Position-sensitive transition-edge sensors

We report the latest results from our development of Position-Sensitive Transition-edge sensors (PoSTs), which are one-dimensional imaging spectrometers. In PoSTs with segmented Au absorbers, we obtained 8 eV energy resolution on K K α lines, which is consistent to the baseline energy resolution and the design values, on all of the nine pixels, by choosing the best combination of the thermal conductance in absorbers and in links that connects the absorbers. The pulse decay time of 193 μ s is fast enough for our purpose. In a PoST with a continuous Bi/Cu absorber, by dividing the events into 63 effective pixels, we obtained energy resolutions of 16 eV at the center “pixel”, which is comparable to the baseline energy resolution, and 33 eV at the outer “pixel”. The degradation of the energy resolution in the outer “pixel” is due to position dependence, which we can cancel out by dividing the events into smaller “pixels” when we have sufficient X-ray events.