Correction of radiation-induced charge transfer inefficiency in CCDs for the SMILE mission

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The Solar Wind Magnetosphere Ionosphere Link Explorer (SMILE) mission will investigate the dynamic response of the Earth's magnetosphere under the impact of the solar wind and geomagnetic variations. Due for launch in 2021, the mission will use a combination of soft X-ray imaging of the Earth's magnetopause and magnetosphere cusps alongside UV imaging of the Northern Aurora. As part of a collaboration between ESA and the Chinese Academy of Sciences, the UK is leading the Soft X-ray Imager (SXI), baselined to use a focal plane of two e2v CCDs.The Centre for Electronic Imaging (CEI) has a key role in the SXI, leading the detector development, testing and performance verification. The CEI has very strong collaborative links with e2v technologies and extensive experience in testing, development and optimisation of e2v CCDs for past and present missions such as Gaia and Euclid. This strong collaboration will continue to the benefit of the SMILE SXI focal plane development.The CEI and its group leader, Prof. Andrew Holland, have successfully trained a large number of STFC CASE students, all of whom have moved directly into employment following completion of their studies, be that with the space agencies (ESA and NASA), e2v technologies, local and national related industries, or continuing in academia (both inside the CEI and at other universities).The CCDs used for the SMILE SXI will suffer from radiation damage in-orbit, creating traps in the silicon, potentially removing signal and smearing the images with every pixel-to-pixel transfer, which is particularly serious with the use of a detector of this size, requiring a maximum of over 9000 pixel-to-pixel transfers. The degradation of the X-ray spectra will require precise correction to allow spectral lines to be resolved; this will be achieved through software developed by the CEI, as a key part of their role in the mission, that must be ready for post-launch operation. A new understanding of charge storage dynamics and studies of radiation-induced traps are essential towards the creation of effective correction algorithms for the SMILE SXI to remove the smearing and achieve the required spectral resolution.The student will begin by bringing together the new understanding of charge storage with the new developments in the dynamics of traps in silicon. Taking this forwards with their own device simulations, laboratory experiments and bespoke model code, alongside a new and thorough analysis of the impact of noise sources on the correction, the student will develop charge transfer inefficiency correction algorithms towards the SMILE SXI. The student will work with the post-doctoral researchers that implemented the initial research. The techniques developed will open up new ideas and methodologies for other missions, such as PLATO and Euclid. Through the collaboration with e2v, the student will benefit from access to training, facilities and expertise that are not available within a purely academic setting