Mobilities of doubly charged rare-gas ions in their parent gases

The mobilities of the doubly charged rare-gas ions He/sup 2 +/, Ne/sup 2 +/, Ar/sup 2 +/, Kr/sup 2 +/, and Xe/sup 2 +/ in their parent gases have been determined in a drift-tube mass-spectrometer apparatus. The finding of more than one mobility for each of the doubly charged ions (with the exception of He/sup 2 +/) is attributed to the presence of the /sup 3/P, /sup 1/D, and /sup 1/S long-lived, lowest-energy states of these ions. At 300 K the reduced mobilities (in units of cm/sup 2//V sec) extrapolated to zero field have the values ..mu../sub 0/(He/sup 2 +/ in He) = 18.3; ..mu../sub 0/(Ne/sup 2 +/ in Ne) = 6.5(/sup 1/D), 7.0(/sup 3/P), 8.5(/sup 1/S); ..mu../sub 0/(Ar/sup 2 +/ in Ar) = 2.7(/sup 3/P), approx. 2.2(/sup 1/D); ..mu../sub 0/(Kr/sup 2 +/ in Kr) = 1.11 and 1.28; ..mu../sub 0/(Xe/sup 2 +/ in Xe) = 0.65 and 0.75. The measured values are accurate to +- 3%.