The mean lives of excited neon atoms

Since the first experiments by Wien many methods have been used to find the average lives of the excited states of different atoms. Most of these methods are applicable to particular atoms only, and the amount of reliable information in this field is still surprisingly meagre. The method described here depends in effect on the measurement of the lag which exists between the excitation and emission of light from atoms in a high-frequency discharge. This lag, or rather quantity actually measured, is itself a first approximation to the average lifeτ of the state concerned, and it is shown later how a more accurate value ofτ may be deduced from it. Results are given for six excited states of the neon atom, but the method may be used for any substance whose spectrum can be obtained from a high-frequency discharge. The values ofτ for neon range from 3·9 to 20·10-8 seconds, and it is shown that lines originating from the same upper level lead to the same value ofτ for that level.