Dispersion and Cyclotron Damping of Pure Ion Bernstein Waves

“Reduced” multidimensional Vlasov simulations, with applications to electrostatic structures in space plasmas

“…Figure 2 shows the Fourier spectrum of perpendicular electric field ͉E y ͑k z , k y ͉͒ from a run spanning 20 ion gyroperiods ͑2 / ⍀ i ͒ with m i = 100m e and ⍀ i = i / 2. In frame a, the intensity maxima in the versus k y spectrum for k z =0 show good agreement with the dispersion curves for pure ion-Bernstein waves 16 for the first six branches of the dispersion relation ͑dashed white curves͒. In particular, the first Bernstein mode approaches =2⍀ i as k y → 0, as expected.…”

“…This algorithm is based on the qualitative agreement found between the multiple dispersion curves resulting from a linear analysis of the evolution equations and the exact kinetic dispersion relation for "pure" Bernstein modes ͑i.e., k z =0 dispersion͒ in a Maxwellian plasma. 16 The previous analysis revealed that optimal agreement required the ring of modes in the reduced algorithm to have a perpendicular velocity v Ќ that was larger by a factor of ͱ 2 than the perpendicular thermal velocity of the target Maxwellian ͑i.e., a factor of 2 in T Ќ ͒. An analysis of this algorithm, which accounts for the scaling of the effective perpendicular temperature, is provided below.…”

Direct observation of plasma dielectric motion

“…In order of increasing A,,-, the two zeros correspond to the electrostatic ioncyclotron wave (EICW) and the neutralized ion Bernstein wave (NIBW). 5 Figure 1(b) shows the normalized mobility M for the same parameters as in Fig. 1 (a) and indicates that there are currents transverse to both the EICW and the NIBW.…”

Dynamic small-scale self-focusing of a femtosecond laser pulse

“…A substantial fraction of the power launched by the external antenna can be mode converted into IB waves near ion-ion hybrid resonances (or, in a single species plasma, near the first harmonic of the IC frequency ω = 2Ω ci ); it is therefore important to know how this power is finally deposited in the plasma. The properties of IB waves have been intensively studied with different techniques, including analytic and numerical solution of the local dispersion relation [5][6][7], ray tracing in toroidal geometry [8][9][10][11] and the solution of integrodifferential wave equations valid to all orders in the ion Larmor radius in plane stratified geometry [12,13]. Here, we investigate absorption of these waves by electron Landau damping, in view, in particular, of improving the accuracy of power deposition profiles evaluated by full wave numerical codes which solve the wave equations for IC waves in toroidally confined plasmas.…”