Silicon Drift Detectors for Lunar Surface Mapping

Members of our team are working in collaboration with the Brookhaven National Laboratory on a Silicon Drift Detector (SDD) Array for eventual use on lunar missions to perform remote elemental mapping of the lunar surface using X-ray fluorescence. The prototype array consists of hexagon-shaped pixels, each with 15 mm² surface area, acting as independent n-type drift detectors with a central collecting anode. The anode of each pixel is coupled to the input of a 14-channel application specific integrated circuit (ASIC).

The ASIC is also being designed in collaboration with BNL. The readout is done by wire-bonding the anodes to the inputs of the ASIC. The complete 14-pixel unit covers an area of 210 mm² and can be tiled to cover an arbitrarily large detection area. A preliminary resolution of 172 eV at the 6 keV peak of 55Fe has been measured.

Here is the paper Development of Thin-Window Silicon Drift Detector for X-ray Spectroscopy from the IEEE 2007 Nuclear Science Symposium and the paper Front-End ASIC for High Resolution X-Ray Spectrometers from the June 2008 issue of IEEE Transactions on Nuclear Science.