HELICONS - THE EARLY YEARS

Helicon waves are right-hand polarized (RHP) waves which propagate in radially confined magnetized plasmas for frequencies omega(ci) much le ss than omega much less than omega(ce) where omega(ci) is the ion cycl otron frequency and omega(ce) is the electron cyclotron frequency, The y are part of a much larger family of waves which can propagate down t o zero frequency and constitute a very rich field for studying complex propagation characteristics and wave-particle interactions, This pape r gives a historical perspective of the waves and their relationship t o plasma source development up to the mid 1980's, presents a simple de scription of their propagation characteristics in free and bounded pla smas, and finishes with their first reported use in plasma processing experiments.