Decay of the TripletPLevels of Neon

The current and pressure dependence of the decay of the ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$ metastable level of neon was measured by using a light absorption method. The decay was found to be nonexponential and current dependent at normal excitation currents. At extremely low excitation current, however, the ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$ decay becomes exponential and current independent. The mean lives associated with such exponential decays were measured as a function of pressure. The results are in agreement with the usual theoretical relation based on metastable destruction by diffusion to the container walls at low pressure and two-body collisions at high pressures. The pressure dependence of the ${}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$ level was also studied. It was found, as previously reported by Grant, that the experimental results for the pressure range from 2 to 20 mm of mercury, where diffusion loss is small, do not agree with the usual theoretical prediction.