DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2008 EXPERIMENTAL CAMPAIGN
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| Title | 326: Exploring the assumptions built in the RWM models: Hu-Bettie-Manickam and MARS codes | ||
| Name: | Michio Okabayashi ( |
Affiliation: | Princeton Plasma Physics Laboratory |
| Research Area: | RWM Physics | Presentation time: | Not requested | Co-Author(s): | M. Chance, M. Chu, J. Manickam, A. Garofalo, Yongkyoon In, G. Jackson, R. LaHaye, H. Reimerdes, Ted Strait, H. Takahashi |
| Description: | Theoretical models for the RWM stabilization have been developed by several groups including various complex stabilizing processes. Among them, MARS code and Hu-Betti-Manicham codes are very comprehensive and should reflect the realistic experimental conditions. These predictions have been found in the range of experimental observations. The detailed comparison between the experiments and the models is the next step we should pursue.
However, through recent workshops and conferences, we have started to notice that there exist potentially- significant differences in the built-in assumptions, which could be important more than simple agreement with experimental results. Here, some differences are summarized. We propose to design the experiment for assessing their built-in assumption by examining one aspect of their predictions. Our aim is to assist the refinement of these codes as well as our understanding | ||
| Experimental Approach/Plan: | Details
According the materials presented at workshops by the two groups, there seem to exist potentially important differences between these codes. Here, some differences of their built-in assumption are summarized. MARS-F Particle bouncing (Including trapped particle and drift) ---yes Diamagnetic drift---------------------------no Ex B------------------------------------------yes Eigen-mode pattern used------------------consistent with rotation profile Volume integration scheme---------------large aspect ratio approximation Bo-Hu-Manicham Particle bouncing (Including trapped particle and drift)---yes Diamagnetic drift--------------------------yes Ex B-----------------------------------------yes Eigen-mode pattern used-----------------with no rotation profile Volume integration scheme--------------full 2D geometry integral One of conclusion of RWM driving energy source MARS-F---------------------------------------------strongly localized near the off-axis Bo-Hu-Manicham----------------------------------peaked near the central area Experiment This difference of stability localization could be related to the diamagnetic effect, eignmode pattern and the volume integration scheme. As an initial step, we propose to examine that pressure profile or q-profile dependence. Especially, the study of pressure profile peaking dependence can provide insight in the modeling. The plasma condition can be made with low rotation target like 127941. The NBI energy may be needed to be adjusted for modifying the pressure profile peakingness | ||
| Background: | -- | ||
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