Abstract
Abstract Strong support for the critical pressure gradient model for the heat flux width has been obtained, in that the measured separatrix pressure gradient lies below and scales similarly to the pressure gradient limit obtained from the ideal, infinite-n stability codes, BALOO and 2DX, in all cases that have been examined. Predictions of a heuristic drift model for the heat flux width are also in qualitative agreement with the measurements. These results have been obtained using an improved high rep-rate and higher edge spatial resolution Thomson scattering system on DIII-D to measure the upstream electron temperature and density profiles. In order to compare theory and experiment, profiles of density, temperature, and pressure for both electrons and ions are needed as well values of these quantities at the separatrix. A simple method to identify a proxy for the separatrix has been developed to do so.
| Original language | English |
|---|---|
| Article number | 48478 |
| Pages (from-to) | 55-60 |
| Number of pages | 6 |
| Journal | Journal of Nuclear Materials |
| Volume | 463 |
| DOIs | |
| State | Published - Jul 22 2015 |
| Externally published | Yes |
Funding
This work was supported by the U.S. Department of Energy under DE-AC52-07NA27344, DE-FC02-04ER54698, and DE-AC02-09CH11466 . DIII-D data shown in this paper can be obtained in digital format by following the links at https://fusion.gat.com/global.D3D_DMP .