Speaker
Description
The Planetary Instrument for X-ray Lithochemistry (PIXL) is an instrument on the Mars 2020 rover. It provides high spatial resolution X-ray fluorescence (XRF) spectra of Martian samples. The instrument has a spot size of ~150um and is mounted on the rovers arm, allowing rastering over a ~cm^2 sample. Although it is not a dedicated X-ray diffraction (XRD) instrument, the dual detectors of the instrument, positioned at opposing angles to the target, can sometimes capture X-ray diffraction (XRD) signals. These artifacts can skew elemental abundances, particularly for transition metals such as Fe, Mn, Ca, and Ni, complicating mineralogical interpretations. This project aims to identify, analyze, and eventually model these XRD effects to extract the likely mineralogy of the samples. Detector comparisons are used to statistically flag anomalous signals beyond expected counting noise. Differences are modeled with a constant calibration factor plus Gaussian peak fitting to isolate diffraction contributions. The resulting PIXL data from Mars 2020 will be compared with chemistry and mineralogical results from the Alpha Particle X-ray Spectrometer (APXS) on the Mars Exploration Rover (MER) and Mars Science Laboratory (MSL) missions. By applying this approach across entire rasters, we aim to extract both robust XRF compositions and complementary diffraction information.
| Keyword-1 | X-ray Flourescence |
|---|---|
| Keyword-2 | X-ray Diffraction |
| Keyword-3 | Planetary Science |