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摘要: 高能量激光聚焦空气产生等离子体，等离子体进一步吸收激光能量会形成激光支持等离子体爆轰波。等离子体爆轰波温度是表征爆轰波的一个重要参数，研究等离子体爆轰波温度对于深入了解激光支持等离子体爆轰波形成机理有重要意义。分析了激光聚焦空气形成等离子体爆轰波过程和影响等离子体爆轰波温度的主要因素。采用多通道瞬态光学高温计，测量了不同激光发射能量下空气中形成的激光支持等离子体爆轰波的辐射强度，获得了一系列等离子体爆轰波温度动态变化曲线。测量结果表明：等离子爆轰波温度在随时间演化过程中出现3个峰，最高温度在7 000～10 000 K范围内；激光能量与等离子体爆轰波温度没有明显的相关性。Abstract: When a highly intensive laser beam is focused into quiescent air, a laser induced plasma detonation wave is generated. The plasma temperature is an important parameter to describe the plasma detonation wave characters. It is significant to obtain the plasma temperature by experimental method for understanding the mechanism of laser supported detonation wave. In this paper, the ignition, growth and propagation of the laser induced plasma detonation waves were theoretically analyzed and a laser supported detonation wave model was given. The main factors of influence on plasma temperature were deduced in this model. We used pyrophotometer to measure the light emission produced by laser induced plasma to determine values of the laser supported detonation wave temperature at atmospheric pressure. The temporal evolution of plasma temperatures under different laser energies was obtained. The results show that three wave peaks appeared in the temperature history curve, the maximum temperature of laser induced plasma detonation wave is about 7 000～10 000 K, and variation in the laser energy has no apparent change in the temperature.
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Key words:
- plasma /
- temperature /
- laser /
- detonation wave /
- shock wave
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