Confinement of a Currentless Plasma in the Heliotron-E

Confinement of a plasma initiated and heated by electron cyclotron-resonance-frequency waves has been studied in the Heliotron-E. The observed plasma parameters were ${T}_{e}=500\ensuremath{-}100$ eV, ${T}_{i}\ensuremath{\simeq}100$ eV, ${\overline{n}}_{e}=4\ifmmode\times\else\texttimes\fi{}{10}^{12}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ at $B=10$ kG. The electron energy decay time was 40\ifmmode\pm\else\textpm\fi{}8 msec and the particle confinement time was estimated to be more than 70 msec. These results offer a considerable improvement in energy confinement over Ohmically heated plasmas.