Volume 49 Number 3

Effects of neoclassical and anomalous transport on ELMdynamics based on three-field bifurcation model

Danis Klanurak^a, Apisit Dang-iad^a, Jiraporn Promping^b, Nopporn Poolyarat^b, Siriyaporn Sangaroon^c, Apiwat Wisitsorasak^d, Ponkris Klaywittaphat^e, Boonyarit Chatthong^a,*

 
ABSTRACT:     The edge localized mode (ELM) instability based on peeling-ballooning models in fusion plasma is studied based on the bifurcation concept. Three field transport equations including thermal, particle, and toroidal momentum transport are numerically solved simultaneously. The transport includes both neoclassical and anomalous effects with the shearing suppression effect acting on only the anomalous channel. The total plasma current is contributed by the given driven plasma current and bootstrap current driven by local pressure gradient. An ELM is violated in the form of thermal and particle loss once either the critical pressure gradient or edge total plasma current has been reached. The ELM repetition frequency is analyzed by fast Fourier transform (FFT). The result of ELM instability exhibits a periodic fluctuation of plasma profiles as found in experiments. The energy and particle loss can be observed by the percentage drop in plasma profiles. The ELM mechanism affected by the heat source and plasma transport coefficients is examined to impose appropriate plasma conditions for avoiding deleterious ELM (type-I ELM) and creating benign ELM (type-III ELM) for tokamak devices. In addition, the percentage drop of plasma profiles is investigated by the ELM cycle.

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* Corresponding author, E-mail: boonyarit.ch@psu.ac.th

Received 26 Feb 2024, Accepted 4 Oct 2024