Transition-Edge Sensor Characteristics in a Modified Bias Circuit for Multiplexed Readout
The X-ray Integral Field Unit (X-IFU) on the NewAthena X-ray telescope will use a 1,504-pixel array of transition-edge sensor (TES) microcalorimeters, read out via time division multiplexing (TDM). To allow testing of multiplexer chips before TES integration, each unit cell includes a “TES-bypass” resistor that substitutes for a TES during characterization. After integration, this resistor remains as a high-resistance shunt: minimal for DC operation but can influence the frequency response due to its placement with the Nyquist inductor. We modeled the modified bias circuit, derived the small-signal response, and evaluated noise contributions, including Johnson noise from the bypass resistor. We analyzed the effects on pulse height, slew-rate, and energy resolution. Simulations were compared with measurements from prototype X-IFU microcalorimeters. Our results indicate that as long as the resistor value exceeds the TES dynamic resistance, performance is largely unaffected.
Authors
- Stephen J Smith (ORCID: https://orcid.org/0000-0002-2290-8701)
- Joshua D. Fuhrman (ORCID: https://orcid.org/0000-0002-9159-6561)
- Malcolm Durkin (ORCID: https://orcid.org/0000-0001-5640-2525)
- Christian Kirsch (ORCID: https://orcid.org/0000-0001-6293-1538)
- Tannaz Farrahi (ORCID: https://orcid.org/0000-0002-2814-3631)
- E. J. Wassell (ORCID: https://orcid.org/0000-0003-3380-7540)
- F. M. Finkbeiner (ORCID: https://orcid.org/0000-0001-6842-0544)
- J. S. Adams (ORCID: https://orcid.org/0009-0009-6310-5495)
- Samuel V. Hull (ORCID: https://orcid.org/0000-0003-3132-0536)
- H. Muramatsu (ORCID: https://orcid.org/0000-0001-7980-3559)
- Paul van der Hulst (ORCID: https://orcid.org/0000-0002-2635-833X)
- Nicholas A. Wakeham (ORCID: https://orcid.org/0000-0001-8397-9338)
- Edoardo Cucchetti (ORCID: https://orcid.org/0000-0002-5548-4351)
- M. C. Witthoeft (ORCID: https://orcid.org/0000-0001-6237-7776)
- Sang H. Yoon
- Meng P. Chiao (ORCID: https://orcid.org/0000-0003-4542-9663)
- Joel Ullom
- Ambarish C. Venkatasubraman
- R. L. Kelley
- C. A. Kilbourne
- S. R. Bandler
- J. A. Chervenak
- W. Bertrand Doriese
Institutions
- Goddard Space Flight Center (US)
- National Institute of Standards and Technology (US)
- Centre National d'Études Spatiales (FR)
- National Aeronautics and Space Administration (US)
- Space Research Organisation Netherlands (NL)
- University of Bamberg (DE)
Publication Details
- Journal
- IEEE Transactions on Applied Superconductivity
- Published
- 2026-02-12
- DOI
- https://doi.org/10.1109/tasc.2026.3664193
- Primary Topic
- Superconducting and THz Device Technology
- Type
- article
- Field-Weighted Citation Impact
- 0.00