Application of an ordinary electron microscope to a micro-focus X-ray diffraction apparatus is devised by the use of a simple target and a small diffraction camera. The relationship between the aperture angle of electron beam and the position of the filament in the aperture of the Wehnelt cylinder is studied for determining the condition under which the smallest possible aperture angle could be obtained. The projector lens of the electron microscope without the pole piece is wised to project the reduced image of cross-over point of the electron beam onto the target which is a tapered copper cylinder of about 13mm in diameter, cooled by flowing water. A small gold plate is provided on the tapered surface of the target for generation of white X-ray beam. With the accelerating voltage of about 35kV and the tube current of about 300μA, a small focus of about 30μ in diameter is obtained on the target. The size of the focus is determined by analysing microphotometric curves of X-ray shadow micrograph of a thin tungsten wire and also by direct measurement of contamination on the target itself. The method of the analysis and the interpretation of the focus size thus obtained are discussed. As examples of the application, cases of potassium silicofluoride powder, quartz powder, single crystals of plagioclase and copper phthalocyanine, a single crystal of, biotite partly transformed to chlorite by natural weathering, twinned single crystal of copper, and thin section of Nylon fibre are cited.
Following the completion of interference filter of monochromatic high transmission characteristics with narrow pass band, three types of photoelectric filter-photometer-the standard type, the wide range precision type and the simple type-have been made which are suited to routine analytical work because of the simple construction, easy operation, light weight and low cost. Their per-formance is fair; the accuracy is as good as that of a spectrophotometer. As application, flame photometer, fluorophotometer and reflectometer have been produced.
The magnetic states of metals are studied by utilizing the Lorentz effect observable in electron diffraction. The strain-induced transformation of austenitic steel and the magnetic induction of iron single crystal and ferromagnetic films are investigated by the process of electron diffraction.
A mass spectrometer has been designed for the use of analysing very small amount of gas samples and for the study of adsorption in ultra high vacuum. The spectrometer is of 60° type and made of all glass. The radius of ion orbit is 11cm and the resolving power is 60. All-glass greaseless valves are used for the spectrometer to be operated statically. The operating pressure is 1.1s×10-9mmHg which can be maintained over two hours. As the operation is static, the sensitivity (the amount of sample required to obtain signal of the same order as noise) is reduced to 1.3×10-9cc N. T. P. for argon, which is 1/15, 000 of the amount needed by the usual flow method. The tests of analysis are made with rare gases, nitrogen, carbon-monoxide, methane, n-butane, hydrogen, oxygen and carbon-dioxide. The gases so far found analysable by static method are rare gases, nitrogen, carbon-monoxide and methane, but because of the rapid decrease of enclosed samples, other gases can not be analyzed: carbon-dioxide and oxygen due to adsorption in the analyzer tube, and n-butane due to thermal decomposition by filament. The spectrometer is also used for analysing radiogenic argon in minerals and residual gases in a magnetron and for studying adsorption of various gases by Bayard-Alpert gage in ultra-high vacuum.
Films of ZnS:Mn, Cl (about 15 microns in thickness) are prepared by the vapor reaction method of Cusano and Studer. Measurements of temperature and frequency dependence of electroluminescent brightness under a. c. field excitation and the thermoluminescence for such films demonstrate that there are two main trapping levels near 0.3 and 0.5eV, and a frequency-dependent maximum in brightness occurs at a certain temperature within the range from 170° and 250°K. Some speculations are made on the occurrence of the maximum in brightness. As the deeper trap seems to be associated with the ionized center at the distance of a few times of the lattice spacing, the trapped electrons must jump across the potential barrier arising from the Coulomb interaction between the trap and the center in order to be liberated from the associated system as the charge carriers for acceleration. This transition can be effected by the application of electric field of suitable frequency. For the trap near 0.5eV, the activation energy of transition is 0.25eV. The experimental value of the activation energy, obtained from the relationship of temperature and frequency where the maximum in brightness occurs, is about 0.24eV and seems to coincide with the energy value mentioned above. In addition to the effect of the traps, the behaviors of the film to d. c. field and other effects are described.
Spectroscopic characteristic of photocurrent and of photoreverse-current and the creation of electron trapping levels by print out in particular are examined at low temperatures in air annealed silver bromide crystals. The effect of foreign ions on photochemical process is also studied. It is shown that, by irradiation, a great number of electron traps are created in the forbidden gap. These traps have their origin in color-center-like aggregates of silver atoms (green part, easily bleached by halogen gas) and in colloidal specks of metallic silver (red part, produced by strong irradiation). The apparent work function for raising the electron from metallic silver to the bottom of conduction band of the crystal is found to be 1.0 eV. The addition of cadmium ions considerably reduces the effect of irradiation upon the formation of additive photoconductive band, whereas the addition of ferric ions enhances the effect greatly and a marked peculiarity in photo-reverse-current is observed. As a subsidiary phenomenon of interest, when there are a large number of electron traps, the additive band is enhances by low temperature irradiation and at the same time the photocurrent at the edge of absorption band is reduced. This may be explained by the recombination of (shallow trapped) photoelectrons with remaining free holes, the number of which is the number of trapped electrons minus the number of hole traps.