Compact Plasma and Focused Ion Beams

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Review of the Cutoff Problem

A Brief History of Earlier Work

Since the early days of research in ECR plasmas in 1980s, heating and con-

nement in electron cyclotron resonance (ECR) plasmas were brought about

by electromagnetic coils. Coils arranged on either side of the experimental

device can produce an axial magnetic eld. Depending upon the applica-

tion, the axial eld can be linear, diverging, or in the form of a magnetic

mirror. A linear eld [1–3] has been used in plasma experiments, while a

diverging eld [4,5] is known to be benecial for particle directionality to a

downstream plasma processing area or for controlling the energy of ...