A Photon-Counting Spectrometer for Elemental Analysis using LIBS

Scientists have used laser-induced breakdown spectroscopy (LIBS) over the past decade to perform elemental analysis of soil, water and gases. The formation of laser-induced plasma, which produces a localized blackbody source for atomic emissions, enables this technology. Collection of the plasma's spectral signature by a lens or optical fiber allows examination for elemental components of numerous materials. Recently, it has been shown that the stand-off measurement capabilities and ablative nature of the LIBS instrument would provide an extremely useful tool for space and planetary exploration. Geological features can be examined from a distance, reducing the time required to position a rover and expanding the area investigated during each mission. To further the usefulness of the LIBS instrument for space flight conditions, compact, lightweight, low power and robust systems are required. To meet this end, Radiation Monitoring Devices, Inc. (RMD) will develop a highly sensitive, echelle spectrometer and an array of Geiger photodiodes (GPD). Matching the GPD array format with the output from an echelle spectrometer will provide simultaneous monitoring of the major and minor elements of greatest interest, while eliminating the need for a scanning or multiple grating system.