Analysis of the He(3 3S)-He(2 3P) line profile obtained in dense helium plasmaN. F. Allard1, B. Deguilhem2, F. X. Gadea2, N. Bonifaci3 and A. Denat3
1 Observatoire de Paris, GEPI, UMR 8111, CNRS, 61 - Avenue de l'Observatoire, F-75014 Paris, France, EU
2 Laboratoire de Physique Quantique, UMR5626, CNRS, Université Paul Sabatier - 118 route de Narbonne, F-31400 Toulouse, France, EU
3 G2Elab, Laboratoire de Génie Electrique, UMR 5269, CNRS, Université Joseph Fourier - 25 rue des Martyrs, F-38042 Grenoble, France, EU
received 21 August 2009; accepted in final form 16 November 2009; published December 2009
published online 15 December 2009
The emission spectrum produced at 300 K in dense plasmas of helium excited by a corona discharge shows an asymmetric atomic line at 706 nm that may be associated with quasi-molecular states of He2. We present here the first calculations of He-He collisional profiles of this line done in a unified line shape semi-classical theory using ab initio molecular potentials. The excellent agreement between experimental and theoretical determinations of the near wing of the line profiles establishes the accuracy of the interaction potentials. The strong pressure dependence of the collision profiles can then be used as a diagnostic of the physical parameters of the source.
32.70.Jz - Line shapes, widths, and shifts.
31.15.ac - High-precision calculations for few-electron (or few body) atomic systems.
52.80.Hc - Glow; corona.
© EPLA 2009