Narrowband emission of argon dimers in a dc discharge with supersonic expansion

Narrowband emission of Ar₂ ^* at 126 nm was observed in a dc discharge with supersonic expansion and cooling of Ar gas through a metallic nozzle. The bandwidth of the excimer emission was 5.7 nm, which was lower than the values reported in the literature. The short bandwidth was attributed to the increased contribution of the singlet excimer state to the emission that could lead to a partial amplification of the radiation. PACS 33.20.Ni; 42.55.Lt; 52.80.Yr