Wide-band spectroscopic investigation of the state-to-state dependence of the ArH+ ion average mobility in a Ar/He plasma

A wide-band experimental study on the quantum dependence of an ion average mobility in the positive column of a glow discharge is reported: no vibrational nor rotational energy dependence of the ArH+ ion average mobility in a mixture Ar/He is observed, within an experimental uncertainty of 5%. This conclusion is obtained from electric field-induced Doppler-shift measurements in the Δv=1 sequence vibration–rotation bands, around 5 μm. Two approaches, involving high-resolution Fourier transform spectroscopy, are employed. The two results agree well.