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AbstractAbstract
[en] We describe and discuss the properties of two kinds of antenna installed in the TFR Tokamak. The first type of antenna is an array of 8 narrow radiating elements which could transfer 2 MW to the plasma. The second type is made of two much wider radiating elements located on the low field side of the Tokamak. Particular emphasis is given to the measurements of the coupling properties as a function of magnetic field, density, gas composition, frequency and distance between the antenna and the plasma. Both toroidal and radial eigen mode are clearly observed. They appear as a fast toroidal modes or slow radial modes variation of the loading resistance when the plasma density changes. Theses fluctuations disappear when a strong damping mechanism is established: hydrogen-deuterium hybrid resonance or second harmonic hydrogen resonance. The conditions of appearance of radial eigen-modes are found to agree precisely with the magnetosomic wave resonance. Current theory also correctly predicts the variation of the loading resistance with the distance between the antenna and the plasma. A rapid increase of the loading resistance with frequency is observed. The effect could not be related to the predictions of coupling theories
[fr]
On presente les proprietes de deux sortes d'antennes installees sur le TFR. Le premier type est un faisceau de huit elements rayonnants etroits qui peuvent transferer 2 MW au plasma. Le second type est fait de deux elements rayonnants plus larges limites au cote faible champ du tore. On a etudie specialement les proprietes de couplage en fonction du champ magnetique, de la densite, de la composition du gaz, de la frequence et de la distance antenne-plasma. Les modes propres toroidaux et radiaux sont clairement observes. Ils apparaissent comme modes toroidaux rapides ou modes radiaux lents en fonction de la densite du plasma. Ces fluctuations disparaissent lorsqu'une couche absorbante traverse le plasma: resonance hybride ion-ion dans un plasma de deuterium-hydrogene ou seconde resonance harmonique dans un plasma d'hydrogene pur. Les conditions d'apparition des modes radiaux suivent avec une grande precision les caracteristiques de l'onde magnetosonique. La theorie predit aussi correctement la variation de la resistance avec la distance antenne-plasma. La resistance de couplage semble croitre avec la puissance. On ne peut lier cet effet aux predictions des theories de couplageOriginal Title
Les antennes de chauffage cyclotronique ionique installees sur TFR. Caracteristiques generales et proprietes de couplage
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Sep 1981; 56 p
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