PPPL-5392
Observation of flat electron temperature pro files in the Lithium
Tokamak Experiment
Authors: D.P. Boyle, R. Majeski, J.C. Schmitt, R.
Kaita, M. Lucia
Abstract: It has been predicted for over a decade that
low-recycling plasma-facing components in fusion devices would allow
high edge temperatures and at or nearly at temperature
pro files. In recent experiments with lithium wall-coatings in the
Lithium Tokamak Experiment (LTX), a hot edge (>200 eV) and flat
electron temperature pro files have been measured following the
termination of external fueling. Reduced recycling was demonstrated
by retention of ~60% of the injected hydrogen in the walls
following the discharge. Electron energy confinementt followed
typical Ohmic confinement scaling during fueling, but did not
decrease with density after fueling terminated, ultimately exceeding
the scaling by ~200%. Achievement of the low-recycling, hot edge
regime has been an important goal of LTX and lithium plasma-facing
component research in general, as it has potentially signi ficant
implications for the operation, design, and cost of fusion devices.