DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2008 EXPERIMENTAL CAMPAIGN
Login | Review | Submit | Logout | Help
Questions about this website? Contact Andrew LeBlanc Questions about ROF? Contact Chuck Greenfield
| Title | 284: Test contribution of edge ion orbit loss to intrinsic toroidal rotation | ||
| Name: | Keith Burrell ( |
Affiliation: | General Atomics |
| Research Area: | Rotation Physics | Presentation time: | Not requested | Co-Author(s): | -- |
| Description: | Investigate intrinsic rotation in H-mode plasma with reduce edge ion orbit loss | ||
| Experimental Approach/Plan: | Run inner-wall limited H-mode plasma using shape with X-points well beyond the last closed flux surface. A possible discharge is 129470, which has no X-points in the vacuum vessel. Adjust plasma interaction with centerpost to achieve H-mode with convenient input power (< 7.5 MW). Change beam co-counter balance to scan toroidal rotation from counter to co with the goal of finding the point where the net torque is zero. Measure toroidal rotation profiles for all cases and determine intrinsic rotation. Compare magnitude of intrinsic rotation with results from previous experiments. | ||
| Background: | C.S. Chang has proposed a theory of the intrinsic toroidal rotation says that the effect is due to loss of counter-going ions at the plasma edge. These leave behind a distribution with net angular momentum in the co-direction, thus producing the rotation. Calculations by C.S. Chang indicate that most of the thermal ion orbit loss in H-mode plasmas is through the X-point. Accordingly, running a plasma without X-points should reduce this loss substantially. Fast ion orbit loss can be reduced by running a large outer gap. The experiment will investigate whether the intrinsic rotation follows the same scaling with toroidal beta that this seen in D III-D X-point discharges. If it is much lower, then that would indicate that ion orbit loss is a significant player. | ||
| Resource Requirements: | All profile diagnostics. Modulate 30LT and 330LT out of phase for improved CER measurements. | ||
| Diagnostic Requirements: | -- | ||
| Analysis Requirements: | -- | ||
| Other Requirements: | -- | ||
Print this page