@InProceedings{motley85,
  author =       {Robert W. Motley and Ronald E. Bell and
                  Stefano Bernabei and Alfred J. Cavallo and Tsu-Kai Chu
                  and Samuel A. Cohen and Boel G. Denne and
                  Phillip C. Efthimion and Nathaniel J. Fisch and
                  Einar Hinnov and William M. Hooke and Joel C. Hosea
                  and Forrest C. Jobes and Charles F. F. Karney and
                  Ernesto Mazzucato and E. B. Meservey and
                  James E. Stevens and Szymon Suckewer and Gary Taylor
                  and John R. Timberlake and Schweickhard E. von Goeler
                  and J. Randall Wilson},
  title =        {Lower Hybrid Current Ramp-up in the {PLT} Tokamak},
  booktitle =    {Plasma Physics and Controlled Nuclear Fusion Research
                  1984},
  pages =        {473-478},
  year =         1985,
  volume =       1,
  reprint =      {iaea85},
  publisher =    {IAEA, Vienna},
  note =         {Proc. Tenth International Conf., London, England,
                  Sept. 12--19, 1984},
  annote =       {Paper IAEA--CN--44/F--II--2},
  abstract =     {A study of radiofrequency current ramp-up in the PLT
                  tokamak is reported.  The plasma current was first
                  raised to 200–300 kA by the Ohmic heating
                  transformer, and the current in the transformer
                  primary circuit was then held constant to remove the
                  OH drive.  After the current fell below 200 kA, up to
                  300 kW of toroidally-directed RF power at 800 MHz was
                  transmitted into the PLT plasma via a 6-element phased
                  waveguide array.  Current ramp-up rates between 0 and
                  120 kA/s for a 0.35 s time interval
                  ((&frac12;&ndash;1/3) <i>L</i>/<i>R</i> time) where
                  measured at densities between 2 and 4 &times;
                  10<sup>12</sup> cm<sup>&minus;3</sup>. It is estimated
                  that about 20\% of the RF energy introduced into the
                  vacuum vessel was converted into poloidal magnetic
                  field energy, <i>LI</i><sup>2</sup>/2, where <i>L</i>
                  &cong; 3 &mu;H is the total inductance of the plasma
                  current loop.  This conversion ratio should depend on
                  a variety of factors, including the percentage of RF
                  power absorbed by resonant electrons and the magnitude
                  of the back current induced by the changing poloidal
                  flux <i>LI</i>.  The high ramp-up efficiencies are
                  predicted theoretically in the regime in which the PLT
                  ramp-up experiments operate, i.e., where the phase
                  velocity of the waves is approximately equal in
                  magnitude to the runaway velocity due to the back
                  voltage.  Comparison of the raw data with theory
                  suggest that about &frac12; to &frac34; of the
                  incident RF power is absorbed by resonant
                  high-velocity electrons.}
}