Characterization of laser-induced breakdown spectroscopy (LIBS) for application to space exploration
Characterization of laser-induced breakdown spectroscopy (LIBS) for application to space exploration
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DOI：
10.1366/0003702001949591
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发表时间：
2000-03-01
影响因子：
3.5
通讯作者：
Ferris, MJ
中科院分区：
文献类型：
--
作者：
Knight, AK;Scherbarth, NL;Ferris, MJ
在下一个世纪的早期，计划进行几次太空任务，目标是在小行星、彗星、月球和火星上着陆。为了增加这些飞行任务的科学回报，需要新的方法来提供（1）在每个使命寿命期内显著更多的分析，和（2）扩大分析能力。有可能满足地质样品元素分析这两种需求的一种方法是激光诱导击穿光谱法（LIBS）。这些能力是可能的，因为激光等离子体提供快速分析，并且激光脉冲可以聚焦在远程定位的样品上以执行远离测量。间隔距离被定义为目标和激光器之间最多20 m的距离。在这里，我们提出了一个表征的LIES的土壤在降低的空气压力和模拟火星大气（5-7毫米的二氧化碳压力）显示的可行性LIES的空间探索的分析的结果。例如，它表明，一个分析有用的激光等离子体可以产生的距离高达19米，仅使用35毫焦耳/脉冲从一个紧凑的激光器。研究了减压下激光等离子体的一些特性。时间和光谱分辨成像显示随着压力降低，血浆中发生艾德显著变化，并且还显示从目标消融的分析物信号和质量强烈依赖于压力。随着压力从590 ℃降低到40-100 ℃范围，信号增加约3-4倍，并且随着压力进一步降低，信号降低。这种行为可以解释为压力依赖的变化，在物质蒸发的质量和等离子体中的物种之间的碰撞频率。还检查了温度和等离子体的电子密度随压力的变化，并确定了所选元素的检测限。
Early in the next century, several space missions are planned with the goal of landing craft on asteroids, comets, the Moon, and Mars. To increase the scientific return of these missions, new methods are needed to provide (1) significantly more analyses per mission lifetime, and (2) expanded analytical capabilities. One method that has the potential to meet both of these needs for the elemental analysis of geological samples is laser-induced breakdown spectroscopy (LIBS), These capabilities are possible because the laser plasma provides rapid analysis and the laser pulse can be focused on a remotely located sample to perform a stand-off measurement. Stand-off is defined as a distance up to 20 m between the target and laser. Here we present the results of a characterization of LIES for the stand-off analysis of soils at reduced air pressures and in a simulated Martian atmosphere (5-7 torr pressure of CO2) showing the feasibility of LIES for space exploration. For example, it is demonstrated that an analytically useful laser plasma can be generated at distances up to 19 m by using only 35 mJ/pulse from a compact laser. Some characteristics of the laser plasma at reduced pressure were also investigated. Temporally and spectrally resolved imaging show ed significant changes in the plasma as the pressure was reduced and also showed that the analyte signals and mass ablated from a target were strongly dependent on pressure, As the pressure decreased from 590 torr to the 40-100 torr range, the signals increased by a factor of about 3-4, and as the pressure was further reduced the signals decreased. This behavior can be explained by pressure-dependent changes in the mass of material vaporized and the frequency of collisions between species in the plasma. Changes in the temperature and the electron density of the plasmas with pressure were also examined and detection limits for selected elements were determined.