Abstract
A critical gradient threshold has been observed for the first time in a systematic, controlled experiment for a locally measured turbulent quantity in the core of a confined high-temperature plasma. In an experiment in the DIII-D tokamak where LTe-1=Te|/Te and toroidal rotation were varied, long wavelength (kθρs0.4) electron temperature fluctuations exhibit a threshold in LTe-1: below, they change little; above, they steadily increase. The increase in δTe/Te is concurrent with increased electron heat flux and transport stiffness. Observations were insensitive to rotation. Accumulated evidence strongly enforces the identification of the experimentally observed threshold with Te-driven trapped electron mode turbulence.
| Original language | English |
|---|---|
| Article number | 045003 |
| Journal | Physical Review Letters |
| Volume | 110 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jan 23 2013 |
| Externally published | Yes |