NO^+离子解离复合反应的激波管研究

Shock Tube Stodies on the Association Recombination of NO^+ and Electronics

在激波管上用反射激波加热气体使之离化，继之以强稀疏波快速冷却，造成电离非平衡状态，构成一种新的电离复合动力学实验研究方法。测定了温度在3100～3700K范围内NO^+离子与电子的解离复合速率常数：

A new shock tube method is developed, in which the gases are ionized by the shock wave and subsequently quenched by a strong rarefaction wave. As the quenching sped 106K/s has ho reached, the ionization is in non-equilibrium during the process. A piezo-electric tiansducer and a langmuir probe are used to monitor the changing state parameters, and the variation of the ion density.The composition of the experimental gases are 4.7% air mixed in argon. At the reflection shock region, the equilibrium temperature T5=4150K, pressure P5=0.4 MPa and ion density [NO+]=2.7×1012cm-3 are determined by shock speed consistent with the dired meastirements.The kinetic equation for the recombination reaction of NO++e N+O in the quenching kr+'proals has been derived aswhere K+=kf+/kr is the equilibrium constant, [N] and [O] is the local number density of atom N and atom O respectively. As the [N] ~ 1015cm-3 and [O] ~ 1017cm-3 in this one, in the evaluation of the variation of [N] and [O] we let auction 2N+Ar N2+Ar is in the frozen,2O + Ar O2 + Ar is in equilibrium and N + O→NO+ is in finite rate. Using the calculated value of the local [N], [O] and the measured p/p5, [NO+]/[NO+]5, the value of kr= 5.5×1017 T-0.52cm3 mol-1 S-1at 3100K<T<3700K is deteremined. The comparison of this result with the existal data shows that the dependence of kr on T is consistent with Hanson's estimate, and the quantity of the kr+ is consistent with Lin's data, and three times smaller than Dunn's measurement.