On the Primary Vacuum Test of the Cyclotron of Kyoto University

On the Vacuum Test of the Cyclotron.III

Abstract

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.