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The laboratory experiment on modeling a sub-Alfvénic interaction of expanding plasma cloud with vacuum magnetic field is described. We produce spherically symmetric cloud by 4-beam laser irradiation of the pellet. The presented data reveal complex dynamic of cloud deceleration and formation of two field aligned jets, development of the flute instability and rapid collapse of the diamagnetic cavity. It is shown that cavity collapse can't be explained by plasma motion or anomalous diffusion and requires for explanation a new mechanism. [ABSTRACT FROM AUTHOR]

Structural instabilities that develop during pulsed injection of dense plasma jets into vacuum in the presence of an external quasi-homogeneous magnetic field are studied by high-speed photography using ICCD cameras. The experiments are carried out in the chamber of the "Krot" stand, which has record-breaking dimensions in its class of installations (diameter—3 m, length of the working section—10 m), and makes it possible to study plasma dynamics by various diagnostic methods at scales of more than 1 m both along the magnetic field and in the direction transverse to the magnetic field. During injection along the magnetic field, a transverse collimation of the flow of ionized matter and the development of a flute instability of the plasma boundary are observed, which, at the late stages of expansion, leads to the plasma leaving the injection region in the form of several jets across the field. During transverse injection, the formation of a collimated flow, a "plasma sheet," is observed, in which, as the plasma moves across the field, inhomogeneous structures develop in the direction of injection. [ABSTRACT FROM AUTHOR]

The paper presents the results of laboratory experiment modeling the interaction between Lunar magnetic anomalies and Solar wind. To model the LMA we use quadrupole magnetic field. The main dimensionless parameter of the problem, the ion inertia length relative to the mini-magnetosphere size, well corresponds between experiment and LMA conditions. The main result is measurement of the magnetically reflected proton fluxes, which show qualitative agreement to available satellite data. [ABSTRACT FROM AUTHOR]

The signs of an expanding atmosphere of HD209458b have been observed with far-ultraviolet transmission spectroscopy and in the measurements of transit absorption by metastable He  i. These observations are interpreted using the hydrodynamic and Monte Carlo numerical simulations of various degree of complexity and consistency. At the same time, no attempt has been made to model atmospheric escape of a magnetized HD209458b, to see how the planetary magnetic field might affect the measured transit absorption lines. This paper presents the global 3D MHD self-consistent simulations of the expanding upper atmosphere of HD209458b interacting with the stellar wind, and models the observed H  i (Ly α), O  i (1306 Å), C  ii (1337 Å), and He  i (10 830 Å) transit absorption features. We find that the planetary dipole magnetic field with the equatorial surface value of Bp = 1 G profoundly changes the character of atmospheric material outflow and the related absorption. We also investigate the formation of planetary magnetosphere in the stellar wind and show that its size is more determined by the escaping atmosphere flow rather than by the strength of magnetic field. Fitting of the simulation results to observations enables constraining the stellar XUV flux and He abundance at F XUV ∼ 10 erg cm2 s–1 (at 1 au) and He/H ≈ 0.02, respectively, as well as setting an upper limit for the dipole magnetic field of Bp < 0.1 G on the planetary surface at the equator. This implies that the magnetic dipole moment µP of HD209458b should be less than 6 per cent of the Jovian value. [ABSTRACT FROM AUTHOR]

The results of a laboratory experiment on the simulation of the reflection of protons over regions of the local magnetization of the lunar crust have been reported. Quadrupole and dipole sources have been used to simulate a local magnetic field. The magnetic-field-induced reflection of protons near lunar magnetic anomalies reaches 50% of the incident flow. A significant difference between the quadrupole and dipole configurations has been detected both in the structure of the mini-magnetosphere and in the reflection of protons. The data obtained are in qualitative agreement with in situ measurements by spacecrafts over lunar magnetic anomalies. [ABSTRACT FROM AUTHOR]

We investigate the interaction between themagnetized stellarwind plasma and the partially ionized hydrodynamic hydrogen outflow from the escaping upper atmosphere of non-magnetized or weakly magnetized hot Jupiters. We use the well-studied hot Jupiter HD 209458b as an example for similar exoplanets, assuming a negligible intrinsic magnetic moment. For this planet, the stellar wind plasma interaction forms an obstacle in the planet's upper atmosphere, in which the position of the magnetopause is determined by the condition of pressure balance between the stellar wind and the expanded atmosphere, heated by the stellar extreme ultraviolet radiation.We show that the neutral atmospheric atoms penetrate into the region dominated by the stellar wind, where they are ionized by photoionization and charge exchange, and then mixed with the stellar wind flow. Using a 3D magnetohydrodynamic (MHD) model, we show that an induced magnetic field forms in front of the planetary obstacle, which appears to be much stronger compared to those produced by the solar wind interaction with Venus and Mars. Depending on the stellar wind parameters, because of the induced magnetic field, the planetary obstacle can move up to ≈0.5-1 planetary radii closer to the planet. Finally, we discuss how estimations of the intrinsic magnetic moment of hot Jupiters can be inferred by coupling hydrodynamic upper planetary atmosphere andMHDstellar wind interaction models together with UV observations. In particular, we find that HD 209458b should likely have an intrinsic magnetic moment of 10-20 per cent that of Jupiter. [ABSTRACT FROM AUTHOR]

This paper presents the results of laboratory experiments with laser plasma flow around a magnetic dipole which model the extreme compression of the Earthś magnetosphere by the plasma generated by high-power coronal mass ejections. Data on the formation of an artificial magnetosphere, the boundary-layer structure, and the size of the magnetosphere as a function of the magnetic moment are given. It is shown that in the presence of a conducting dipole shell modeling the ionosphere, conditions are created for the flow of intense longitudinal currents in the polar regions. It is established that the longitudinal currents have little effect on the position of the plasma stagnation point and the transition layer but make a significant contribution to the disturbance of the magnetic field in the magnetosphere. [ABSTRACT FROM AUTHOR]

The paper deals with the physical and electrotechnical principles of the promising method of direct conversion of the kinetic energy of an expanding plasma cloud to electrical energy by inductive generation of currents in short–circuited load coils that enclose the plasma and are oriented across the external magnetic field. An analysis of plasma deceleration by a magnetic field and transfer of plasma energy to an inductive load gave a solution of the problem in general form and the dimensionless parameters of the problem that determine the deceleration radius, the coil current, and the theoretical conversion efficiency. The role of the basic physical effects, including parasitic ones (plasma instabilities and Joule heating), influencing the real efficiency is assessed. A comparison of the results with data of experiments with laser–produced plasma clouds on a KI–1 facility and with available numerical results shows that in the optimized version of the method for conversion of inertial confinement fusion energy, a 30% efficiency can be achieved. [ABSTRACT FROM AUTHOR]

In the present series of papers we propose a consistent description of the mass loss process. To study in a comprehensive way the effects of the intrinsic magnetic field of a close-orbit giant exoplanet (a so-called hot Jupiter) on atmospheric material escape and the formation of a planetary inner magnetosphere, we start with a hydrodynamic model of an upper atmosphere expansion in this paper. While considering a simple hydrogen atmosphere model, we focus on the self-consistent inclusion of the effects of radiative heating and ionization of the atmospheric gas with its consequent expansion in the outer space. Primary attention is paid to an investigation of the role of the specific conditions at the inner and outer boundaries of the simulation domain, under which different regimes of material escape (free and restricted flow) are formed. A comparative study is performed of different processes, such as X-ray and ultraviolet (XUV) heating, material ionization and recombination, cooling, adiabatic and Lyα cooling, and Lyα reabsorption. We confirm the basic consistency of the outcomes of our modeling with the results of other hydrodynamic models of expanding planetary atmospheres. In particular, we determine that, under the typical conditions of an orbital distance of 0.05 AU around a Sun-type star, a hot Jupiter plasma envelope may reach maximum temperatures up to ∼9000 K with a hydrodynamic escape speed of ∼9 km s–1, resulting in mass loss rates of ∼(4-7) · 1010 g s–1. In the range of the considered stellar-planetary parameters and XUV fluxes, that is close to the mass loss in the energy-limited case. The inclusion of planetary intrinsic magnetic fields in the model is a subject of the follow-up paper (Paper II). [ABSTRACT FROM AUTHOR]