Ti/Au TES 32 × 32 Pixel Array: Uniformity, Thermal Crosstalk and Performance at Different X-Ray Energies

Emanuele Taralli*, Matteo D'Andrea, Luciano Gottardi, Marcel Ridder, Martin De Wit, Sven Visser, Davide Vaccaro, Marcel Bruijn, Jian Rong Gao, More Authors

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)


Large format arrays of transition edge sensor (TES) are crucial for the next generation of X-ray space observatories. Such arrays are required to achieve an energy resolution of Δ E < 3 eV full-width-half-maximum (FWHM) in the soft X-ray energy range. We are currently developing X-ray microcalorimeter arrays as a backup option for the X-IFU instrument on board of ATHENA space telescope, led by ESA and foreseen to be launched in 2031. In this contribution, we report on the development and the characterization of a uniform 32 × 32 pixel array with (length × width) 140 × 30 μ m2 TiAu TESs, which have a 2.3 μ m thick Au absorber for X-ray photons. The pixels have a typical normal resistance Rn = 121 m Ω and a critical temperature Tc ∼ 90 mK. We performed extensive measurements on 60 pixels out of the array in order to show the uniformity of the array. We obtained an energy resolutions between 2.4 and 2.6 eV (FWHM) at 5.9 keV, measured in a single-pixel mode at AC bias frequencies ranging from 1 to 5 MHz, with a frequency domain multiplexing (FDM) readout system, which is developed at SRON/VTT. We also present the detector energy resolution at X-ray with different photon energies generated by a modulated external X-ray source from 1.45 keV up to 8.9 keV. Multiplexing readout across several pixels has also been performed to evaluate the impact of the thermal crosstalk to the instrument's energy resolution budget requirement. This value results in a derived requirement, for the first neighbour, that is less than 1;× 10-3 when considering the ratio between the amplitude of the crosstalk signal to an X-ray pulse (for example at 5.9 keV).

Original languageEnglish
Article number9360474
Number of pages5
JournalIEEE Transactions on Applied Superconductivity
Issue number5
Publication statusPublished - 2021


  • Crosstalk
  • energy resolution
  • modulated X-ray source
  • superconducting devices
  • X-ray detectors


Dive into the research topics of 'Ti/Au TES 32 × 32 Pixel Array: Uniformity, Thermal Crosstalk and Performance at Different X-Ray Energies'. Together they form a unique fingerprint.

Cite this