The monitoring of the degree of oxygen dissociation in the discharge plasma is critical for various plasma applications associated with the etching and oxidation of surfaces or the reactive deposition of oxide coatings. The use of existing measurement techniques is limited owing to their complexity, significant error rate, or application conditions. This study deals with the development of a catalytic probe method for measuring the degree of oxygen dissociation in dense arc discharge plasma. A method for measuring and processing the experimental results is presented, which allows the determination of the thermal contribution of the heterogeneous recombination of oxygen atoms at a high total heating power of the catalytic probe by particle streams and plasma radiation. The atomic oxygen concentration was measured in low-pressure arc plasma with a self-heating hollow cathode in an Ar/O₂ mixture with changes in the discharge current and oxygen partial pressure over a wide range of 30–70 A and 0.2–0.6Pa, respectively. It has been demonstrated that the maximum degree of oxygen dissociation (up to 25% of the O₂ content) is achieved at the maximum discharge current and is practically independent of the oxygen flow, whereas the highest concentration of atomic oxygen is achieved when the maximum current and O₂ flow values are combined. This conclusion is important for technologies based on plasma-chemical processes in high-current discharges.

对于与表面的蚀刻和氧化或氧化物涂层的反应性沉积相关的各种等离子体应用，放电等离子体中氧离解程度的监控至关重要。由于其复杂性，明显的错误率或应用条件，限制了现有测量技术的使用。这项研究涉及催化探针方法的发展，该方法可测量致密电弧放电等离子体中的氧离解程度。提出了一种测量和处理实验结果的方法，该方法可以确定粒子流和等离子体辐射在催化探针的高总加热功率下氧原子的非均相重组的热贡献。_2种混合物的放电电流和氧分压分别在30–70 A和0.2–0.6Pa的宽范围内变化。已经证明，在最大放电电流下可以实现最大程度的氧离解（最多达到O ₂含量的25％），并且实际上与氧的流量无关，而当最大氧原子解离度达到最大时电流和O ₂流量值组合在一起。该结论对于基于大电流放电中的等离子体化学过程的技术很重要。