Messung der Driftgeschwindigkeiten von Elektronen und positiven Ionen in Gasen

Abstracts

Values of the drift velocities of electronsv ₋ and positive ionsv ₊ in gases were measured under uniform electric field conditions atE/p-values ranging from some 100 to several 1000 volts/cm Torr. — For oxygen, nitrogen and also for acetone and benzene the velocityv ₋ is prop, to √E/p whereas for methane, carbon dioxide and other organic vaporsv ₋ is prop, to (E/p)^v withv between 0.5 and 0.8. The individual constants are given. Besides a diagram shows the valuesv ₋ obtained for hydrogen. — The drift velocities of the positive ions in oxygen, nitrogen, and several other gases and vapors were found to hold the square root relationv ₊ prop. √E/p at highE/p changing over to the linear relationv ₊ prop.E/p which is valid in the lowerE/p-region. The factors for the gases are given. By comparing the experimental results with the various theoretical approaches for the ionic mobility it is shown that at lowE/p polarisation forces are governing the interaction between ions and molecules whereas at highE/p the hard sphere model gives good agreement except for oxygen and nitrogen, in which charge exchange is the main interaction process.