Time-division multiplexing switching transients and bandwidth effects on the X-ray Integral Field Unit readout performance

Cucchetti E, Geoffray H, Beaumont S, Doriese WB, Durkin M, Kirsch C, Denis-Jung R, Maisonnave O, Panglosse A, Peille P, Sakai K, Smith SJ, Wakeham NA (2026)

Publication Type: Journal article

Publication year: 2026

Journal

IEEE Transactions on Applied Superconductivity Institute of Electrical and Electronics Engineers (IEEE)

Book Volume: 36

Journal Issue: 6

DOI: 10.1109/TASC.2026.3664442

Abstract

The X-IFU (X-ray Integral Field Unit), on the future European X-ray observatory NewAthena, will perform high-resolution imaging spectroscopy over an array of 1,504 transition-edge sensors operated at 55 mK. Its readout is performed via time-division multiplexing (TDM) at a few MHz, which relies on fast (but not instantaneous) switching between pixels of the same column. Differences in the currents of consecutive rows lead to signal-dependent transients in the readout. These transients, and how they settle before sampling of the final row signal, are in turn governed by the open-loop bandwidths in the system. Limitations of the bandwidths smear the transients and contaminate the settling of photon pulses, resulting in a frequency-and amplitude-dependent error on the output signal. Switching transients have thus ultimately a direct impact on the instrument's energy scale. Although the origin of these perturbations is well-understood, quantifying their end-To-end impact on performance remains challenging. We compare here experimental data with simulations to assess the accuracy of numerical predictions. We also present an end-To-end analysis of nonlinearity in the X-IFU energy scale due to switching transients, and compare it against current performance budget allocations. These simulations show that the X-IFU can meet its energy scale requirements.

Authors with CRIS profile

Christian Kirsch Professur für Astronomie und Astrophysik

Involved external institutions

University of Maryland, Baltimore County (UMBC) US United States (USA) (US) National Aeronautics and Space Administration (NASA) US United States (USA) (US) National Centre for Space Studies / Centre national d'études spatiales (CNES) FR France (FR) National Institute of Standards and Technology (NIST) US United States (USA) (US)

How to cite

APA:

Cucchetti, E., Geoffray, H., Beaumont, S., Doriese, W.B., Durkin, M., Kirsch, C.,... Wakeham, N.A. (2026). Time-division multiplexing switching transients and bandwidth effects on the X-ray Integral Field Unit readout performance. IEEE Transactions on Applied Superconductivity, 36(6). https://doi.org/10.1109/TASC.2026.3664442

MLA:

Cucchetti, E., et al. "Time-division multiplexing switching transients and bandwidth effects on the X-ray Integral Field Unit readout performance." IEEE Transactions on Applied Superconductivity 36.6 (2026).

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