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It is important to consider a combination of inhomogeneities, which drive and/or damp instabilities
in magnetized plasmas. The inhomogeneity of neutral particle density is taken into account for
analyzing turbulent states in linear devices by combining two kinds of simulations in this research.
One is a simulation for 2D profiles of neutral particles and the other is that for resistive drift wave
turbulence. Radial and axial profiles of neutral particles are calculated by the Monte Carlo method
with a configuration of linear device PANTA. The ratio for ionization of neutral particles depends
on the electron temperature, and the higher temperature in the operation range makes the neutral
density smaller near the center of the plasma. Then, the radial profile of the ion-neutral collision
frequency is set by introducing these neutral density profiles into resistive drift wave turbulence
simulations. Smaller ion-neutral collision frequency makes the instabilities more unstable, and its
inhomogeneity enhances mean electrostatic potential formation. The eigenmode structure is
changed with the inhomogeneous ion-neutral collision frequency, and convective derivative nonlinearity
generates the azimuthal flow near the center of the plasma. Two roles of the neutral particles
on the turbulence, the direct change in linear instabilities and formation of background flows,
become clear.
Turbulence simulation taking account of inhomogeneity of neutral density in linear devices
