| Project/Area Number |
16K13923
|
|---|
| Research Category |
Grant-in-Aid for Challenging Exploratory Research
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Plasma science
|
|---|
| Research Institution | Chubu University (2017-2018)
National Institute for Fusion Science (2016) |
|---|
Principal Investigator |
ITOH Kimitaka 中部大学, 総合工学研究所, 特任教授 (50176327)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
山田 琢磨 九州大学, 基幹教育院, 准教授 (90437773)
杉田 暁 中部大学, 中部高等学術研究所, 准教授 (20650708)
|
|---|
| Research Collaborator |
IDA Katsumi
IDO Takeshi
|
|---|
| Project Period (FY) |
2016-04-01 – 2019-03-31
|
| Project Status |
Completed (Fiscal Year 2018)
|
| Budget Amount *help |
¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000)
Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
|
|---|
| Keywords | 突発現象 / 亜臨界不安定性 / 多スケール乱流相互作用 / トリガー問題 / 多スケー ル乱流相互作用 |
|---|
| Outline of Final Research Achievements |
The essential in the abrupt events in hot plasmas (e.g., solar flare, disruption in tokamaks, etc.) is the “trigger problem”, i.e., ‘the growth rate of deformation grows very rapidly’. In this project, contrary to the conventional view that focuses on linear instabilities, we have achieved two major breakthroughs: (1) It was demonstrated that the subcritical excitation of nonlinear instability takes place in the case of abrupt excitation of geodesic acoustic mode in a toroidal plasma. (2) In another type of abrupt event, the plasma deformation in the ‘trigger phase’ was found localized at particular toroidal location (so as to be called ‘tongue’ shape rather than ‘mode’ shape). The tongue deformation turns into mode type deformation later. These achievements are far-beyond conventional view, and induce paradigm shift for the study of abrupt events in high temperature plasmas, and will show strong influences in understanding abrupt events in nature.
|
| Academic Significance and Societal Importance of the Research Achievements |
本計画により、成長率が突発的に急増する現象に新たな物理的描像が得られた。即ち、線形モードを考察するのではなく、亜臨界励起や、「舌型」変形に注目し探査・解析すべきである。トリガー問題にかかわる基本的描像を書き直し、今後の研究の方向に大きな波及効果もたらしたと考える。その成果は、プラズマ物理学の方法論の進展として学術的な意義がある。
更に、突発的豪雨への応用も試行され、また、本研究で得られた学理を応用することによって核融合燃焼プラズマの制御（例えばディスラプション対応）や地球環境問題（例えば太陽フレア爆発の発生の理解）に寄与出来るという社会的な意義がある。
|
