高温气体中的激光击穿效应

Effect of laser induced breakdown in hot atomic oxygeng gas

通过对电子能量分布函数所满足的 Boltzmann方程的求解 ,得到了高温氧原子气体中激光产生电离击穿效应时的束流强度阈值。这一阈值远小于在低温氧分子气体中产生电离击穿的阈值 ,最多可相差两个数量级。导致这一现象出现的主要原因是原子和分子的能级分布和激发自由度有很大的差别。

The threshold of laser induce d breakdown in high temperature atomic oxygen gas is obtained by solving quantum B oltzmann equation for electrons numerically. This threshold is much more smaller than that in low temperature molecular gas. The reason is that in the hi gh temperature gas, the distribution of energy level and the degree of freedom is much more different fr om that in molecular gas. The vibrational excitation of molecule in molecular gas dose not exist in atomic gas, which reduces the energy loss of electrons and increases ionization rate.