Nature of Xe[font size=-1] I[/font] laser line superradiance in the presence of a buffer gas

A helium-initiated inelastic channel for collisions between excited states of Xe [font size=-2]I[/font] was discovered experimentally. The contribution of the helium to this channel was found to be an order of magnitude greater than that of the electrons. An isotopic effect was identified in the multipletmixing reactions.