5-9 September 2016
Prague Congress Centre
Europe/Prague timezone

O4A.1 Response of the imaging cameras to hard radiation during JET operation

8 Sep 2016, 11:00
20m
Forum Hall 2nd floor (Prague Congress Centre)

Forum Hall 2nd floor

Prague Congress Centre

5. května 65, Prague, Czech Republic
Board: 1
Oral D. Diagnostics, Data Acquisition and Remote Participation O4A

Speaker

Alexander Huber (Forschungszentrum Jülich GmbH)

Description

In magnetic fusion devices of the next generation such as ITER, high neutron and gamma-ray yields could be detrimental to the applied diagnostic equipment such as video imaging systems as well as to electronic components of machine control systems. Semiconductors devices are particularly sensitive to the radiation, both ionizing (formation of traps at the Si/SiO2 interface with energy levels within the silicon bandgap) and non-ionizing (displacement damage effects). Defects degrade the performance of CCD image sensors by increasing the average dark-current and dark-current non-uniformity, which result in the appearance of individual pixels with high dark-currents (“hot-pixels”). The main objective of this contribution is to summarize the experience of camera operation acquired during the D-D experimental campaigns on the JET machine. The analysis of the radiation damage of imaging systems is based on all different types of analogue/digital cameras with uncooled as well as actively cooled image sensors in the VIS/NIR/MWIR spectral ranges. MCNP code has been used to determine the neutron fluence and energy distribution at different camera locations in JET. An explicit correlation between the sensor damage and the neutron fluence has been observed. Sensors show an increased dark-current and increased numbers of hot-pixels. Uncooled cameras must be replaced once per year after exposure to a neutron fluence of ~1.9-3.2×101212neutrons/cm22. Such levels of fluence will be reached after ≈14-22 ELMy H-mode pulses (reference #74176(4.5MA/3.6T, PNBI=25MW/tNBI=6s) during the future D-T campaign. Furthermore, dynamical noise seen as a random pattern of bright pixels was observed in the presence of hard radiation (neutrons and gammas). Failure of the digital electronics inside the cameras as well as of industrial controllers is observed beyond a neutron fluence of about ~4×109 9 neutrons/cm22. The impact of hard radiation on the different types of electronics and possible application of cameras during future D-T campaign will be discussed.

Co-authors

Alberto Milocco (University of Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy) Alexander Huber (Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), Jülich, Germany) Christian Linsmeier (Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), Jülich, Germany) David Kinna (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Gennady Sergienko (Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), Jülich, Germany) Guy Matthews (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Horst Lambertz (Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), Jülich, Germany) Itziar Balboa (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Klaus-Dieter Zastrow (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Laurent Mercadier (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Philippe Mertens (Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung – Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), Jülich, Germany) Scott Silburn (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Sean Conroy (Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden) Sergey Popovichev (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Simon Cramp (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Uron Kruezi (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom) Valentina Huber (Forschungszentrum Jülich GmbH, Supercomputing Centre, 52425 Jülich, Germany) Vasili Kiptily (CCFE, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom)

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