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 | 249: Determination of intrinsic rotation using torque ramps | ||
| Name: | Wayne M. Solomon ( |
Affiliation: | Princeton Plasma Physics Laboratory |
| Research Area: | Rotation Physics | Presentation time: | Not requested | Co-Author(s): | J. deGrassie, K.H. Burrell |
| Description: | The goal of this experiment is to establish a more efficient way of estimating the intrinsic rotation using our beam-based CER diagnostic. | ||
| Experimental Approach/Plan: | Nominally balanced neutral beam injection will be used as a rough baseline for intrinsic rotation measurements. Unfortunately, balanced NBI does not imply a zero torque profile across the plasma, and so the plasma rotatino profile can be influenced relative to 'intrinsic' level. By using occasional torque ramps from slightly co to counter, it should be possible to refine the crude estimate of the intrinsic rotation profile from balanced injection. This correction can then be applied for the time history. The intrinsic rotation inferred in this way can be compared with the traditional method, where the NBI power is replaced with ECH (probably can only match one effective NBI source with ECH). | ||
| Background: | Historically, the intrinsic rotation has been measured using short beam blips in combination with fast CER timing. In this way, the unperturbed rotation profile can be deduced by extrapolating the measurement back to prior to the NB pulse. Sufficient time must elapse between these blips to allow the rotation to return to the 'intrinsic' level. This approach, while accurate, is not very efficient (especially for measuring time histories), since typically acquiring one or a few points per shot. | ||
| Resource Requirements: | Machine Time: 1 day Experiment
Number of neutral beam sources: 5 AMAP gyrotrons + co/counter NBI | ||
| Diagnostic Requirements: | CER, Mach probe measurement of SOL flows if possible | ||
| Analysis Requirements: | -- | ||
| Other Requirements: | -- | ||
Print this page