1 / 10

Emilia R. Solano, Stefan Jachmich, Yann Corre, Wojciech Fundamenski

Apparent observation of downward strike point jumps: caution. Emilia R. Solano, Stefan Jachmich, Yann Corre, Wojciech Fundamenski. Why look at the same problem with multiple diagnostics? To get multiple answers? ; )

janice
Download Presentation

Emilia R. Solano, Stefan Jachmich, Yann Corre, Wojciech Fundamenski

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Apparent observation of downward strike point jumps: caution Emilia R. Solano, Stefan Jachmich, Yann Corre, Wojciech Fundamenski Emilia R. Solano TFE Meeting

  2. Why look at the same problem with multiple diagnostics? To get multiple answers? ; ) Infra Red Camera and Langmuir Probes must be used in conjunction to study strike point movements. Small ELMs are harder to study... Emilia R. Solano TFE Meeting

  3. heat flux downward Downward strike point jumps in reversed Bt plasmas? High temperature peaks located below average position (average position presumed to be inter-ELM strike position) Emilia R. Solano TFE Meeting

  4. At ELM, a little hotter above time brighter area below Z(m) Get back to data, look at one time slice Before ELM: lower T, darker area see strike position It appears that heat flux arrives below the pre-ELM position Emilia R. Solano TFE Meeting

  5. ELM starts t=400s t=0s expected temperature profile at tpeak=tELM+t before ELM during ELM Plot a profile of IR temperature along a toroidal cut of the image. Emilia R. Solano TFE Meeting

  6. In fact, very little power arrived below strike point, the large downward shift was apparent, not real. Next time slice (2.8 ms later) The apparent downward jump of the strike point is in fact evidence of deposited layers in a different location, below strike, for reversed Bt plasmas. Emilia R. Solano TFE Meeting

  7. at ELM after ELM before ELM What does a real strike point jump look like? (standard Bt, large ELM) Clearly the upward strike point jump is associated with considerable heat flux at a new vertical location, higher up. Z(m) Emilia R. Solano TFE Meeting

  8. 5 ms Langmuir Probe data for Reversed Bt shot studied by IR Z=-1.606 m Z=-1.566 m Jsat ion(106 A/m2) Z=-1.639 m Z=-1.395 m JET 59635 Reversed Bt Langmuir Probe data analysed by S.Jachmich Da(1016 p/scm2sr) Evidence of upward jump of strike point from high time resolution LP data. Not inconsistent with IR observations. Emilia R. Solano TFE Meeting

  9. Separatrix breaking (current peeling) model (ERS) predicts upward jump in strike points, unaffected by Bt direction. Ratio of inboard/outboard jump given by details of equilibrium. Orbit model with strong radial electric field effects (WF) predicts upward jump in position of maximum heat flux in both cases Standard Bt: displacement is larger inboard. Reversed Bt: displacement is larger outboard. Data not available to check that detail. Emilia R. Solano TFE Meeting

  10. Conclusions: there is no discrepancy between Langmuir Probe observations and IR camera, when IR data is correctly interpreted. Therefore, the data shows that strike points jump upwards at an ELM, both for forward and reversed Bt. Details of the size of the jump may be different, and are difficult to evaluate, as there is very little data from LP in reversed Bt campaign. Emilia R. Solano TFE Meeting

More Related