Mirror mode: A superconducting space plasma analogue


We re-examine the physics of the mirror mode in its final state of saturation, the thermodynamic equilibrium, to demonstrate that the mirror mode is the analogue of a superconducting effect in a classical anisotropic-pressure space plasma. Two different spatial scales are identified which control the behaviour of its evolution. These are the ion inertial scale λ_im(τ) based on the excess density N_m(τ) generated in the mirror mode, and the Debye scale λ_D(τ). The Debye length plays the role of the correlation length in superconductivity. Their dependence on the critical temperature ratio τ = T∥/T⊥ < 1 is given. The mirror mode equilibrium structure under saturation is determined by the Landau-Ginzburg ratio κ_D = λ_im/λ_D or κ_ρ = λ_im/ρ depending on whether the Debye length or the thermal-ion gyroradius ρ serve as correlation lengths. Since in all space plasmas κ_D ≫ 1 always holds, space plasmas with λ_D as relevant correlation length behave like type II superconductors, naturally giving rise to chains of local depletions of the magnetic field of the kind observed in the mirror mode. In this way they provide the plasma a magnetic bubble texture. The problem becomes more subtle when ρ is taken as correlation length. In this case evolution of mirror modes is more restricted. Their existence implies that another threshold is exceeded.

Further Information
http://arxiv.org/abs/1804.10900 https://www.ann-geophys.net/36/1015/2018/
  author = {Treumann, R. A. and Baumjohann, W.},
  doi = {10.5194/angeo-36-1015-2018},
  journal = {arXiv:1804.10900 [physics.space-ph], Annales Geophysicae},
  language = {en},
  note = {12 pages, 2 figure, Discussion paper},
  pages = {1015-1026},
  title = {Mirror mode: A superconducting space plasma analogue},
  url = {http://arxiv.org/abs/1804.10900
  volume = {36},
  year = {2018},
%O Journal Article
%A Treumann, R. A.
%A Baumjohann, W.
%R 10.5194/angeo-36-1015-2018
%J arXiv:1804.10900 [physics.space-ph], Annales Geophysicae
%G en
%O 12 pages, 2 figure, Discussion paper
%P 1015-1026
%T Mirror mode: A superconducting space plasma analogue
%U http://arxiv.org/abs/1804.10900
%V 36
%D 2018