A new detection system for x-ray microanalysis based on a silicon drift detector with Peltier cooling

A detection system made with a silicon drift detector cooled by a Peltier element has been designed and tested. This system has been conceived to be implemented in electron probe microanalyzers for the x-ray microanalysis of the specimen. The good energy resolution of the detector, 155 eV full width at half-maximum at the Mn-K alpha line, obtained at moderately low temperature (- 15 degrees C) by a small single-stage Peltier cooler, let this module be used in many applications in place of a standard Si(Li) detector, without the need of a liquid-nitrogen cryostat and with a good geometrical collection efficiency. Also, the particularly low values of shaping time (<2 mu s) used for optimum energy resolution suggest the use of this system in operations with high counting rates (> 30 000 counts/s) like, for example, fast scannings for elemental mapping. The module has been implemented in an electron microscope and the test results are reported in the article. (C) 1997 American Institute of Physics.