Laser initiation of energetic materials is a topic of significant interest. An extremely important parameter of initiation for numerous applied tasks is the time delay of initiation from the beginning of laser exposure. Experimental studies of the process of initiation of a number of primary explosives (lead styphnate (LS), lead azide, (LA)) and initiating mixtures (potassium perchlorate and potassium hexacyanoferrate (III) (PP/PH), bismuth oxide and aluminum ‐ nanothermite (NT)) under the exposure of a continuous IR (0.915 μm) laser with a power of up to 10 W were carried out. The time delay of initiation of these explosives was measured. It is shown that nanothermite (NT) has the lowest time delays and minimal initiation thresholds. At a laser power of 1 W and a light spot diameter of 0.5 mm (intensity 0.5 kW / cm²) the time delay of NT initiation was 1.2–1.8 ms. For other explosives with such a laser spot diameter, the initiation threshold was 2–3 W (1–1.5 kW/cm²). It is shown that mixtures of these explosives photosensitized by 0.5 % nanoaluminum have an initiation threshold ten times lower than for pure materials. For such compositions, the initiation time delay was 2–10 ms at the laser radiation intensity of 0.5 kW/cm². It was found that for the PP/PH material there is a certain limit on the minimum time delay of initiation, which was 0.1–0.15 ms. It is suggested that this effect is associated with the micro‐hotspot nature of laser initiation of EM and the presence of a critical zone of initiation.

中文翻译：

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暴露于连续红外激光辐射下，一些主要炸药和起爆混合物起爆的时间延迟

激光引发高能材料是一个令人关注的话题。对于许多应用任务而言，启动的一个极其重要的参数是从激光曝光开始到启动的时间延迟。多种初级炸药（苯甲酸铅（LS），叠氮化铅（LA））和混合物（高氯酸钾和六氰铁酸钾（III）（PP / PH），氧化铋和铝）的引发过程的实验研究在连续的IR（0.915μm）激光照射下以高达10 W的功率进行了纳米碳纳米管（NT）的扫描。测量了引爆这些炸药的时间延迟。结果表明，纳米盐（NT）具有最低的时间延迟和最小的起始阈值。在1 W的激光功率和0.5 mm的光斑直径（强度0.5 kW / cm ²）NT启动的时间延迟为1.2-1.8 ms。对于具有这种激光光斑直径的其他炸药，起爆阈值为2–3 W（1–1.5 kW / cm ²）。结果表明，用0.5％纳米铝光敏化的这些炸药的混合物的起始阈值比纯物质低十倍。对于此类组合物，在0.5 kW / cm ²的激光辐射强度下，启动时间延迟为2-10 ms 。发现对于PP / PH材料，最小引发延迟有一定限制，即0.1-0.15 ms。建议该效应与EM的激光激发的微热点性质和临界激发区的存在有关。