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Title: 140 GHz EC waves propagation and absorption for normal/oblique injection on FTU tokamak

Abstract

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.

Authors:
; ; ; ; ; ; ; ; ;  [1]; ; ; ;  [2]
  1. IFP, Ass. EURATOM-ENEA-CNR, Via R. Cozzi 53, 20125 Milano (Italy)
  2. CRE Frascati, Ass. EURATOM-ENEA-CNR, Via E. Fermi 45, 00044 Frascati, Roma (Italy)
Publication Date:
OSTI Identifier:
21210464
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 485; Journal 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); Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANTENNAS; ECR HEATING; ELECTRON TEMPERATURE; ELECTRONS; ENERGY ABSORPTION; FT TOKAMAK; GHZ RANGE; ION TEMPERATURE; PLASMA; PLASMA DIAGNOSTICS; PLASMA RADIAL PROFILES; POWER DENSITY; SPATIAL RESOLUTION; WAVE PROPAGATION

Citation Formats

Nowak, S., Airoldi, A., Bruschi, A., Cirant, S., Gandini, F., Granucci, G., Lazzaro, E., Ramponi, G., Simonetto, A., Sozzi, C., Buratti, P., Panaccione, L., Tudisco, O., and Zerbini, M. 140 GHz EC waves propagation and absorption for normal/oblique injection on FTU tokamak. United States: N. p., 1999. Web. doi:10.1063/1.59677.
Nowak, S., Airoldi, A., Bruschi, A., Cirant, S., Gandini, F., Granucci, G., Lazzaro, E., Ramponi, G., Simonetto, A., Sozzi, C., Buratti, P., Panaccione, L., Tudisco, O., & Zerbini, M. 140 GHz EC waves propagation and absorption for normal/oblique injection on FTU tokamak. United States. doi:10.1063/1.59677.
Nowak, S., Airoldi, A., Bruschi, A., Cirant, S., Gandini, F., Granucci, G., Lazzaro, E., Ramponi, G., Simonetto, A., Sozzi, C., Buratti, P., Panaccione, L., Tudisco, O., and Zerbini, M. Mon . "140 GHz EC waves propagation and absorption for normal/oblique injection on FTU tokamak". United States. doi:10.1063/1.59677.
@article{osti_21210464,
title = {140 GHz EC waves propagation and absorption for normal/oblique injection on FTU tokamak},
author = {Nowak, S. and Airoldi, A. and Bruschi, A. and Cirant, S. and Gandini, F. and Granucci, G. and Lazzaro, E. and Ramponi, G. and Simonetto, A. and Sozzi, C. and Buratti, P. and Panaccione, L. and Tudisco, O. and Zerbini, M.},
abstractNote = {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.},
doi = {10.1063/1.59677},
journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 485,
place = {United States},
year = {1999},
month = {9}
}