Nine nuclear interactions, observed in a stack of nuclear emulsions, are analyzed in the center-of-mass system. The angular distribution of secondary particles is isotropic for primary energy, E_p, up to several tens of GeV. The distribution shows an appreciable forward-backward collimation for E_p\simeq200 GeV. The average energy of a produced pion is 0.48 GeV. The number of pions at the total energy less than 0.21 GeV is fairly small. The energy spectrum can be represented by a power law with exponent −2 for the middle region of pion energy. An inspection of experimental results so far published shows that the corresponding exponent for E_p\gtrsim1400 GeV is −1. The mechanism of multiple production probably changes between 200 and 1400 GeV, and does not differ markedly from severel GeV to 200 GeV.

View full abstract

The energy spectrum and the angular distribution of photoprotons from Mg have been measured. The energy spectrum has larger number of fast protons than that expected from the evaporation model and shows the fine structure. The yield of the process leading to the ground state of Na estimated from the experimentally obtained spectrum has some correspondence with that of the inverse proton capture process. The angular distribution of protons of the intermediate energy region in the spectrum has a form a+bsin²θ and that of higher energy region shows the possible presence of an interference between electric dipole and electric quadrupole absorptions of photons.

View full abstract

Elastic scattering cross section of photons by a nucleus near the particle threshold energy was studied at 120 degrees for Mg, Fe, Zn, As, Cd, Sb and Bi using bremsstrahlung gamma rays. Each element has a gross peak in this energy range. This is consistent with the earlier results reported by T\={o}hei et al. The peak values are 0.5, 1.3, 1.3, 0.6, 1.6, 1.2, and 8 mb, respectively. A systematical relation between the mass number and the energy dependence of the cross section was discussed.

View full abstract

The angular distributions of neutrons from the Be⁹(α, n)C¹² reaction which leaves C¹² in its ground-, 4.43- and 9.6-MeV excited states have been measured for alpha-particle energies between 17.5 and 22.1 MeV. These angular distributions show patterns which may be interpreted in terms of direct interaction theory. The essential feature of the distributions for each neutron group seems not to change with incident energy. The angular distributions of the ground-state neutron group from the C¹²(α, n)O¹⁵ reaction were taken at alpha particle energies from 20.0 to 21.8 MeV. Marked change of distributions with bombarding energies is not found, while it was seen in the C¹²(α, p)N¹⁵ reaction at the same energy range.

View full abstract

A general method to expand the transport coefficients of dense gases in powers of the number density is developed, on the basis of the statistical mechanics of irreversible processes. The Ursell-Mayer expansion method is applied to the Liouville operator with use of the perturbation method which is reformulated for classical mechanics in this paper. This expansion method enables us to obtain the transport coefficients in the form of power series in the density. The exponential decay of the correlation functions of fluxes is obtained from the theory. The second approximation to the viscosity coefficient is obtained in the form which is useful for the numerical calculation.

View full abstract

At liquid helium temperature, electrons in germanium are easily heated with electric fields and hence excited from donor states in the conduction band. Under the condition of complete ionization of donors, the distribution function for phonons is investigated and the current density is calculated by assuming temperature and constant drift velocity for electrons and phonons, respectively.
It is shown that the drift of phonons has no appreciable effect on electric current, but that the phonon temperature determind as a function of field strengths affects considerably the magnitude of the current density. The current density, j, calculated is proportional to F^1⁄5 where F is the field strength, provided that phonons are in equilibrium with the heat bath. If phonon temperature is increased by electric fields and becomes nearly equal to electron temperature, j is proportional to F^5⁄11. Conditions for these cases are discussed.

View full abstract

The cyclotron resonance of electrons heated by the microwave field in n-type germanium is investigated. The half-width of the resonance line is calculated as the function of microwave power on the basis of the classical model and the concept of the electron temperature. The relation between the number of electrons in a valley and their temperature is discussed.

View full abstract

The change of the Curie temperature by the application of 3 katm. of hydrostatic pressure to the indium Heusler alloy as well as the intermetallic compound Au₄Mn was measured. It was found that the rate of change takes positive values, 1.5×10⁻³ and 2.7×10⁻³ deg/kg/cm² for the Heusler alloy and the Au₄Mn respectively. It was also elucidated that the relative changes of absolute saturation of magnetization for both alloys are negative, −2.1×10⁻¹² and −7.2×10⁻¹² cm²/dyne respectively.

View full abstract

The magnetic susceptibility of a powdered sample of Wurster’s blue perchlorate, which is a free radical, has been measured as a function of temperature between room and liquid-air temperature by a Gouy balance. The susceptibility maximum at 189°K is probably due to a transition from a paramagnetic to a diamagnetic state. The Curie-Weiss law with the paramagnetic Curie temperature of −23±5°K is applicable to the susceptibility above 220°K.

View full abstract

Small-angle scattering cross-section for slow neutrons by FeCl₂ above but near the Néel temperature is calculated with a method which is an extension of Zernike’s theory of propagation of order. The result is compared with the experimental data and a reasonable agreement is found if the ratio of the two exchange coupling constants in this crystal is assumed to be about 0.08.

View full abstract

The absorption spectrum of the manganese impurity ion in calcium fluorophosphate is calculated by using crystalline field approximation, taking into account the effect of polarization of oxygen ions near the manganese ion, and taking the ionicity in the bond between oxygen and phosphorus in phosphate ions as a parameter.
Among the coefficients in the expression of crystalline field potential at the position of Mn⁺⁺ ion, c₂⁰ can be compared with the coefficient D in the spin Hamiltonian, which appears in the theory of Watanabe. From a comparison of the calculated c₂⁰ with that deduced from ESR experiment, it is concluded that the ionicity is about 40%.
Although the energies of the absorption band of Mn⁺⁺ ion in calcium fluorophosphate phosphor are not observed, they can be estimated from the consideration of the mechanism of luminescence in this crystal. Comparison of these estimated energies with the calculated energies shows that the ionicity in phosphate ion is about 35% which is consistent with that obtained from the comparison of calculated c₂⁰ with that deduced from ESR experiment.

View full abstract

Ferromagnetic domain pattern was observed on the c-plane of wedge-shaped cobalt crystals and the width of domain strips was determined as a function of thickness of the crystal for several specimens with different wedge angles. Magnetostatic energy was calculated for coplanar parallel strips with alternate signs of free poles, each of which is embedded with a number of square areas with free poles of the opposite sign and with a smaller square area of the same sign at its center.
The optimum sizes of outside and inside squares were determined by minimizing the magnetostatic energy. The result was in good agreement with experiment. It was found that the minimum magnetostatic energy is to be 0.186 I_s²D, where D is the width of the main domain strips.

View full abstract

Neutron diffraction study of the atomic and spin arrangement of the κ phase of ternary alloys Cu₂₀–Mn_30+x–Al_50−x(x=0 5 and 10) has beed performed. It is shown that, for alloys x≠0, excess Mn atoms replace Al atoms at body center sites of CsCl type crystal lattice, and their spins couple antiparallel with those at corner sites of the unit cell, confirming Tsuboya’s model proposed to explain the results of magnetic measurements.

View full abstract

Measurements have been made with strain gauges of the magnetostriction, λ, and the thermal expansion coefficient, α, of gadolinium single crystals from 4°K to above the Curie point. The four magnetostriction constants appropriate for a hexagonal crystal have been evaluated, and special attention has been given to the forced magnetostriction and its relation to the anomalous thermal expansion near the Curie point. By the use of the usual thermodynamic relations the results show that compressive stress when applied parallel to the hexagonal c axis reduces the molecular field, as in iron, and when applied parallel to the a axis it increases the molecular field, as in nickel. The anomaly in the thermal contraction is unusually large in the c direction. Both λ and α were also measured for polycrystalline material.

View full abstract

Phase transformation of γ-Fe₂O₃ to α-Fe₂O₃ was studied by electron diffraction. Above 400°C γ-Fe₂O₃ is transformed to α-form which consists of twins. The orientation relationship of the transformation is (111)_γ//(0001)_α and [1\bar10]_γ//[01\bar10]_α. The twinning plane of transformation product was determined to be basal or (01\bar10) Plane. The transformation mechanism consists of the re-stacking of close-packed oxygen ion layers and the synchronous displacement of ferric ions located at the interstices of oxygen. These cooperative movements are discussed by dislocation models.

View full abstract

Cupric benzoate trihydrate crystallizes in the monoclinic system, space group I2⁄c, with four formula units in a unit cell of dimensions, a=6.98, b=34.12, c=6.30 Å; β\doteqdot90°. There are two kinds of benzoate groups. The carboxyl oxygen atoms of benzoate group I are in direct contacts with copper atoms, while those of group II are coordinated to copper atoms through water molecules. Each copper atom is situated at the center of a deformed octahedron consisted of four water molecules and two oxygen atoms from benzoate group I. The octahedra are linked, by sharing two water molecules, into a column parallel to the c-axis. Within this column, copper atoms lie on a line at an interval of 3.15 Å, which suggests the presence of magnetic anisotropy.

View full abstract

It is shown that the degree of crystallinity of a partially crystalline polymer may be evaluated theoretically from its dynamical properties, and that such a dynamical degree of crystallinity is connected with the static one. The theory is also applied to NMR data.

View full abstract

A molecular theoretical investigation of the viscoelastic properties of amorphous polymeric substances within the rage of long relaxation time has been pursued using a temporarily crosslinked network structure model. The origin of the energy dissipation is ascribed to the slipping of chains and the change in number of chains induced by deformation.
Since the slipping of chains exists, the inner deformation tensor of chains which is different from the observable deformation tensor of network structure can be introduced. Assuming that the inner deformation tensor is characterized by a single average deformation tensor, the relation between the observable and inner deformation tensors is obtained.
The expression of the rate of change in number of chains is also obtained in the same formula with that of chemical reaction.
The stress-deformation-time relation is proved to be the generalization of Maxwell model. This shows that the system considered is equivalent to the generalized three dimensional Maxwell model.

View full abstract

Transport coefficients of a magnetoplasma in the simultaneous presence of an alternating electric field and a temperature gradient are investigated. They are shown to be expressed in terms of the transport coefficients in a stationary electric field and to satisfy symmetry relations between the electron cyclotron frequency and the frequency of the electric field. As an example, these results are applied to the electrical conductivity and the transport coefficient between the heat flow and the electric field.

View full abstract