Single photon imaging X-ray spectrometers

We have developed superconducting, single-photon imaging x-ray detectors wi th an energy resolution of 26 eV FWHM at 6 keV and a spatial resolution of 0.5 mu m over an effective area of 18 mu m x 100 mu m. The energy resolutio n is among the best reported for this kind of detector and is within a fact or of approximate to 4 of it's theoretical limit. The calculated absorption efficiency of the detector is 28%. Scaling to larger areas and higher quan tum efficiency appear possible. We discuss the device design and readout al ong with possible sources of resolution broadening.