磁旋转电弧中热阴极弧根形态的实验研究.docxVIP

DOI: 10.13336/j.1003-6520.hve.2014.10.012磁旋转电弧中热阴极弧根形态的实验研究城 1，查俊 1,2，李皖皖 1，夏维珞 3，夏维东 1王（1. 中国科学技术大学，合肥 230027；2. 合肥通用机械研究院，合肥 230027；3. 中国科学院合肥物质科学研究院，合肥 230031）摘 要：阴极弧根形态对电弧状态和电极损耗有着重要影响。在同轴电极磁旋转电弧等离子体发生器中，利用高速 CCD 观察了阴极弧根斑点形态随外加轴向磁场的演化过程，采用双波长法从 CCD 影像得到阴极端面温度分布； 利用水冷电探针对近阴极区等离子体参数进行诊断，得到了阴极附近电子温度及阴极区位降。实验结果表明：(1) 在 50 A 电弧电流下，随着轴向磁场从 0.01 T 增加到 0.02 T，阴极端面最高温度下降，阴极弧根斑点增大，阴极附 近等离子体电子温度逐渐降低，阴极弧根为收缩模式；(2)在 100 A 电弧弧电流下，轴向磁场从 0.01 T 增加至 0.015T，阴极状态变化趋势与前相同；(3)在 100 A 电弧弧电流下，当轴向磁场增大到 0.02 T 时，弧根斑点弥散均匀， 阴极区位降明显升高，阴极弧根模式由收缩模式转变为扩散模式。分析认为，磁旋转电弧中弧根模式的转变是一 个突变的过程。关键词：磁旋转电弧；阴极弧根；阴极弧根斑点；阴极温度；阴极区位降；双波长法Experimental Study of the Thermal Cathodic Arc Root in Magnetically Rotating Arc PlasmaWANG Cheng1, ZHA Jun1,2, LI Wanwan1, XIA Weiluo3, XIA Weidong1(1. University of Science and Technology of China, Hefei 230027, China; 2. Hefei General Machinery Research Institute, Hefei230027, China; 3. Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China)Abstract：The configuration of cathodic arc root influences the state of arc and electrode erosion significantly. Hence, wecaptured the evolution of cathode spot in a magnetically rotating arc plasma generator in external axial magnetic field us- ing a high-speed CCD camera, and acquired the end-face temperature distribution of the cathode using two-wavelength pyrometry. We also diagnosed the electron temperature in near-cathode region using a water-cooling electric probe and hence calculated the electron temperature and cathode fall in the region. The main results are as follows: (1) With 50 A arc current, as the magnetic field increases from 0.01 T to 0.02 T, the region of cathode spot increases gradually, meanwhile both the cathode’s highest temperature and the electron temperature in the near-cathode region decrease, and the cathodic root is always in spot mode. (2) With 100 A arc currents, as the magnetic field increases from 0.01 T to 0.015 T, a similar variation tendency is obtained. (3) With 100 A