EFFECTS OF DOWNSTREAM MAGNETIC-FIELD COLLIMATION ON ION BEHAVIOR IN ELECTRON-CYCLOTRON-RESONANCE MICROWAVE PLASMA

Effects of a magnetic field collimation on ion behavior in the downstr eam region of an electron cyclotron resonance (ECR) plasma device are clarified experimentally using a directional ion energy analyzer. The drift energy and its spread of the ion beam observed in the downstream region decrease and the beam temperature increases with the collimati ng magnetic flux density. Then, the ion temperature measured perpendic ular to the axis of the plasma stream slightly decreases. The ion beam is found to be almost parallel to the magnetic field lines, that is, the beam tends to be collimated.