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 | 310: Giant sawteeth that never crash | ||
| Name: | William W. Heidbrink ( |
Affiliation: | University of California, Irvine |
| Research Area: | Energetic Particles | Presentation time: | Requested | Co-Author(s): | Kramer, Pinsker, Van Zeeland, Petty |
| Description: | Create giant sawteeth with 4th and 6th harmonic heating of deuterium beam ions. Use ECCD to arrest current diffusion, allowing operation without sawtooth crashes at q0 < 0.9 | ||
| Experimental Approach/Plan: | Attempt to reproduce the giant sawteeth observed in 1998, i.e., discharge 96043, using 4th harmonic heating of beam ions in a L-mode plasma. Use ECCD in two ways to increase the sawtooth period. (1) to flatten the magnetic shear near the q=1 surface. (2) As an off-axis current source to arrest current diffusion. In practice, the ECCD deposition layer will be scanned to both destabilize and stabilize the giant sawteeth. | ||
| Background: | There was a combined experiment with this objective in 2007. Due to the unavailability of 60 MHz power, we tried 3rd harmonic acceleration of hydrogen beams at 90 MHz but that failed to create giant sawteeth. Now we want to go back to our original plan of using 4th harmonic acceleration of deuterium beam ions. This experiment has multiple purposes: apply our outstanding Alfven eigenmode diagnostics to a new regime, accurate validation of sawtooth trigger models, and relevance to high-li AT operation. It is also an ITPA joint experiment. | ||
| Resource Requirements: | 1 MW of 60 MHz power essential; 2 MW of 90 MHZ power desirable. 330LT and 30 LT beams essential; others desirable. At least 2 MW of ECCD. | ||
| Diagnostic Requirements: | FIDA, MSE, and ECE essential, as well as all plasma profile diagnostics for sawtooth trigger validation. | ||
| Analysis Requirements: | Fit AE eigenfunctions with NOVA. Model fast-ion distribution with CQL3D and ORBIT-RF. Model sawtooth stability with MHD codes. | ||
| Other Requirements: | -- | ||
Print this page