Das Energiespektrum und die mittlere freie Bahn der deformierenden Excitonen in Molekularkristallen

A study is made of the energy spectrum of a deforming exciton and its temperature dependence in molecular crystals. The mean free path and diffusion coefficient of the deforming exciton with respect to multi-phonon collisions with crystal lattice vibrations are theoretically determined. The possibility of distinguishing the propagation of excitation in molecular crystals in the form of deforming excitons from that in the form of non-deforming excitons and from the propagation of excitation by random jumps from one molecule to another is discussed on the basis of the theoretically derived temperature dependence of the diffusion coefficient of the deforming exciton.     

The static model of the nucleon

In this paper the author calculates the magnetic moment of the proton and neutron. It is assumed that both particles are systems composed of the core, nucleon and a cloud of electrically charged mesons. The numerical results are in qualitative agreement with experiment.This paper is a report from part of the Candidate's thesis elaborated under the guidance of Academician A. V. Fok in Leningrad.     

On the anisotropy of a heterogeneous medium with respect to the diffusion of neutrons I

Equations are derived for the diffusion of monoenergetic neutrons in a stratified heterogeneous medium. The neutron sources are plane and are located at infinity. The problem of homogenization and anisotropy of the heterogeneous medium is solved on the assumption of microscopic isotropy of scattering of the neutrons. The problem is solved quite generally (general position of the source, active and inactive medium). It confirms the conclusions reached in paper [3]from the more general point of view and is again in disagreement with the conclusions of paper [8].This disagreement is explained by the use of equations of the kinetic theory of the diffusion of neutrons.     

Spherical and deformed configurations of18O in the model of K-harmonics with a potential well

From the point of view of the model ofK-harmonics an estimation of the relative positions of the spherical (K=K _min) and deformed (K=K _min+2) configurations of¹⁸O is carried out, which is useful for more exact calculations. In these configurations the structure (1s)⁴ (1p)¹² of the 16 nucleons (the hypothetical nucleus¹⁶O) is separated out as determining and their binding energy is calculated. Nuclear forces are taken in the schematic form of a rectangular potential well. At first it is derived from the realistic nucleon-nucleon rectangular well and results in overbound states. It is, therefore, derived directly from the experimental data (the binding energy and the root mean square radius of¹⁶O and¹⁸O respectively). Although the energies of the hypothetical nucleus¹⁶O are close together in both configurations of¹⁸O, they differ. In Appendix a very effective expression for the logarithmic derivative of the MacDonald function is given.The work has been begun in the Nuclear Research Institute of the Czechoslovak Academy of Sciences, e.     

Realistic forces and deformed state admixtures in18O

Structure of states of¹⁸O nucleus is investigated assuming two-neutron configurations in the (2s–1d) shell with an admixture of deformed (SU₃) configurations of the same shell being composed of two neutrons and two protons transferred from the 1P_1/2 shell as well as under the action of residual realistic Elliott potential matrix and Tabakin potential with some corrections of the second order of nuclear matter theory. Splitting of levels between the ld_5/2 and 1p_1/2 shells is used as free parameter. The calculated level positions and E2 transition probabilities when using the effective charge 0·5. e for nucleons are for some of the cases in a good agreement with the experiment.