Uniformity of Kilo-Pixel Arrays of Transition-Edge Sensors for X-ray Astronomy

Abstract

We are developing kilo-pixel arrays of transition-edge sensor (TES) microcalorimeters for use in future laboratory and space based X-ray astrophysics experiments. These arrays are required to achieve an energy resolution of ΔE FWHM <; 3 eV full-width-half-maximum (FWHM) in the soft X-ray energy range. In this contribution we report on the development of 32 × 32 arrays of Mo/Au TESs with Bi/Au X-ray absorbers. We present measurements from 8 × 8 test arrays and 32 × 32 uniform arrays. Measurements of the bias point resistance and magnetic field dependence of the transition properties show that by carefully tuning the applied magnetic field the requirements on T C and magnetic field uniformity can be reduced whilst maintaining the target energy resolution. Results show ΔE FWHM ≈ 2.0 - 2.5 eV FWHM at a photon energy of 6 keV, measured across several pixels. Despite larger than typical T C variation across the detector, time division multiplexed readout of 30 common electrically biased pixels in the 32 × 32 array (in a 2 column × 16 row configuration) show an average ΔE FWHM = 3.0 ± 0.3 eV.