A Fast Omni-Directional Ion Detector for the Study of Space Plasmas

Abstract. Dispersive properties of linear and nonlinear MHD waves, including shear, kinetic, electron inertial Alfvén, and slow and fast magnetosonic waves are analyzed using both analytical expansions and a novel technique of dispersion diagrams. The analysis is extended to explicitly include space charge effects in non-neutral plasmas. Nonlinear soliton solutions, here called alfvenons, are found to represent either convergent or divergent electric field structures with electric potentials and spatial dimensions similar to those observed by satellites in auroral regions. Similar solitary structures are postulated to be created in the solar corona, where fast alfvenons can provide acceleration of electrons to hundreds of keV during flares. Slow alfvenons driven by chromospheric convection produce positive potentials that can account for the acceleration of solar wind ions to 300–800 km/s. New results are discussed in the context of observations and other theoretical models for nonlinear Alfvén waves in space plasmas.

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General dispersion properties of magnetized plasmas with drifting bi-Kappa distributions. DIS-K: Dispersion Solver for Kappa Plasmas

Journal of Plasma Physics ◽

10.1017/s0022377821000593 ◽

2021 ◽

Vol 87 (3) ◽

Author(s):

R.A. López ◽

S.M. Shaaban ◽

M. Lazar

Keyword(s):

Dominant Role ◽

High Energy ◽

Distribution Functions ◽

Magnetized Plasma ◽

Unstable Wave ◽

Space Plasmas ◽

Good Representation ◽

Particle Interactions ◽

Particle Collisions ◽

Dispersion Tensor

Space plasmas are known to be out of (local) thermodynamic equilibrium, as observations show direct or indirect evidences of non-thermal velocity distributions of plasma particles. Prominent are the anisotropies relative to the magnetic field, anisotropic temperatures, field-aligned beams or drifting populations, but also, the suprathermal populations enhancing the high-energy tails of the observed distributions. Drifting bi-Kappa distribution functions can provide a good representation of these features and enable for a kinetic fundamental description of the dispersion and stability of these collision-poor plasmas, where particle–particle collisions are rare but wave–particle interactions appear to play a dominant role in the dynamics. In the present paper we derive the full set of components of the dispersion tensor for magnetized plasma populations modelled by drifting bi-Kappa distributions. A new solver called DIS-K (DIspersion Solver for Kappa plasmas) is proposed to solve numerically the dispersion relations of high complexity. The solver is validated by comparing with the damped and unstable wave solutions obtained with other codes, operating in the limits of drifting Maxwellian and non-drifting Kappa models. These new theoretical tools enable more realistic characterizations, both analytical and numerical, of wave fluctuations and instabilities in complex kinetic configurations measured in-situ in space plasmas.

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Development of a high-time/spatial resolution self-impedance probe for measurements in laboratory and space plasmas

Review of Scientific Instruments ◽

10.1063/5.0029009 ◽

2021 ◽

Vol 92 (1) ◽

pp. 015118

Author(s):

Ami M. DuBois ◽

Erik M. Tejero ◽

George R. Gatling ◽

William E. Amatucci

Keyword(s):

Spatial Resolution ◽

High Time ◽

Space Plasmas ◽

Impedance Probe

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The Whistler Traveling Wave Parametric Amplifier Driven by an Ion-Ring Beam Distribution from a Neutral Gas Injection in Space Plasmas

IEEE Transactions on Plasma Science ◽

10.1109/tps.2021.3079130 ◽

2021 ◽

pp. 1-14

Author(s):

Paul A. Bernhardt

Keyword(s):

Traveling Wave ◽

Gas Injection ◽

Parametric Amplifier ◽

Space Plasmas ◽

Neutral Gas

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Identification of a novel click-derived 1,2,3-triazole as selective Hg2+ ion detector: computational and experimental investigations

Chemical Papers ◽

10.1007/s11696-021-01804-7 ◽

2021 ◽

Author(s):

Rabail Ujan ◽

Nasima Arshad ◽

Fouzia Perveen ◽

Pervaiz Ali Channar ◽

Bhajan Lal ◽

...

Keyword(s):

Experimental Investigations ◽

Ion Detector

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A compact exact law for compressible isothermal Hall magnetohydrodynamic turbulence

Journal of Plasma Physics ◽

10.1017/s0022377821000374 ◽

2021 ◽

Vol 87 (2) ◽

Author(s):

Renaud Ferrand ◽

Sébastien Galtier ◽

Fouad Sahraoui

Keyword(s):

Source Term ◽

Reynolds Numbers ◽

Space Plasmas ◽

Order Structure ◽

Magnetohydrodynamic Turbulence ◽

Statistical Homogeneity ◽

Background Magnetic Field ◽

Taylor Hypothesis ◽

Spacecraft Data

Using mixed second-order structure functions, a compact exact law is derived for isothermal compressible Hall magnetohydrodynamic turbulence with the assumptions of statistical homogeneity, time stationarity and infinite kinetic/magnetic Reynolds numbers. The resulting law is written as the sum of a Yaglom-like flux term, with an overall expression strongly reminiscent of the incompressible law, and a pure compressible source. Being mainly a function of the increments, the compact law is Galilean invariant but is dependent on the background magnetic field if one is present. Only the magnetohydrodynamic source term requires multi-spacecraft data to be estimated whereas the other components, which include those introduced by the Hall term, can be fully computed with single-spacecraft data using the Taylor hypothesis. These properties make this compact law more appropriate for analysing both numerical simulations and in situ data gathered in space plasmas, in particular when only single-spacecraft data are available.

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