Analytical nonlinear collisional dynamics of near-threshold eigenmodes. (27th February 2019)

• Record Type: Journal Article
• Authors: Duarte, V.N.; Gorelenkov, N.N.
• Is Part Of: Nuclear fusion. Volume 59:Number 4(2019:Apr.)
• Publication Date: 2019-02-27
• Subjects: nonlinear dynamics -- Alfvén wave -- wave instability -- mode saturation; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/ab0135
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: The nonlinear dynamics of isolated, near-threshold waves is studied in the presence of strong resonant particle scattering. In this limit, a simple closed-form analytical solution is found and compared with numerical simulations, which shows reasonable agreement when the wave evolves quasi-steadily to saturation, even for moderate tokamak-relevant collisionality levels. The solution can be useful in verifying codes that deal with Alfvénic instabilities and thermal plasma turbulence in fusion plasmas, as well as a rapid means for predicting and analyzing experimental outcome.