On the plasma rotation in a straight magnetized filter of a pulsed vacuum arc

L. GIULIANI,; D. GRONDONA,; H. KELLY,; F. O. MINOTTI

JOURNAL OF PHYSICS - D (APPLIED PHYSICS)

IOP PUBLISHING LTD

Año: 2007 vol. 40 p. 401 - 408

0022-3727

In vacuum arcs of interest for ion deposition, in which a magnetic filter isused, significant plasma rotation about the filter axis can develop. In thepresent work we present experimental evidence and simplified models tointerpret relatively fast rotation of plasma generated in a pulsed vacuum arcwith a straight magnetic filter and with a magnetic field strength in the range52?430 G. The plasma rotation is produced in the first part of the filter (thedriving region) where either the expanding or the contracting plasmaencounters a mainly axial magnetic field. In the next part of the filter (therotation region) a quasi-equilibrium is achieved and the plasma does notevolve further significantly. A rigid-rotor type of equilibrium is consideredto model the rotation region, with experimentally obtained parameters, and asimple model is employed in the driving region to quantify the magnitude ofthe plasma rotation. It is found that at the quoted values of the magneticfield plasma rotation is an essential constituent to consider in anyself-consistent theoretical model for the plasma inside the filter.