Table of contents

This review is devoted to the phenomena induced by negative ion processes in weakly ionized gases and plasmas. It briefly describes the electron attachment and detachment processes. The consideration focuses on the salient features of charged particle transport in electronegative gases. New types of instability and wave modes in plasmas with negative ions are discussed. Relevance of the negative-ion processes to modern technologies is indicated with emphasis on the ecological aspects and environmental applications.

Studies of reactions involving excited atoms, which result in the release of electrons with energies exceeding the mean plasma electron energy, are reviewed. Particular attention is devoted to plasma electron spectroscopy (PES) which combines the advantages of studies of elementary plasma processes with those of traditional electron spectroscopy. Data obtained by investigating the following reactions are reported: chemoionization with the participation of two excited inert-gas atoms, Penning ionization of atoms and molecules by metastable helium atoms, and electron quenching of excited inert-gas atoms and mercury atoms. The effect of processes in which fast electrons are emitted on plasma properties is discussed.

It is pointed out that the classical rules for matching at a tangential discontinuity, viz., continuity of the pressure and displacement, are nonuniversal. It is shown that in open systems both the pressure and the displacement can be discontinuous. The presence of a jump in the displacement renders meaningless the textbook use of the hydrodynamic concept of a perturbed surface of tangential discontinuity: the perturbed tangential discontinuity is not a single surface but a small spatial region bounded by nonparallel surfaces. It turns out that matching rules which are independent of the structure of the jump can be obtained only for a narrow (one-parameter) class of tangential discontinuities. In general the matching rules are different for different structures of the jumps in the main parameters of the medium. The examples cited in this paper are based on the real tangential discontinuity observed in the gaseous disk of the Milky Way galaxy.

Contemporary studies of fullerenes-carbon clusters as C₆₀, C₇₀, C₇₆, C₈₄ etc., whose atoms are located on a spherical or ellipsoidal surface are reviewed. Fullerene structures, methods for producing them, processes involving fullerenes, and the production of fullerenes are considered. The properties of fullerites (carbon crystals consisting of fullerenes) and the properties of compounds are discussed.