在针-针电极结构的放电装置中以环境空气作为工作气体, 大气压下产生了刷形等离子体羽。 尽管使用的是直流电源, 但放电发光呈现出脉冲性质, 发光脉冲频率几乎不受气体流速的影响, 但与电源输出功率成正相关关系。 等离子体羽的长度与气体流速或者电源功率成正相关关系。 通道出口附近, 7774 nm的氧原子谱线强度分布是非对称的, 阴极附近处的谱线强度高于阳极附近处的谱线强度。 远离通道出口位置, 谱线强度逐渐趋于轴对称分布。 电学特性和10 μs曝光高速影像结果表明, 空气等离子体羽实际上是由拱形放电丝在远离通道出口的运动过程中叠加而成, 同时放电从弧光放电丝向均匀辉光放电转化。

Considering the time delay in different hohlraum wall positions caused by oblique incidence, the spatio-temporal optical field distribution characteristics of a hohlraum wall, especially during the rising edge of a flat-topped pulse, is simulated by a fast Fourier transform method together with chromatography. Results demonstrate that beam propagation along the hohlraum wall is a push-broom process with complex dynamic spatial–temporal evolution. In the first few picoseconds, the optical intensity of the front position increases rapidly, while that of the rear position is relatively weak. The ratio R of the optical intensity during the rising edge is smaller than that of the steady state. R gradually increases and finally tends to the value of the steady state with time. Calculation also shows that, with shorter total width of the rising edge, R of the optical field decreases and the difference compared to the steady state becomes larger. The evolution is more severe with smaller angle of inclination.

Considering the time delay in different hohlraum wall positions caused by oblique incidence, the spatio-temporal optical field distribution characteristics of a hohlraum wall, especially during the rising edge of a flat-topped pulse, is simulated by a fast Fourier transform method together with chromatography. Results demonstrate that beam propagation along the hohlraum wall is a push-broom process with complex dynamic spatial–temporal evolution. In the first few picoseconds, the optical intensity of the front position increases rapidly, while that of the rear position is relatively weak. The ratio R of the optical intensity during the rising edge is smaller than that of the steady state. R gradually increases and finally tends to the value of the steady state with time. Calculation also shows that, with shorter total width of the rising edge, R of the optical field decreases and the difference compared to the steady state becomes larger. The evolution is more severe with smaller angle of inclination.

为了了解激光诱导等离子体的演化过程，得到等离子体的相关参量，采用横向激励大气压CO2激光器在抛物反射面中聚焦击穿空气形成等离子体，利用成像光谱仪和增强型CCD探测器对激光诱导等离子体进行了时间和空间分辨的实验分析，取得了激光诱导空气等离子体的时间演化和空间分辨光谱。分别利用氧原子的线状谱和连续谱的比值及谱线半峰全宽计算得到电子温度达到了4×104K，电子密度在1018cm-3量级。结果表明，相比于低能量的激光诱导等离子体的辐射光谱，高能量激光诱导的等离子体则向外辐射出很强的连续光谱，同时，等离子体以激光支持爆轰波的形式快速向外膨胀，由于外围等离子体对激光能量的屏蔽作用，等离子体出现了空间分离的现象。该研究结果对理解等离子体和高能量脉冲激光的相互作用过程是有帮助的。