The far-infrared absorption spectra due to the two-phonon difference process have been observed. Peaks are found at about 27 and 35 cm⁻¹ in TlCl and at 35.2 cm⁻¹ in TlBr, which are due to saddle points in the difference energy surface of two phonons. The second order Raman spectra of TlCl and TlBr at low temperature have been measured and the assignments of the spectral peaks to particular combinations of two phonons are made. In the near resonant region, the scattering efficiency of the overtone of the LO phonon shows a more remarkable resonant behavior than that of other phonons. From the analysis of the experimental result by the theory of Ganguly and Birman, it is concluded that the two LO phonons at the Γ point are successively scattered by the exciton, while two phonons of other modes with finite wave vectors are, presumably, scattered simultaneously.

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Ultra fine palladium particles with the mean size of 20 A, prepared by VEROS (Vacuum Evaporation and Running Oil Substrate) method, were identified to be the same f.c.c. structure as the bulk specimen by X-ray diffraction method. The lattice parameter was found to be larger than the bulk value by an amount of 1.3%. From the profile analysis of the 220 Debye-Scherrer line the size distribution of the specimen was obtained, which is a very sharp distribution with a peak at 21±3 A. This result was confirmed by a direct measurement of electron micrograph.

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The experimental electron energy-loss spectrum is normalized by two different types of sum rules. Using this normalization method, the complex dielectric function for a finite momentum transfer can be obtained from an observed electron energy-loss spectrum alone. This method can be applied even to a broad spectrum with a low energy resolution, and the corresponding broad dielectric function can be obtained without any significant error. Such a property has never been obtained by any other normalization methods and makes it possible to study electronic structures in solid at least qualitatively even if the spectrum is measured with a low energy resolution.

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Spin-lattice relaxation time (T₁) and specific volume of trans-1,2-dichloroethylene were measured at high pressure. T₁-pressure curves at various temperatures had one or two jumps, and pressure dependence of specific volume had also a singular point besides the solidification.
Magnitude of the T₁ values and the compressibility indicated that the state is liquid above and below the singular points. It is confirmed that there are three liquid phases and the novel liquid phases are similar to the liquid crystals.

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We study burning processes in inertial confinement fusion driven by intense light ion beam (LIB) with a 1-D Lagrangian code. It is found that burning processes have two phases; they are an ignition and its propagation phase, and a recompression phase. In the ignition of nuclear reactions and its propagation phase, ρR is kept at 1.5 g/cm² but in the recompression phase ρR increases steeply up to 3.5 g/cm². An Au shell surrounding a DT fuel plays two roles in each phase i.e. in the former phase it acts as a tamper to confine the DT fuel and in the latter phase it recompresses the DT fuel to lead high ρR.

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Interaction between an ion beam and turbulent waves which are excited by an axial electron current in a beam-generated plasma along a magnetic field line is investigated experimentally. The correlation length λ_c of the turbulent waves is controlled and varied widely by changing the electron drift velocity. The energy spectrum of the ion beam passed through the turbulent plasma along the magnetic field line is measured with a 90° deflection electrostatic energy analyzer. When λ_c∼1⁄k_o, the maximum broadening of the energy spectrum of the beam due to the interaction with ion acoustic turbulence is observed where k_o is the characteristic wave number of the turbulent waves. When λ_c>>1⁄k_o, the broadening is found to be approximately proportional to 1⁄\sqrtλ_c. These experimental results agree with results derived from the theory of stochastic heating, qualitatively.

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A method to generate an electrical breakdown and a hot plasma in a high pressure gas is proposed. A boundary layer was formed transiently between high pressure gas and vacuum. The breakdown was triggered at this boundary with so low voltage that it was impossible to make a breakdown in the high pressure gas region. The quasi-equilibrium state was achieved between gas and vacuum magnetic field through the produced plasma-layer.

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The collective absorption of high intensity laser radiation is analyzed numerically. Density profile modification due to the ponderomotive force associating laser radiation and the excited electron plasma waves is self-consistently taken into account, and the intensity dependences of the absorption efficiency are obtained. In the high intensity regime, the absorption efficiency is found to be strongly enhanced in the plasma without flow, but reduced with supersonic flow.

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Two-dimensional MHD pinch simulation code, “TOPICS”, which includes the effects of the impurity ions, the neutral atoms and anomalous resistivity, has been applied to the investigation of the RFP-plasmas at the setting-up phase of the TPE-1R. Results from the simulations are compared with the typical two cases of the experiment: (a) the lower initial bias field and the higher plasma current density and (b) the higher initial bias field and the lower plasma current density.
By comparing the simulated and experimental results, it is found that the magnetic field profiles at the early phase of the RFP setting-up strongly depend on the ionization degree of the initial plasma and the largest increase is obtained by assuming the 50% ionization degree and the presence of 10% oxygen. It is also found from this study that the radiation loss due to 5 to 10% impurities is the dominant loss mechanism of the electron energy. The toroidal magnetic field profile inside the plasma calculated by using the isotropic anomalous resistivity is more peaked than that by the classical resistivity.

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The coalescence instability so far has been analyzed for the Finn-Kaw model in which parallel currents in neighboring islands tend to attract each other. The current distribution of magnetic islands resulting from the compressible tearing mode, however, is opposite to that of the Finn-Kaw model. It was found by simulations that the coalescence instability does not take place for magnetic islands generated by a tearing mode instability. An apparent coalescence is induced by an external force, but it appears to reflect the growth of the linear tearing mode instability with the wavelength longer than the original one.

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The ionization waves guided by H⁺ and H₃⁺ ions in the positive columns of H₂ gas is theoretically calculated by dissolving the variables in the basic equations. The frequency increases as the increase of the wavenumber with the minimum damping rate in a certain range of small wavenumbers. A forward wave property appears with the same directions of the group and phase velocities to the anode from the cathode. The theoretical dependences of the frequency on the discharge current and the gas pressure for the minimum damping rate agree with the experimental ones for the excited wave.

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The paper develops an exact analysis of MHD Falkner-Skan flow of an electrically conducting, incompressible viscous fluid. The existence of similarity solutions is demonstrated when the applied magnetic field is inversely proportional to the boundary layer thickness. Numerical solutions for velocity, temperature, skin-friction and rate of heat transfer are obtained. The numerical values of skin-friction and rate of heat transfer are tabulated and the velocity and temperature are graphically exhibited.

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Homogeneous two-dimensional turbulence in the presence of a mean flow is investigated using the modified zero-fourth-order-cumulant approximation. The homogeneity of turbulence is shown to be compatible with mean flows which have uniform velocity gradients, and among such flows the axisymmetric extension flow perpendicular to the plane of turbulent motions and co-planar flows with uniform velocity gradients are dealt with. In the former case, turbulence can be isotropic and a stationary state with a finite energy and enstrophy is shown to be possible. For the latter case, turbulence cannot be isotropic being distorted by the mean flow and no stationary state is possible since the enstrophy decays in time irrespective of the presence of the mean flow.

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The validity of the usual simulation method for a numerical solution of the Bhatnager-Gross-Krook equation is ascertained in two ways, firstly by using the probability theory and secondly by actually obtaining the simulation solution of such a problem as a temporal relaxation of a spatially uniform gas.

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We have experimentally investigated the propagation of a soliton in a nonlinear LC circuit with inhomogeneity and dissipation. In a homogeneous and dissipative circuit, the amplitude of a soliton decreases with the distance. The damping of a soliton is weakened if the inhomogeneity is introduced in a dissipative circuit, and the amplitude begins to increase in the circuit of strong inhomogeneity. The disintegration of soliton is not clearly observed in the present experiment. The experimental result is qualitatively explained by the Korteweg-de Vries equation with inhomogeneity and dissipation.

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The disintegration of solitons is observed in a nonlinear LC circuit with inhomogeneity. Experimentally the inhomogeneity is realized by connecting linear capacitors in the shunt branch parallel to the nonlinear capacitors or by changing gradually the inductance of linear inductors in the series branch. It is experimentally shown that the evolution of a wave in an inhomogeneous circuit depends on the initial amplitude of a soliton. The result is explained by the K-dV type equation taking account of the inhomogeneous effect.

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