Electromagnetic turbulence in increased β plasmas in the Large Plasma Device. (9th August 2021)

• Record Type: Journal Article
• Authors: Rossi, G.D.; Carter, T.A.; Seo, B.; Robertson, J.; Pueschel, M.J.; Terry, P.W.
• Is Part Of: Journal of plasma physics. Volume 87:Number 4(2021)
• Publication Date: 2021-08-09
• Subjects: plasma waves -- plasma instabilities; Plasma (Ionized gases) -- Periodicals; 530.4405
• DOI: 10.1017/S0022377821000672
• Languages: English
• ISSNs: 0022-3778

Abstract

Abstract : The variation of pressure-gradient-driven turbulence with plasma $\beta$ (up to $\beta \approx 15\, \%$ ) is investigated in linear, magnetized plasma. The magnitude of magnetic fluctuations is observed to increase substantially with increasing $\beta$ . More importantly, parallel magnetic fluctuations are observed to dominate at higher $\beta$ values, with $\delta B_\parallel / \delta B_\perp \approx 2$ and $\delta B / B_0 \approx 1\, \%$ . Parallel magnetic fluctuations are strongly correlated with density fluctuations and the two are observed to be out of phase. The relative magnitude of and cross-phase between density and parallel magnetic field fluctuations are consistent with the dynamic pressure balance ($P+{B_{0}^2}/{2\mu _0} = \textrm {constant}$ ). A local slab model theory for electromagnetic, modified drift Alfvén waves, including parallel magnetic fluctuations, shows partial agreement with experimental observations.