The hyperfine interaction of the carriers in semiconductors (involving the Fermi-contact and noncontact terms) has been treated by a "pseudo-contact interaction", which acts on the effective mass wavefunction. For the Si29 nucleons and the holes in silicon, it can be represented by {S1(Jxμnx+Jyμny+Jzμnz)+S2(Jx3μnx+Jy3μny+Jz3μnz)}δ(r-rn). The coupling parameters S1 and S2 are certain integrals conn...
Using the 24-litre propane chamber, photographs from JINR π0-meson production in inelastic interactions of π--mesons of momentum 6.8 GeV/c with nucleons are examined. About 2700 pairs of stereoscopic pictures have been scanned and 1275 events of π--N inelastic interactions have been found in an effective region 29.3 cm wide. In these events, 936 π--p and 339 π--n events, 240 and 89 electron-positr...
The ion-optical properties of the accerlerating tube made of a series of coaxial cylinders in a DC accerlerator have been investigated. The potential distribution in such an accerlerating tube has been found both theoretically and experimentally by means of an electrolytic trough. The field in the accerlerating tube is found to be not exactly uniform as usually considered but it should also consis...
It is proved that for a class of nonlocal potentials, the S matrix element S(λ,k) as a function of the angular momentum λ is meromorphic in λ in the region Re λ > 0. It is proved further that as λ→∞ along the positive real axis or the negative imaginary axis, [S(λ, k)-1] exp(-iπλ)→0. Under more restrictive assumptions, it is shown that S(λ, k) is meromorphic with respect to the momentum variable k...
The energy spectra of π0 in Kμ3+ and Ke3+ decays, and the energy spectrum and longitudinal polarization of μ+ in Kμ3+ decay have been calculated by the dispersion relation method on the assumptions that 1) the weak interaction is of a universal V-A form and 2) the strange vector current is not conserved. Consequently one subtraction is made for each of the dispersion relation for the form factors ...
In this paper, the effect of electron-phonon coupling on the bandwidth of impurity absorption has been considered with a one-dimensional model of crystal lattices. The eigenfunctions of lattice vibrations in the presence of an impurity have been seriously treated by using a field theoretic method. The strength of electron-phonon coupling was obtained in analytical form as a function of the wave nu...
It is shown that in the direct product of two wave vector stars k?k′, if k"∈k?k′, the wave vector group, Gk", may belong to any one of the following cases: A) Both Gk and Gk′ are subgroups of Gk"; B) Gk=Gk′= Gk"; C) Gk" = Gs; D) Gs is the subgroup of Gk". The reduction of an integral A=μ″i″(k″)|fμi(k)|fμ′i′(k′)>, is then studied for each of the four cases. It is found that for all cases, the value...
The heat capacity of Nb3Sn has been measured between 16.0°K and 20.3°K. A jump in specific heat at Tc is found with ΔC = 2.21 (±5%) joule/mole·deg. The transition temperature of the sample is Tc= 17.88°K, and the transition interval is ΔTc ≈ 0.2°K. From the measured ΔC and by using the thermodynamic relationship, the thermodynamic critical magnetic field at 0°K, H0≈5300 Oe, was obtained. Using the...
A simple two-band model was used to investigate the influence of the multiconnec-tivity of the Fermi surface on the properties of superconductors. It was shown that the effect is analogous to that of anisotropy. The effect of impurity scattering was considered by the Green's function method of Абрикосов and Горъков. There is a unique energy gap for both bands in the presence of impurities. The new...
The ordering of the alloy AgAuZn2 has been studied by means of X-ray diffracto-metry. The specimens were quenched from 600℃ and subsequently annealed at 100℃ for various periods of time. It was shown that in the quenched condition almost all of the Zn atoms were at their appropriate lattice sites, whereas the Ag and Au atoms were comparatively less readily to occupy their right places. A very shor...
The crystal structure of FeGa3 has been determined by means of Debye-Scherrer photographs. The unit cell is tetragonal, with a = 6.2628? and c = 6.5559? at 20℃. There are four formula units per unit cell. The space group is D4h14——P42/mnm. The four Fe atoms are situated at the 4(f) positions, while the twelve Ga atoms are situated at the 4(c) and 8(j) positions, the atomic parameters being xf=0.34...
Starting from the discussion of analytic properties and using the Landau relation to improve the diagrammatic technique of Dzyaloshinskii, the Feynman diagrammatic technique for double time dependent causal Green's function is established. There is a correct limit of zero temperature and may be used to calculate the various dynamical properties of nonequlibrium processes.
After systematic experimental investigations, the chief factors which influence the sensitivity, stability and resolution of the ESR spectrometer have been ascertained. Effective means of improving these characters have been worked out. As a result, the sensitivity has reached 2.7×10-12M DPPH. (RC = 2sec., microwave power into cavity ≈l0mw.). The resolution has been found to be better than 1×10-4....