The principles and characteristics of X-ray diffraction micrography are briefly mentioned compared with electron and optical microscopies. Various effects of diffraction utilized for obtaining the intensity contrast are explained: extinction effect, anomalous absorption, deviation in diffraction peak, satellite or diffuse scattering, anomalous dispersion and interference -between different wave fields. Techniques developed for realizing one-to-one correspondence of the specimen and the diffraction image are reviewed: the use of white or monochromatic X-rays from a point source, the use of monochromatic X-rays from a line source, scanning beam method by movement of the specimen and the double-crystal spectrometer arrangement. Literatures of applications are given for each method above mentioned. Some topics, such as defects in silicon crystals, determination of sign of the Burgers vector, domain structures, Moire patterns, X-ray interferometer and effects of impurities on rocking curves, are mentioned in some details. Dynamical theories on a slightly distorted crystal, studies on the image formation of a dislocation and on the interference fringes due to a strain field or a stacking fault, are reviewed.
This paper deals with a method of automatic plotting of the trajectories of charged particles which move under simultaneous application of electric and magnetic fields. The plotting is performed by combining an electrolytic tank and an electronic analog computer. The equation of motion of charged particle is solved by an analog computer. The variable parameters are the components of the electric and magnetic fields acting upon the particle. These fields are analogically produced in the electrolytic tank and detected by a probe array dipped in the tank, The array positions are adjusted automatically in order to obtain consistent outputs, and the trajectories of the particles are traced on an x-y recorder. The results for a parallel electrode system are in good agreement with the theoretical calculation. Also, the trajectory of electrons in a magnetron tube is obtained by the same method.
The frequency characteristics of a cascade multiple-voltage rectifier equipped with an appropriate number of compensation coils is discussed. It is shown that, when the frequency is increased above the optimum operating point, the input impedance and voltage efficiency decrease. In the lower frequency range, on the other hand, the input impedance increases at first and then showss alternatively parallel and series-resonance characteristics. The voltage efficiency increases and becomes infinitely large at the series resonance points. The experimental results which confirm the present discussion are also shown.
A helium level indicator was made on the basis of the superconducting-to-normal-state transition of Pb-Sn alloy. The probe of the indicator consists of a manganin wire with a thin layer of Pb-Sn coating part of the wire. The level of liquid helium can be detected by the voltage across Pb-Sn part. The abrupt change of the electrical resistance of Pb-Sn at the liquid level is interpreted as being enhanced by the heat developed in the manganin wire. From the results of the investigation, the optimum conditions for the level indicator were determined. This helium level indicator shows a high sensitivity and reliability.