Elastic and inelastic scattering of 28.5 MeV alpha-particles have been investigated.
Blair’s phase rule is fairly well satisfied in forward angles (<90°) with a few exceptions. Some anomalous diffractive patterns were obtained for 4⁺ states in O¹⁶, Ne²⁰ and Mg²⁴, which have some common feature with each other. A relatively large yield from a doublet at 6.88 MeV in Si²⁸ seems to contradict the current assignment of spin-parity of the doublet.
The inelastic scattering from unnatural-parity states in these nuclei shows a diffractive pattern and the relation between the phase and the angular momentum transfer is similar to the Blair’s phase rule in spite of the reverse parity, except in the case of O¹⁶ where the relation is almost reverse. The reaction mechanism is considered most probably to be a successive multiple excitation and/or an exchange process.

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The behaviours and properties of a defect introduced into high purity p-type silicon by γ-irradiation at 82°K, which is considered to be a single vacancy, were investigated by means of Hall coefficient and resistivity measurements. It anneals out between about 150°K and about 220°K. This defect shows a character of net acceptors, of which the predominant energy level is located at about 0.2 eV above the valence band. This means that the 5 electron model of a single vacancy should be adopted. Some experimental results pertinent to divacancies in p-type silicon were also obtained.

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ESR experiments were performed to clarify possible origins of the additional spin resonance, i.e., so called “new” resonance observed in Sb-doped Ge by Pontinen and Sanders.
All of ESR experiments and application of uniaxial compressive stress were done at liquid helium temperatures. Appearance of the new resonance has a definite relation with the pulling direction of the crystals. By application of the stress, changes occurred in the new resonance lines. After removing the stress, the spectrum changed to donor electron resonance in the first kind of samples. In the second kind of samples, slight change in intensities was observed. In a particular sample, an aging effect was observed. These results can be qualitatively understood by the idea proposed by Keyes and Price.

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A model of three-band conduction is proposed to explain the magnetic-field dependence of Hall coefficient and the deviation from the H²-dependence of magnetoresistance, which are observed in high purity bismuth at temperatures above the liquid hydrogen temperature. The present model takes into account the effect of thermally-excited light holes as the 3rd carrier. In the model of two-band conduction so far assumed, the field dependence of the galvanomangetic effects in pure bismuth has been interpreted in terms of the unequal number of electrons and holes, while, in the present model, the Hall coefficient is expected to have the magnetic-field dependence even in a perfectly pure bismuth in which the number of electrons and holes is equal.

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When a small amount of silver is added to the copper metal, there appears electric field gradient at copper atom sites surrounding silver atoms. We have calculated the electric field gradient arising from the redistribution of conduction electrons which are scattered by the displaced copper atoms. The present result explains reasonably the observation by Redfield. A distinctive feature of our result is that the electron charge density shows a cubic anisotropy having the well-known oscillatory behavior with distances from each impurity atom.

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The semiconductor to metal transition in VO₂ is discussed in connection with the crystal distortion on the basis of a simplified one-dimensional model. It is shown that a localized electron state forming ion pairs will be stabilized at low temperatures when the transfer energy makes a sudden increase for a small contraction of ionic distance. The occurrence of the semiconductor to metal transition is explained by the stabilization of the delocalized state at high temperatures due to the excitation of electrons from the bonding to the antibonding state in each ion pair.

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Both the diagonal and the off-diagonal parts of the magnetic susceptibility tensor are calculated by examining the limit, ω→0 and q→0, of the frequency and wave-vector dependent dielectric tensor, ε_ij(q ω). It is shown that the diagonal part reduces to the expression obtained by Hebborn and Sondheimer. Gauge-invariance of the formalism is made explicit.

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The effect of solute concentration, heat treatment and ageing on the strain amplitude dependence of internal friction in Al-rich Al-Cu alloys containing 0.5, 1.0 and 2.0 wt. % Cu has been investigated. The internal friction of quenched alloys is generally found to decay for all the cases during room temperature ageing, except for Al-2% Cu alloy, where it increases temporarily after an initial decrease at the beginning of measurement, and then decreases. The results are discussed in terms of possible clustering, handling strain and dislocation climb, and also in the light of the dislocation damping model of Granato and Lücke.

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The specific heat of a ferrimagnet Co₂TiO₄ which has a spinel structure was measured between 2°K and room temperature. An anomalous heat due to a magnetic transition was observed. The Curie temperature is found to be 49.0°K. The total entropy of the transition is approximately Rln8 which suggests that the degeneracies of ground states of Co²⁺ ions in tetrahedral and octahedral sites are fourfold and twofold respectively. The Debye temperature is 560°K. The observed magnetic specific heat below about 30°K shows the modified T^3⁄2 dependence which is predicted from the spin wave theory taking into account the anisotropy energy, except at very low temperature. The effective anisotropy field, 2K⁄M_S, is 4.8×10⁴ Oe. The absolute magnitude of the exchange Interaction of the spin, 3/2, of a Co²⁺ ion in a tetrahedral site with the fictitious spin, 1/2, of a Co²⁺ ion in an octahedral site, J_AB′, is evaluated to be 3.23 k_B.

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The effects of sintering ambient and cooling procedure on the electrical resistivity of Gd-doped polycrystalline BaTiO₃ have been investigated. Effects of thermal annealing in air on the resistivity-temperature characteristic have been also studied, of Gd-doped specimens as well as reduced BaTiO₃ both in polycrystalline and single crystal forms. The specimens sintered in nitrogen or those sintered and followed by quenching in air have been found to be semiconducting in a wide range of Gd content (0.2∼1.0 atomic %). The high resistivity of highly doped specimens, obtained by the usual sintering process, results from the oxidation during cooling in air. The resistivity anomaly at the Curie point of some reduced single crystals is shown to be surface effect. The PTC anomaly of resistivity in polycrystalline materials may be due to oxidized grain boundary. The oxygen partial pressure during cooling is more effective for the PTC anomaly than that during sintering.

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The formation energy and the formation entropy of a single vacancy in copper were obtained by quenching method to be (1.06±0.07) eV and (−0.3±0.9)k, respectively.

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Proton magnetic resonance spectra of benzene, aniline and like molecules confined in the cage of the dicyan-ammine-nickel clathrate have revealed that all the trapped molecules other than benzene are generally fixed in the cavities except for the reorientations of their constituent atomic groups. Benzene is the only one exception studied so far to the fact that the rotational transition of the trapped molecule occur at temperature lower than that of the molecule in its own crystal. A height of the potential barrier to rotation of the trapped benzene molecule was found to be 4.0 kcal/mole. The shift of the resonance line of the trapped benzene molecules at 4.2°K has confirmed that no electronic binding exists between the benzene molecule and the nickel ions. Disappearance of the proton resonance line has been noticed in benzene clathrate at about 2°K.
The adduct of cyclohexane molecules trapped in the channel of thiourea, is also examined in comparison with the results of solid cyclohexane.

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The Born approximation is applied to the study of relative importance of various parts of the interaction between an incident electron and a hydrogen molecule in exciting vibration of H₂. It is found that the polarization force is most important. Then the distorted wave method is applied to obtain a more reliable cross section. The resulting cross section has a magnitude comparable to experimental data reported by Engelhardt and Phelps and by Schulz. The calculated cross section is finite over the whole energy region beyond the threshold in contrast with Schulz cross section which is negligibly small until the incident energy becomes nearly twice the threshold energy.

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The small amplitude plasma oscillations of a fully ionized plasma, in which collisions are neglected, in a constant external magnetic field are studied by expanding the velocity distribution about its equilibrium value. Use is made of full set of Maxwell’s equation. It turns out in the case of a one component electron plasma the dispersion relation (which shows jumps in the frequency spectrum) for longitudinal oscillations in a plane perpendicular to the magnetic field has no solution for ω<ω_e (ω and ω_e being the frequency of the wave and cyclotron frequency respectively) while for low values of β (=Particle pressure/Magnetic pressure) the system is stable to transverse oscillations in the high frequency limit i.e. ω>ω_e.

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The characteristic electron energy loss spectra of Ag-Au alloy are studied at various compositions using the Möllenstedt-Watanabe type analyzer at 30 KeV. The energy spectra do not show remarkable change in all range of composition. The energy loss due to the plasma oscillation decreases continuously from 3.5 eV to 2.65 eV with increase in the Au concentration. Comparison with the results of optical measurements shows that the 2.65 eV loss in pure Au the surface plasma.

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Alfven wave transmission at 52.6 Gc has been observed and studied for all the principal directions of bismuth. The results are seen to agree fairly well with theory based on either the one fluid model or the plasma dielectric constant, and two modes are observed in the general case. The field at which the Alfven wave propagation is attenuated has been studied in terms of the appropriate cyclotron resonance term in the conductivity tensor. For the case of propagation parallel to the bisectrix axis, transmission is possible down to at least 750 oersteds because the heavy hole cyclotron resonance is not excited. The doppler shift in this cut-off field is also calculated. When thin samples were used, evidence was found for “split modes” for some orientations. The origin of this effect was not studied in detail. Finally, an attempt was made to look for “giant quantum oscillations” at T=1.8°K, but none was observed.

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Some examples of resonance phenomena in a magnetoplasma are investigated. First, the energy loss by a sequence of fast charges moving across the magnetic field is calculated. In the resonance regions where the ratio of the plasma frequency ω₀ to the cyclotron frequency ω_H satisfies certain conditions the energy-loss rate has a dominant term proportional to ln(v⁄v_T). Here the velocity v of the charge of the sequence is assumed to be much larger than the thermal velocity, v_T, of the plasma. Next, the energy loss by a charge gyrating in a plane perpendicular to the magnetic field is calculated. The rate in this case is the same as that of the first case in the off-resonance regions, while in the resonance regions there is a little difference between the two cases.

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On the basis of the cavity picture of Fabry Perot resonator which we have developed previously, a theory of deformed resonator is presented, and applied to the circular Fabry Perot resonators with a tilted mirror and a curved mirror. The loss of the resonator is expressed as the imaginary part of the diagonal element of the radiative perturbation matrix, in the representation by the eigenfunctions of the closed resonator with the mirror deformed. The radiation loss per one transit is given for the tilt deformation by the concise formula: δ_d=A_lmN^−1.5+B_lmK²N^0.5, where N≡a²⁄μL, a denotes the radius of disc, L the axial length, μ the wave length and K the ratio of maximum deformation to the wave length, i.e. K=Da⁄μ where D is the tilt angle. For the curve deformation, δ_d=A_lmN^−1.5±C_lmKN^−0.5, where K=a²⁄2Rμ, R denotes the radius of curvature, and ±refers to the negative or the positive curvature of the mirror. A_lm, B_lm and C_lm are constants corresponding to the modes of resonance and numerically tabulated in the tables. It is seen that, as the tilt deformation K increases, it becomes possible for some higher modes to have the least radiation loss, and a map for the modes of the least radiation loss is drawn in a N-K diagram.

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The steady slow flow of an incompressible viscoelastic fluid in a conical duct has been analysed by using Oldroyd’s constitutive equations for an elastico-viscous fluid. The method of solution is one of successive approximation, in which it is assumed that the velocity components, pressure, etc. can be expanded in ascending powers of a suitable dimensionless parameter. It is found that flow pattern, unlike the case of Newtonian fluid does not remain purely radial, but is accompanied with a secondary flow.

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