140 GHz EC waves propagation and absorption for normal/oblique injection on FTU tokamak
- IFP, Ass. EURATOM-ENEA-CNR, Via R. Cozzi 53, 20125 Milano (Italy)
- CRE Frascati, Ass. EURATOM-ENEA-CNR, Via E. Fermi 45, 00044 Frascati, Roma (Italy)
Most of the interest in ECRH experiments is linked to the high localization of EC waves absorption in well known portions of the plasma volume. In order to take full advantage of this capability a reliable code has been developed for beam tracing and absorption calculations. The code is particularly important for oblique (poloidal and toroidal) injection, when the absorbing layer is not simply dependent on the position of the EC resonance only. An experimental estimate of the local heating power density is given by the jump in the time derivative of the local electron pressure at the switching ON of the gyrotron power. The evolution of the temperature profile increase (from ECE polychromator) during the nearly adiabatic phase is also considered for ECRH profile reconstruction. An indirect estimate of optical thickness and of the overall absorption coefficient is given by the measure of the residual e.m. power at the tokamak walls. Beam tracing code predictions of the power deposition profile are compared with experimental estimates. The impact of the finite spatial resolution of the temperature diagnostic on profile reconstruction is also discussed.
- OSTI ID:
- 21210464
- Journal Information:
- AIP Conference Proceedings, Vol. 485, Issue 1; Conference: 13. topical conference on radio frequency power in plasmas, Annapolis, MD (United States), 12-14 Apr 1999; Other Information: DOI: 10.1063/1.59677; (c) 1999 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
Similar Records
High power heating of the FTU tokamak plasma at the fundamental electron cyclotron resonance of 140 GHz
The 110-GHz Electron Cyclotron Range of Frequency System on JT-60U: Design and Operation