$cobalt x ray diffraction pattern$

A cartoon of the CheMin geometry is shown in the figure below. photon energy that constitutes an energy-dispersive X-ray histogram of the sample. All of the X-rays detected by the CCD are summed into a histogram of number of photons vs. Diffracted X-rays strike the detector and are identified by their energy, producing a two-dimensional image that constitutes the diffraction pattern. When operated in this manner, the CCD can be used to measure the charge generated by each photon (and hence its energy). The CCD detector is exposed to the X-ray flux, read out and erased a large number of times for each analysis (1000 or more exposures). The CCD detector is operated in single-photon counting mode (the detector is read out at a frequency that ensures that the vast majority of pixels contain charge from either zero or one photon). An X-ray sensitive CCD imager is positioned on the opposite side of the sample from the source and directly detects X-rays diffracted or fluoresced by the sample. In operation, a collimated X-ray beam from the X-ray tube is directed through a transmission sample cell containing powdered material prepared and delivered by the SA/SPaH system. These data products are transmitted to Earth for further processing and analyses. Raw CCD frames are processed into data products onboard the rover to reduce the data volume. CheMin utilizes a microfocus cobalt X-ray source, a transmission sample cell, and an energy-discriminating X-ray sensitive CCD to produce simultaneous 2-D X-ray diffraction patterns and energy-dispersive histograms from powdered samples. Each analysis may take up to 10 hours of analysis time, spread out over two or more Martian nights, although some samples may provide acceptable results in a single sol. CheMin will analyze as many as 74 samples delivered by the SA/SPaH system during the nominal prime mission, but is capable of analyzing many more because its sample cells can be reused for additional analyses. CheMin is part of the Analytical Laboratory of the MSL rover, which is located inside the main body of the rover. Instrument DescriptionĬheMin, short for “Chemistry and Mineralogy,” is a powder X-ray Diffraction (XRD) instrument that also has X-ray Fluorescence (XRF) capabilities. CheMin can unequivocally identify and quantify minerals above its detection limits in complex natural samples such as basalts, multicomponent evaporite systems, and soils. In addition, CheMin data will be useful in the search for potential mineral biosignatures, energy sources for life or indicators of past habitable environments. By determining the mineralogy of rocks and soils, CheMin will assess the involvement of water in their formation, deposition, or alteration. Chemistry & Mineralogy (CheMin) is a definitive mineralogy instrument that will identify and quantify the minerals present in rocks and soil delivered to it by the Sample Acquisition, Sample Processing and Handling (SA/SPaH) system. Contributions of CheMin to MSL Science ObjectivesĪn important science goal of the MSL mission is to identify and characterize past or present habitable environments as recorded in sediments and rocks.

$cobalt x ray diffraction pattern$

Cobalt x ray diffraction pattern