The results of theoretical and experimental investigations of dense pl
asma source resonantly excited by helicon wave are presented. Driven b
y a single-loop low-voltage (congruent-to 300 V) antenna, a source gen
erates a plasma of density up to 5 X 10(11) cm-3 at gas pressures 0.5-
20 mTorr, operates at magnetic, fields < 100 Gs, and produces low-ener
gy ion fluxes (< 60 eV) with current densities up to 7 mA/cm2 and 3.5%
nonuniformity within a diameter 10 cm. A high-efficiency helicon sour
ce originates in a special kind of ''resonance'' wave discharge, where
a sharp increase of plasma resistance occurs near the helicon wave di
spersion branches.