Spectroscopic investigation of corona discharge in liquid Helium

The corona discharge has been realized close to point electrode under both negative and positive high voltage in normal liquid helium (LHe) at 4.2 K. The experiments have been carried out at constant temperature and for different pressures in a wide range. An intensity of the visible light emitted from the zone closed to tip was enough for its spectroscopic analysis. The shift and width of the spectra observed were measured as a function of the applied pressure. It is shown that the spectra belong to excited atoms inside of empty cavity in LHe. The significant ldquored satellitesrdquo were observed in the spectra of positive corona.