[en] Paper discuss the results of the numerical MHD simulation of variation of magnetic configuration and of plasma flow field within the finite thickness current layer due to the development of plasma abnormal resistance area. The process of magnetic characteristics for the earlier phase of the process development are obtained

[en] Diffusion coefficients within the velocity space that correspond to the scattering of energetic particle fluxes in the main essentially slowed-down types of the waves with energy isotropic spectral density in the magnetoactive plasma, are calculated

[en] The present paper is devoted to the study of the following relations: Sun-solar wind up to the Earth orbit that form the ground of the problem of the solar-terrestrial interaction physics. The recent results obtained in this science branch are analyzed and generalized in terms of this approach

[en] Intensification of the oscillation amplitude of the natural electromagnetic field within 60-240 min period interval at practically all the latitudes was observed during the Earth re-entry to plasma high-speed flow

[en] The solar wind is principally composed of protons which are canalized by the Earth's magnetic field lines and perturbs the terrestrial radio-communications. The study of the UV radiation from the sun surrounding space in December 1994, using the Ulysse probe, revealed that more protons are emitted by the southern hemisphere and the equator of the sun than by the northern hemisphere. In order to determine the temporary or permanent character of this effect, an indirect method was developed which is based on the UV light emitted by the hydrogen atoms from the region of the space where the sun passes through. The hydrogen atoms are ionized by the protons from the solar wind and simultaneously excited by the sun light. The deexcitation produces UV radiations of 121.6 nm which correspond to the Lyman-α ray. The detectors from the SWAN instrument (Aeronomy Service, CNRS, Verrieres-le-Buisson, France) have shown that the region situated south of the sun ecliptic is less luminous and corroborate the observations of the Ulysse probe. Short paper. (J.S.). 2 figs

[en] Short communication

[en] Imaging of the earth's auroral regions in the ultraviolet provides information on a global scale on the energy flux and characteristics of precipitating particles an on the composition of the atmosphere in which the energy is deposited. The authors report the design of an imager with 0.6-mrad angular resolution over an 8-deg field of view sampled with 39,500 pixels, yielding global auroral coherent imaging from above 6 R_E(Earth radii). High-performance filters provide spectrally pure measurements of four key far-UV (FUV) features, with 5 x 10^-5 out-of-band rejection. Together with a solar blind intensified CCD detector, a net rejection of 10^-9 of all out-of-band emissions is achieved. The optical design comprises a three-mirror f/3 system that yields a noise equivalent sensitivity of 10 rayleighs (R) for a 37-s frame rate. The intrascene and interscene dynamic ranges are 1,000 and 10⁵, respectively. The optical surface microroughness is less than 2 nm, providing exceptionally low light scattering characteristics, allowing simultaneous observations of very weak and bright emissions. The imager should provide about two orders of magnitude improvement in performance over previous designs

[en] A balloon-borne x-ray pinhole camera has been developed to detect and image auroral x-rays in the energy range 20 to 120 keV. The authors have flown this camera on four different occasions and have imaged bremsstrahlung x-rays from precipitated energetic electrons in the auroral zone and from a circumpolar navigating balloon in Antarctica. The images, which include several dynamic precipitation temporal forms, show that auroral x-rays persistently include small spatial structures of ∼20 km (at ionospheric heights). The x-ray energy spectral information as a function of space and time shows that electron precipitation often includes two energy components that can be fit by exponential functions. Typical e-folding energies of these spectra are a few kilo-electron-volts and several tens of kilo-electron-volts. The x-ray camera remote senses characteristics of energetic electron sources in the distant magnetosphere that cannot be achieved by any other means

[en] Absorption of electromagnetic waves in a magnetized plasmas is investigated in a tremendous number of papers. No account has been taken however of the influence of a strong quasistationary electric field. By a strong electric field one means the case, when the electric drift velocity is comparable with the particle velocity /λ-3/. It corresponds to the magnetohydrodynamic (MHD) approximation. In this approximation dynamics of the charged-particle in a resonant high-frequency wave packets is considered. Weak relativistic effects are taken into account. It is shown that a strong electric field can alter substantially the character of the resonant wave-particle interaction and the mechanism of energy exchange between them. In particular one can see that the presence of a strong electric quasistationary field makes it possible for a particle to experience Cerenkov resonance in a transverse electromagnetic wave, propagating along an external magnetic field. It is in principle not realizable in a weak electric field. As an example, the nonlinear damping rate of the whistler is calculated for Cerenkov resonance and it is shown that it can be comparable with the damping rate in cyclotron-resonance interaction between a wave and a particle. In the case of a longitudinal wave propagating along a magnetic field cyclotron-resonance interaction can take place, something impossible in principal in a weak electric field

[en] The long standing program at U.C. Irvine will be reviewed, as well as programs at other institutions. The objective of these experimental programs is to model phenomena observed in the magnetosphere by rockets and satellites. Since these observations are taken at relatively few points, some of the theoretical explanations would benefit from verification in a laboratory situation, where a much higher degree of control of the experimental parameters can be achieved than is possible in the magnetosphere. While it is not practical to model the magnetosphere itself, it is possible to do so with specific observations. Laboratory experiments have been done in a variety of environments. At U.C. Irvine the authors have specialized in the techniques of laser induced fluorescence [LIF] in a barium plasma, in a Q-Machine. This technique allows the determination of ion velocity distributions which can be extended to three dimensions using optical tomography. By using the technique of optical tagging, they can follow ions in real and velocity space. By using these techniques they have been able to observe, experimentally, the development of ion conics in velocity space. Current work involves observing the development of ion conics in a dipole magnetic field under the influence of ion heating by lower hybrid waves. These and other experiments, including some at other institutions will be described in some detail. In addition, the results of a workshop on the subject of the interrelation between laboratory and space plasma experiments held in Alpbach, Austria in July 1991 will be discussed