In this paper it is proposed to give both methods and applications for temperature mea-surements of gases by a variety of optical means. Of the basic methods of measurement, optical ones in general have the advantage in that they do not disturbe the high temperature gases. We shall endevour to indicate the principles of the various methods which have been suggested, and to point out their advantages and limitations.
After a brief survey of the possibilities of obtaining informations about temperature by means of infrared radiation, proposed is a classification of realizable methods into three schemes; the equilibrium scheme, the active scheme and the passive scheme. Among others the pas-sive scheme, which covers the so-called radiation thermometry, is discussed in detail; the factors causing the degradation of information along the path of radiation, namely the effective emis-sivity of the radiation source, the absorption and the scattering of radiation in the atmospheric path as well as the performances of the detecting devices, are examined. Finally reviewed are various examples of success and trial which seem to be instructive in view of improving the quality of information about temperature transmitted by infrared radiation.
Secondary electron channel multipliers consisting of parallel plate dynodes were made and the effects of various factors on the gain were examined. The dynode surface is a three-layered film consisting of three layers of alumina, molybdenum, and alumina evaporated in that order. The detailed method of the production is described. The gain is about 105 at 3 kV with multipliers of α=40. The effect of the field distortion and “the field-correction electrodes” are described. The lowering of the gain is found to originate from the heating and the decomposition by electron bombardment of dynodes. The multiplier may be baked at 250°C in a vacuum. Discussion is also given on the composition and thickness of the outer alumina layer.
A simple, small galvanic cell oxygen detector employing a mesh-type electrode for the cathode is developed for use in gases. The detector is disk shape (3cm in diameter and 1cm thick) and consists of a Pb | KOH electrolyte | O2 cell in which a Teflon film is used as the oxygen permeable membrane. The cathode materials used are perforated Ag, Au and Pt sheets, and Ag wire gauzes (20-100mesh). Curves of current versus oxygen concentration in the range of 0.6 p, p. m. -100% O2 are given. It is found that the current generated is very stable and the operating life of the cell is considerably long. Results of continuous operation for several hundred hours in the laboratory atmosphere are shown. Data of open circuit voltage versus oxygen partial pressure for the cells of Ag, Au and Pt cathodes are presented and the electrode reactions are discussed.
In the Electron Probe Microanalysis, the effect of grain size in multi-phase systems on the observed X-ray intensities was taken into account, and some experiments were carried out by the use of the ARL-type EPMA. Theoretical calculation, although a rough one, revealed that the X-ray intensities are greatly affected by the presence of grain or the granularization of elements whose mass absorption coefficient ü or density ρ is considerably from that of the matrix, even if the grain-size is much smaller than the spot-size of the electron beam. For example, Si-Kα intensity from Al-12wt%Si alloy, having precipitated Si particles of the grain-size of 1ü or less (the same order or less compared to the smallest electron beam size or the X-ray emitting area), is about 10% higher than that expected from Birk's formula under the assumption that the specimen is uniform and of the same chemical composition. Experimental results showed rather good agr-eement with theoretical values.
The method of X-ray diffraction topography was used to examine dislocation structures in large single crystals of ice grown from water by a modified Czochralski's method. Character-istic features of dislocations in the crystals are as follows. Screw dislocations of which Burgers vector is c  hardly appear in the crystals grown to the direction of c-axis, whereas small angle boundaries consisting of edge dislocations of Burgers vector a/3 (1120) on the basal plane extend to the direction of the c-axis. In the crystals grown to the direction perpendi-cular to the c-axis, the dislocations run parallel to the direction of growth. These results suggest different mechanisms of crystal growth with respects to the growth direction; two dimensional nuclei mechanism is prevailing in the case of c-axis parallel growth and spiral growth around screw dislocations is occuring in the case of c-axis perpendicular growth.
It is often observed in the case of conventional evaporators with electron-bombardment heating that scattered electrons onto the surface of a deposit film cause twig-like cracks and minute structural irregularities. In order to prevent such charge accumulation on the film surface, the present authors have developed an evaporator of a new type which includes a Pierce gun with an electrostatic deflector. When the cathode is grounded and positive high voltage is supplied to both the anode and the crucible, uniform films can be obtained even on a glass substrate. In this case the thickness is easily monitored through measuring the ion current into detectors near the substrate.