Direct Observation of Ba(+) Velocity Distributions in a Drift Tube Using Single-Frequency Laser-Induced Fluorescence

摘要

First results are presented on velocity distribution measurements of Ba+ ions drifted in helium using a well-characterized drift tube and single-frequency laser-induced fluorescence detection. Reduced mobilities of Ba+ in helium are obtained for E/N values between 7.74 and 23.2 Td. The velocity distributions that are observed parallel to the electric field fit a displaced Maxwell-Boltzmann distribution, in agreement with theoretical predictions. However, the temperatures parallel and perpendicular to the field are not in good agreement with theoretical treatments. Keywords: Ion; Laser; Mobility; Velocity; Barium.