Photon absorption in the isoelectronic series of Xe
Photon absorption in the isoelectronic series of Xe
S.Ya. Goroshchenko, V.S. Rostovskii, N.P. Yudin
The Hartree-Fock approximation is used to study the 3d photoabsorption in the near-threshold region for the following atoms and ions: $I^-, Хе, Cs^+, Ва^{2+}, La^{3+}$. We discuss the hypothesis of 4f-state collapse in the isoelectronic series of Xe. It is shown that the features of the absorption cross section in $Cs^+$ can be explained without invoking the hypothesis of 4f-state collapse.
Show AbstractSome properties of the resolvent of the energy operator of a system of several nonrelativistic particles
Some properties of the resolvent of the energy operator of a system of several nonrelativistic particles
V.V. Komarov, A.M. Popova, V.L. Shablov
We consider the problem of construction of the resolvent of the operator which is a contraction of a given operator to a subspace generated by an orthogonal projection. We establish the equivalence of various methods of construction of these resolvents, and also the connection of this problem with the Vainshtein-Aronshain degenerate-perturbation theory. We show how these problems can be applied to the analysis of spectral properties of the Hamiltonian of a system of several quantum-mechanical particles.
Show AbstractВладимир Александрович Красильников (к семидесятилетию со дня рождения)
Владимир Александрович Красильников (к семидесятилетию со дня рождения)
В.Б. Брагинский, Л.К. Зарембо, Б.С. Ишханов, А.П. Сухоруков, В. С. Фурсов
14 сентября 1982 г. исполнилось семьдесят лет со дня рождения зав. кафедрой акустики проф. Владимира Александровича Красильникова.
Show AbstractScattering and absorption of small particles by a black hole
Scattering and absorption of small particles by a black hole
A.B. Gaina, G.A. Chizhov
The scattering and absorption processes of weakly relativistic electric and scalar particles in Kerr-Newman fields with an event-horizon radius less than the particle wavelength are considered. Particle absorption by the event horizon is due to polarizational phenomena $\sim r_g/\lambda$ in electron scattering. Corrections of the same order to the differential scattering cross section are obtained, together with expressions for the total absorption cross sections. The general formulas are used to consider analogous processes involving the neutrino.
Show AbstractSeeking short-term increases in the heavy-nucleus flux of cosmic rays from the data of measurements on Prognoz spacecraft
Seeking short-term increases in the heavy-nucleus flux of cosmic rays from the data of measurements on Prognoz spacecraft
N.N. Volodichev, I.A. Savenko, A.A. Suslov
A search is made for short-term increases in the cosmic-ray flux of predominantly heavy nuclei of energy E $\ge$500 MeV/nucleon from the data of measurements on the Prognoz-2 and Prognoz-3 spacecraft. These increases were recorded in the course of the first space flights by Soviet rockets, orbital spacecraft, and the Elektron and Molniya-1 satellites. No such increases were observed by the Prognoz spacecraft. Moreover, the increase on 2 January 1974, observed by the Molniya-1 spacecraft by a telescope consisting of scintillational and Cherenkov counters was not recorded by the analogous devices on the Prognoz-3 spacecraft. Therefore, the nature of the short-term increases in the heavy-nucleus flux remains an open question.
Show AbstractSpectral properties of dielectric mirrors on a metallic substrate
Spectral properties of dielectric mirrors on a metallic substrate
A.V. Tikhonravov
Dielectric mirrors on a metallic substrate are investigated taking account of absorption in the layers. Simple formulas are obtained for the reflection coefficient of such mirrors. It is shown that the basic obstacle to the achievement of high values of R is absorption in the dielectric layers, and this is the basis for the selection of the best mirror construction. It is also shown that, under certain conditions, the system consisting of a dielectric mirror on a metallic substrate is a selective absorber of wave energy. Simple expressions are obtained allowing the construction of such an absorber to be calculated and its basic spectral characteristics to be determined.
Show AbstractShock waves excited by a relativistic charged beam in media with dissipation
Shock waves excited by a relativistic charged beam in media with dissipation
V.K. Grishin
The possibility of the propagation of electromagnetic waves with a shock profile cophasally related with a beam of relativistic particles and localized at its leading edge is considered. The conditions of dynamic equilibrium are found, when the energy losses of the wave are compensated by its "pumping" with freezing of the fast particles of the beam in the intrinsic field.
Show AbstractPrediction of the optical properties of ruby and leucosapphire under conditions of cosmic-plasma action
Prediction of the optical properties of ruby and leucosapphire under conditions of cosmic-plasma action
A.I. Akishin, T.S. Bessonova, A.I. Sobko, E.M. Akulenok
On the basis of the results obtained earlier in the experimental and theoretical investigation of radiation-optical effects in ruby and leucosapphire, methods of practical importance are developed for the computer prediction of the optical transparency of ruby and the luminescent-noise intensity from a leucosapphire lens of a spacecraft under conditions of cosmic-plasma action. The change in optical density of ruby and the level of luminescent noise from the leucosapphire lens of a spacecraft moving in interplanetary space in the course of a solar flare described by the Bailey method is calculated.
Show AbstractConditions of oscillation development in a spin generator
Conditions of oscillation development in a spin generator
L.S. Kornienko, A.L. Kotkin, D.M. Litvak, Yu.V. Pavlov, R.M. Umarkhodzhaev
"Peak" conditions of transition of a spin generator to a steady level of oscillation, occurring at large feedback-loop amplification factors, are investigated theoretically and experimentally.
Show AbstractAnalysis of the statistical treatment of a random process on the example of the velocity pulsations of a waterway flow
Analysis of the statistical treatment of a random process on the example of the velocity pulsations of a waterway flow
V.P. Petrov, O.P. Petrosyan, I.P. Kharchenko
A method of statistical treatment is proposed for the random process of velocity pulsation of a waterway flow, allowing the true values of the given process to be obtained in the specified frequency range.
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