Saint-Hilaire G
Appl Opt. 1977 Jul 1;16(7):1975-81. doi: 10.1364/AO.16.001975.
Using two different empirical density profiles for the end region of a theta-pinch plasma, one with a maximum density on the axis (radiation-dispersing profile) the other with a pronounced axial minimum (radiation- trapping profile), the trajectory of the CO(2) laser beam (10.6 microm) focused axially on such a plasma was studied numerically. This calculation is used to evaluate the optical influence of the plasma, since the maximum power density in the focal plane can be reduced by several orders of magnitude owing to the presence of the plasma. This influence can be substantial even for very subcritical electron densities (n(e) << 10(19) cm(-3)). In cases of large dispersion, the characteristics of a multifocal lens capable of producing perfect focusing are found, and it is shown that the solution is not unique. The radial distribution of the laser beam power density is also calculated and shows numerous irregularities and discontinuities due to the nonuniform beam dispersion.
使用两种不同的经验密度分布来描述θ箍缩等离子体的端部区域，一种在轴上具有最大密度（辐射分散分布），另一种具有明显的轴向最小值（辐射俘获分布），对轴向聚焦在这种等离子体上的CO(2)激光束（10.6微米）的轨迹进行了数值研究。该计算用于评估等离子体的光学影响，因为由于等离子体的存在，焦平面中的最大功率密度可以降低几个数量级。即使对于非常亚临界的电子密度（n(e) << 10(19) cm(-3)），这种影响也可能很大。在大色散的情况下，发现了能够产生完美聚焦的多焦点透镜的特性，并且表明该解决方案不是唯一的。还计算了激光束功率密度的径向分布，结果显示由于光束色散不均匀，存在许多不规则性和不连续性。
