Wide-Field Imager (WFI)
|NOTE: In March 2011 ESA announced a new way forward for the L-class candidate missions: IXO, EJSM-Laplace and LISA.|
At this time the IXO concept ceased to be a candidate and ESA, along with the scientific community, is now investigating to what extent a European-led mission could preserve the original science case of IXO. The new study is called ATHENA (Advanced Telescope for High ENergy Astrophysics).
The IXO Wide Field Imager (WFI) is an imaging X-ray spectrometer with a large field of view (18x18 arcmin²). The purpose of the WFI is to provide images in the energy band 0.1 - 15 keV, simultaneously with spectrally and time resolved photon counting.
The device consists of a silicon array of individually accessed DEPFET (Depleted p-channel FET) active pixels integrated onto a common silicon bulk. Based on the principle of sideways depletion, these devices combine the advantages of sideway depleted silicon detectors with new benefits arising from the innovative DEPFET concept. Low-noise operation is an important aspect of the instrument. The detectors will operate at about 210K with the associated electronics running at room temperature.
The WFI is based on well-developed technology which is currently being space qualified. A WFI-type instrument will be flown on ESA's BepiColombo spacecraft – the flight model is currently under construction – and on the French/Italian Simbol-X spacecraft. Future evolution of the WFI concept requires the development of a specific design compatible with the IXO payload configuration and to demonstrate that a full wafer sensor can be used. In addition, further work is planned for the proximity electronics, in particular in developing faster ASICs.
Last Update: 07 February 2012