Band structures of the ¹³⁵La, ¹³³La and ¹²⁹Cs nuclei have been studied by means of in-beam γ-ray spectroscopy following the (α, 2n) and (³He, 3n) reactions. The 11/2⁻ decoupled bands and positive-parity bands built on the 5⁄2⁺ and 7/2⁺ states have been observed. A new isomeric state of ¹²⁹Cs with a half-life of 0.69±0.03 μsec has been discovered.

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Low-lying excited states of ⁵²Fe were investigated by using the ⁵⁰Cr (³He, nγ) ⁵²Fe reaction at E_³He=8 MeV. A gamma-ray decay scheme has been proposed based on n-γ and γ-γ coincidence measurements. The lifetimes of four excited states, as well as the lower limit for the lifetime of the first excited state, have been obtained from the analysis of Doppler-shift attenuation measurements.

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In the light of the Higgs mechanism in the spontaneous breakdown of symmetry, we discuss the properties of quantized vortex in superfluid helium. We introduce quantum mechanically the depletion velocity field which couples with particle fields. The coulping constant needs not be assumed to be equal to m, the mass of the (helium) particles. We will define the vorticity in terms of the depletion velocity instead of defining it by the gradient of the phase of the condensate wavefunction. A possibility of the half-integer quantum of vortices is suggested.

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The temperature dependence of EPR frequencies is studied theoretically for pure and pseudo-one dimensional Heisenberg magnets by means of Mori’s theory of generalized Brownian motions. In a system with uniaxial symmetry, simple expressions for resonance frequencies are obtained. It is seen that the resonance frequencies are shifted from the Zeeman frequency when the magnetic susceptibility is anisotropic. Fisher’s classical spin model is used to calculate the spin correlation functions. The anisotropy of the magnetic susceptibility is found to be enhanced by an effect of the short range order. The pseudo-one dimensional systems are treated with the help of the mean field approximation to interchain interactions. The result is reduced to that of a pure-one dimensional system, when the interchain interactions are absent. The effects of interchain interactions are negligible for antiferromagnets even near the Néel point, whereas those for ferromagnets are divergent near the Curie point. Nagata and Tazuke’s expressions for a g-shift can be obtained from the present theory in an approximation .

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High momentum components in the momentum distribution of annihilation photons from Cu single crystal have been investigated using the crossed-slit rotating-specimen method. The obtained data have been analyzed by using a simple model based on the Wigner-Seitz approximation. Agreement of the calculated results with the experimental data is good in high momentum region, suggesting that, away from the zone boundaries, the “umklapp” annihilation rate does not strongly depend on the momentum. However, the observed intensity of the “umklapp” annihilation relative to the “normal” annihilation has been considerably smaller than that predicted by the Wigner-Seitz model.

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X-ray edge singularities in the spin-dependent final-state interactions have been calculated perturbationally in the most divergent term approximation for the photoelectron and absorption spectra of the narrow-band metals (and also the simple metals). For the ferromagnetic exchange couplings (J>0) of conduction electrons with the core-hole or the narrow-band electron spins S, the exchange interaction is found to make the two different contributions: (i) the Mahan threshold singularity is modified by a logarithmic factor (1–2ρJlog|ω⁄D|)^η, and (ii) the Anderson orthogonality exponent is increased by ζ(ρJ)², where η and ζ depend on the spin S multiplicity, and ρ and D are the density of states and the cut-off width of the conduction band, respectively. A possibility is pointed out that the edge singularities may be suppressed at the absorption threshold of the transition metals.

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The boundary conditions of hydrodynamic equations are formulated by introducing a phase shift into each hydrodynamic mode of a linearized Boltzmann equation. Its rigorous treatments are shown, and an analytic form of the phase shift is obtained for the BGK model.

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Approximate solutions of the nonlinear equation that describes the behavior of microwave-irradiated superconducting weak links are obtained. The method of the solution is based on the fact that the phase of Josephson oscillation is locked to an externally applied coherent radiation under a bias current of a microwave-induced step. It can be concluded that the approximate solutions have three internal variables which are functions of d.c. bias current and microwave current. The d.c. voltage-current relation when d.c. current is biased to a current step is found to follow Ohm’s law when the step vanishes. This result has been confirmed experimentally. The height of a current step as a function of the incident microwave current has been numerically calculated. The calculated values agree well with those obtained by an analog computer. The internal three variables have been also calculated numerically.

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The host ²⁷Al nuclear spin-lattice relaxation in the normal and superconducting states of the (La_1−nGd_n)₃ Al and (La_1−nCe_n)₃ Al systems has been studied for low impurity concentration and over wide ranges of temperature (1.2∼20 K) and field (6.8∼13.5 kOe). The measured relaxation rate 1⁄T₁ shows strong impurity concentration and field dependences in both the normal and superconducting states. An analysis of the experimental results indicates that the direct process induced by the longitudinal dipolar fluctuations of the localized magnetic impurity moment plays an important role. The results are compared with the pair breaking theory qualitatively in the vicinity of the superconducting transition temperature.

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Magnetic and crystallographic measurements on Fe_2.1−xMn_xAs with 0≤x≤2.1 are made in the temperature range between 77 and 600 K. The compounds with 0≤x<1.29 and 1.52<x≤2.1 have the antiferromagnetic spin structures of the Fe₂As and Mn₂As types, respectively. The compounds with 1.29≤x≤1.52 show a first order phase transition between the ferrimagnetic state of the Mn₂Sb type and the antiferromagnetic state of the Fe₂As type. A magnetic phase diagram of Fe_2−xMn_xAs system is proposed and discussed qualitatively on the basis of the molecular field theory.

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The nuclear orientation experiment on ⁵⁴Mn nuclei in Au metal and Au(Cr), Au(Mn), and Au(Fe) alloys have been made to study the nature of the spin glass and the Kondo effect in these alloys. Concentrations of impurities in the alloys were between 5 and 500 at. ppm and measurements were performed in the temperature range between 7 and 8 mK. Gamma-ray anisotropy from oriented ⁵⁴Mn in the Au(Mn) and Au(Cr) alloys can be explained by the 3-dimensional Lorentzian distribution function, when the molecular field approximation is applied to the spin glass state. For the Au(Fe) alloys, however, widths of the distribution function are less than those expected from the molecular field approximation, which may be attributed to the Kondo effect. Nuclear orientation of ⁵⁴Mn in Au metal is explained by the slow relaxation model with S_Mn=5⁄2. This indicates that the Kondo temperature of Au(Mn) is lower than 7 mK.

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A model for the temperature and the magnetization dependences of the magneto-crystalline anisotropy energy for Ni has been proposed based on the itinerant electron model by considering the effect of thermally excited magnons on the spin-orbit interaction. The temperature variation of K₁ at low temperatures can be expressed by the terms proportional to T^3⁄2, T² and T^5⁄2. Experimentally determined values of the coefficient of the term T^3⁄2 is 586 erg/cm³deg^3⁄2, and other terms are found to be negligibly small. This small value of the term T² can be expected from the present model. Experimental values of the magnetization derivative of K₁ at a constant field are found to be much larger than those at a constant temperature, and this fact can also be explained by the present model.

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Nuclear magnetic resonance and nuclear spin-lattice relaxation of ⁴⁵Sc in an itinerant-electron ferromagnet Sc₃In have been studied in both ferro- and paramagnetic states. The temperature dependences of the Knight shifts and susceptibilities give the hyperfine field due to d-spin of +58.4kOe per Bohr magneton per Sc atom suggesting strong s-d admixture in the wave function at the Fermi surface and the d-spin contribution to the susceptibility. The external field dependence of the internal field at ⁴⁵Sc has been measured and analyzed in terms of the hyperfine fields proportional to d-spin moment and the external field. The observed magnetic field dependence of (T₁T)⁻¹ in both states is explained very well by the self-consistent renormalization theory of spin fluctuations in which the effect of magnetic field was taken into account, in conjunction with the negative magnetoresistance measured by us.

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The nuclear magnetic relaxation of ⁵⁹Co in dilute Cr_1−xV_xCo (x\lesssim0.05) and Cr_1−xMo_xCo (x\lesssim0.25) alloys in the ordered state was investigated. T₁ is proportional to 1⁄T in the region of T<<T_N. T₁T decreases rapidly with the decrease of the ordering temperature associated with the increase of x. This decrease of T₁T with the decrease of the ordering temperature is generally observed in randomly ordered systems in metals irrespective of the ferro and antiferromagnet. Approximate model calculations based on the Weger mechanism, where the nuclear Zeeman energy relaxes to the kinetic energy of the conduction electrons via the virtual excitation of the spin waves, have been carried out in PdCo, whose T₁ was already measured, and in CrVCo alloys. The experimental results are explained qualitatively well by the Weger mechanism.

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The temperature dependence and the magnetic field dependence of the resistivity of polycrystalline α-Mn metal were measured between 1.3 and 20 K in external transverse and longitudinal magnetic fields of up to 100 kOe. The anomalously large coefficient of the T² term in the low-temperature resistivity of α-Mn was found to decrease appreciably for increase in the applied magnetic fields. These results are interpreted in terms of the suppression of spin fluctuations in the antiferromagnetic α-Mn by the high applied fields. The magnetic field dependence of the resistivity, which was corrected for the effect of cyclotron orbital motion, is shown to be a linear function of the applied fields.

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The Grüneisen parameters of alkali metals (Li, Na, K & Rb) have been computed at various temperatures from the experimental and the recent theoretical values of the pressure dependence of the elastic constants, using an improved CGW model for their lattice dynamics. The computation is carried out by a modified Houston’s method in which the integral is evaluated by a six term approximation. The Grüneisen parameters calculated in our present study show reasonably satisfactory agreement with experimental observations.

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Angular correlation of positron annihilation radiation in Cr and Mo were measured. Self-consistent band structure calculations for Mo were carried out by the APW method with state-dependent potentials. Theoretical angular correlations for Cr and Mo were also calculated by the APW method. Observed fine structures on the angular correlations and the crystalline anisotropies were well reproduced by the calculations. However, when the theoretical and experimental correlation curves were normalized to an equal area, the theoretical curves were consistently lower in counting rate than the experimental ones in small angle region, and higher in large angle region. This type of discrepancy between the theory and the experiment is the same as we previously found in V and Nb, and is ascribed to the electron-positron correlation effects.

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The electronic band structure of the first-stage potassium-graphite intercalation compound C₈K was calculated by a semi-empirical tight-binding scheme. The calculated Fermi surfaces can be classified into two distinct types. One is potassium-like and nearly isotropic; the other is carbon-like and of cylindrical shape. In addition, the cylindrical portions show nesting property, which is likely to induce charge-density-wave instability. The isotropic portions of the Fermi surfaces are responsible for the large reduction of anisotropy in conductivity of C₈K relative to graphite. The calculated density of states has a peak around the Fermi level and is in good agreement with the observed density of states derived from the specific heat measurements.

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A point detector geometry with a resolution of 0.7 mrad. by 1.1 mrad. has been used to study the Fermi surface for several α phase alloys of CuGe. The variation of the [111] neck diameter and the [110] Fermi radius has been determined as a function of germanium concentration. Comparisons are made with previous work on this and other copper alloy systems, and also with the rigid band predictions.

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Annealing profiles of vacancies in zone-refined aluminum were studied by electrical resistance measurement after quenching, and discussed under either assumption of uniform distribution of dislocations or non-uniform one. The annealing curves calculated for the non-uniform distribution of dislocations, using E_m¹=0.65 eV, E_m²=0.50 eV and B₂=0.17 eV, show the excellent fit to the experimental annealing curves. It is suggested from such an analysis that the annealing experiment should be made on the specimen with a controlled dislocation density and configuration in order to clarify the fundamental properties of point defects in metals.

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The Ti Kβ X-ray spectra of metallic titanium and its oxides the precisely measured with a two-crystal spectrometer. It is found that the Ti Kβ_1,3 line width is strongly affected by the oxygen concentration. The behavior is interpreted as being due to the interaction between 3d electrons and a 3p hole produced upon emission of the Kβ_1,3 radiation. Also, the screening effect of 4s conduction electrons seems to play an important role in reducing the width at relatively low oxygen concentration.

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The structure of liquid Au–Co alloys with 10, 20, 27, 30, 35 and 40 at% Co has been examined by X-ray diffraction. The shape of all these structure factors is very close to that of liquid gold and no additional peak and deformation in the structure factor S(Q) were confirmed. The temperature dependence of S(Q) for liquid Au-27 at% Co alloy has been also carefully investigated at six temperatures above the melting point and no anomalous behaviour was observed.

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Isolated D⁻ states in Sb-and As-doped germanium crystals have been studied by means of long-wavelength (submillimeter plus millimeter) photoconductivity measurements with a lamellar grating Fourier transform spectrometer at an extremely low temperature, 0.38 K. The electron binding energies of the isolated D⁻ states are accurately determined and the shift of the D⁻ state energy is clearly observed between the samples with different impurities. The many valley effect of the conduction band on the D⁻ state energy is confirmed by comparing the spectra under high [111] stress with those of stress free. The energy shemes of the D⁻ states in Sb-and As-doped germanium crystals are clarified.

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The binding energies of a D⁻ ion in the stress free and high stress cases are calculated with use of the Chandrasekhar type variational function. In the approximation of neglecting the valley-orbit interaction, the ionization energy of an electron from a D⁻ ground state to a conduction band in the intravalley electron configuration corresponds to the D⁻ binding energy in the high stress case while that in the intervalley configuration to the binding energy in the stress free case. In the former case the calculated value is the half of the observed one while in the latter case the calculated value is in fair agreement with the observed one. The energy difference between two cases is mainly due to the difference between the intra-and inter-valley Coulomb interactions.

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The photoelectron spectra of PbCl₂, PbBr₂ and SnCl₂, which have the lead chloride-type crystal structure, have been measured with X-rays and extreme ultraviolet rays in order to investigate the electronic structures of their valence bands. The photoelectron spectra of TlCl and Pbl₂ have also been measured for comparison because they have the same electronic configuration as PbCl₂ et al. though the crystal structures are different. It was found that the spectra of all above materials have a common feature, namely, the bands observed in the valence region consist of two parts, the lower binding energy band being much more intense than the other, and it further splits into three. It has been concluded that the higher part of the valence band of these crystals (the lower binding energy band) is mainly composed of p electrons of halogen ions but considerable admixing of metal s electrons is present.

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It is shown that an electron and a hole interacting mutually through the Coulomb force in the acoustic-phonon field take, within the adiabatic approximation, four possible phases depending upon the coupling constants: the lowest state is the free exciton in phase[I], the large-radius self-trapped exciton in [II], the small-radius self-trapped exciton in [III⁺], and a pair of self-trapped electron and self-trapped hole in [III⁻]. The center-of-mass motion of exciton changes discontinuously to be self-trapped as one moves from [I] to [II] or [III⁺] with increase in the phonon-coupling constants. The relative motion of exciton changes discontinuously to be self-shrinked as one moves from [I] or [II] to [III⁺]. [III⁺] and [III⁻] are realized respectively for the same and opposite sign of the deformation potentials of electron and hole. When the Coulomb interaction energy is so large as to be comparable to the electron and hole band widths, discontinuous boundary between [II] and [III⁺] disappears.

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Forward Raman scattering of excitonic molecule in CuCl has been studied at the giant two-photon excitation with using laser light having a wave vector K₀ but three different half band-widths, 0.2, 1.4 and 2.5 meV. In cases of laser excitation with broader half band-widths, the Raman and luminescence processes coexist and give emission lines called (LEP)_R and (LEP)_B, respectively. Both lines show the similar dependence of energy change upon the scattering angle. The (LEP)_R and (LEP)_B lines show red and blue shift, respectively, with the increase of laser excitation intensity. The excitonic molecule-state generated at K=2K₀ is responsible for the (LEP)_R line, while the (LEP)_B line is considered to arise from a state having a certain K value smaller than 2K₀. Excitonic molecules generated coherently by the giant two-photon excitation are assumed to relax towards K=0 with keeping their individual momentum at almost the same value.

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Following a previous paper, the present paper also investigates incommensurate modulation in K₂SeO₄. While the direction of modulation previously was assumed ⁄⁄ x, it presently is assumed ⊥ x. Directions ⊥ x are represented by the y axis for simplicity’s sake. In view of the number of equivalent wavevectors, the transition parameter system adopted for the x axis cannot be entirely analogous to that to be adopted for y; this new system is determined. The thermodynamic potential function is found. A certain number of possible ferroic phases are deduced, which include phases incommensurate along one or both of the x and y axes. The problem “To which of these ferroic phases should the prototypic phase change if the transition is assumed second order?” is solved.

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The behaviours of two kinds of radicals, NH₃⁺(α) and NH₃⁺(β) in the γ-irradiated ammonium sulfate crystals were examined in more detail. Above T_c each radical flipped between two stable configurations around the a–b plane with the frequency higher than 10⁸ sec⁻¹, but below T_c it tilted from the a–b plane with a certain angle. One half of the flipping angle was two or three times as large as the tilt angle. Based on the results a microscopic model for the ferroelectric phase transition of ammonium sulfate was considered. In the model it was assumed that at T_c the SO₄²⁻ tetrahedron was newly deformed owing to the correlated movement in the NH₄⁺(α)–SO₄²⁻–NH₄⁺(β) bonding and an abrupt increase of the dipole-dipole interaction energy occured. The small Curie constant of ammonium sulfate can then be explained satisfactorily by the model.

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It is shown that (011) and (031) twin planes can be introduced in the orthorhombic phase of K₂SO₄ and K₂SeO₄, and both twin planes can be moved smoothly through crystals by appropriate external stress in the temperature range from about 300°C to the orthorhombic-hexagonal phase transition point. It is inferred from the crystal structure in the orthorhombic phase that SO₄⁻⁻ (or SeO₄⁻⁻) radicals must have two stable states (the up and down states), and change from one state to another during the passage of twin planes. It is suggested that the space group of the hexagonal phase is D_6h⁴–P6₃/mmc, and the hexagonal-orthorhombic phase transition is essentially due to the ordering of SO₄⁻⁻ (or SeO₄⁻⁻) radicals.

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Precise dilatometric measurements of TGS revealed an existence of a distinct departure in the coefficients β₂ of thermal expansion from the mean field theory (MFT). In the reduced temperature range, −3.17<log₁₀−t<−1.87, the data of β₂ fit well to the formulas given by a connection between the Larkin-Khmel’nitskii theory (LKT) and the Pippard relations. The fitted formulas explain satisfactorily also the behavior above T_c, except for the close vicinity of T_c considered as the region of ‘rounding’. In the wide range, 80 K to 321 K, a good agreement with the MFT is obtained by taking suitable parameters. The jump Δβ₂ derived from the MFT-fit is comparable with the corresponding value in the LKT. A comparison between the results of TGS and dipolar Ising ferromagnet LiTbF₄ was made.

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Dielectric properties were studied on fourteen langbeinite-type crystals. Measurements were performed in the temperature range 20∼−196°C for single or polycrystalline samples. It was newly found that five crystals undergo phase transitions; (NH₄)₂Mg₂(SO₄)₃ at −52°C, (NH₄)₂Ni₂(SO₄)₃ at −113°C, K₂Co₂(SO₄)₃ at −147°C, (NH₄)₂Ca₂(SO₄)₃ at −115°C and Rb₂Ca₂(SO₄)₃ at −90°C. A tentative discussion is made to classify the bahaviors of phase transitions in langbeinite family in respect to the lattice constants and ionic radii of constituent ions.

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A nonlocal phenomenological equation is introduced for a multicomponent fluid where chemical or nuclear reactions are taking place. The reciprocity between the nonlocal linearcoefficients is examined closely. An approximation reduces the nonlocal equation to the ordinary phenomenological relation with correction terms which show clearly a coupling of the reaction with the diffusion and the thermal conduction in an isotropic system.

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The electrical conductivity is calculated in the single-bond coherent-potential approximation for the electrons in the disordered lattice with only the fluctuation of transfer energy. The results are discussed in connection with the behaviour of the mobility edge, determined recently by Economou and Antoniou, as a function of the magnitude of fluctuation of transfer energy.

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Dissociative chemisorption process of a molecule on a metal surface is discussed through the Anderson model. The density of states, the bond order, and the potential energy curve are calculated for various values of molecule-metal coupling constants.
A qualitative explanation is given for the reason why the activation energy of H₂-dissociation is larger on a Cu surface than on a Ni surface.

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For the B¹Σ_u⁺ and b³Σ_u⁺ states of the H₂ molecule, CI calculations are carried out using a small basis. The mixing of Rydberg and valence-shell characters in these states is analyzed for a wide range of internuclear distance (1.4 a.u.≤R≤10 a.u.). The B¹Σ_u⁺ state shows a complicated R dependence. It is Rydberg type in small R(1.4 a.u.≤R≤2.44 a.u.), a heavy mixture of valence-shell type and Rydberg type for intermediate region (2.44 a.u.<R<6.0 a.u.), and Rydberg type for large R(R≤6.0 a.u.). The b³Σ_u⁺ state, on the other hand, changes rapidly from Rydberg type to valence-shell type at R=2.0 a.u. when R increases. During the course of the above analysis an index to the degree of the mixing is found. This index would be useful in discussion about Rydberg and valence-shell characters.

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Several patterns are observed in the electrohydrodynamic instability of binary mixtures of nematic and cholesteric liquid crystals. The phase diagrams are obtained for the composition and frequency.

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The dielectric constant and dielectric loss of ethyl trichloroacetate in non-polar solvents were measured at eight microwave frequencies at 25°C. In cyclohexane and p-xylene solutions, the Cole-Cole plots for ethyltrichloroacetate were symmetrical, but the plot was unsymmetrical in p-dioxane solution. The data were also analysed using two relaxation times τ₁ and τ₂, which were associated with the overall and group relaxation processes of molecules, respectively. The overall relaxation time τ₁ increased in the solvent order; cyclohexane<p-xylene<p-dioxane. This fact indicates that the solute-solvent interaction, mainly the dipole-induced dipole interaction, increases in the solvent order.

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The electrostatic ion stoppering in a magnetic mirror field is demonstrated experimentally in rather high plasma density (10¹⁰<n₀\lesssim10¹³cm⁻³). The ion loss from the mirror throat expressed by a loss factor δ, is reduced to about one quarter of the initial value. It is discussed as a confinement mechanism of ions that particles are reflected back adiabatically by the electrostatic field at the mirror throats of the magnetic field.

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The fast magnetosonic waves in cylindrical and inhomogeneous plasmas propagating towards the axis are studied by a computer simulation and a theoretical analysis. The velocity and amplitude of the wave excited by a magnetic field perturbation increase due to the cylindrical and nonlinear effects.
The propagation characteristics of the fast magnetosonic waves depend on σ²⁄2, the ratio of amplitude to the square of frequency. The large amplitude soliton-like pulses are efficiently excited for 1\lesssimσ²\lesssim100 by a positive half cycle of a sinusoidal wave. The wave packets are produced for σ²\gtrsim1 by a sinusoidal perturbation.

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The instabilities of electron cyclotron harmonic waves due to the anisotropy of the electron velocity distribution produced by the injection of the electron beam perpendicular to the magnetic field. A strong spontaneous emission growing up 60 dB above background noise appears near the electron cyclotron harmonics. This instability cannot be launched or sychronized by external modulation. The amplitude is usually not steady in time, but switches off and on in time intervals of 10∼100 μsec. It grows exponentially in time initially, saturates and disappears. This instability can be explained by dispersion relations of electron cyclotron harmonic waves propagating perpendicular to the magnetic field in a plasma with a mixture of ring and Maxwellian electron distributions. The measured growth rate is smaller by 2 to 5 times than the theoretical ones.

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Ion heating by the strong current in the Texas Turbulent Torus has been investigated with the charge exchange fast neutral measurement with respect to correlation with a current penetration into the plasma column. At relatively low density (n≅2×10¹² cm⁻³), the number of heated ions increases as the current penetrates into the central region of plasma column until the current peak (t≅1.5 μsec). Ion energy distribution function is Bi-Maxwellian and bulk ions are heated up to temperature in excess of 300 eV at about 200 nsec from the start of heating current. Temperature of the high energy tail, of which population is several % of total ions, increases to a maximum temperature of 3.5 keV at 0.8 μsec. At high density (n≅7×10¹² cm⁻³), temporal evolution of radial distribution of heated ions shows that energetic ion production is restricted within the skin current region during 1.5 μsec.

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It is shown by computer simulations that a diverging thermonuclear reaction wave in a high density plasma is an accelerating overcompressed detonation. The propagation stages of the reaction wave are classified according to different processes of energy transfer such as the α-particle diffusion, the shock heating and the electron thermal conduction. The front of the reaction wave consists of the shock compressed region proceeded by a pre-heating zone, where the effect of α-particle diffusion exceeds that of the electron thermal conduction.

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In a weakly ionized plasma with a perpendicular electric field E_⊥ and an axial magnetic field B, ion temperature has been observed to be approximately proportional to (E_⊥⁄B)². The observed ion heating is well explained by simple calculations based on a Joule heating which is caused by E×B drift.
The transient process of the heating is also investigated in a pulsed experiment, a loss of the initial cold ions and a slow production of hot ions have been observed.

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A new type of impurity drift instability is studied in the limit of short mean free path. The mode is driven by the ion parallel viscosity, and is stabilized by the collisional diffusion across the magnetic field when the impurity concentration is less than a certain value. This coincides with the stability condition for the collisionless impurity drift mode.

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Three-dimensional nonlinear Schrödinger equation for an electrostatic ion cyclotron wave coupled to an ion acoustic wave is derived with the use of the reductive perturbation method. Electrons are assumed to obey the Boltzmann law under the influence of the electrostatic potential. Cold fluid equations are used for the ions. Instability of a plane electrostatic ion cyclotron wave against a two-dimensional modulation is investigated and the unstable regions are graphically plotted in the wavenumber space.

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A statistical-mechanical analysis is made of Kolmogoroff’s−5⁄3 power law in the inertial subrange of turbulent field. This paper proposes a method of removing the divergence of the response equation at low wave numbers, which is caused by the convection of small eddies by big ones and is a stumbling block to the analytical derivation of Kolmogoroff’s spectrum. Results obtained are in good agreement with the experimental value of Kolmogoroff’s constant.

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A systematic method for isolating certain nonlinear partial difference equations that exhibit solitons is proposed. A nonlinear partial difference equation which approximates the Korteweg-de Vries equation in the weakly nonlinear and continuum limit, is obtained. N-soliton solutions, the Bäcklund transformation and the inverse scattering transform for this equation are presented.

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The behavior of a slightly rarefied vapor gas flowing around its spherical condensed phase is investigated on the basis of the linearized BKW (or BGK) equation and the diffuse reflection boundary condition.
It is shown that the pressure field induced by velocity field plays an important role. The condensation occurs over the front part of the condensed phase and the evaporation over the rear due to this pressure field. This interphase transfer process reduces the total drag acting on the spherical condensed phase.

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The nonlinear self-dual network equation is exactly solved by the inverse scattering method. The equation is the discrete version of the modified Korteweg-de Vries equation with negative dispersion coefficient. Considerating the integral on the Riemann surface, the Gel’fant Levitan (Marchenko) equation is obtained. Soliton and shock wave solutions with non-zero asymptotic values are given.

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