DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2008 EXPERIMENTAL CAMPAIGN
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| Title | 340: Low triangularity, low nu*, RMP ELM control | ||
| Name: | Todd E. Evans ( |
Affiliation: | General Atomics |
| Research Area: | ELM Control & Pedestal Physics | Presentation time: | Not requested | Co-Author(s): | tbd |
| Description: | The goal of this experiments is study the heat flux splitting in RMP ELM suppressed H-modes by using the upper cryopumps to obtain low density (nu*) in a slightly downward biased plasma with the lower outer strike point positioned on top of the lower shelf where it can be seen by the IR and DiMES cameras. | ||
| Experimental Approach/Plan: | Using the shape described above, obtain the lowest possible density by optimizing the pumping due to the upper (inner and outer) and the lower outer cryopumps. This will require adjusting dRsep and the x-point positions. Do an I-coil current and phase scan with the highest NBI power possible (lowest nu*) to obtain strike point splitting data. Using the best ELM suppressed case, do an NBI power scan to assess how the splitting scales with nu*. If we are successful in obtaining RMP ELM suppression in this configuration future experiments will designed ot test other aspect of RMP physics will benefit. | ||
| Background: | In LSN ITER similar shapes the OSP is not within the giew of the IR cameras or the DiMES TV so the only way to measure strike point splitting is to move the OSP inward. This reduces the pumping due to the lower cryopump and the density increases until small ELMs return which then make it difficult to observe OSP splitting. A critical issues for understanding RMP ELM control and steady-state heat flux control in RMP H-modes is the level of heat flux on the target plates in the ELM suppressed state. These measurements will also help us understand the energy trnasport in RMP H-modes and the degree of RMP penetration (i.e., the level of stochasticity) across the pedestal. | ||
| Resource Requirements: | I-coil, upper and lower cryopumps, 7 NBI sources | ||
| Diagnostic Requirements: | lower divertor IR cameras (2 toroidal positions if possible), DiMES TV, filterscopes, tangential TVs and all the standard ELM diagnostics. | ||
| Analysis Requirements: | -- | ||
| Other Requirements: | -- | ||
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