Single photon imaging X-ray spectrometers using low noise currentpreamplifiers with dc voltage bias

摘要

We have developed superconducting single-photon imaging X-ray detectors with an energy resolution of 54 eV at 6 keV and a spatial resolution of 1 μm over an effective length of 40 μm. They utilize a current-sensitive low-noise preamplifier with a dc voltage bias. It has a signal bandwidth of 300 kHz, current noise of in=0.26 pA/√(Hz) and voltage noise of en=0.5 nV/√(Hz) with an input capacitance of 200 pF under operating conditions. Injected pulses with a charge Q=3.7·106 electrons have been measured with a standard deviation σQ=3400 electrons, corresponding to an electronic noise of 13 eV at 6 keV