Performance and uniformity of a kilo-pixel array of Ti/Au transition-edge sensor microcalorimeters

Abstract

Uniform large transition-edge sensor (TES) arrays are fundamental for the next generation of X-ray space observatories. These arrays are required to achieve an energy resolution $\Delta E$ < 3 eV full-width-half-maximum (FWHM) in the soft X-ray energy range. We are currently developing X-ray microcalorimeter arrays for use in future laboratory and space-based X-ray astrophysics experiments and ground-based spectrometers. In this contribution we report on the development and the characterization of a uniform 32$\times$32 pixel array with 140$\times$30 $\mu$m${}^2$ Ti/Au TESs with Au X-ray absorber. We report upon extensive measurements on 60 pixels in order to show the uniformity of our large TES array. The averaged critical temperature is $T_{\mathrm{c}}$ = 89.5$\pm$0.5 mK and the variation across the array ($\sim$1 cm) is less than 1.5 mK. We found a large region of detector's bias points between 20\% and 40\% of the normal-state resistance where the energy resolution is constantly lower than 3 eV. In particular, results show a summed X-ray spectral resolution $\Delta E_{\mathrm{FWHM}}$ = 2.50$\pm$0.04 eV at a photon energy of 5.9 keV, measured in a single-pixel mode using a frequency domain multiplexing (FDM) readout system developed at SRON/VTT at bias frequencies ranging from 1 to 5 MHz. Moreover we compare the logarithmic resistance sensitivity with respect to temperature and current ($\alpha$ and $\beta$ respectively) and their correlation with the detector's noise parameter $M$, showing an homogeneous behaviour for all the measured pixels in the array.

References in corpus (3)

• High Aspect Ratio Transition Edge Sensors for X-ray Spectrometry
• Complex impedance of TESs under AC bias using FDM readout system
• Characterization of high aspect ratio TiAu TES X-ray microcalorimeters array using the X-IFU Frequency Domain Multiplexing readout

Cited by in corpus (5)

• A Review of X-ray Microcalorimeters Based on Superconducting Transition Edge Sensors for Astrophysics and Particle Physics
• Performance of the SRON Ti/Au Transition Edge Sensor X-ray Calorimeters
• Mitigation of the Magnetic Field Susceptibility of Transition Edge Sensors using a Superconducting Groundplane
• TiAu TES 32$\times$32 pixel array: uniformity, thermal crosstalk and performance at different X-ray energies
• System performance of a cryogenic test-bed for the time-division multiplexing readout for NewAthena X-IFU