MOTION OF GASEOUS IONS IN STRONG ELECTRIC FIELDS 191 



10^ 



6 8 10 15 



ACCELERATION 



30 40 



60 



80 100 

 X10"6 



NUMBER DENSITY 



Fig. 5 — Drift velocity in an electric field of A+ ions in argon gas. Comparison 

 of observed results with an ''asymptotic" straight line of slope H. 



NUMBER DENSITY 



Fig. 6 — Drift velocity in an electric field of Kr+ ions in krypton gas. Com- 

 parison of observed results with an "asymptotic" straight line of slope }^. 



