1. Monday Physics Meeting, 05/05/081 XP-815 – Characterization of divertor heat flux width and mid-plane SOL widths J-W. Ahn 1, R. Maingi 2, J. Boedo 1, V. Soukhanovskii 3, R. Maqueda 4, S. Zweben 5 1 University of California – San Diego 2 Oak Ridge National Laboratory 3 Lawrence Livermore National Laboratory 4 Nova Photonics 5 Princeton Plasma Physics Laboratory

2. Monday Physics Meeting, 05/05/082 Motivation and goals of the experiment Topics of investigation in FY08 (all in H-mode) (1) To find dependence of λ q (target), λ Te and λ ne (upstream) on plasma parameters (Ip, nebar and Power) (2) To develop SOL width scalings (3) To find the relation between SOL widths and the edge turbulence characteristics

3. Monday Physics Meeting, 05/05/083 Fast probe vs TS measurement  Both diagnsotics are well validated against each other  Fast probe data in FY08: limited due to some technical difficulties (eg, Low power H-mode access, LCFS position control, tip arcing, etc)  Use TS data to complement probe data

4. Monday Physics Meeting, 05/05/084 Ip scan result 1 – Fast probe Te and ne decay lengths  1MA  0.8MA:  Te increases by a factor of ~2 but λ ne unchanged : λ q also increases by a factor of ~2 (0.9cm vs 1.6cm) therefore, λ Te dominates λ q ??

5. Monday Physics Meeting, 05/05/085 Ip scan result 2 – IR heat flux decay lengths  1MA  0.7MA:  q increases by more thana factor of 2  Fast probe Te and ne data incomplete  use TS data

6. Monday Physics Meeting, 05/05/086 Ip scan result 3 – TS profiles  TS profiles seem to indicate: Ip↓  λ Te ↑ & λ ne unchanged  However, TS data points too sparse, does not allow for scale length fitting  To Ensemble TS data points as a function of R-Rsep

7. Monday Physics Meeting, 05/05/087  Ip↓  λ Te ↑ & λ ne unchanged  consistent with fast probe result Ip scan result 4 – λ Te & λ ne from TS data

8. Monday Physics Meeting, 05/05/088 Density scan result 1 – λ q unchanged with ↑  nebar increase by ~40%  λ q stays remarkably similar  Fast probe data does not show consistent trend

9. Monday Physics Meeting, 05/05/089 Density scan result 2 – TS profiles  Although some decay length variation seen, no consistent tendency is observed

10. Monday Physics Meeting, 05/05/0810 Density scan result 3 – λ Te & λ ne from TS data  Considering the uncertainty of R-Rsep for each TS profile, therefore responsible for the data scatter of the ensembled TS data, λ Te and λ ne seem to stay unchanged with nebar increase from 4.1 to 5.6e13

11. Monday Physics Meeting, 05/05/0811 Power scan result 1 – λ q ↓ with Power ↑  P NBI ↑  λ q ↓  No fast probe data obtained for power scan

12. Monday Physics Meeting, 05/05/0812  P NBI ↑  λ Te ↓ & λ ne unchanged Power scan result 2 – λ Te & λ ne from TS data

13. Monday Physics Meeting, 05/05/0813  Ip, nebar, and Power scan to confirm dependence of λ q, λ Te, and λ ne were completed  λ q data robust  λ Te and λ ne data from fast probe + TS  λ q has a strong dependence on Ip (-) and power (-)  nebar does not affect any scale length  λ q variation primarily comes from λ Te  λ ne seems unchanged by any parameter scan Summary and future work  More data point and confidence  SOL Scaling  Relation between SOL widths and the edge turbulence characteristics  Analysis of GPI data and probe Isat data underway