Abstract

A novel method is described for remotely interrogating bulk molecular composition of rocky materials. Laser energy heats a local area on the substrate; flux is optimized to melt and evaporate target constituents with low rates of molecular dissociation. Substrate temperature rises until an equilibrium is established between incident flux and latent phase-change energies, reaching ˜2500 K in vacuum. A blackbody signal is emitted by the heated spot, traveling outward through the evaporated material; reflective optics direct the signal into a spectrometer. Ro-vibrational absorption in the plume provides a diagnostic for identifying bulk molecular composition of the substrate. Absorption spectra are modeled for compounds with available a priori molecular cross-sections, based on laser and receiver characteristics, and target material properties. Mass ejection flux drives the plume density profile. Qualitative, species-specific spectral profiles are derived by integrating molecular cross section along a path through the plume. Simulations indicate robust absorption profiles.

摘要

描述了一种用于远程询问岩石材料的散装分子组成的新方法。激光能量加热基板上的局部区域；助焊剂经过优化，可以以低分子解离率熔化和蒸发目标成分。衬底温度升高，直到在入射通量和潜在相变能量之间建立平衡，在真空中达​​到～2500 K。加热点发出黑体信号，通过蒸发的材料向外传播；反射光学将信号导入光谱仪。羽流中的 Ro-振动吸收为识别底物的大分子组成提供了诊断。根据激光和接收器特性以及目标材料特性，为具有可用先验分子横截面的化合物建模吸收光谱。质量喷射通量驱动羽流密度分布。定性的、物种特异性的光谱分布是通过沿穿过羽流的路径整合分子横截面而得出的。模拟表明稳健的吸收曲线。