Temperature Measurement of Laser-Induced Plasma Detonation Wave

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.