The role of clustered particles in the formation of a secondary flow (“wake”) upon the outflow of gas into a rarefied medium in condensation modes is found out. The boundaries of the “wake” are found by comparing the spectral and photometric measurements. Possible mechanisms of the initiation of its glow are considered. The role of the energy exchange of clusters with background gas in the afterglow of the “wake” is established. The wavelengths and corresponding transitions in the neutral (Ar-I) and singly ionized (Ar-II) argon atoms, which cause the anomalous glow, are determined. The lifetimes of particles in the excited state in the central part and on the periphery of the clustered flow are found. The effect of condensation on the penetration of the background gas into the primary traditional supersonic jet and into the “wake” zone is found.
- anomalous emission
- supersonic gas flow