Superconducting tunnel junction array development for high-resolution energy-dispersive X-ray spectroscopy

Cryogenic energy-dispersive X-ray detectors are being developed because of their superior energy resolution (10 eV FWHM for keV X-rays) compared to th at achieved in semiconductor energy-dispersive spectrometry (EDS) systems. So far, their range of application is limited because of their comparably s mall size and low count rate. We present data on the development of superco nducting funnel junction (STJ) detector arrays to address both of these iss ues. A single STJ detector has a resolution of around 10 eV below 1 keV and can be operated at count rates of the order 10,000 counts/sec. We show tha t the simultaneous operation of several STJ detectors does not dimish their energy resolution significantly, and it increases the detector area and th e maximum count rate by a factor given by the total number of independent c hannels.