堆芯换料方案的优化是一个典型的组合优化问题, 其搜索空间异常庞大。传统的优化算法很难在如此巨大的搜索空间中寻找出全局最优解。遗传算法以其优良的自适应能力和优化能力, 为组合优化问题提供了一个非常有效的解决途径。采用遗传算法对柱状高温气冷堆堆芯装料方案进行了优化, 并编写了相应程序。为了提高堆物理的计算精度, 堆芯临界计算采用26群输运计算。由于多群输运计算需要大量计算时间, 为此对遗传算法进行了并行优化。为了验证遗传算法对柱状高温气冷堆换料的优化能力, 构造了一个8组件的小型柱状高温气冷堆换料优化基准题。结果表明, 遗传算法在柱状高温气冷堆换料优化问题中具有良好的优化能力和计算稳定性。

Thermal effect is still the most serious problem: it restricts the high power and high beam quality of solid laser to be further enhanced. The efficient thermal management is an important approach to suppress the thermal effect. In this paper, the thermal effect in a gas-cooled laser diode pumped multislab Nd:glass amplifier operating at a repetition rate is investigated in detail both theoretically and experimentally. The three-dimensional distributions of temperature, stress, strain, and birefringence are calculated by a finite element analysis. Based on these data, the thermally induced wavefront distortions and depolarization losses are determined with considering six slabs and one laser head. It is revealed that the theoretical data are in good agreement with the experimental results: the total wavefront distortion is 6.77λ and a depolarization loss of more than 90% accumulates over six slabs when the heat deposition is 0.7 W/cm3.

Laser diode pumped solid-state lasers (DPSSL) has become an important way to realize the next generation of laser-driven device for energy conversion efficiency and repetition rate requirements. High repetition frequency leads to heat accumulation on the memory medium, which will cause thermo-optical effect, elasto-optical effect and bulk displacement, then resuls in the generation of wavefront distortion and affects the beam quality. Aimed at 100 J output energy and 10 Hz repetition frequency amplifier module, the extraction efficiency and gain performance storage are analyzed, and the sheet laser diode pumped amplifier module structure is designed using gas cooling technology. Thermal analysis models of single slice amplifier are established using the finite element analysis. The influence of signal slice thickness and convective heat transfer coefficient to the wavefront distortion are researched, in consideration of the limitation of the total wavefront distortion, we obtain the optimal value of single slice thickness. Using super-Gaussian beam on behalf of pump source and considering the distribution of helium gas flow, we analysis the thermal designed data and simulate the temperature, bulk displacement and stress distribution to get the related wavefront distortions.

激光二极管抽运的固体激光器（DPSSL）成为实现下一代激光器驱动装置对能量转换效率和重复频率要求的重要途径。高重复频率导致介质内存在热积累，引起热光效应、弹光效应和形变，导致波前畸变的产生，影响光束质量。针对目标输出能量100 J，重复频率10 Hz的放大模块，分析其储能提取效率和增益性能，采用气体冷却技术，设计激光二极管抽运的片状放大模块结构。利用有限元数值分析方法，建立了该装置单片放大器热分析模型，研究了单片增益介质厚度、对流换热系数对波前畸变的影响，结合波前畸变的要求，得到了单片厚度的最优值，并对该设计进行热分析，利用超高斯光束近似抽运光源，结合氦气气流分布情况，模拟单片介质的温度、形变和应力分布，计算得到了热光效应、形变和弹光效应对波前畸变的贡献以及单片增益介质的总波前。

介绍了铜蒸气激光器的发展及其输出特性。总结了近年来改善铜蒸气激光输出特性的研究。