SUPERCONDUCTING NB-TA-AL-ALOX-AL X-RAY-DETECTORS WITH SPATIAL-RESOLUTION

Superconducting X-ray detectors based on SIS tunnel junctions offer po tential for high spectral resolution and single photon efficiency. Whe n used in a double junction geometry, they also offer spatial resoluti on needed for focal plane imaging. We are developing Nb-Ta-Al-AlOx-Al detectors for space-based X-ray astronomy applications. The design emp loys superconductor bandgap engineering for improved charge collection and adaptability for double junction geometries. For irradiation of a single junction device with 6 keV X-rays at a single location, the de tectors have an energy resolution of 87 eV at 0.27 K. Initial studies of double junction detectors show a spectral resolution of 178 eV and an inferred spatial resolution of 4 mu m over an effective length of 6 0 mu m.