Divertor heat and particle flux due to ELMs in DIII-D and ASDEX-Upgrade
- General Atomics, San Diego, CA (United States)
- Max Planck Inst. for Plasma Physics, Garching (Germany); and others
The authors characterize the divertor target plate heat and particle fluxes that occur due to Edge-Localized-Modes (ELMs) during H-mode in DIII-D and ASDEX-Upgrade. During steady-state ELMing H-mode the fraction of main plasma stored energy lost with each ELM varies from 6% to 2% as input power increases above the H-mode power threshold. The ELM energy is deposited near the strikepoints on the divertor target plates in a fast time scale of {le} 1 ms. The spatial profile of the ELM heat pulse is flatter and broader, up to about a factor of 2, than that of the heat flux between ELMs. On ASDEX-Upgrade the inboard strike-point receives the greatest fraction, {ge} 75%, of ELM divertor heat flux, while on DIII-D the in/out split is nearly equal. The toroidal asymmetry of the heat pulse has produced a peaking factor on DIII-D of no more than 1.5. The particle flux, as measured by Langmuir probes, has also been found to be localized near the divertor strike-points. The increased particle flux during ELMs is a significant fraction of the total time-integrated divertor plate particle flux.
- Research Organization:
- General Atomics, San Diego, CA (United States); Sandia National Labs., Albuquerque, NM (United States); California Univ., San Diego, La Jolla, CA (United States); Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC03-89ER51114; AC04-94AL85000; FG03-95ER54294; W-7405-ENG-48
- OSTI ID:
- 463671
- Report Number(s):
- GA--A22346; CONF-960569--20; ON: DE97004593
- Country of Publication:
- United States
- Language:
- English
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