The role of optical transitions between ionic and Rydberg states in a KrF laser

The upper laser level of a KrF laser is treated as a cluster containing several hundreds vibration-rotation energy levels of the electronic state B, which is mixed due to collisions with the close ionic state C. The KrF (C) state is depleted as a result of optical transitions to a higher Rydberg state. This model explains the experimental data on the picosecond dynamics of the light amplification. The possibility of using a KrF laser as an amplifier of radiation with a wavelength of 120 nm is discussed.