A new method for determination of volume ratios and also the absolute value of volumes of vacuum vessels is presented. Method is based on a measurement of rate of pressure rise in a vacuum chamber at constant flow of inert gas. An example of measurement of a volume of a chamber with a nominal volume of 7 L is presented. For pressure measurements we have used a spinning rotor gauge (SRG) and He permeation leak was used as a gas source.
COBISS.SI-ID: 798122
Solid solutions of lithium in Ag and Cu in the form of balls, wires, or strips are convenient sources for depositing lithium films as getters on the walls of vacuum vessels. Measurement of the O2, CO and CO2 sorption characteristics have shown that these films(generated electrothermally from Ag/Li solid solutions) excel the best getters of the Ba-film type or the high porosity getters based on Ti, V and Zr alloys. It has been found that tight lithium films passivate as a sorption depth of approximately 10 nm is reached.
COBISS.SI-ID: 618666
The kinetics of lithium evaporation from Ag-Li wire has been studied experimentally in the temperature interval 520-630°C. The initial stage of the process takes place in the kinetic regime and later moves to the diffusion region where the evaporation flow and the mass of the deposited film can be described quantitatively with the help of simple analytical expressions.
COBISS.SI-ID: 618922
To study O diffusion in NEG St 707 in the form of pills compressed from powder of typical particle size 50 to 100 µm the samples were loaded at 450 and 500 °C with different amount of O (from 0.6 to 18 at.%). Diffusion of O at 450 °C was too slow to show observable distribution of O inside the NEG. Observable effects were obtained at 500 °C The EDS analysis confirmed that St 707 is biphasic (grains of pure Zr and Laves phase Zr(V0.83Fe0.17)2) before and after heating to 500 °C. It also showed increased O concentration in the Laves phase and particularly at the boundaries of getter particles.
COBISS.SI-ID: 850602