An Active X-Ray Spectrometer for the SELENE-2 Rover

Abstract

The Active X-ray Spectrometer (AXS) for the Japanese SELENE-2 rover has been proposed for elemental analysis on the lunar surface to measure the major elements: Mg, Al, Si, Ca, Ti, and Fe; the minor elements, Na, K, P, S, Cl, Cr, and Mn and the trace element Ni, all depending on their concentrations at a landing site. The elemental data of the AXS allow us to not only classification but also quantification of surface rocks on the Moon. The AXS is a compact low-weight instrument for elemental analysis based on the principle of X-ray fluorescence spectrometry using an X-ray spectrometer and two (four) pyroelectric crystals as X-Ray Generators (XRG). This paper introduces the current status of the pre-project to develop an AXS for the SELENE-2 Rover including the investigations on the generation of X-ray flux of the XRG, required surface roughness for the XRS measurement, and a thermal design of the AXS.