Abstract
This paper studies the broadening of the injected rf line in the frequency spectra detected during the lower hybrid (LH) experiment in Asdex. The parametric decay instabilities (PDI) and the scattering due to density fluctuations as possible causes of the broadening are considered. The analysis of the parametric dispersion relation shows that parametric instabilities driven by ion-sound quasimodes have the highest growth rates, but their rf power threshold is higher than the rf power available in the experiment. This was confirmed by the negative results of the measurements performed to detect the presence of PDI. Measurements of the density fluctuation behaviour during rf power injection were also carried out. The results obtained from observations made with a microwave reflectometer and a Langmuir probe show a correlation of the fluctuations in the scrape-off plasma with the line broadening.
Citation Formats
Cesario, R, Bartiromo, R, Cardinali, A, Paoletti, F, Pericoli-Ridolfini, V, and Schubert, R.
Density fluctuations and spectral broadening during lower hybrid current drive experiment on ASDEX.
Italy: N. p.,
1991.
Web.
Cesario, R, Bartiromo, R, Cardinali, A, Paoletti, F, Pericoli-Ridolfini, V, & Schubert, R.
Density fluctuations and spectral broadening during lower hybrid current drive experiment on ASDEX.
Italy.
Cesario, R, Bartiromo, R, Cardinali, A, Paoletti, F, Pericoli-Ridolfini, V, and Schubert, R.
1991.
"Density fluctuations and spectral broadening during lower hybrid current drive experiment on ASDEX."
Italy.
@misc{etde_10147367,
title = {Density fluctuations and spectral broadening during lower hybrid current drive experiment on ASDEX}
author = {Cesario, R, Bartiromo, R, Cardinali, A, Paoletti, F, Pericoli-Ridolfini, V, and Schubert, R}
abstractNote = {This paper studies the broadening of the injected rf line in the frequency spectra detected during the lower hybrid (LH) experiment in Asdex. The parametric decay instabilities (PDI) and the scattering due to density fluctuations as possible causes of the broadening are considered. The analysis of the parametric dispersion relation shows that parametric instabilities driven by ion-sound quasimodes have the highest growth rates, but their rf power threshold is higher than the rf power available in the experiment. This was confirmed by the negative results of the measurements performed to detect the presence of PDI. Measurements of the density fluctuation behaviour during rf power injection were also carried out. The results obtained from observations made with a microwave reflectometer and a Langmuir probe show a correlation of the fluctuations in the scrape-off plasma with the line broadening.}
place = {Italy}
year = {1991}
month = {Nov}
}
title = {Density fluctuations and spectral broadening during lower hybrid current drive experiment on ASDEX}
author = {Cesario, R, Bartiromo, R, Cardinali, A, Paoletti, F, Pericoli-Ridolfini, V, and Schubert, R}
abstractNote = {This paper studies the broadening of the injected rf line in the frequency spectra detected during the lower hybrid (LH) experiment in Asdex. The parametric decay instabilities (PDI) and the scattering due to density fluctuations as possible causes of the broadening are considered. The analysis of the parametric dispersion relation shows that parametric instabilities driven by ion-sound quasimodes have the highest growth rates, but their rf power threshold is higher than the rf power available in the experiment. This was confirmed by the negative results of the measurements performed to detect the presence of PDI. Measurements of the density fluctuation behaviour during rf power injection were also carried out. The results obtained from observations made with a microwave reflectometer and a Langmuir probe show a correlation of the fluctuations in the scrape-off plasma with the line broadening.}
place = {Italy}
year = {1991}
month = {Nov}
}