@inproceedings{33f4c9a14b9e426c8fc4fe937ae48e3f,
title = "Analysis of the spectral width and validation of the LHBEAM code",
abstract = "A crucial point of the theoretical study of lower-hybrid (LH) current drive in a tokamak plasma is the spectral gap problem, i.e., the fact that the parallel (to the magnetic field) refractive index spectrum generated at the plasma edge does not appear to be wide enough for the interaction of the wave with a large number of electrons. This is in contrast with experimental observations. Diffraction is one of the mechanisms that can lead to the observed wave spectrum broadening and solve the spectral gap problem. For this reason, a new beam tracing code, LHBEAM, has been developed in order to study the diffraction effects on the propagation and the absorption of LH waves in tokamak plasma. In this work, the parallel spectral width is addressed on the basis of the beam tracing approximate solution. A preliminary implementation of the results is done in LHBEAM which has been also compared with the ray tracing code C3PO for the assessment of the trajectory of the central ray and of the evolution of the parallel refractive index on this ray.",
keywords = "current drive, diffraction, lower hybrid waves, spectral gap, spectral width",
author = "N. Bertelli and O. Maj and E. Poli and Pereverzev, \{G. V.\} and Y. Peysson and J. Decker",
note = "Publisher Copyright: {\textcopyright} 2008 American Institute of Physics.; Joint Varenna-Lausanne International Workshop on Theory of Fusion Plasmas ; Conference date: 25-08-2008 Through 29-08-2008",
year = "2008",
doi = "10.1063/1.3033710",
language = "English (US)",
series = "AIP Conference Proceedings",
publisher = "American Institute of Physics Inc.",
pages = "259--264",
editor = "Olivier Sauter and Elio Sindoni and Xavier Garbet",
booktitle = "Theory of Fusion Plasmas - Joint Varenna-Lausanne International Workshop",
}