The Drift Velocity of Potassium Ions in Hydrogen at 293°K

Abstract

Although there exists a large body of data for the drift velocity of positive ions in gases (Loeb 1955; McDaniel 1964), some of the data are conflicting or ambiguous due to uncertainty concerning the identity of the ion being studied (Dalgarno, McDowell, and Williams 1958; Davies et al. 1966). This ambiguity isparticularly serious in the case of atomic or molecular ions moving in the parent gas, since ion-molecule reactions may occur in the ion source or within the drift chamber. The necessity for simultaneous drift velocity measurements and ion identification has led a number of workers (e.g. Edelson and McAffee 1964; Keller, Martin, and McDaniel 1965; Madson, Oskam, and Chanin 1965; Saporoschenko 1965) to design experiments in which such identification is possible. In these experiments the gas pressure in the drift chamber is of the order of a few torr while that in the mass spectrometer is usually less than 10-5 torr.