HIGH-RESOLUTION SUPERCONDUCTING X-RAY-DETECTORS WITH 2 ALUMINUM TRAPPING LAYERS

Superconducting tunnel junctions coupled to superconducting absorbers may be used as high-resolution, high-efficiency x-ray spectrometers. W e have tested three detectors with niobium x-ray absorbing layers coup led to aluminum layers that serve as quasiparticle traps. Two detector s differed only in barrier thickness. A third detector includes an ext ra absorbing layer. Here we present a comparison of detector performan ce. The best energy resolution measured was 36 eV full width at half m aximum at 6 keV.