Isotope mass and charge effects in tokamak plasmas
Artikel i vetenskaplig tidskrift, 2011

The effect of primary ion species of differing charge and mass - specifically, deuterium, hydrogen, and helium - on instabilities and transport is studied in DIII-D plasmas through gyrokinetic simulations with GYRO [J. Candy and E. Belli, General Atomics Technical Report No. GA-A26818, 2010]. In linear simulations under imposed similarity of the profiles, there is an isomorphism between the linear growth rates of hydrogen isotopes, but the growth rates are higher for Z > 1 main ions due to the appearance of the charge in the Poisson equation. On ion scales the most significant effect of the different electron-to-ion mass ratio appears through collisions stabilizing trapped electron modes. In nonlinear simulations, significant favorable deviations from pure gyro-Bohm scaling are found due to electron-to-ion mass ratio effects and collisions. The presence of any non-trace impurity species cannot be neglected in a comprehensive simulation of the transport; including carbon impurity in the simulations caused a dramatic reduction of energy fluxes. The transport in the analyzed deuterium and helium discharges could be well reproduced in gyrokinetic and gyrofluid simulations while the significant hydrogen discrepancy is the subject of ongoing investigation.

gyrokinetic simulations

tokamak

transport analysis

isotope scaling

microinstabilities

turbulent transport

Författare

Istvan Pusztai

Chalmers, Teknisk fysik, Nukleär teknik

Jeff Candy

General Atomics

P. Gohil

General Atomics

Physics of Plasmas

1070-664X (ISSN) 1089-7674 (eISSN)

Vol. 18 122501- 122501

Drivkrafter

Hållbar utveckling

Styrkeområden

Energi

Ämneskategorier

Fusion, plasma och rymdfysik

DOI

10.1063/1.3663844