M. G. Golubkov

Microwave radiation in the upper atmosphere of the earth during strong geomagnetic disturbances

The influence of N2 and O2 molecules on spontaneous microwave radiation spectrum was studied over the decimeter range. This radiation appears in the D and E upper earth atmosphere layers during strong magnetic storms. It was shown to be caused by radiation transitions between medium-perturbed orbitally degenerate Rydberg atom and molecule states A** that occur without changes in the principal quantum number, δn = 0. The available experimental data were used to calculate the dependences of orbitally degenerate state populations on the density of medium and electron flux and temperature. Effective radiation bands were constructed for transitions between highly excited quasi-molecule levels A**N2 and A**O2. The emission spectrum was shown to be inhomogeneous and contain three frequency regions in which a noticeable decrease in the intensity of radiation occurred. The physical reason for the formation of these regions was a shift of the emission spectra of quasi-molecules containing unexcited N2 and O2 molecules. The frequency profiles of radiation intensity within these frequency regions were calculated as depending on the storm level. Radiation profiles were shown to noticeably change as the storm level increased, they strongly increased close to the right region edge corresponding to high transition frequencies. Nonmonotonic behavior of this profile in the middle of the lower region was observed; this was related to emission spectrum inhomogeneity. A sharp increase in radiation intensity as the magnetic storm level increased occurred in the region of frequencies situated close to the right edge of the upper region (50–100 GHz), which was most interesting for biophysical studies of the action of microwave radiation on living organisms during strong geomagnetic disturbances.

Laser stimulation of low-temperature dissociative recombination of electrons and oxygen molecular ions

AbstractA theory of dissociative recombination of slow electrons and molecular ions in a strong monochromatic light field is developed. The theory takes into account interference between various reaction channels and is constructed in a rigid basis adiabatic with respect to rotation (the approximation of a fixed molecular axis). The mathematical apparatus of the theory is based on the stationary formalism of the matrix of radiation collisions, whose poles correspond to “quasi-energy” states of a composite system. Along with transitions into dissociative configurations, field-induced nonadiabatic transitions into bound intermediate states of valence (non-Rydberg) configurations are considered. As a particular application of the theory, the e− + O2+(2Πg) →

Emission of Highly Excited Atoms and Molecules in the Upper Atmosphere

O(^{2s_1 + 1} l_1 ) + O(^{2s_2 + 1} l_2 )

Microwave radiation of the atmosphere induced by a pulsed gamma source

reaction is analyzed. A study of this reaction requires detailed information about the potential curves of the states participating in it with taking into account the external electromagnetic field (l and s are the electronic angular momenta and reaction product spins). For this purpose, the general problem is divided into three stages. At the first stage, the theoretical approach is formulated, and at the second stage, the corresponding potential curves are calculated and the main reaction mechanisms are determined. The third stage should include calculations of the total and differential cross sections. This work is concerned with the first two stages; that is, the adiabatic potential curves of the singlet and triplet dissociative states of the O2** oxygen molecule are calculated, a classification of all possible transition types is given, and reaction mechanisms in the presence of monochromatic laser radiation are determined. The frequency regions of external radiation in which these mechanisms are most effective are found.

Associative ionization reaction N + O → NO+ + e– in slow collisions of atoms

A theory is developed to describe dissociative recombination of a slow electron with a ground-state molecular ion of oxygen driven by a strong monochromatic electromagnetic field. Mathematically, the theory is based on the time-independent formalism of radiative scattering matrix whose poles correspond to dressed intermediate states of the complex. The analysis embraces both transitions to dissociative states and laserinduced nonadiabatic transitions to intermediate bound states of valence configurations. Key reaction mechanisms are considered, and a classification is given of all allowed transitions to dissociative states. Partial and total reaction cross sections are calculated by taking into account the contributions from Rydberg, valence, and dissociative states of O2**. A detailed discussion of results is presented, and feasibility of laser control of the reaction is demonstrated.

Perturbation of highly excited states of an atom by the field of a neutral particle

The emission ability of Rydberg atoms and molecules in the orbitally degenerate states is considered. The mechanisms of their formation in the F, E, and D upper atmosphere layers are analyzed. The characteristic lifetimes of these states in the microwave range are estimated. It is shown that radiation in this range can be accompanied by a cascade of transitions. The possibility of studying the influence of intense atmospheric microwave radiation on living organisms is discussed.

Simulation of the behavior of excited gaseous components in the atmosphere of the Earth: Hot oxygen

The special features of the behavior of the potential energy surfaces of the system comprising a highly excited A** atom and a neutral B atom with a filled electronic shell were thoroughly analyzed. This was done using the integral variant of theory combined with the generalized finite radius potential method correctly describing the scattering of a weakly bound electron by the B atom. The method allows P scattering to be taken into account. This scattering causes the additional splitting of potential energy surfaces into separate groups of interacting terms classified according to the projection m of the electron angular momentum l onto the quasimolecular axis. Calculations of the nl(2s + 1Λ) state potential curves of the Na** + He quasi-molecule (n, l, and Λ are the principal quantum number, angular momentum, and its projection onto the molecular axis, and s is the spin of the system) were performed. The calculation results were compared to those obtained by other authors.

Potential energy of the K**-He quasimolecule

The model problem of the perturbation of the atmosphere by an isotropic gamma source (pulse width Δτ ≤ 100 ns) situated at various altitudes (0 ≤ h ≤ 100 km) and assumed to be a “point” source was solved. The action of emitted gamma quanta caused the formation of a spatial region in the atmosphere containing highly excited atoms and molecules, the emission from which was recorded over a certain microwave range (0.8–1.0 GHz). The amplitudes of the electric component intensity of the field of noise Rydberg radiation over the range specified were calculated. Rydberg radiation duration, type, and the degree of polarization were estimated. The shape of the emission line and the character of broadening of signals received by two receivers situated at an altitude of H1 = 20000 km and on the surface of the Earth (H1 = 0 km) were analyzed. During measurements, both receivers were situated on the axis perpendicular to the surface of the Earth.