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The Impact of Crosstalk in the X-IFU Instrument on Athena Science CasesIn this paper we present a first assessment of the impact of various forms of instrumental crosstalk on the science performance of the X-ray Integral Field Unit (X-IFU) on the Athena X-ray mission. This assessment is made using the SIXTE end-to-end simulator in the context of one of the more technically challenging science cases for the XIFU instrument. Crosstalk considerations may influence or drive various aspects of the design of the array of high-count-rate Transition Edge Sensor (TES) detectors and its Frequency Domain Multiplexed (FDM) readout architecture. The Athena X-ray mission was selected as the second L-class mission in ESA's Cosmic Vision 2015–25 plan, with alaunch foreseen in 2028, to address the theme ''Hot and Energetic Universe"1. One of the two instruments on boardAthena is the X-ray Integral Field Unit2 (X-IFU) which is based on an array of ~3800 Transition Edge Sensors (TES's)operated at a temperature of ~90 mK. The science cases pose an interesting challenge for this instrument, as they requirea combination of high energy resolution (2.5 eV FWHM or better), high spatial resolution (5 arcsec or better) and highcount rate capability (several tens of counts per second per detector for point sources as bright as 10 mCrab).The performance at the single sensor level has been demonstrated3, but the operation of such detectors in an array, usingmultiplexed readout, brings additional challenges, both for the design of the array in which the sensors are placed and forthe readout of the sensors. The readout of the detector array will be based on Frequency Domain Multiplexing (FDM)4.In this system of detectors and readout, crosstalk can arise through various mechanisms: on the TES array, neighboringsensors can couple through thermal crosstalk. Detectors adjacent in carrier frequency may suffer from electrical crosstalkdue to the finite width of the bandpass filters, and shared sources of impedance in their signal lines. The signals from theindividual detectors are summed and then amplified by a pair of SQUID amplifiers before being sent to warm front-endelectronics. The transfer function of the SQUID amplifiers is non-linear, which will give rise to higher harmonics ofcarriers and intermodulation products when multiple signal pulses are simultaneously present in the SQUID. Under highcount rate conditions this is another source of crosstalk. The effect of all these crosstalk sources is that parasitic pulseswill appear in the record of a signal pulse which will create a stochastic offset of the measured energy and thus adegradation of the energy resolution.
Document ID
Document Type
Conference Paper
External Source(s)
Hartog, R. Den (Space Research Organization Netherlands Utrecht, Netherlands)
Peille, P. (Centre National de Recherches Meteorologiques Toulouse, France)
Dauser, T. (Erlangen-Nuernberg Univ. Erlangen, Germany)
Jackson, B. (Space Research Organization Netherlands Groningen, Netherlands)
Bandler, S. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Barret, D. (Centre National de Recherches Meteorologiques Toulouse, France)
Brand, T. (Erlangen-Nuernberg Univ. Erlangen, Germany)
Herder, J-W Den (Space Research Organization Netherlands Utrecht, Netherlands)
Kiviranta, M. (Technical Research Centre of Finland Espoo, Finland)
Kuur, J. Van Der (Space Research Organization Netherlands Utrecht, Netherlands)
Smith, S. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Wilms, J. (Erlangen-Nuernberg Univ. Erlangen, Germany)
Date Acquired
June 14, 2017
Publication Date
July 26, 2016
Publication Information
Publication: Proceedings of SPIE
Volume: 9905
Subject Category
Space Communications, Spacecraft Communications, Command and Tracking
Report/Patent Number
Meeting Information
Space Telescopes and Instrumentation 2016(Edinburgh)
Distribution Limits
energy resolution
TES detectors