分类: 物理学 >> 气体、等离子体、放电物理 分类: 数学 >> 数学(综合) 提交时间: 2022-12-27
摘要: 对三维向量场中的双曲环的不变流形,本文给出其柱坐标下的生长公式。其流形初始生长方向取决于 Poincar 映射的 Jacobian 矩阵,文中给出这一矩阵在环上的演化公式。这一演化公式也适用于任意有限维的自治连续时间动力系统。本文构造有非莫比乌斯型、莫比乌斯型的鞍环,以及仿造的 X-环,以演示公式的使用方法。 对于真实的数值例子,取东方超环运行中的一磁场时间切片作为演示。
分类: 物理学 >> 气体、等离子体、放电物理 分类: 物理学 >> 交叉学科物理及相关领域的科学与技术 分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2019-03-31
摘要: 等离子体湍流(如太阳风)中体现的(矢端图)螺旋现象和信号(近似)谐振现象并不一定表示线性波动行为。不同环境下等离子体可以有不同的动力学特征,容许存在各种非线性结构。这里讨论在一定时空范围内与线性螺旋波表现类似的有单手性主导的湍动涡模态和呼吸子。前者先通过回顾最近利用扩展磁流体模型统计解特征研究太阳风中的建议得以说明;后者的具体例证还是一个开放的问题,但是我们列举各种来自水波、等离子体和玻色-爱因斯坦凝聚的信息来说明太阳风中应该存在这样的结构。
分类: 物理学 >> 气体、等离子体、放电物理 提交时间: 2018-06-07
摘要: A detailed analysis of the synchrotron radiation intensity and energy of runaway electrons are presented for EAST. In order to make the energy of the calculated runaway electrons more accurate, we take the shafranov shift into account. The results of the analysis show that the synchrotron radiation intensity and energy of runaway electrons did not reach the maximum at the same time. The energy of runaway electrons reached the maximum value first, and then the synchrotron radiation intensity of the runaway electrons reached the maximum. We also analyzed the runaway electrons density, and it shows the density of runaway electrons continuously increased. For this reason, although the energy of the runaway electrons drops but the synchrotron radiation intensity of the runaway electrons will continue rising for a while
分类: 物理学 >> 电磁学、光学、声学、传热、经典力学和流体动力学 分类: 物理学 >> 气体、等离子体、放电物理 提交时间: 2017-11-27
摘要: An important feature of China Fusion Engineering Test Reactor(CFETR) project is represented by the additional heating obtained from the injection of neutral beams based on accelerated negative ions. For the neutral beams based on negative ions, the most important measurements are beam uniformity, beamlet divergence and stripping losses. According to the CFETR requirement, the maximum allowed beam divergence angle and beam non-uniformity are 6 mrad and ±10%,respectively. As 1D carbon tiles have large ratio between perpendicular conductivity and parallel conductivity and high stability, they can be used for beam uniformity and beamlet divergence measurement. This paper presents the investigation of the influence on the response of 1D carbon tile having the thermal characteristics and features of some dedicated diagnostics. Simulations show that it will be possible to verify experimentally whether the beam meets the requirement about the maximum allowed value. This work lays a foundation for design and application of high precision beam diagnostic targets.
分类: 物理学 >> 气体、等离子体、放电物理 提交时间: 2017-09-03
摘要: We propose a more effective fluid description on Vlasov-Maxwell (V-M) system. It is via an open set of off-center moments, which obey an open set of motion equations.This new description is of more advantage to give exact macroscopic information of the V-M system than the well-known moments-description. The new description implies that obtaining exact solutions of all moments is not necessary condition of obtaining those of self-consistent fields. 我们对Vlasov-Maxwell系统提出一更有效的流体描述。该描述通过一开放的偏心矩系列。该偏心矩系列服从一开放的流体方程组。与著名的矩描述相比,该新描述更具有优势去获得准确的V-M系统的宏观信息。该新描述意味着所有矩的准确解不是自洽场准确解的必要条件。