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Magnetic Reconnection during Fast Ion Driven Alfvenic Activity
https://repo.qst.go.jp/records/76847
https://repo.qst.go.jp/records/7684731d7964f-9f60-46f7-b736-1f4c175ac77c
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2019-09-18 | |||||
| タイトル | ||||||
| タイトル | Magnetic Reconnection during Fast Ion Driven Alfvenic Activity | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Bierwage, Andreas
× Bierwage, Andreas× Shinohara, Koji× Todo, Yasushi× Aiba, Nobuyuki× Yagi, Masatoshi× Bierwage, Andreas× Shinohara, Koji× Aiba, Nobuyuki× Yagi, Masatoshi |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Recent simulations of so-called Abrupt Large-amplitude Events (ALE) driven by beam ions in JT-60U show evidence of transient changes in the magnetic topology on the millisecond time scale, giving rise to moderately sized magnetic islands. The present sensitivity study has the goal to throw more light on the reconnection process that occurs in the simulations. It is performed using the hybrid code MEGA, which simulates the self-consistent interaction between beam ions (modelled kinetically) and MHD fluctuations. We have tested how the numerical parameters affect the evolution of MHD fluctuations with n = 1, 2, 3 during one of the events reported in [Bierwage et al., Nature Comms. 9 (2018) 3282]. The general robustness of the results with respect to resolution is confirmed. Randomizing the initial quasi-particle positions along the toroidal angle was found to have a noticeable influence on the timing of the ALE, akin to the proverbial “wing of a butterfly triggering a tornado”. Variations between ALEs in different simulations provide new insight concerning multi-mode interactions. Finally, it is found that reducing the strength of resistive dissipation in the simulation reduces the threshold in the energetic particle pressure gradient at which an ALE occurs. At the same time, the amplitude of the fluctuations increases, causing the same amount of overall transport, so that the length of the time interval between ALEs is not affected and our simulations remain consistent with experimental observations. | |||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 16th IAEA Technical Meeting on Energetic Particles in Magnetic Confinement Systems - Theory of Plasma Instabilities | |||||
| 発表年月日 | ||||||
| 日付 | 2019-09-03 | |||||
| 日付タイプ | Issued | |||||
