Experimental study of the newly designed vertical oil ejector pump, which has a boiler at the top, a condenser at the bottom and a gear pump for the return of oil, is described.
We studied characteristics of JLV-3, 5 (the trial pump of this type, 3, 5″inlet diameter) and confirmed its stable pump action at very high boiler pressure, then we designed and made JLV-16 and JLV-5 based on the results of JLV-3, 5
Critical backing pressure of JLV-16 and -5 are respectively 0.11 mmHg and 110 mmHg : pressure range of higher speed are respectively 0.010.1 mmHg and the combination of these pumps has practically uniform Q, value (3050 1mmHg/sec) in the pressure range from 3 to 0.01 mmHg.

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The applicability of vacuum arc to a source of vacuum evaporation has been investigated.Two methods have been examined ; the intermittent arc with vibrating electrode and the continuous arc. By the former method, Zn, AI, Cu, Ni, Mo and W Was deposited by the former method, so it is expected that in principle, most metals may be able to evaporate in vacuum. By the latter method, Zn and Al were evaporated finely, and other substances of higher boiling temperature seem to be able to evaporate. In Particular, thermal efficiency of the continuous arc method was excellent and more than 60% for Zn.

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By using contact angle measurements, we have observed. the sealing range of glass-to-metal seals. Sealing is preferable at contact angles between 25° and 70°.
Over-oxidation of metals generally inhibit the wettability of glasses.
Some components of glasses probably decompose at high temperature and react to the oxide of metals.

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Synopsis : The sorption of gases in “Silicone-grease” and “Silicone-oil” (D.C.) (which was for vacuum technique use) was studied experimentally.
The result indicated that so much water vapor was absorbed into “Silicone-grease”, while little into “Silicone-oil”.However, H₂, N₂, Co, Co₂ and etc. were not entirely absorbed into both Silicone-grease and oil.
These were, at the same time, recognized by means of electron microscope, spectrophotometer, and thermo balance.
Considering from these results we made, for trial, the “Silicone-oil rotary manometer”, which had a very good efficiency.

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Gas absorption characteristics of titanium have many interesting problems and they suggest useful applications in the field of vacuum engineerings. Experiments have been carried out for studying the gas absorption rate of titanium for such gases, nitrogen, oxygen, carbon mono-and dioxide. at various temperatures. The pressure of gas, sealed in a vessel and cont octed with titanium surface, decrease exponentially with time in the pressure range of this experiment and then it is concluded that the absorption speed is nearly constant.-from its temperature dependency the activation energies of absorption for these gases are calculated. Moreover, some interesting phenomena, such as hysteresis effect of gas absorption and jump of speed which is occured abruptly in the process of carbon dioxide absorption, are found.

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An investigation of the adsorption of water vapour on copper, nickel and alumina ceramic surfaces has been carried out using a time lag method of molecular flow. It is estimated that the amounts adsorbed at 10^-510^-6Hg, 0°C125°C (0°C50°C for copper) are 28×10^-7, 120×10^-7and 390×10^-7c.c. S.T.P/cm² for copper, nickel and alumina ceramic surfaces respectively.These results are compared with the data on glass surfaces and are discussed.
The B.E.T. method for ethylene adsorption has also been studied.

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The cyclotron framed with many equipments has been inspected already and vacuum leakage test was tried for the first time with both the propane and the helium gas detectors for a month.
After seventeen leaks detected were treated eight times, the final chamber pressure became 1.1×10^-5mmHg and the total quantity of liberated gas was 1.0×10^-3mmHg·1· sec^-1 by the air scale of the ionization gauge.
This amount of librated gas per cm² per sec, was less than that of gas evolved from copper parts only, about which measurement had been done before assembling and the spectra fron Geissler discharge tube shew a nitrogen band only.
Analysing this work, we found followings;
a) the total quantity of leaked air was expressed by a negative exponential curve against the times of repair, b) the detected leakage being compared with the standard capillary leak of glass, a leakage value estimated with the propane gassingle ionization gauge system was about one third of the one estimated with the helium gas-spectrometer system.

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