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Nonlinear kinetic structures, called electron phase-space holes (EHs), are regularly observed in space and experimental magnetized plasmas. The existence of EHs is conditioned and varies according to the ambient magnetic field and the parameters of the electron beam(s) that may generate them. The objective of this paper is to extend the 3D Bernstein–Greene–Kruskal model with cylindrical geometry developed by L.-J. Chen et al. ["Bernstein–Greene–Kruskal solitary waves in three-dimensional magnetized plasma," Phys. Rev. E 69, 055401 (2004)] and L.-J. Chen et al., ["On the width-amplitude inequality of electron phase space holes," J. Geophys. Res. 110, A09211 (2005)] to include simultaneously finite effects due to (i) the strength of the ambient magnetic field B 0 , by modifying the Poisson equation with a term derived from the electron polarization current, and (ii) the drift velocity ue of the background plasma electrons with respect to the EH, by considering velocity-shifted Maxwellian distributions for the boundary conditions. This allows us to more realistically determine the distributions of trapped and passing particles forming the EHs, as well as the width-amplitude relationships for their existence. [ABSTRACT FROM AUTHOR]

The linear Landau effect is revisited by the means of numerical simulations and analytical calculations. The existence of non-Landau solutions to the Vlasov-Poisson system is emphasized and the consistency of these solutions with respect to the arguments based on energy is investigated. The present article briefly summarizes the content of two articles already published on the subject and introduces a discussion based on the exchanges that occurred at Marseille during the Vlasovia meeting. [ABSTRACT FROM PUBLISHER]

The JUpiter ICy moons Explorer (JUICE) mission is the first large-class (L1) mission in ESA Cosmic Vision. JUICE is planned for launch in 2022 with arrival at Jupiter in 2029 and will spend at least four years making detailed observations of Jupiter's magnetosphere and of three of its largest moons (Ganymede, Callisto and Europa). The Radio and Plasma Wave Investigation (RPWI) consortium will carry the most advanced set of electric and magnetic fields sensors ever flown in Jupiter's magnetosphere, which will allow to characterize the radio emission and plasma wave environment of Jupiter and its icy moons. Here we present the scientific objectives and the technical features of the Search Coil Magnetometer (SCM) of RPWI. SCM will provide for the first time high-quality three-dimensional measurements of magnetic field fluctuations' vector in the frequency range 0.1 Hz – 20 kHz within Jupiter's magnetosphere. High sensitivity (~4 fT / Hz^1/2 at 4 kHz) will be assured by combining an optimized (20 cm long) magnetic transducer with a low-noise (4 nV / Hz^1/2) ASICs pre-amplifier for the front-end electronics. Perturbations by the spacecraft are strongly reduced by accommodating SCM more at ~ 10 m away from the spacecraft on the JUICE magnetometer boom. The combination of high sensitivity and high cleanliness of SCM measurements will allow unpreceded studies of waves and turbulence down to electron scales, in particular in key regions such as the magnetopause, the auroral region and the magnetotail current sheet of Ganymede's magnetosphere. This will lead to important advances in understanding plasma transport and particle energization mechanisms in Jupiter's magnetosphere. [ABSTRACT FROM AUTHOR]

More than a third of all exoplanets can be classified as super-Earths based on radius (1–2 R ⊕ ) and mass (<10 M ⊕ ). Here we model mass-radius relations based on silicate mantle and iron core equations of state to infer to first order the structure and composition range of rocky super-Earths assuming insignificant gas envelopes. As their core pressures exceed those in the Earth by an order of magnitude, significant extrapolations of equations of state for iron are required. We develop a new equation of state of hexagonal close packed (hcp) iron for super-Earth conditions (SEOS) based on density functional theory results for pressures up to 137 TPa. A comparison of SEOS and extrapolated equations of state for iron from the literature reveals differences in density of up to 4% at 1 TPa and up to 20% at 10 TPa. Such density differences significantly affect mass-radius relations. On mass, the effect is as large as 10% for Earth-like super-Earths (core radius fraction of 0.5) and 20% for Mercury-like super-Earths (core radius fraction of 0.8). We also quantify the effects of other modeling assumptions such as temperature and composition by considering extreme cases. We find that the effect of temperature on mass (<5%) is smaller than that resulting from the extrapolation of the equations of state of iron, and lower mantle temperatures are too low to allow for rock and iron miscibility for R <1.75 R ⊕ . Our end-member cases of core and mantle compositions create a spread in mass-radius curves reaching more than 50% in terms of mass for a given planetary radius, implying that modeling uncertainties dominate over observational uncertainties for many observed super-Earths. We illustrate these uncertainties explicitly for Kepler-36b with well-constrained mass and radius. Assuming a core composition of 0.8 ρ Fe (equivalent to 50 mol% S) instead of pure Fe leads to an increase of the core radius fraction from 0.53 to 0.64. Using a mantle composition of Mg 0.5 Fe 0.5 SiO 3 instead of MgSiO 3 leads to a decrease of the core radius fraction to 0.33. Effects of thermal structure and the choice of equation of state for the core material on the core radius of Kepler-36b are small but non-negligible, reaching 2% and 5%, respectively. [ABSTRACT FROM AUTHOR]

Thinning and thickening of the near-Earth plasma sheet is the result of a variety of processes such as substorms, large scale plasma waves, isolated moving structures like flux-ropes or plasmoids, etc. On 28th of August 2018 at 5:30 UT, MMS and Cluster were located in the magnetotail at about 16 Earth radii (RE). They both crossed the plasma sheet boundary layer. Cluster transitioned from the lobe region to the plasma sheet whereas MMS, located at 4 RE duskward of Cluster, transitioned the opposite way. At 05:50 UT MMS returned to the plasma sheet and detected a quasi-parallel earthward flow ~ 400 km/s and increased energetic ion and electron fluxes. While MMS transitioned from the plasma sheet to the lobe and back to the plasma sheet, Cluster remained in the plasma sheet. We use observations from both missions during this conjunction to describe the possible macroscale evolution of the magnetotail as well as some associated kinetic processes. [ABSTRACT FROM AUTHOR]