS-IV explosive under flyer impact. The results show that the flyer velocity is positively correlated with the initiation voltage. When the initiation voltage ranged from 900 to 1500 V, flyer velocity exiting the acceleration chamber was measured at 2000 to 4200 m/s. HNS-IV-based explosives demonstrated a short detonation growth distance; for instance, stable detonation was achieved within just 2.14 mm when impacted by a 3455 m/s flyer. Further analysis of the detonation wave structure indicated that HNS-IV has a fast detonation reaction rate, with a reaction time of less than 27 ns and a reaction zone width of only 0.13 mm. Under the condition of a 3 mm diameter micro-charge, the main detonation reaction of HNS-IV explosives remained largely unaffected, but a rapid energy decay was observed in the late stage of the reaction. The detonation reaction rate model was first calibrated by experimental results and then simulations were conducted to study the effect of charge size on the energy output. The results showed that increasing the charge thickness is more effective in enhancing energy output at the end of charge than increasing the charge diameter.

Key words: electric explosion-driven flyer, HNS, detonation reaction zone, shock initiation, detonation reaction rate equation