DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2008 EXPERIMENTAL CAMPAIGN
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| Title | 305: Turbulence spreading experiment in the plasma edge | ||
| Name: | Keith Burrell ( |
Affiliation: | General Atomics |
| Research Area: | Transport Model Validation | Presentation time: | Not requested | Co-Author(s): | -- |
| Description: | The goal of this experiment is to determine whether we can
experimentally detect the spatial spreading of turbulence which is predicted by various analytic calculations and gyrokinetic code runs. | ||
| Experimental Approach/Plan: | Look at changes in turbulence across the L to H transition in the
region just inside the edge pedestal using BES and/or reflectometry. See if the turbulence decreases much more rapidly than can be explained by the change in local profiles. In order to give an exact time marker, we want a sharp, single step transition during a period when the beam power has been constant for some time. One possible way to do this is to use a Drsep change to change the power threshold. | ||
| Background: | Recent theoretical work indicates that there is a nonlocal character
to turbulence in magnetized plasmas. Turbulence can be driven from free energy sources in one location and manifest itself both at that location and in more distant areas. The issue is that, in most cases, the plasma is also unstable to microturbulence in that more distant location. Accordingly, to do a meaningful experiment, we need to find ways to separate the local and nonlocal effects. | ||
| Resource Requirements: | -- | ||
| Diagnostic Requirements: | Edge turbulence diagnostics | ||
| Analysis Requirements: | -- | ||
| Other Requirements: | -- | ||
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