Biomedical subjects

F Jenko

Publications and source records attributed to F Jenko.

2 recordsLinked to original sources

PubMed2002

Prediction of significant tokamak turbulence at electron gyroradius scales.

The experimental conditions under which tokamak turbulence at hyperfine (electron gyroradius) scales is predicted to be significant and observable are described. The first quantitative predictions of fluctuation amplitudes, spectral features, and the associated electron energy transport are presented. A novel theoretical model which quantitatively describes the boundaries of the high-amplitude streamer transport regime is presented and shown to explain the gyrokinetic simulation results. This model uniquely includes consideration of two distinct secondary instabilities.

Journal Article↗

PubMed2000

Electron temperature gradient turbulence.

The first toroidal, gyrokinetic, electromagnetic simulations of small scale plasma turbulence are presented. The turbulence considered is driven by gradients in the electron temperature. It is found that electron temperature gradient (ETG) turbulence can induce experimentally relevant thermal losses in magnetic confinement fusion devices. For typical tokamak parameters, the transport is essentially electrostatic in character. The simulation results are qualitatively consistent with a model that balances linear and secondary mode growth rates. Significant streamer-dominated transport at long wavelengths occurs because the secondary modes that produce saturation become weak in the ETG limit.

Journal Article↗