Plasma density turbulence obtained from a Hasegawa-Wakatani drift-wave turbulence model within the BOUT++ framework

A Hasegawa-Wakatani drift-wave turbulence model [1] within the BOUT++ framework [2] was used to generate a set of turbulent plasma density profiles. Drift-wave turbulence is thought to be the dominant mechanism responsible for the anomalous transport observed in the edge of tokamak plasmas.

The motivation to generate this rather large set of density profiles was to properly study the influence of plasma density fluctuations on traversing microwaves which requires ensemble-averaging to get statistically relevant results.

The density data is given in normalized units (1.0 would correspond to 100 % fluctuation degree) on a mean-free background and the spatial coordinates are given in units of the ion Larmor radius.

The form of equations used was the un-modified Hasegawa-Wakatani model [3]. Input parameters were kappa = 1.0 (normalised background density gradient), alpha = 0.5 (adiabaticity parameter), and diffusion constant D=1e-2.

1. Wakatani, M., Hasegawa, A. (1984). A collisional drift wave description of plasma edge turbulence. Phys. Fluids 27(3), 611. doi:10.1063/1.864660
2. Dudson, B. et al. (2009). BOUT++: A framework for parallel plasma fluid simulations. Comp. Phys. Comm. 180(9), 1467. doi:10.1016/j.cpc.2009.03.008
3. Numata, R., Ball, R., & Dewar, R. L. (2007). Bifurcation in electrostatic resistive drift wave turbulence. Phys. Plasmas 14(10), 102312. doi:10.1063/1.2796106