A single-X-ray photon detector with possible energy resolution based on superconducting W0.8Si0.2 stripes

We fabricated a superconducting single X-ray photon detector based on W0.8Si0.2 and the basic detection performance for keV-photons was measured. The detector has a critical temperature of 4.97 K and it is able to work just below the critical temperature with negligible dark counts. We measured the detection efficiency at different temperatures and bias currents, and a saturated detection characteristics on bias current was observed at all temperatures. The signal pulse amplitude histograms show three distinct peaks, similar to the characteristic peaks from the used tungsten target. This demonstrates a possible energy resolution for superconducting X-ray detectors based on the current biased two dimensional stripes.