Peille, PhilippePhilippePeilleden Hartog, RolandRolandden HartogMACCULI, CLAUDIOCLAUDIOMACCULIBarbera, MarcoMarcoBarberaLOTTI, SimoneSimoneLOTTICucchetti, EdoardoEdoardoCucchettiKirsch, ChristianChristianKirschDauser, ThomasThomasDauserWilms, JoernJoernWilmsBandler, Simon R.Simon R.BandlerSmith, Stephen J.Stephen J.SmithJackson, BrianBrianJacksonGeoffray, HervéHervéGeoffrayMesnager, Jean-MichelJean-MichelMesnagerPajot, FrançoisFrançoisPajotBarret, DidierDidierBarretLam-Trong, ThienThienLam-Trongden Herder, Jan-WillemJan-Willemden HerderPIRO, LUIGILUIGIPIRO2020-10-132020-10-132018978151061951797815106195240277-786Xhttp://hdl.handle.net/20.500.12386/27783The X-ray Integral Field Unit (X-IFU) is a next generation microcalorimeter planned for launch onboard the Athena observatory. Operating a matrix of 3840 superconducting Transition Edge Sensors at 90 mK, it will provide unprecedented spectro-imaging capabilities (2.5 eV resolution, for a field of view of 5') in the soft X-ray band (0.2 up to 12 keV), enabling breakthrough science. The definition of the instrument evolved along the phase A study and we present here an overview of its predicted performances and their modeling, illustrating how the design of the X-IFU meets its top-level scientific requirements. This article notably covers the energy resolution, count-rate capability, quantum efficiency and non X-ray background levels, highlighting their main drivers.ELETTRONICOenConference paper10.1117/12.23137202-s2.0-85051850739000452819200107https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10699/2313720/The-performance-of-the-ATHENA-X-ray-Integral-Field-Unit/10.1117/12.2313720.full?SSO=12018SPIE10699E..4KPFIS/05 - ASTRONOMIA E ASTROFISICA