@InProceedings{jobes86,
author = {Forrest C. Jobes and Stefano Bernabei and Tsu-Kai Chu
and Nathaniel J. Fisch and William M. Hooke and
Charles F. F. Karney and E. B. Meservey and
Robert W. Motley and James E. Stevens and
Schweickhard E. von Goeler},
title = {Start-up and Ramp-up of the {PLT} Tokamak by Lower
Hybrid Waves},
preprint = {Princeton Univ. Rept. \eref{PPPL-2241}{PPPL--2241}
(Aug. 1985) 31 pp.},
booktitle = {Tokamak Start-up},
pages = {203-216},
year = 1986,
editor = {H. Knoepfel},
volume = 26,
series = {Ettore Majorana International Science Series, Physical
Sciences},
publisher = {Plenum Press, New York (EUR 10114 EN)},
note = {Proc. Seventh Course of the International School of
Fusion Reactor Technology, Erice, Sicily, July 14--20,
1985},
abstract = {Lower hybrid waves have been used on the PLT tokamak
both to start the plasma current and to ramp it up
from pre-existing levels. The waves, at 800 MHz, were
launched from a 6-waveguide grill. The phasing
between adjacent guides could be selected
electronically, and thus the launched spectrum could
be set and changed at will. For start-up, the
waveguide phase difference was initially set at 0°
in order to create a plasma, then switched to 90°
to drive the current. Over 100 kA of plasma current,
at a density of 0.5–1 × 10<sup>12</sup>
cm<sup>−3</sup>, was generated in this manner.
Ramp-up experiments were performed under a wide
variety of conditions. The most efficient ramp-up was
found at the lowest plasma densities and with the
fastest launched spectrum (<i>n</i><sub><i>e</i></sub>
∼ 2 × 10<sup>12</sup> cm<sup>−3</sup>,
N<sub>||</sub> ∼ 1.6 peak); ∼ 20\% of the
launched RF power was converted to (increased)
poloidal field energy. All of the ramp-up results are
in excellent agreement with a theory which determines
the efficiency of ramp-up from the consideration of
the relative energy losses of the superthermal
current-carrying electrons to collisions and to the
opposing inductive <i>E</i>-field.}
}