First observed in gaseous plasmas in the early 1960's, helicon dischar
ges lay like a sleeping giant until they emerged in the 1980's, when t
heir usefulness as efficient plasma sources for processing microelectr
onic circuits for the burgeoning semiconductor industry became recogni
zed, Research on helicons spread to many countries; new, challenging,
unexpected problems arose, and these have spawned solutions and novel
insights into the physical mechanisms in magnetized radio-frequency di
scharges, Among the most baffling puzzles were the reason for the high
ionization efficiency of helicon discharges and the dominance of the
right-hand polarized mode over the left-hand one, The most recent resu
lts indicate that a nonobvious resolution of these problems is at hand
.