Speaker
Dr
Tongnyeol Rhee
(NFRI, Daejeon, South Korea)
Description
The importance and urgency of ELM control for ITER urge to develop tractable reduced model to understand ELM mitigation experiments because first principle models of ELMs have not been developed due to terrific complexities of ELM-related physics. In this work, we present such an effort particularly focused on ELM mitigation experiment by supersonic molecular beam injection (SMBI) and pellet injection (PI). We employs cellular automata model (CA) including key physical elements for transport (i.e. turbulent transport, its suppression by diamagnetic shear flow, and MHD limit) in the H-mode pedestal and expand it to include the SMBI and PI. A finding is that extended CA model can capture many essential features of the experiments, and both SMBI and pellet injection can be seen as different regions of a continuous spectrum of experiments with varying amounts and penetration depths of injected material. Shallow and small injection (SMBI) can mitigate large ELMs by triggering more frequent, yet smaller scale ejection events. With larger and deeper deposition of material, injection forces the formation of pedestal pressure profiles which trigger large ELMs. Therefore, repetitive deep injection emerges as ELM pacing.
| Country or International Organisation | Korea, Republic of |
|---|---|
| Paper Number | TH/P2-9 |
Primary author
Dr
Tongnyeol Rhee
(NFRI, Daejeon, South Korea)
Co-authors
Dr
Jae Min Kwon
(National Fusion Research Institute)
Prof.
Patrick H. Diamond
(NFRI, UCSD)
Dr
Sang-hee Hahn
(National Fusion Research Institute)
Dr
Sumin Yi
(National Fusion Research Institute)
