Plasma flow in a linear magnetized plasma

We have been investigating the drift wave turbulence in the linear magnetized plasma. To realize the fully developed drift wave turbulence in the device, the ion-neutral collision frequency has to be less than the threshold value by reducing the neutral density and/or by increasing the ionization ratio from the MHD simulation. The Monte Carlo simulation has shown that the Mach number, M, and the electron temperature, T_e, affect the neutral density profile. When T_e is low, the neutral density, n_n, depends on M. The baffle plate increases (decreases) the neutral density if M is below (above) the critical value. When T_e is high, the ionization rate rises and the neutral density does not strongly depend on M. The electron density has a hollow profile under the present experimental condition. Based on the unmagnetized kinetic model, M was 0.3 (up stream) ∼ 0.6 (near end-plate). This was higher than the critical value in the calculation where the baffle plate becomes effective. The measured ion and neutral temperatures were T_i ≈ 0.6 eV and T_n ≤ 0.2 eV, respectively. More precise measurements on T_e, T_i, and T_n, as well as enhanced neutral pumping, will be performed for the control of the neutral density distribution to excite the drift wave turbulence.