Abstract
The stability with respect to a peelingballooning mode (PBM) was investigated numerically with extended MHD simulation codes in JET, JT-60U and future JT-60SA plasmas. The MINERVA-DI code was used to analyze the linear stability, including the effects of rotation and ion diamagnetic drift (w∗i), in JET-ILW and JT-60SA plasmas, and the JOREK code was used to simulate nonlinear dynamics with rotation, viscosity and resistivity in JT-60U plasmas. It was validated quantitatively that the ELM trigger condition in JET-ILW plasmas can be reasonably explained by taking into account both the rotation and w∗i effects in the numerical analysis. When deuterium poloidal rotation is evaluated based on neoclassical theory, an increase in the effective charge of plasma destabilizes the PBM because of an acceleration of rotation and a decrease in w∗i. The difference in the amount of ELM energy loss in JT-60U plasmas rotating in opposite directions was reproduced qualitatively with JOREK. By comparing the ELM affected areas with linear eigenfunctions, it was confirmed that the difference in the linear stability property, due not to the rotation direction but to the plasma density profile, is thought to be responsible for changing the ELM energy loss just after the ELM crash. A predictive study to determine the pedestal profiles in JT-60SA was performed by updating the EPED1 model to include the rotation and w∗i effects in the PBM stability analysis. It was shown that the plasma rotation predicted with the neoclassical toroidal viscosity degrades the pedestal performance by about 10% by destabilizing the PBM, but the pressure pedestal height will be high enough to achieve the target parameters required for the ITER-like shape inductive scenario in JT-60SA.
| Original language | English |
|---|---|
| Article number | 014032 |
| Journal | Plasma Physics and Controlled Fusion |
| Volume | 60 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2018 |
Funding
The authors would like to thank S Ide and G Giruzzi for providing an opportunity for the collaborative study between the EU and Japan. The authors are grateful to Drs Y Kamada, M Yagi, N Oyama, C F Maggi, E de la Luna and J Garcia for their beneficial comments and suggestions. Some of the authors (NA and MH) gratefully acknowledge contributions from Drs S Satake and Y Suzuki in the NTV calculations. This work was partially supported by JSPS KAKENHI Grant Number 15K06656, and has been partly carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The computations were partly carried out using the HELIOS supercomputer system at IFERC-CSC, Aomori, Japan under the Broader Approach collaboration between Euratom and Japan, implemented by Fusion for Energy and Japan. The MARCONI supercomputer at CINECA in Italy was also used to analyze JET plasmas.
| Funders | Funder number |
|---|---|
| Euratom research and training programme 2014–2018 | |
| Horizon 2020 Framework Programme | 633053 |
| Horizon 2020 Framework Programme | |
| Japan Society for the Promotion of Science | 15K06656 |
| Japan Society for the Promotion of Science |
Keywords
- ELM
- H-mode
- extended MHD model
- rotation
- tokamaks
