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Abstract

Synchrotron radiation losses become significant in the power balance of high-temperature plasmas envisaged for next step tokamaks. Due to the complexity of the exact calculation, these losses are usually roughly estimated with expressions derived from a plasma description using simplifying assumptions on the geometry, radiation absorption, and density and temperature profiles.

In the present article, the complete formulation of the transport of synchrotron radiation is performed for realistic conditions of toroidal plasma geometry with elongated cross-section, using an exact method for the calculation of the absorption coefficient, and for arbitrary shapes of density and temperature profiles. The effects of toroidicity and temperature profile on synchrotron radiation losses are analysed in detail. In particular, when the electron temperature profile is almost flat in the plasma centre, as for example in ITB confinement regimes, synchrotron losses are found to be much stronger than in the case where the profile is represented by its best-generalized parabolic approximation, though both cases give approximately the same thermal energy contents. Such an effect is not included in present approximate expressions.

Finally, we propose a seven-variable fit for the fast calculation of synchrotron radiation losses. This fit is derived from a large database, which has been generated using a code implementing the complete formulation and optimised for massively parallel computing.

Additional information

Authors: ALBAJAR F, Association Euratom-C.E.A. Departement de Recherches sur la Fusion Controlee.;JOJNER J, Association Euratom-C.E.A. Departement de Recherches sur la Fusion Controlee.;GRANATA G, Association Euratom-C.E.A. Departement de Recherches sur la Fusion Controlee.
Bibliographic Reference: Report: EUR-CEA-FC-1702 (2000) 16pp., Euro: FREE of charge
Availability: Available from European Commission, DG XII Communication Unit rue de la Loi/Wetstraat 200, B-1049 Bruxelles (BE) Tel: +32-2-2950001 Fax:+32-2-2958220 email: rtd-info@ec.europa.eu
ISBN: ISBN Not available
Record Number: 200012913 / Last updated on: 2000-12-18
Category: PUBLICATION
Original language: en
Available languages: en
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