The elastic scattering of photons near the particle threshold energy was studied for Al, Si, S, K, Ca, Ni, Cu, Cd, Sn, Pb and Bi. The bremsstrahlung x-rays from a 25 Mev betatron were used. The pulse of the primary x-rays was expanded up to about 30 μ sec to decrease the pile-up effect. The scattered photons were detected at the scattering angle of 120 degrees with the scintillation spectrometer using an 8″φ×8″NaI(T1) crystal and a 30 channel pulse height analyser gated the expansion signal of the betatron orbit. The energy at which the cross section has a peak was compared with the particle threshold energy and the value of cross section was compared with that of particle emission.

View full abstract

Several new nuclides were produced in the internal target of the INS cyclotron from the fast neutron bombardments of Ge, Mo, Gd, Er, Yb and Hf. Their radiation characteristics were determined with the aid of beta and gamma ray scintillation spectrometers. The new activities observed are as follows:
(Remark: Graphics omitted.)
The radiation characteristics were analysed in the light of the unified model and the conventional nuclear level systematics.

View full abstract

Weak gamma rays of energy 0.63 MeV was found in the decay of La¹⁴⁰ by means of a scintillation summing Compton spectrometer. This gamma rays are ascribed to the transition between the 2.53-MeV and 1.90.MeV states of Ce¹⁴⁰. The transition between this 1.90-MeV state and the 1.60-MeV state was not detected. The results of the present investigations on the conversion electrons and Gamma rays support the suggestion of D\v{z}elepow et al that the 1.90-MeV state is a O⁺ one.

View full abstract

The magnetic susceptibilities of Cu-n butyrate monohydrate, Cu-stearate and Cu-acetate monohydrate were measured in the temperature range from 90°K to the room temperature. The energy of exchange interaction J between the cupric ions Cu⁺⁺ in the nearest neighbour sites were evaluated from the observed values and the relation χ_m=(0.125 g²⁄T)·[1+(1⁄3)exp(+J⁄kT)]⁻¹. The magnitude of J-values thus obtained were J_Cu-butyrate=430±150°K, J_Cu-stearate=485±15°K and J_Cu-acetate=430±15°K. And it seems that the g-value of Cu-stearate is somewhat larger than the value of Cu-acetate monohydrate.

View full abstract

It is assumed that the observed dislocation velocity is the average velocity during the successive jumps, and that the jumping distances are large compared with the atomic spacing. The excitation probabilities for large jumps are calculated the forces on dislocation, in which the thermal effects are introduced as the fluctuation of the local shear stress. The dislocation velocity in otherwise perfect crystals of relatively large Peierls stress are obtained as the functions of applied stress and temperature.

View full abstract

A careful consideration on lattice vibrations in the ionic ferroelectric crystals such as BaTiO₃reveals that a correct physical picture of the ferroelectric transition in these crystals may rather be regarded as an order-disorder transition of orientation of dipoles. A strong local order in the disordered phase is a characteristic feature. The model gives natural interpretation of the occurrence of three successive transitions in BaTiO₃, and predicts dielectric dispersion of relaxation type in the paraelectric phase.

View full abstract

The effective magnetic field at nuclei in rare earth metals has been calculated. The contribution from the orbital angular momentum of 4f electrons was found to amount to several thousand kilo-oersteds.

View full abstract

From the difference in the electrical resistivity change induced quenching between pure Au and Au–Pd solid solutions, the binding energy for a vacancy and a solute atom was determined. The rate of decrease of quenched-in additional resistivity with decreasing temperature in the alloy was more rapid than in the pure metal and the resistivity after quenching was smaller than that before quenching in high concentration alloys below a certain quenching temperature. It was concluded that the interaction of a Pd atom and a vacancy in Au–Pd alloys was attractive, which formed a contrast with the expectation of Lazarus theory, and an additional resistivity the solute atom was canceled partly the binding of the vacancy. In Ag-Pd alloys the same results would be expected.

View full abstract

The temperature dependence of magnetization of polycrystalline hematite (αFe₂O₃) which contains several per cent of foreign atoms (Al, Mn, Ga and Cr) was measured at various field strengths. The results were analyzed into so-called parasitic magnetic moment σ₀ and susceptibility term χ_g. It has been found that the parasitic nature of σ₀ is not influenced severely the addition of foreign atoms but the transition temperature is lowered in general and the step transition in σ₀ vs temperature curve becomes gradual.
The residual magnetization was measured with an astatic magnetometer. It was found that the memory effect (in the ratio of the residual magnetization between before and after cooling treatment) is little affected the addition of foreign atoms or change in oxidation. The residual magnetization decreased about 50% at the first cooling-heating cycle. but is maintained completely in following cycles.

View full abstract

With use of Peterlin and Mizutani’s light scattering function P(θ), a simple method has been developed to determine the mean square end-to-end distance ⟨r²⟩. Following Peterlin and Mizutani, ⟨r²⟩ is assumed to be proportional to N^γ, where N is the degree of polymerization and γ is a parameter. Obtained values of ⟨r²⟩ are (5.53)²×10⁻¹⁶N^1.15, (42.51)²×10⁻¹⁶N^0.70, and (6.39)²×10⁻¹⁶N^1.11 for polystyrene in toluene, in methylethylketone and in cyclohexane solutions, respectively. These results suggest that the excluded volume of chain elements and the interaction between the polymer and the solvent are important factors to determine the extension of polymer molecules in both good and poor solvents. Brief discussions on the polydispersity of the system are also given.

View full abstract

The quantum mechanical behavior of the three-level maser was experimentally studied using the rotational spectrum of HCOOH molecule at microwave frequencies. By using the 2₁₁←1₁₀ line at the frequency of 46581 Mc as the pumping, the induced emission of the 2₁₁→2₁₂ line at the frequency of 4916 Mc was obtained. For a strong pumping, the splitting of emission line due to resonant modulation effect was observed. The line-shape of emission signal under off-resonant pumping was studied in detail. The emission spectrum due to simultaneous emission and absorption of two photons corresponding to the signal and the pumping was observed for the condition of far off-resonant pumping. The results were compared with the theory described in the previous paper, and was found to be in good agreement in many respects. Some discrepancies concerning emission intensity are also discussed. An application of the multiple quantum transition to a four-level system of HC·OOH is described.

View full abstract

Plasma oscillations are considered under uniformly applied electric and magnetic fields. When the external field is so weak that the particle runaway is not yet appreciable and the drift motion between electrons and ions is regarded as quasi-stationary compared with the oscillation frequency and particle gyrations, the usual Laplace transform method can be approximately employed. The dispersion relation thus obtained describes the excitation of ion waves. Behaviors of these waves are discussed, their temporal developments being taken into account.

View full abstract

Design, construction and operating characteristics of an ammonia beam-type maser are described with particular emphasis on the J=3, K=2 line. The maser with an eight-pole focuser of 40 cm length starts oscillation on the 3, 2 line at a focuser voltage of 5.6 kV when the maximum available source flux of about 1.2×10¹⁸ molecules per second is used.
Threshold conditions of oscillation as functions of the focuser voltage, lengths of the focuser and of the cavity are calculated the theory on the Maxwell velocity distribution.
The observed frequency-change with the cavity tuning and with the focuser voltage is compared with theory in some detail. The effect of traveling wave component in the cavity and the pulling due to cavity tuning are calculated. It is shown that the frequency shift with the focuser voltage becomes very small, when the beam flux is reduced.

View full abstract

A domain structure previously concluded an X-ray study of aniline hydrobromide was directly confirmed optical means. The domain walls were found to move easily a shearing force. The temperature dependence of the extinction angle was obtained. The thermal transition of transparency was measured, and interpreted on the basis of the domain structure. The refractive indices were also measured. Although the double refraction was found to be fairly large, any anisotropy of optical absorption was not detected within the limit of experimental error.

View full abstract

In colored LiF crystals, two bands at 320 and 378 mμ have been investigated and assigned as R₁ and R₂ bands the correspondences to R bands in other alkali halides. Intensity ratio of the R₁ band to the R₂ band is almost constant irrespective of irradiation conditions of β or γ-rays as well as of photochemical treatments. Both the bands are bleached irradiation with either R₁ or R₂ light, where the former has a higher efficiency for the bleaching. The results support the interpretation that R₁ and R₂ bands are due to transitions in the same center. Emission spectra excitation with R₁ and R₂ lights are distinct: the latter has a peak at 495 mμ and the former at 730 mμ or above.
By polarized R lights, dichroism is induced in the R₁, R₂ and M bands and also polarization of the emissions is observed. Then symmetries of the models which have been proposed as complexes of F centers are examined the experimental results and it is considered that F₃-model lying in [111] plane is the most adequate for R center. In addition to characteristic M-center luminescence, which has a peak at 710 mμ and value of 0.6 for P[011], an emission band at 525 mμ is observed M-light excitation but P-factor for this emission is less than that of the M-center luminescence.

View full abstract

The drag of a circular cylinder set in uniform motion impulsively from rest in a viscous fluid is calculated. On the assumption of small Reynolds numbers, Oseen’s equations for unsteady motion are employed. The two limiting cases corresponding to the initial and final periods, respectively, are investigated.

View full abstract

Temperature variation of ultrasonic velocity and density is studied in some organic liquids, low melting point organic solids in melt state, and corrosive inorganic liquids. It is found that in all the cases the ultrasonic velocity decreased linearly with increase of temperature. The temperature independence of Rao’s molar sound velocity was studied for the first time in corrosive inorganic liquids and is established. The new relations put forward Kishimoto and Nomoto for temperature coefficients of velocity, density and adiabatic compressibility in terms of boiling point are examined and confirmed. The relation put forward Lagemann M^1⁄2. ΔV⁄ΔT was also examined.

View full abstract