[en] A rocket borne Critical Ionization Velocity (CIV) experiment was carried out from Wallops Island at dusk on May 4, 1989. Two barium shaped charges were released below the solar terminator (to prevent photoionization) at altitudes near 400 km. The ambient ionospheric electron density was 5x10⁵ cm^-3. The neutral barium jet was directed upwards and at an angle of nominally 45 degrees to B which gives approximately 3x10²³ neutrals with super critical velocity. Ions created by a CIV process in the region of the neutral jet would travel up along B into sunlight where they can be detected optically. Well defined ion clouds (max. brightness 750 R) were observed in both releases. An ionization rate of 0.8%s^-1 (125s ionization time constant) can account for the observed ion cloud near the release field line, but the ionization rate falls off with increasing distance from the release. It is concluded that a CIV process was present in the neutral jet out to about 50 km from the release, which is significantly further than allowed by current theories

[en] Several recent proposals to image sunlit magnetospheric O⁺ have been difficult to assess because of the lack of detailed knowledge of the solar spectrum at 834 angstrom. An NRL solar spectrograph flown on a sounding rocket in 1962 actually had sufficient resolving power to allow the calculation of scattering rates. Using these solar data, examples of scattering rates for a range of thermal and bulk velocities are presented for both O⁺ and O⁺⁺, and the effects of ionospheric albedo are estimated. The scattering rates are significantly lower than previously estimated for hot or moving plasma and exhibit substantial structure

[en] The standard expression for the polarization current assumes that a gyrating particle experiences the same electric field gradient over its entire orbit. For weak magnetic fields and small-scale potential structures this assumption may not be valid, especially for the heavier ions such as O+. Here the authors trace individual particle trajectories through a small-scale region of electric field reversal simulating an auroral arc. An earthward EXB drift is included. It is found, for example, that the topology of the ion orbits inside the arc dramatically changes when dE/dx > eB²/M which results in an effective heating of the ions. This condition is easily satisfied for O+ at L = 6. Potential implications of the results on auroral arc structure will be discussed. They will also consider the application of their results to crossed field electron devices

[en] Empirical model is presented of the electron collision frequency for the 100-200 km height interval of the middle-latitude ionosphere. The seasonal dependence character is changed with solar activity growth and devergences increase

[en] Quantitatively are considered the main mechanisms of damping geomagnetic pulsations - ionospheric dissipation and non-dissipative signal attenuation due to transverse scale splintering. Numerical simulation shows that owing to breaking conditions of thin ionosphere approximation applicability at low latitudes (L<2) takes place sharp decreasing the Alfven resonator Q factor

[en] It is shown that appearance of young EAS with high concentration of electromagnetic (EM) energy in the EAS cores at the energy of 1-10 PeV at the mountain level, difference in slopes of the EAS spectra in the particle number and EM energy and also the EM energy per an electron in EAS have the same origin, connected with usual longitudinal development of EAS

[en] Mathematical model of the stationary pitch-angle distributions of the Earth radiation belts ions is constructed for the region, where the dissipative processes during radial particle diffusion may be neglected. The model reflects all characteristic features of the space-energy dependences of the the pitch-angle distributions of the Earth radiation belt ions. The angular and energy distributions are connected closely one with other. Analytical expressions for the anisotropy index are obtained. 20 refs

[en] Results are presented of test calculations by means of the method of diagnostics of the integral parameters of an electric equivalent RL network of the polar magnetosphere. Results are agreed with the circuit where the primary generator-dynamo is a voltage source, having ordinary (linear) contact with a magnetospherical-ionospherical loading. 10 refs., 1 fig., 4 tabs

[en] On the base of regular observations of energetic particle fluxes by means of the 'Meteor' satellite apparatus is found the new phenomenon - the narrow belt of trapped relativistic electrons with the maximum at L=1.8-1.9. Continuous observations permit to obtain elaborate information on the features of the belt spatial structure, its dynamics and energy spectra with the moment of its generation 24.3.1991

[en] Preliminary data on the fluxes of trapped electrons with the energy of 50-200 MeV in the Earth inner radiation belt are presented. Results of the paper are based on the observations by means of the 'GAMMA' gamma-telescope from November 1990 to April 1991