Mid-IR laser action in the H3 Rydberg molecule and some possible astrophysical implications

Abstract

Abstract. Mid-IR lasing has been observed in supersonic plasmas and assigned to d to p transitions in tri-atomic hydrogen Rydberg states. Possible astrophysical implications are discussed.

Rydberg States of H3 and HeH as Potential Coolants for Primordial Star Formation

“…While the ground state of this molecule is unbound and very short-lived, the excited (Rydberg) states are metastable. − As such, they either decay radiatively with lifetimes proportional to n 3 or predissociatively. As a prototype Rydberg molecule, H 3 has been studied extensively since Herzberg’s discovery by both theory and experiment, although not until recently in the context of primordial star cooling. − …”

“…As such, they either decay radiatively with lifetimes proportional to n 3 or pre-dissociatively. As a prototype Rydberg molecule, H 3 has been studied extensively since Herzberg's discovery by both theory and experiment, although not until recently in the context of primordial star cooling (Saykally et al, 2010) (Wright, 2011) (Saykally, 2015).…”

“…The experimental–theoretical comparisons are included in Figure . While the experimental conditions under which these laser lines were discovered are not directly relevant to primordial gas conditions, their discovery and characterization of is a significant step toward understanding the energetics of excited H 3 Rydberg molecules. − …”

“…Experimental laser strength is in arbitrary units while theoretical stimulated emission B-coefficients are in the units of 1022 m J –1 S 2– on a logarithmic scale. Reprinted with permission from ref . Copyright 2015 AIP Publishing.…”

“…4: Comparison of experimental and theoretical nd → np transitions of the H 3 Rydberg molecule.Intensities should not be compared directly. Experimental laser strength is in arbitrary units while theoretical stimulated emission B-coefficients are in the units of 1022 m J -1 S -2 on a logarithmic scale(Saykally et al, 2015).…”