Alignment creation and deviation from statistical population distribution in hydrogen =3 levels observed on MSE spectra of LHD plasma

Iwamae, Atsushi; Sakaue, Atsushi*; Atake, Makoto*; Sawada, Keiji*; Goto, Motoshi*; Morita, Shigeru*

We have observed motional-Stark-effect (MSE) spectra of Balmer- line emitted from a heating neutral-hydrogen beam on the Large Helical Device. Polarization-resolved spectral profile indicates that the magnetic-sublevel populations in the upper level slightly deviate from the statistical distribution, i.e., alignment is created. The theoretical proton-impact cross sections with the assumption of corona equilibrium, however, lead to a profile in gross disagreement with the observed one. It is suggested that, the observed profile is the result of time integration of light emission of atoms during the relaxation process, i.e., the aligned population distribution is created by the directional proton collisions and elastic proton collisions destroy the alignment, finally leading to statistical distribution.