Sep 12 – 17, 2021
University of Birmingham
Europe/London timezone

Modelling CTI effects in irradiated Gaia CCDs

Sep 15, 2021, 10:25 AM
Teaching and Learning Building (University of Birmingham)

Teaching and Learning Building

University of Birmingham

Edgbaston Campus University of Birmingham B15 2TT UK


Saad Ahmed


The European Space Agency’s Gaia spacecraft was launched in 2013 and has been in operation ever since. It has a focal plane of 106 Charge-Coupled Devices (CCDs) which are of the CCD91-72 variant, custom-designed by Teledyne e2v. The detectors have been making measurements of parallaxes, positions, velocities, and other physical properties of over one billion stars and other astronomical objects in the Milky Way. Whilst operating in space, CCDs undergo non-ionizing displacement damage from incoming radiation. This causes radiation induced defects to form in the silicon lattice which can trap electrons during readout and increase the charge transfer inefficiency (CTI) of the devices. From analysis of in-flight calibration data, Gaia’s CTI values have been measured to be much lower than what was expected based on the on-ground pre-flight tests.

In this study, the CTI and trap landscape in both in-flight and irradiated on-ground devices are modelled to fit the new datasets. These results provide more insights into the nature of radiation damage and the resulting trap landscapes, both in space and from on-ground irradiations.

Nationality Irish
Institute The Open University
Your name Saad Ahmed
Title Mr

Primary authors

Saad Ahmed David Hall Jesper Skottfelt (Open University) Cian Crowley (ESA/ESAC) Ben Dryer (The Open University) Mr Jose Hernandez (ESA) Andrew Holland (The Open University)

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