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DOE OSTI · 2511356

First-wall fluxes from large and small ELMs

Perillo, R. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000166965970)·Boedo, J. A. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000322304112)·Lasnier, C. J. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000271092278)·McLean, A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000206974397)·Marini, C. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000348197765)·Bykov, I. [General Atomics, San Diego, CA (United States)] (ORCID:0000000165196081)·Glass, F. [General Atomics, San Diego, CA (United States)] (ORCID:0000000311011859)·Kapat, A. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000228529067)·Nelson, A. O. [Columbia University, New York, NY (United States)] (ORCID:0000000296121936)·Rudakov, D. L. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000252664269)
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Abstract

Experimental analysis at DIII-D shows that small edge localized modes (ELMs) deposit a larger fraction of their energy to the first wall, compared to type-I ELMs in similar magnetic configuration and input power. The energy (λQ) and particle (λΓ) flux decay lengths in the scrape-off layer (SOL) are up to 3 and 5 times larger, respectively, for small ELMs than for larger type-I ELMs. Transport dynamics of ELM filaments in the SOL are found to be related to divertor conditions, where high divertor collisionality, typical for partially detached plasmas, is associated with increased cross field ELM radial fluxes. Results show that a sufficiently large outer wall gap and/or limiters might be needed in future scenarios to protect the first wall, if operating with small ELMs and a cold divertor. This might also have implications for RF heating in future devices, where the coupling efficiency is dependent to some degree to the outer-wall gap.

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70 PLASMA PHYSICS AND FUSION TECHNOLOGYFusion reactorsPlasma confinementPlasma instabilitiesPlasma properties and parametersTokamaks

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Perillo, R. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000166965970), Boedo, J. A. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000322304112), Lasnier, C. J. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000271092278), McLean, A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)] (ORCID:0000000206974397), Marini, C. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000348197765), Bykov, I. [General Atomics, San Diego, CA (United States)] (ORCID:0000000165196081), Glass, F. [General Atomics, San Diego, CA (United States)] (ORCID:0000000311011859), Kapat, A. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000228529067), Nelson, A. O. [Columbia University, New York, NY (United States)] (ORCID:0000000296121936), Rudakov, D. L. [University of California, San Diego, La Jolla, CA (United States)] (ORCID:0000000252664269). 2025-02-05. First-wall fluxes from large and small ELMs. https://doi.org/10.1063/5.0243880

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