You searched for: “gas focusing
ionic focusing, gas focusing (s) (noun); ionic focusings, gas focusings (pl)
A method of concentrating an electron beam by utilizing the residual gas in a tube: The beam electrons ionize the gas molecules, forming a core of positive ions along the path of the beam which attracts beam electrons and so makes the beam more compact resulting in ionic focusings and gas focusings.
This entry is located in the following units: focus-, foci- (page 1) ion, ion- + (page 5)