The Development of a Silicon-Drift-Detector-Based X-Ray Spectrometer for Remote Surface Analysis

Over the past three years NASA Marshall Space Flight Center has been collaborating with Brookhaven National Laboratory and with colleagues at Bear Fight Center to develop a modular Silicon Drift Detector (SDD) X-Ray Spectrometer (XRS) intended for fine surface mapping of light elements of planetary bodies. The SDD is ideally suited to this task, having modest power and cooling requirements and high radiation hardness. The modular form permits tailoring to multiple platforms, from orbiters to surface landers. In the former, possible targets include any airless bodies with sufficient ambient radiation to excite surface fluorescence. These include our moon, Mercury, the moons of Mars and Jupiter, asteroids and comets. Our SDD-XRS instrument can operate with a low energy threshold (i.e. is capable of detecting carbon), has comparable energy resolution to current CCDs (<150 eV at 5.9 keV) and has an order of magnitude lower power requirement. The target radiation hardness for this XRS is the Mrad level, sufficient for observations even within the Jovian system. Full details of the current status of the instrument will be presented. This effort is funded in part through the NASA Research Opportunities in Space and Earth Sciences - Planetary Instrument Definition and Development Program (PIDDP).