Physics of Plasmas | 2019
Electron temperature gradient turbulence induced energy flux in the large volume plasma device
Abstract
The Large Volume Plasma Device (LVPD) has successfully demonstrated excitation of the Electron Temperature Gradient (ETG) driven turbulence in the finite plasma beta ( β ∼ 0.06 − 0.4) condition, where the threshold condition for ETG turbulence is, η ETG = L n / L T > 2 / 3 satisfied, where, L n = 1 n dn dx − 1 is the density scale length and L T e = 1 T e d T e dx − 1 is the temperature scale lengths [Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. The observed mode follows wave vector scaling and frequency ordering as k ⊥ ρ e ≤ 1 ≪ k ⊥ ρ i , Ω i 2 / 3 satisfied, where, L n = 1 n dn dx − 1 is the density scale length and L T e = 1 T e d T e dx − 1 is the temperature scale lengths [Mattoo et al., Phys. Rev. Lett. 108, 255007 (2012)]. The observed mode follows wave vector scaling and frequency ordering as k ⊥ ρ e ≤ 1 ≪ k ⊥ ρ i , Ω i < ω ≪ Ω e, where k ⊥ is the perpendicular wave vector, ρ e , ρ i are Larmor radii of the electron and ion, respectively, and Ω i , Ω e , ω are the ion, electron gyro frequencies and the mode frequency, respectively. Simultaneous measurement of fluctuations in electron temperature, δ T e ∼ ( 10 − 30 ) %, plasma density, ...