||On the Radial Eigenmode Structure of Drift Wave Instability with Inhomogeneous Damping in Cylindrical Plasmas
Kasuya, N. ,
Sasaki, M. ,
Abe, S.Yagi, M.
Journal of the Physical Society of Japan
024501-5 , 2018-03 , The Physical Society of Japan
Plasma flows can be driven by turbulent stresses from excited modes in magnetized plasmas. Our recent numericalsimulation of resistive drift wave turbulence in a linear device has shown that the radial inhomogeneity of the neutraldensity affects azimuthal flow generation by changing the phase structure of the most unstable eigenmodes. Eigenmodeanalyses show that the mode structure has a complex Bessel-type function shape in the central region of the plasma, andthe imaginary part arises from the radial inhomogeneity of the damping term caused by ion-neutral collisions. Theamplitude of turbulent stress is proportional to the inhomogeneity under a marginally stable condition. Global structuralformation is an important factor for determining the plasma turbulent state, and this result clearly shows that severalkinds of radial background distributions, the plasma and neutral densities in this case, can influence the global structures.