Collision cross sections for the neon 2p levels at 870K

The authors have measured the alignment destroying collision cross sections for the levels of the 2p5 3p configuration of neon for helium and neon perturbers in a mild discharge at a temperature of 870K. Some of the cross sections, notably those of the 2p2 and 2p6 levels, increase rapidly above room temperature and they attribute this to the effect of collisional transfer of excitation to neighbouring levels in the configuration. The relationship between these nonadiabatic cross sections and the cross sections for the collisional relaxation of population reported by other authors is discussed. The authors show that collisional cascade of populations is important for the 2p levels. Most of the other cross sections in the configuration continue to show a weak temperature dependence consistent with an adiabatic collision model with combined repulsive and attractive interatomic potentials.