Spontaneous generation of temperature anisotropy in a strongly coupled magnetized plasma

Abstract

A magnetic field was recently shown to enhance field-parallel heat conduction in a strongly correlated plasma whereas cross-field conduction is reduced. Here we show that in such plasmas, the magnetic field has the additional effect of inhibiting the isotropization process between field-parallel and cross-field temperature components, thus leading to the emergence of strong and long-lived temperature anisotropies when the plasma is locally perturbed. An extended heat equation is shown to describe this process accurately.

Reduction of electron heating by magnetizing ultracold neutral plasma

“…The spontaneously generated temperature anisotropy, will relax at a rate that depends on the coupling strength Γ and the magnetic field strength β [10][11][12]. Recent results [27] (for the one component plasma) suggest that for a coupling strength of Γ = 0.1 and magnetic field strength of β = 100, the temperature isotropization time is ∼ 10 6 ω −1 pe .…”

“…Eventually this anisotropy relaxes, and heating also occurs in the perpendicular directions. However, if the magnetic field is strong enough, the relaxation can be dramatically suppressed [8][9][10][11][12], and may be delayed long enough that measurements could be made before heating occurs in the perpendicular directions. This may increase the effective Coulomb coupling strength, Γ as measured in terms of the kinetic temperature.…”

“…At the density n 10 8 cm −3 relevant to UCPs, β e = 1 if B = 32 G. A much more substantial reduction in transverse DIH is observed for β e > ∼ 10 (corresponding to B > ∼ 320 G). Previously, Glinsky et al [8], Dubin et al [10,11] and Ott et al [12] have shown that the long lived temperature anisotropy can be maintained for β > 1 in weakly, moderately and strongly coupled plasmas, respectively. Recently, Baalrud et al has provided the temperature anisotropy relaxation rates ranging from weak to strong coupling strength regime and for magnetic field strength β ranging from 0 to 100 using MD simulations [27].…”

Permutation-blocking path-integral Monte Carlo approach to the static density response of the warm dense electron gas

“…Naturally, in the linear response regime both ways to obtain χ(q) are equal. For completeness, we mention that the dynamic response can be obtained in a similar fashion by considering explicitly time dependent perturbations, e.g., using non-equilibrium Green function techniques [82,83] for quantum systems or molecular dynamics [84,85] in the classical case.…”

Dynamic structure factor of the magnetized one-component plasma: crossover from weak to strong coupling

“…Examples range from ions in warm dense matter [1,2] (solid densities), ultra cold neutral [3] and nonneutral plasmas [4] (mK temperatures), to complex (or dusty) plasmas [5] (highly charged dust particles). Recent experimental advances in the magnetic confinement of ultra cold neutral plasmas [6], high energy density matter [7], and dusty plasmas [8][9][10][11], as well as theoretical efforts concerning, e.g., the stopping power [12][13][14][15] and transport coefficients [16][17][18][19][20][21][22][23][24] demonstrate growing interest in the physics of magnetized strongly correlated plasmas-conditions relevant to the outer layers of neutron stars [25][26][27][28][29], confined antimatter [30,31], or magnetized target fusion [32,33]. In this challenging regime, the familiar theory of Braginskii [34] is no longer applicable, and new theoretical concepts as well as first-principle simulations are required.…”