F. Pajot, D. Barret, T. Lam-Trong, J.-W. den Herder, L. Piro, M. Cappi, J. Huovelin, R. Kelley, J. M. Mas-Hesse, K. Mitsuda, S. Paltani, G. Rauw, A. Rozanska, J. Wilms, M. Barbera, F. Douchin, H. Geoffray, R. den Hartog, C. Kilbourne, M. Le Du, C. Macculi, J.-M. Mesnager & P. Peille. 2019. The Athena X-ray Integral Field Unit (X-IFU). Journal of Low Temperature Physics 193, 5-6, 901-907, DOI: 10.1007/s10909-018-1904-5
The X-ray Integral Field Unit (X-IFU) of the Advanced Telescope for High-ENergy Astrophysics (Athena) large-scale mission of ESA will provide spatially resolved high-resolution X-ray spectroscopy from 0.2 to 12 keV, with 5 » pixels over a field of view of 5 arc minute equivalent diameter and a spectral resolution of 2.5 eV (FWHM) up to 7 keV. The core scientific objectives of Athena drive the main performance parameters of the X-IFU. We present the current reference configuration of the X-IFU, and the key issues driving the design of the instrument.