PIXL (Planetary Instrument for X-ray Lithochem.) is a micro-focus X-ray fluorescence instrument for
examg. fine scale chem. variations in rocks and soils on planetary surfaces. Selected for flight on the Mars
2020 rover science payload, PIXL can measure elemental chem. of tiny features obsd. in rocks, such as
individual sand grains, veinlets, cements, concretions and crystals. The PIXL sensor head is mounted on the
turret at the end of the Mars 2020 rover arm. It combines a novel, 28 kV power supply (S. Battel, University
of Michigan) with a newly developed side-window, grounded-cathode x-ray tube (Moxtek), and a polycapillary xray
optic (XOS) to generate a 120 mm diam. x-ray beam that is rastered over a 24 mm x 24 mm field of view.
Two SDD detectors are used to collect the fluoresced spectra and an optical fiducial subsystem is used to image
rock morphol., guide placement of PIXL, and det. the x-ray beam location on the targeted surface. The overall
PIXL design, performance and operational concepts will be presented, along with a summary of development
test results