Global to push GA events into
skip to main content

Title: Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within themore » resonance zone.« less
 [1];  [1]
  1. (Plano, TX)
Issue Date:
OSTI Identifier:
ASTeX-PlasmaQuest, Inc. (Wilmington, MA) OAK
Patent Number(s):
US 6163006
Application Number:
Contract Number:
Research Org:
Country of Publication:
United States