Jul 22 – 26, 2019
Europe/Rome timezone

Updates of frequency domain multiplexing for the X-ray Integral Field Unit (X-IFU) on board the Athena mission

Jul 22, 2019, 6:40 PM
Auditorium G. Testori (Milano)

Auditorium G. Testori


Piazza Città di Lombardia, 1, 20124 Milano MI
Oral Presentation Detector readout, signal processing, and related technologies Orals LM 002


Dr HIROKI AKAMATSU (SRON Netherlands Institute for)


We are developing the frequency domain multiplexing (FDM) read-out of transition-edge sensor (TES) microcalorimeters for the X-ray Integral Field Unit (X-IFU) instrument on board of the future European X-Ray observatory Athena. The X-IFU instrument consists of an array of $\sim$3000 TESs with a high quantum efficiency (>90 % at 7 keV) and spectral resolution $\Delta E$=2.5 eV @ 7 keV ($E/\Delta E\sim$2800).

FDM is the baseline readout system for the X-IFU instrument. In FDM, TESs are coupled to a passive LC filter and biased with alternating current (AC bias) at MHz frequencies. Each resonator should be separated beyond their detector thermal response (< 10 kHz) to avoid crosstalk between neighboring resonators. To satisfy the requirement of the X-IFU, a multiplexing factor of 40 pixels/channel in a frequency range from 1 to 5 MHz required.
Using high-quality factor LC filters and room temperature electronics developed at SRON and low-noise two-stage SQUID amplifiers provided by VTT, we have recently demonstrated good performance with the FDM readout of Mo/Au TES calorimeters with Au/Bi absorbers. We have achieved a performance requested for the demonstration model (DM) with the single pixel AC bias mode. We have also demonstrated 14-pixel multiplexing with an average energy resolution of 3.3 eV, which is currently limited by non-fundamental issues related to FDM readout in our current lab setup.

In this paper we report on the concept of the focal plane assembly, their requirements, detector performance under FDM scheme, recent results from pre-demonstration model setup and future prospect.

Student (Ph.D., M.Sc. or B.Sc.) N
Less than 5 years of experience since completion of Ph.D N

Primary author

Dr HIROKI AKAMATSU (SRON Netherlands Institute for)


Dr Luciano Gottardi (SRON - Netherlands Institute for Space Research) Jan van der Kuur (Netherlands Institute for Space Research) Dr C.P. de Vries (SRON) Dr Marcel Bruijn (SRON - Netherlands Institute for Space Research) Dr James, A. Chervenak Mr Mikko Kiviranta (VTT) A.J. van den Linden (SRON) Brian Jackson (Netherlands Institute for Space Research) Antoine Miniussi (NASA/GSFC - UMBC) Mr Kevin Ravensberg (SRON Netherlands Institute for Space Research) Kazuhiro Sakai (NASA/GSFC) Stephen Smith (NASA GSFC / UMBC) Dr Nicholas, A. Wakeham (NASA-GSFC / UMBC)

Presentation materials