每年出版 4 期
ISSN 打印: 1093-3611
ISSN 在线: 1940-4360
Indexed in
OPTICAL STUDIES OF CATHODE AND NEAR-CATHODE PLASMA REGION IN DC FREE-BURNING ATMOSPHERIC ARC IN ARGON
摘要
This work is devoted to the comparative study of diffuse and contracted forms of the cathode arc attachment. We studied DC free-burning atmospheric pressure argon arc at currents 20 ÷ 200 A. The arc was oriented vertically with a cathode at the bottom. The cathode rod of 2 mm in diameter was made of pure tungsten. The water-cooled plane copper anode was set 10 mm above the cathode tip. Measurement results have showed: 1) a surface temperature and its distribution along the cathode rod axis are differed considerably one from another in two attachment forms; 2) in the case of the contracted form, the near-cathode plasma temperature exceeds greatly that in the diffuse form and is about 3 eV at its maximum in the immediate vicinity of the cathode tip (so, to determine the plasma temperature the ArIII lines radiation was used); 3) a plasma temperature in the contracted attachment root doesn't depend on current; 4) for both attachment forms the current densities on the cathode surface don't depend on current, being in the contracted form the current density is about four times higher than in diffuse one and comes to (1 ÷ 1.5)·104 A/cm2. Data obtained were compared with published experimental results and calculations.