Resonant laser radiation transport at Balmer-α through a partially ionised hydrogen plasma

Abstract

The transport of laser radiation, resonant with the optically deep H- alpha transition in a well diagnosed, partially ionised hydrogen plasma was investigated experimentally. The results were compared with the numerical solution of a one-dimensional radiation transport model which included all the significant collisional and radiative rates for the first five levels of the hydrogen atom. The result was a substantial disagreement between theory and experiment for the two plasma conditions investigated; i.e. Ne=5*1014 cm-3, Te=0.8 eV and Ne=8.5*1014 cm-3, Te=1.14 eV. No reasonable mechanism that would account for the disagreement is forthcoming.