Status of the wide field imager instrument for Athena

The Wide Field Imager (WFI) instrument for ESA’s next large X-ray mission Athena is designed for imaging and spectroscopy over a large field of view, and high count rate observations up to and beyond 1 Crab source intensity. The other focal plane instrument, the cryogenic X-IFU camera, is designed for high-spectral resolution imaging. Both cameras share alternately a mirror system based on silicon pore optics with a focal length of 12 m and unprecedented large effective area of about 1.4 m2 at 1 keV. The WFI instrument employs DEPFET active pixel sensors, which are fully depleted, back-illuminated silicon devices of 450 μm thickness. These provide high quantum efficiency over the 0.2 keV to 15 keV range with state-of-the art spectral resolution and extremely fast readout speeds compared to previous generations of Si detectors for X-ray astronomy. The sensors are controlled and read out by customized ASICs developed for this project. The focal plane comprises a Large Detector Array (LDA) with over 1 million pixels of 130 μm × 130 μm size, providing oversampling of the PSF by a factor