Lunar surface composition from X-ray fluorescence spectroscopy

• Main Author: Carter, James Andrew
• Other Authors: Grande, Manuel ; Cook, Anthony
• Published: Aberystwyth University 2013
• Subjects: 523.3
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577695

What is the composition of the surface of the Moon? This investigation aims to map the abundances of some of the main rock-forming elements over the surface of the Moon. Accurately determining the magnesium, aluminium and silicon abundances would have great advantages when performing geological and geochemical studies of the Earth-Moon system, helping to answer questions about its formation and evolution. This thesis uses data from the Chandrayaan-1 X-ray Spectrometer (C1XS) instrument on Chandryanaan-1, a high quality instrument that nevertheless flew in one of the lowest solar minima on record. Modelling software is described and written to predict the performance of an orbiting X-ray spectrometer (XRS) under different conditions, a vital task for premission planning and post-mission analysis. Surface factors, such as compositional modification by crater rays and the enhancement of X-ray returns by volatile sodium, are modelled to assess their effects on XRS signals. The C1XS data is processed using a data pipeline, and inspected and analysed. After some post-pipeline processing maps are produced, first elemental line intensity ratio maps, and then absolute elemental abundance maps. These are produced for the southern nearside lunar highlands, and are then compared to previous datasets and ground truth.