Nonlinear lower hybrid modeling in tokamak plasmas

F. Napoli, C. Castaldo, R. Cesario, G. Schettini

Research output: Contribution to conferencePaper

1 Citation (Scopus)

Abstract

We present here new results concerning the nonlinear mechanism underlying the observed spectral broadening produced by parametric instabilities occurring at the edge of tokamak plasmas in present day LHCD (lower hybrid current drive) experiments. Low frequency (LF) ion-sound evanescent modes (quasi-modes) are the main parametric decay channel which drives a nonlinear mode coupling of lower hybrid (LH) waves. The spectrum of the LF fluctuations is calculated here considering the beating of the launched LH wave at the radiofrequency (RF) operating line frequency (pump wave) with the noisy background of the RF power generator. This spectrum is calculated in the frame of the kinetic theory, following a perturbative approach. Numerical solutions of the nonlinear LH wave equation show the evolution of the nonlinear mode coupling in condition of a finite depletion of the pump power. The role of the presence of heavy ions in a Deuterium plasma in mitigating the nonlinear effects is analyzed. © 2014 AIP Publishing LLC.
Original languageEnglish
DOIs
Publication statusPublished - 2014
Externally publishedYes
Event20th Topical Conference on Radiofrequency Power in Plasmas - , Italy
Duration: 1 Jan 2014 → …

Conference

Conference20th Topical Conference on Radiofrequency Power in Plasmas
CountryItaly
Period1/1/14 → …

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All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Napoli, F., Castaldo, C., Cesario, R., & Schettini, G. (2014). Nonlinear lower hybrid modeling in tokamak plasmas. Paper presented at 20th Topical Conference on Radiofrequency Power in Plasmas, Italy. https://doi.org/10.1063/1.4864585