CRYOGENIC HIGH-RESOLUTION X-RAY SPECTROMETERS FOR SR-XRF AND MICROANALYSIS

Experimental results are presented obtained with a cryogenically coole d high-resolution X-ray spectrometer based on a 141 x 141 mu m Nb-Al-A l2O3-Al-Nb superconducting tunnel junction (STJ) detector in an SR-XRF demonstration experiment. STJ detectors can operate at count rates ap proaching those of semiconductor detectors while still providing a sig nificantly better energy resolution for soft X-rays. By measuring fluo rescence X-rays from samples containing transition metals and low-Z el ements, an FWHM energy resolution of 6-15 eV for X-rays in the energy range 180-1100 eV has been obtained. The results show that, in the nea r future, STJ detectors may prove very useful in XRF and microanalysis applications.