Absorption spectra of Na atoms in dense He

Nicole F. Allard (1, 2) , Akira Nakayama , Fernand Spiegelman (3) , John F. Kielkopf , Frank Stienkemeier

1 IAP - Institut d'Astrophysique de Paris
2 GEPI - Galaxies, Etoiles, Physique, Instrumentation
3 MAD - Modélisation, Agrégats, Dynamique (LCPQ)

We present an analysis of Na-He collisional profiles at high density and very low temperature in a unified line shape semi-classical theory which contains the impact as well the quasistatic limits. Clearly understanding the variation of shape of the two fine-structure components of the 3s−3p line with increasing helium density allows us to understand experimental spectra of a Na atom attached to He nanodroplets. We compare our collisional approach to path integral Monte Carlo calculations using the same ab initio Na-He molecular potentials.

Domaines: Physique [physics]; Astrophysique [astro-ph]

Nicole F. Allard, Akira Nakayama, Fernand Spiegelman, John F. Kielkopf, Frank Stienkemeier. Absorption spectra of Na atoms in dense He. The European Physical Journal D : Atomic, molecular, optical and plasma physics, 2013, 67, pp.52/1-52/8. ⟨10.1140/epjd/e2013-30523-x⟩. ⟨hal-00862196⟩