High Aspect Ratio Transition Edge Sensors for X-ray Spectrometry

Abstract

We are developing large TES arrays in combination with FDM readout for the next generation of X-ray space observatories. For operation under AC-bias, the TESs have to be carefully designed and optimized. In particular, the use of high aspect ratio devices will help to mitigate non-ideal behaviour due to the weak-link effect. In this paper, we present a full characterization of a TES array containing five different device geometries, with aspect ratios (width:length) ranging from 1:2 up to 1:6. The complex impedance of all geometries is measured in different bias configurations to study the evolution of the small-signal limit superconducting transition parameters, as well as the excess noise. We show that high aspect ratio devices with properly tuned critical temperatures (around 90 mK) can achieve excellent energy resolution, with an array average of 2.03 +- 0.17 eV at 5.9 keV and a best achieved resolution of 1.63 +- 0.17 eV. This demonstrates that AC-biased TESs can achieve a very competitive performance compared to DC-biased TESs. The results have motivated a push to even more extreme device geometries currently in development.

11 pages, 10 figures

References in corpus (4)

• The Athena X-ray Integral Field Unit (X-IFU)
• Complex impedance, responsivity and noise of transition-edge sensors: analytical solutions for two- and three-block thermal models
• 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 (10)

• A Review of X-ray Microcalorimeters Based on Superconducting Transition Edge Sensors for Astrophysics and Particle Physics
• Voltage Fluctuations in ac Biased Superconducting Transition-Edge Sensors
• Performance and uniformity of a kilo-pixel array of Ti/Au transition-edge sensor microcalorimeters
• Mitigation of the Magnetic Field Susceptibility of Transition Edge Sensors using a Superconducting Groundplane
• Susceptibility study of TES micro-calorimeters for X-ray spectroscopy under FDM readout
• Impact of the absorber coupling design for Transition Edge Sensor X-ray Calorimeters
• Frequency Shift Algorithm: Application to a Frequency-Domain Multiplexing Readout of X-ray Transition-Edge Sensor Microcalorimeters
• TiAu TES 32$\times$32 pixel array: uniformity, thermal crosstalk and performance at different X-ray energies
• Frequency domain multiplexing readout for large arrays of transition-edge sensors
• Demonstration of MHz frequency domain multiplexing readout of 37 transition edge sensors for high-resolution x-ray imaging spectrometers