ELECTRON DECAY FOLLOWING d-c. DISCHARGE IONIZATION IN NO AND NO–Ne MIXTURES

The time dependence of the electron density, N e (t), and radiation temperature, T e (t), has been measured in d-c. discharge afterglows of NO and NO–Ne mixtures. Microwave wave-guide transmission and noise-sampling techniques were used. In pure NO the experimental results were compared with those computed for a recombination–attachment controlled plasma using Gunton and Shaw's values, and good agreement was found. In the NO–Ne mixtures p(Ne) was about 20 Torr, and p(NO) was varied from 0.5 × 10 −3 to 0.10 Torr. It was found that 1/N e (t) was linear over extensive ranges of N e (t) indicating two-body electron–ion recombination. The results yield [Formula: see text] and the three-body attachment coefficient K = 2.2 × 10 −31 cm 6 sec −1 for T e = T gas = 300 °K. T e (t) decayed nonexponentially varying with p(NO) indicating that Penning ionization takes place together with other collision processes which are briefly discussed.