Modulation technique for measuring diffusion coefficients of Ba in noble gases.

The diffusion coefficient of Ba (6s5d 3DJ) in noble gases was measured with a modulation/lock-in technique. This technique relies on a cylindrically symmetric source for the metastable state, and is independent of cell geometry. It is readily generalizable to other systems where the creation rate of a long-lived state can be modulated. [ABSTRACT FROM AUTHOR]