Radially expanding plasma parameters in a hot refractory anode vacuum arc

I. I. Beilis*, R. L. Boxman, S. Goldsmith, V. L. Paperny

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Electron temperature, plasma density, and plasma potential were measured with a Langmuir probe in the radially expanding plasma streaming from the interelectrode gap of a hot refractory anode vacuum arc. Plasma parameters were measured when the anodic plume was formed, during the first 20 s after arc ignition, at points located 3 to 18 cm from the electrode edge. In addition, the ion energy distribution was determined using a retarding field analyzer. As a function of radial distance, the electron temperature decreased from 1.2 to 0.6 eV, the plasma potential decreased from 3.7 to 1.7 V, and the plasma density decreased from 2·1013 to 1.8·1011 cm-3. The measured mean ion energy per unit charge state increased from 8 eV at an axial distance of 3 cm to 20 eV at 18 cm. The electron temperature and plasma potential decreased with arc duration by about 0.4 and 2 eV, respectively, near the electrode region. The relatively small magnitude of the ion energy observed near the gap may be caused by nonelastic resonance charge exchange scattering of the cathode jet ions on atoms that are reevaporated from the anode. The observed ion acceleration at larger distances from the gap is caused by the gradient in the electron pressure caused by the plasma expansion from the interelectrode gap into the ambient vacuum.

Original languageEnglish
Pages (from-to)6224-6231
Number of pages8
JournalJournal of Applied Physics
Issue number11
StatePublished - Dec 2000


Dive into the research topics of 'Radially expanding plasma parameters in a hot refractory anode vacuum arc'. Together they form a unique fingerprint.

Cite this