Abstract To study the influence of laser energy on the enhancement characteristics of plasma confined by a hemispherical cavity, the time-resolved spectra of the plasma with and without confinement under different laser energies were collected. When the laser energy exceeded 80 mJ, the spectral line intensity was enhanced significantly at the delay time range of 8–14 μs. Significantly, the maximum enhanced factor increased with the increase in the laser energy, while the corresponding delay time decreased gradually. These results indicated that when a laser pulse with relatively high energy is used to ablate the sample, a strongly reflected shockwave will be generated to compress the plasma, resulting in a significant enhancement effect at an early stage. Comparing the distributions of the plasma temperature, it was found that the plasma confined by a hemispherical cavity could maintain a relatively high temperature for a long period, resulting in spectral enhancement.

中文翻译：

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激光能量对半球形腔约束的激光诱导等离子体的影响

摘要 为研究激光能量对半球形腔约束等离子体增强特性的影响，采集了不同激光能量下有约束和无约束等离子体的时间分辨光谱。当激光能量超过 80 mJ 时，谱线强度在 8-14 μs 的延迟时间范围内显着增强。值得注意的是，最大增强因子随着激光能量的增加而增加，而相应的延迟时间逐渐减少。这些结果表明，当使用较高能量的激光脉冲对样品进行烧蚀时，会产生强烈反射的冲击波来压缩等离子体，从而在早期产生显着的增强效果。比较等离子体温度的分布，