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 Pelt ier element has been designed and tested. This system has been conceiv ed to be implemented in electron probe microanalyzers for the x-ray mi croanalysis of the specimen. The good energy resolution of the detecto r, 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 ene rgy resolution suggest the use of this system in operations with high counting rates (> 30 000 counts/s) like, for example, fast scannings f or elemental mapping. The module has been implemented in an electron m icroscope and the test results are reported in the article. (C) 1997 A merican Institute of Physics.