Polarization of emission lines from beryllium-like oxygen ov: analysis based onthe population-alignment collisional-radiative model

摘要

Longitudinal alignment of OV triplet lines for the (2s3s (3)S1-2s3p (3)P0,1,2)transitions is studied on the basis of a population-alignmentc oolisional-radiative (PACR) model, which correlates quantitatively the observed polarization of emission lines from ions and atoms in a plasma with an anisotropy in the electron velocity distribution. The results are compared with measurements on the WT-3 tokamak at Kyoto University. The measured negative values of the longitudinal alignment are qualitatively explained from the anisotropic velocity distributions thathave higher speed in the poloidal direction than that in the toroidal direction.