A comparison of nanosecond and femtosecond laser-induced plasma spectroscopy of brass samples
A comparison of nanosecond and femtosecond laser-induced plasma spectroscopy of brass samples
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DOI：
10.1016/s0584-8547(00)00275-5
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发表时间：
2000-11-01
影响因子：
3.3
通讯作者：
Hergenröder, R
中科院分区：
文献类型：
--
作者：
Margetic, V;Pakulev, A;Hergenröder, R
用等离子体发射光谱法研究了170 fs和6 ns激光脉冲在氩气保护气体中烧蚀黄铜样品的过程。谱线强度在时间行为上的差异可以用Ar等离子体对ns脉冲的屏蔽效应和fs脉冲下烧蚀材料等离子体的自由膨胀来解释。以不同锌铜比的黄铜为试样。在ns-和fs-脉冲的情况下，观察到不同类型的陨石坑形成机制。在40mbar的氩气压力下，fs脉冲和ns脉冲的烧蚀阈值分别为0.1和1.5 jcm（-2）。通过锌到铜的内部标准化，可以纠正烧蚀率的差异并获得线性校准曲线。对于最佳的实验条件，较窄的置信区间，以确定未知浓度的情况下，发现了fs脉冲。在使用的激光强度范围内，没有观察到Zn/Cu线强度比与施加到同一烧蚀点的激光脉冲数的依赖，无论是fs-还是ns脉冲，这被解释为没有分数汽化。(C) 2000 Elsevier Science B.V.版权所有
The ablation of brass samples in argon shield gas by 170 fs and 6 ns laser pulses has been studied by optical emission spectroscopy of the evolving plasmas. Differences observed in the temporal behavior of the spectral line intensities are explained by the shielding effect of the Ar plasma for ns-pulses and the free expansion of the plasma of the ablated material in case of fs-pulses. Brass with different Zn/Cu ratios were used as samples. Different types of crater formation mechanisms in the case of ns- and fs-pulses were observed. At 40 mbar argon pressure the thresholds of ablation were found to be similar to 0.1 and similar to 1.5 J cm(-2) for fs- and ns-pulses, respectively. With an internal standardization of zinc to copper it is possible to correct for differences in the ablation rates and to obtain linear calibration curves. For optimum experimental conditions, narrower confidence intervals for the determination of unknown concentrations were found in case of fs-pulses. Within the range of the laser intensities used, no dependence of the Zn/Cu line intensity ratio on the number of laser pulses applied to the same ablation spot was observed, neither for fs- nor for ns-pulses, which is interpreted as the absence of fractional vaporization. (C) 2000 Elsevier Science B.V. All rights reserved.