Plasma decay was experimentally studied in the afterglow of a repetitively pulsed nanosecond discharge in a stoichiometric H₂:O₂ mixture. An additional bias DC electric field was applied to heat electrons during the discharge afterglow between the high-voltage pulses. The energy input per pulse was so small that the changes in both chemical composition and gas temperature were negligible. Using the microwave interferometer, the temporal evolution of the electron density in the discharge afterglow was measured when it decreased from 3 10¹² to 5 10¹⁰ cm⁻³. Measurements were performed for various numbers of discharge pulses (various degrees of fuel oxidation) at room gas temperature and pressures from 1 to 2 Torr. The effect of electron heating on the rate of plasma decay was most profound for low oxidation degrees and practically disappeared after complete fuel oxidation. A kinetic model was suggested for describing ion-molecule processes and plasma decay in the discharge afterglow at various H₂ oxidation degrees. The analysis of calculated results showed that plasma decay was governed by dissociative recombination of electrons with simple molecular ions at low oxidation degrees and with hydrated H₃O⁺(H₂O) _k ions at sufficiently high oxidation degrees. An increase of H₂O fraction due to H₂ oxidation in the mixture led to a less efficient electron heating during plasma decay in the additional electric field. This was associated with extremely high cross-sections for the elastic and inelastic scattering of low-energy electrons by H₂O molecules. As a result, the rate of electron-ion recombination increased with increasing number of discharge pulses, whereas the effect of electric field became less profound, in agreement with the observations.

在化学计量的 H ₂ :O ₂混合物中重复脉冲纳秒放电的余辉中实验研究了等离子体衰变。在高压脉冲之间的放电余辉期间，施加额外的偏置直流电场以加热电子。每个脉冲的能量输入非常小，以至于化学成分和气体温度的变化都可以忽略不计。使用微波干涉仪，测量了放电余辉中电子密度从 3 10 ¹²降低到 5 10 ¹⁰ cm ^-3的时间演变. 在室温和 1 至 2 Torr 的压力下，对不同数量的放电脉冲（不同程度的燃料氧化）进行了测量。电子加热对等离子体衰变速率的影响在低氧化度时最为显着，在燃料完全氧化后几乎消失。提出了一个动力学模型来描述不同H ₂氧化度下放电余辉中的离子-分子过程和等离子体衰变。计算结果分析表明，等离子体衰变受电子与低氧化度的简单分子离子和水合 H ₃ O ⁺ (H ₂ O) _{k 的}解离复合控制 离子在足够高的氧化度。由于混合物中的H ₂氧化导致H ₂ O 分数的增加导致在附加电场中的等离子体衰变期间电子加热效率较低。这与 H ₂ O 分子对低能电子的弹性和非弹性散射的极高横截面有关。结果，电子-离子复合率随着放电脉冲数量的增加而增加，而电场的影响变得不那么明显，与观察结果一致。