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

Abstract

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–Kα line, obtained at moderately low temperature (−15 °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 μs) 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.