The microwave techniques extensively used for plasma researches have wide applications with limited conditions. Besides electron densities and collision frequencies, the electron and ion temperatures are being considered by the extended theory. The phenomena occuring in interaction of microwave with plasma is also of interest to be compared with theories. The recent reports are comprehensively reviewed with some discussions.
In the mass spectrometry, during the last ten years or so, the great developments of the instrumental and measuring techniques have been carried out. And, according to the developments, the applications areas have been rapidly extended in the various parts of fundamental and applied science, especially in nuclear physics, chemical physics, solid physics, cosmo-science, organic chemistry, etc. Here, the general views on instrumental development and a few topics on mass spectroscopical researches are briefly described.
The effects of hydrostatic pressure on the excess and diffusion currents in Ge and GaSb tunnel diodes were investigated experimentally at room temperatures. The current at a fixed forward bias voltage decreases with increase of pressure, but its change is always greater in GaSb tunnel diodes than in Ge tunnel diodes. These effects are well explained using the ordinary theory of diffusion current and Claassen's theory for excess current.
The basic construction, discharge characteristics and the sputtering rate of a “tetrode sputtering system” are described in detail. Also, experimental results are reported on the electrical and physicochemical properties of tantalum, silica and alumina films deposited in this system. The electrodes of this sputtering system consist of a hot filament cathode, an anode, a target to be sputtered, and a keep-alive electrode, which enables starting of the discharge even below an argon pressure of 1×10-3 torr. By use of a magnetic field which confines the plasma in the space between the target and the oppositting substrate. Tantalum films are sputtered on glass substrates as functions of argon pressure PA and target voltage VT. Silica films and alumina films are deposited by RF sputtering of a fused quartz plate and a ceramic alumina plate, respectively. Infrared absorption spectra and dielectric constant are compared with those of the bulk, and also the frequency dependence of the silica film capacitance is measured.
Zone freezing, as a particular application of zone refining, is proposed for the purification of liquid organic materials. Thermoelectric refrigerators were used for producing frozen zones. The apparatus allowed the passage of three freezing zones through the sample during a single run. Fluorescence analysis indicated that the concentration of impurities in benzene could be lowered to 0.5 p. p. m. by several passages through the three-zone column. The segregation coefficients of several impurities in benzene were determined. The separation of xylene isomers and the concentration of alcohol in aqueous solution are also discussed.
The spatial frequency response of several photographic emulsions have been measured by a holographic method. It was observed that each film had a higher resolving power than a nominal one. A brief discussion shows that this phenomenon can be explained by the fact that the light diffracted by the interference fringes can be measured without being disturbed by the grains of emulsion.