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Integrating Micro-LIBS with Camera Handlens and Microscope Probe for Space Exploration
| Content Provider | Semantic Scholar |
|---|---|
| Author | Mungas, Greg S. Gursel, Yekta Dreyer, Christopher B. Sepúlveda, Claudia Johnson, Karl Boynton, John E. Beegle, Luther W. |
| Copyright Year | 2008 |
| Abstract | Introduction: Detailed investigation of prepared and unprepared surfaces at the microscopic scale has been used extensively to study the origin and history of geologic samples in terrestrial labs [1] and on Mars [2]. An integrated camera, handlens, and microscope probe is in development for prospecting and science investigations that currently integrates visible reflected light imaging with Raman Spectroscopy, Raman/CHAMP. This instrument images from infinity down to high resolution microscopy (4.4x), the closer the instrument is placed to a target the higher the resultant image resolution with an associated smaller field-of-view (Fig. 1). In the vicinity of peak magnification (<3 micron/pixel resolution), a high resolution laser that can probe anywhere across the microscopic field of view is possible with a <10 micron laser spot for purposes of analyzing the surface chemistry of particular microscopic features. This instrument provides its own context imaging for progressive high resolution field microscope investigations, requiring no sample handling, and would ideally eventually incorporate micro-LIBS elemental measurements coupled with Raman spectroscopy. Furthermore, the instrument can provide a 3D microscopic surface map built from multiple image scans with slightly different working distances (i.e. image cube) that are subsequently focal-plane merged together to produce a single in-focus image with local elevation coordinates. This map and fine elevation targeting can be used to optimally focus a laser spot into target surface features by fine adjustments of CHAMP's working distance [3]. Combined LIBS and Raman spectroscopy instruments for planetary exploration has been discussed elsewhere [4,5,6], and are considered to have a high potential due to the similarities in the spectroscopic and laser source requirements of LIBS and Raman, and the complementary nature of the LIBS and Raman data sets. LIBS provides elemental information about a sample, while Raman Spectroscopy provides molecular information. Standoff LIBS and Raman Spectroscopy integrated instruments have received the most attention in the space science community. We have investigated LIBS on rock samples at the microscopic (<20 μm spot diameter) scale and with micro-joule laser pulse energy (<200 μJ), which in the LIBS community is referenced as micro-LIBS. We are investigating the potential to incorporate micro-LIBS in the RamanCHAMP instrument. Hardware Development: We have recently fabricated the two lens cells that provide the multiple scale imaging with a beam-split laser scannable interface that can cover the entire imaging field-of-view at microscopy (Fig. 1D). The first microscopic image acquired Figure 1. A) Raman/CHAMP instrument pixel resoluteion vs. working distance. B) Images from eariler MIDP version of CHAMP instrument continuously variable magnification with simulated scan-able objectplane Raman laser spot (exaggerated in size for clarity) at peak magnification; C) Instrument optical layout and lens cell variable magnification/working distance actuation; D) Fabricated Lens Cells integrated into brassboard test seup. <10μm Translatable laser spot Continuously Variable Magnification/Working Distance CHAMP-ION Spatial Resolution vs. Working Distance ( Handlens-to-Microscopy Range ) |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.lpi.usra.edu/meetings/lpsc2008/pdf/2492.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
