Characteristics of striations in a helium-neon discharge

Experiments were performed to investigate the critical current for the formation of stratified regions in helium-neon discharges for the following parameters: pressure of 2-6 torr, discharge tubes with diameters of 2-6 mm, and different discharge gap lengths. Under certain conditions strataless regions are formed in the discharge; the magnitude of such regions is inversely proportional to the length of the discharge gap and their lower bounds weakly depend on the discharge tube diameter. The critical current for strata formation is inversely proportional to the total pressure of the active mixture. The study has relevance to processes in He-Ne lasers.