Speaker
Description
Athena is a large (L-class) mission from the European Space Agency (ESA) dedicated to the study of the hot and energetic universe. One of its instruments, the X-ray Integral Field Unit (X-IFU), needs temperatures as low as 50 mK for its detectors to reach the required sensitivity. In its newly proposed design, X-IFU uses a 50 K cryostat cooled thanks to radiative cooling. Mechanical coolers provide 20 K and 5 K interface temperatures within this cryostat.
After introducing the thermal design and its constraints, this talk will focus on the multistage adiabatic demagnetization refrigerator (ADR) system planned within this cryostat and operating from a 5 K interface down to 50 mK. Magnetic coolers are indeed well adapted to space operation because of their efficient, reliable and of their independence to orientation. The proposed design is based on a succession of 5 ADR stages providing cooling interfaces at 1.8 K, 325 mK and 50 mK for the focal plan assembly (FPA) unit hosting the detector.
A demonstration model (DM) is being assembled and tested. The first purpose of this model is to validate the functional performances and correlate them with our numerical model. This will help us for the fine optimization of the sizing of the Flight Model. Secondly, the prototype will be integrated by CNES in an instrument prototype to validate the overall performance including the one of the FPA. The talk will present the DM design, as well as results on the 5 K - 1.8 K stage operation. Finally, we will describe the next steps of this long-term project.
| Submitters Country | France |
|---|---|
| Are you a student? | No |
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