Year: 2014
Type: conference-paper
Abstract: We are developing the digital readout electronics (DRE) of the X-Ray Integral Field Unit (X-IFU), one of the two Athena focal plane instruments. This subsystem is made of two main parts: the DRE-DEMUX and the DRE-EP. With a frequency domain multiplexing (FDM) the DRE-DEMUX makes the readout of the 3 840 Transition Edge Sensors (TES) in 96 channels of 40 pixels each. It provides the AC signals to voltage-bias the TES, it demodulates the detector's data which are readout by a SQUID and low noise amplifiers and it linearizes the detection chain to increase its dynamic range. The feedback is computed with a specific technique, so called baseband feedback (BBFB) which ensures that the loop is stable even with long propagation and processing delays (i.e. a few μs) and with high frequency AC-bias (up to 5 MHz). This processing is partly analogue (anti aliasing and reconstruction filters) but mostly digital. The digital firmware is simultaneously applied to all the pixels in digital integrated circuits. After the demultiplexing the interface between the DRE-DEMUX and the DRE-EP has to cope with a data rate of 61.44 Gbps to transmit the data of the individual pixels. Then, the DRE-EP detects the events and computes their energy and grade according to their spectral quality: low resolution, medium resolution and high resolution (i.e. if two consecutive events are too close the estimate of the energy is less accurate). This processing is done in LEON based processor boards. At its output the DRE-EP provides the control unit of the instrument with a list including for each event its time of arrival, its energy, its location on the focal plane and its grade.
DOI: 10.1117/12.2055750
Institutions: Centre National de la Recherche Scientifique, Observatoire Midi-Pyrénées, Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA Paris-Saclay - Etablissement de Saclay, Universidad de Cantabria, Consejo Superior de Investigaciones Científicas, Instituto de Física de Cantabria, Centre National d'Études Spatiales, Space Research Organisation Netherlands, Instituto Nacional de Técnica Aeroespacial
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2061734014