Electrical Discharge Metastable Detector.

摘要

Statistical time lags have been used to measure metastable densities in helium and helium-mercury afterglows with total pressures ranging from 0.2-100Torr. The simpliest geometry employed was a parallel-plate discharge gap that was used for both the production and detection of the metastables. Better spatial resolution was obtained with the nude electrodes of a Nixie-tube inserted into the experimental volume. The sensitivity of the method is 10-100 metastables per cc. The experimental data have been compared with theoretical results based on diffusion of metastable atoms and molecules. The comparison is not good. Even so,due to its extremely high sensitivity,the method can be used to study processes of the second kind in flowing afterglows and laser plasma. (Author)