| Compton and Rayleigh scattering peaks can be used to quantify the content of low atomic number elements that do not generate detectable characteristic peaks in an X-ray spectrum. Here, this method is used for quantifying water content in spectra obtained by the Alpha-particle X-ray spectrometers (APXS) on the Mars Exploration Rovers(MER).;As part of the analysis, a Monte Carlo simulation program is needed to determine the Compton to Rayleigh scattering (C/R) ratio based on sample content. Improvements were made to this simulation program and the new version was used to determine the most important parameters that influence the C/R ratio. Analyzing spectra from MERB, the Endurance Crater and Victoria Crater region were estimated to have 13+/-4% and 18+/-4% water repectively. A new extrapolation method was also developed that reduces the number of simulations required to arrive at a water estimate for any given MER spectrum. |
