Laser induced breakdown spectroscopy analysis of lunar simulants under high vacuum conditions
01 Nov 2010-pp 449-453
TL;DR: In this article, hydrodynamic equations are used to model the plume dynamics under high vacuum conditions and experimental studies are performed to analyze the lunar simulant soil, which shows that plasma characteristic of lunar soil is mainly influenced by silicon which is the major constituent element present.
Abstract: Application of laser induced breakdown spectroscopy (LIBS) is considered for compositional analysis of materials on planetary surfaces. In many such applications, LIBS measurements are conducted in high vacuum and the propagation of the plume produced during laser ablation plays a significant role. Therefore a proper understanding of the plasma parameters under high vacuum is significant for any improvement in the LIBS system. In this study, hydrodynamic equations are used to model plasma dynamics. A model is used to understand laser assisted ablation and plume dynamics under high vacuum condition. Further, experimental studies are performed to analyze the lunar simulant soil. Experimentally observed lunar simulant plasma temperature was comparable with the theoretically estimated Si plasma temperature. This shows that plasma characteristic of lunar soil is mainly influenced by silicon which is the major constituent element present. The emission life time of silicon and lunar simulant are measured under different ambient pressure conditions. The measured life time is very short in vacuum as compared to that of at an atmospheric pressure. This is due to the high velocity and fast expansion of the plume under high vacuum (5×10−9 bar) condition.
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TL;DR: In this article, a very early plasma dynamics (first 100 ns) using direct plasma imaging, light scattering, and transmission measurements from a synchronized 532-nm probe laser pulse was studied.
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TL;DR: In this article, a model is developed to describe the heating and subsequent melting, vaporization and ionization of a target material during LIBS process and an experimental approach of measuring spectral emission from the ablation plume using emission spectroscopy and estimating the plasma state, such as the ionization species, and average plasma temperature, is investigated.
Abstract: Laser Induced Breakdown Spectroscopy (LIBS) can be considered as a prominent technology for compositional analysis of materials in low-pressure space applications. In space applications, usually LIBS is conducted in a low-pressure environment and proper understanding of the plasma parameters is significant for any improvement in the system. A model is developed to describe the heating and subsequent melting, vaporization and ionization of a target material during LIBS process. A numerical model based on one-dimensional thermal conductivity equation is being used to simulate the target evaporation and a hydrodynamic model is used to simulate plume expansion. Further, an experimental approach of measuring spectral emission from the ablation plume using emission spectroscopy and estimating the plasma state, such as the ionization species, and average plasma temperature, is investigated. An important result of this work is that for different ambient conditions, laser ablation plume dynamics can be estimated.
14 citations
"Laser induced breakdown spectroscop..." refers methods in this paper
...Different modeling approaches are available and can be categorized as: i) approach based on hydrodynamic continuity equations, ii) approach based on Monte-Carlo Simulations [4], iii) approach based on analytical expressions derived from the hydrodynamic continuity equations [5,6]....
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