Improvement of the Gyrotron TH 1506B for Tore Supra
R.Magne(a), S. Alberti(b),
A. Arnold(d), D. Bariou(c), F. Bouquey(a), J.
Clary(a), C. Darbos(a), J.P. Hogge(b), M. Jung(a),
R. Lambert(a), F.Legrand(c), M. Lennholm(a),
C. Liévin(c), D. Roux(a), M. Thumm(d)
(a) Association Euratom-CEA: francis.bouquey@cea.fr, jacques.clary@cea.fr, caroline.darbos@cea.fr, marc.jung@cea.fr , renaud.lambert@cea.fr , morten.lennholm@cea.fr , roland.magne@cea.fr , daniel.roux@cea.fr
(b) Association Euratom-Confédération Suisse : stefano.alberti@epfl.ch , jean-philippe.hogge@epfl.ch
(d) Association Euratom-FZK: andreas.arnold@ihm.fzk.de , Manfred.Thumm@ihm.fzk.de
Corresponding author: R.Magne, Association Euratom-CEA, CEA/DSM/DRFC, CEA-Cadarache, 13108 Saint Paul Lez Durance Cedex, France, phone: (33) 4 42 25 62 81, fax: (33) 4 42 25 62 33
The ECRH system of Tore Supra is
based on six 118 GHz gyrotrons delivering 400 kW RF power in long pulses ( 600
s) .
The first generation of TH 1506B
Gyrotron has achieved three years ago 500 kW
5 s and 350 kW 111 s during the long pulse tests in Cadarache. The pulse duration was limited by a fast increase of ion pump currents,
starting 60 s after the
beginning of pulse.
The major limitation was due to the overheating of some internal parts of the tube, explained by the deposited radiated power and insufficient cooling, leading to an excessive pressure. An other important limitation was due to the existence of spurious oscillations appearing at the gyrotron output, due to the geometry of the launcher.
The contribution will first present
the observed limitations and the analysis which has been made, then describe
the solutions defined in a collaborative effort between Thales Electron
Devices, Association Euratom-Confédération Suisse, Association Euratom-FZK and
Association Euratom-CEA.
A new gyrotron has been build according to this new design. The contribution will also present the results obtained during the factory acceptance tests of this second series gyrotron at 500 kW, 5 s before the long pulse (up to 600 s) site tests which have to be made in Cadarache during year 2004.