[en] The distribution in l, following excitation of a hydrogen atom into a state with large n near the threshold, is calculated. The most probable value of l is approximately (n/2)¹2/

[en] The probability of ionization of highly excited states of a hydrogen atom by a low-frequency field is estimated by using the previously derived quasi-classical wave function of an electron in a Coulomb field and in a radiation field. The expression obtained predicts an ionization threshold at field intensities approximately equal to those observed experimentally, but predicts an increase in ionization probability that is approximately ten times the increase observed experimentally when the field intensity in the threshold region is increased. The approximations underlying the derivation of the equation for the ionization probability are discussed

[en] The spectra of electrons scattered at 90⁰ by europium atoms were investigated, and the energy dependence of the elastic differential cross section has been determined. The cross section exhibits resonance features associated with short-lived states of negative europium ions. The electron spectra of autoionizing states were found to contain 90 lines due to multichannel decay of atomic and ionic states

[en] It is shown that the total decay probability depends substantially on the external field only via the quantum parameters chi = E/H/sub c/ and lambda = hω/mc², where E and ω are the amplitude and frequency of the wave and H/sub c/ = m²c³/eh. The field corrections are exceedingly small (< or approx. =10^-12--10^-14) even at the highest presently attainable laser-field intensities. In the case of a low energy release (Epsilon₀-1<<1) the quantum parameters assume a different form, but for decays of real nuclei these corrections remain small as before. At high wave-quantum energies (lambda>>1) the decay time can decrease appreciably. Account is taken of the effects due to the polarization of the initial state of the nucleus and to circular polarization of the wave field. In particular, in the region lambda>>1 the estimate sigma⁺/sigma^-roughly-equal1/6 is valid for the ratio of the total cross sections of the β-decay processes induced by photons having different helicities

[en] A dispersion equation for surface spin waves in the isotropic superfluid phase of ³He (the B-phase) is derived and investigated. It is shown that the spectrum has an end point at small wave vectors k. The velocities of spin waves of various polarizations in a thin ³He-B layer are calculated in the limit of large k

[en] Experiments reveal the induction of magnetic flux in a bimetallic superconducting system: a ring closing the circuit for an SNS Josephson junction: when there is a heat flux through the junction. The behavior of the system is simulated numerically on the basis of a theory derived for the uniform introduction of an electric current into a distributed SNS junction whose circuit is closed by a superconducting ring

[en] We consider the radiation of particles (electrons and positrons) undergoing planar channeling in a single crystal of small thickness L. We show that for Lapprox.πb/theta/sub L/, where b is the lattice constant and theta/sub L/ is the Lindhard angle, in addition to the principal maxima of spontaneous radiation of channeled particles in the spectrum there are additional interference maxima, and the positions of all maxima of the radiation intensity depend on L. We discuss the dependence of the intensity of radiation at various frequencies on the crystal thickness

[en] The g-factors of the 11/2^- and 15/2⁺ isomeric states of the ¹⁴¹Pr and ¹⁴³Pm nuclei (Tables I and II) have been measured by the method of differential and integrated perturbed angular distribution. The parametric corrections were determined for ¹⁴³Pm from the measured temperature dependence gβ(T). The relaxation times have been measured for nuclear states aligned in beam reactions, metal targets, and targets made of La and Pr oxides. The results are analyzed in terms of the quasiparticle-phonon model with allowance for the spin-multipole interaction

[en] A study is made of the autoionization spectrum for transitions of the Eu atom from excited states. The most efficient schemes are found for the three-step laser photoionization of Eu atoms. The data are used for measurement of the isotope shifts in the optical spectrum of the radioactive isotopes of Eu at the laser-nuclear complex at the Leningrad Institute of Nuclear Physics and the Institute of Spectroscopy. On the basis of the measured isotope shifts we have determined for the first time the changes in the mean-square distribution of nuclear charge for the radioactive isotopes /sup 150hyphen145/Eu. The prospects for improving the sensitivity of the method are discussed

[en] The equivalent second-order perturbation theory correction operators for the hydrogen atom in crossed electric and magnetic fields are computed with the aid of the Sturm basis. The corrections themselves are computed, and the question of the lifting the residual degeneracy in this order in the case of perpendicular fields is also investigated