对于无碰撞静电冲击的结构过渡条件
Minh Nhat Ly1, Takayoshi Sano1, Youichi Sakawa1
1Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Physical review. E
|September 19, 2023
概括
无碰撞的静电冲击在高密度梯度下转化为双层结构,临界密度比为~40. 这一发现改善了预测空间等离子体中关键马赫数的模型.
科学领域:
- 空间等离子体物理学 空间等离子体物理学
- 等离子体冲击动态的动态
- 非热粒子加速的非热粒子加速
背景情况:
- 无碰撞冲击在空间等离子体中很常见,加速粒子到非热能.
- 了解冲击结构对于模拟粒子加速和能量转移至关重要.
研究的目的:
- 研究无碰撞静电冲击的结构转变.
- 确定冲击结构变化的值条件.
- 改善对非碰撞冲击的关键马赫数的预测.
主要方法:
- 用不同压力的等离子板进行一维粒子在细胞 (PIC) 模拟.
- 对冲击结构演变和密度梯度的分析.
- 开发和对更新的无碰撞冲击模型进行基准测试.
主要成果:
- 冲击结构以大约40的密度比率 (Γ) 转化为双层,独立于温度比率.
- 更新的模型包含稀缺波效应,改善了关键马赫数预测.
- 半分析方法是为了从初始条件中预测冲击速度而开发的.
结论:
- 密度比 Γ ~ 40 是无碰撞静电冲击结构转换的关键值.
- 更新后的模型提供了更准确的临界马赫数的预测.
- 基于最初的等离子体条件,建立了一种预测冲击速度的新方法.
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