融合的随机动力学低到高的封闭模式 (L-H) 过渡:使用信息几何学的相关性和因果分析
Eun-Jin Kim1, Abhiram Anand Thiruthummal1
1Centre for Fluids and Complex Systems, Coventry University, Coventry CV1 2TT, UK.
Entropy (Basel, Switzerland)
|January 22, 2024
概括
聚变等离子体中的随机噪声会导致逐渐的低到高 (L-H) 限制过渡,H模式特征出现较早,动持续时间比确定性模型预测的更长.
科学领域:
- 等离子体物理学的物理学
- 核聚变能源的使用方式
- 非线性动力学是一种非线性动力学.
背景情况:
- 低至高 (L-H) 封闭模式的转换对于实现持续的聚变反应至关重要.
- 确定性模型预测了急剧的L-H过渡,但实验观测显示了更渐进的行为.
研究的目的:
- 为了研究在磁性封闭的聚变等离子体中控制L-H过渡的随机动力学.
- 了解噪声在流,区域流和输入功率在L-H过渡中的作用.
- 探索涉及L-H过渡的自我调节机制和因果关系.
主要方法:
- 对L-H过渡动态的猎物-掠食者模型的随机模拟.
- 在流和区域流中包含随机噪声.
- 使用GPU计算,模拟超过一百万个轨迹的恒定和时间变化的输入功率 (Q).
- 使用信息几何学的分析来解释自我调节和因果关系.
主要成果:
- 随机噪声导致H模式和动状态的混合,导致逐渐的L-H过渡.
- 在较低的输入功率 (Q
Qc) 之后,动持续存在. - 在临界功率 (Qc) 附近的突出的双模概率密度函数 (PDF) 表明状态和输入功率不确定性的共存.
- 时间变化的输入功率增加了轨迹的可变性,并增强了双模PDF.
结论:
- 随机性从根本上改变了L-H过渡,解释了实验观察到的逐渐过渡和功率不确定性.
- 信息几何学提供了对区域流,流和控制L-H过渡的因果关系之间的相互作用的见解.
- 这些发现强调了将随机效应纳入融合等离子体封闭的准确建模的重要性.
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