ISSN:
1432-0630
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract A characteristic feature of the vacuum are is the existance of a minimum current for stable operation. Actually, the are is chopped at a smaller current. This is caused by repeated re-ignitions. This paper describes measurements of chopping current, dependent on gas pressure and electrode distance, that were carried out to understand the mechanism of these re-ignitions. The results show, that the chopping current depends slightly on the product of ambient pressure and electrode distance. These results are explained by a model that assumes that after the first interruption of the are a small, but relatively dense cloud of ionized vapour remaines above the cathode spot while the rest of the space between the electrodes has only ambient pressure. Re-ignitions take place by avalanche ionisation in that cloud. The space between cloud and anode is responsible for the dependence of chopping current on pressure and electrode distance.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00900324
Permalink