Long-duration nano-second single pulse lasers for observation of spectra from bulk liquids at high hydrostatic pressures
Long-duration nano-second single pulse lasers for observation of spectra from bulk liquids at high hydrostatic pressures
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DOI：
10.1016/j.sab.2014.04.008
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发表时间：
2014-07
期刊：
影响因子：
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通讯作者：
B. Thornton;T. Sakka;T. Masamura;A. Tamura;Tomoko Takahashi;Ayumu Matsumoto
中科院分区：
文献类型：
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作者：
B. Thornton;T. Sakka;T. Masamura;A. Tamura;Tomoko Takahashi;Ayumu Matsumoto
本文研究了在0.1 ~ 30 MPa的流体静压下，激光脉冲宽度对离子溶液光谱发射的影响。瞬态压力，阴影成像和光谱测量进行了持续时间为20和150纳秒的单脉冲。瞬态压力测量结果表明，对于高达30 MPa的静水压力，由聚焦激光产生的高压冲击波的传播导致局部压力在光谱测量可以进行的时间范围内降低到环境水平以下。压力脉冲和随后的压力降低更大，与相同能量的20 ns脉冲相比，后者对于150 ns脉冲持续更长时间。150 ns的脉冲产生较大的空腔，与20 ns的持续时间的脉冲相比，观察到的光谱发射的显着增强的压力高达30 MPa。结果表明，激光诱导击穿使用一个长的ns持续时间的脉冲提供了一个优势，比传统的，短ns持续时间的脉冲在0.1和30 MPa之间的静水压力的散装离子溶液的分析。
The influence of laser pulse duration on the spectral emissions observed from bulk ionic solutions has been investigated for hydrostatic pressures between 0.1 and 30 MPa. Transient pressure, shadowgraph imaging and spectroscopic measurements were performed for single pulses of duration 20 and 150 ns. The transient pressure measurements show that for hydrostatic pressures up to 30 MPa, propagation of the high-pressure shockwave generated by the focused laser causes the local pressure to reduce below ambient levels during the time frame that spectroscopic measurements can be made. The pressure impulse and subsequent reduction in pressure are larger, with the latter lasting longer for the 150 ns pulse compared to a 20 ns pulse of the same energy. The 150 ns pulse generates larger cavities with significant enhancement of the spectral emissions observed compared to the 20 ns duration pulse for pressures up to 30 MPa. The results demonstrate that laser-induced breakdown using a long ns duration pulse offers an advantage over conventional, short ns duration pulses for the analysis of bulk ionic solutions at hydrostatic pressures between 0.1 and 30 MPa.