Influence of number and depth of magnetic mirror on Alfvnic gap eigenmode

Alfvnic gap eigenmode(AGE) can eject energetic particles from confinement and thereby threaten the success of magnetically controlled fusion. A low-temperature plasma cylinder is a promising candidate to study this eigenmode, due to easy diagnostic access and simple geometry, and the idea is to arrange a periodic array of magnetic mirrors along the plasma cylinder and introduce a local defect to break the field periodicity. The present work validates this idea by reproducing a clear AGE inside a spectral gap, and more importantly details the influence of the number and depth(or modulation factor)of magnetic mirror on the characteristics of AGE. Results show that AGE is suppressed by other modes inside the spectral gap when the number of magnetic mirrors is below a certain value, which leads to a weakened Bragg's effect. The structure and frequency of AGE remain unchanged for a decreased number of magnetic mirrors, as long as this number is enough for the AGE formation. The width of spectral gap and decay constant(inverse of decay length) of AGE are linearly proportional to the depth of magnetic mirror, implying easier observation of AGE through a bigger mirror depth. The frequency of AGE shifts to a lower range with the depth increased, possibly due to the unfrozen plasma with field line and the invalidity of small-perturbation analysis. Nevertheless, it is exciting to find that the depth of field modulation can be increased to form AGE for a very limited number of magnetic mirrors. This is of particular interest for the experimental implementation of AGE on a low-temperature plasma cylinder with limited length.     

功能梯度材料结构热力耦合概率分析方法

基于自洽平均微观力学W-T(Wakashima-Tsukamoto)模型和拉丁超立方抽样,建立一种功能梯度平板热力耦合概率分析方法.以材料物理属性和空间分布的不确定性随机参数作为概率分析的输入,以热应力作为输出,基于本征正交分解POD(Proper Orthogonal Decomposition)对热应力的随机时间历...     

失谐周期结构的鲁棒分析模型

周期结构动态特性对失谐参数的敏感程度可以用系统的鲁棒性参数来衡量.文中建立了失谐周期结构的物理模型,通过线性分式变换将失谐参数作为反馈引入到系统中,基于状态空间和传递函数建立失谐系统的鲁棒分析模型,并结合结构奇异值建立了失谐周期结构鲁棒分析框架.通过简化叶盘结构的算例说明了失谐周期结构鲁棒分析的建模过程,并计算了系统的结构奇异值.结果表明,基于本文方法所建立的模型可以方便地进行失谐周期结构的鲁棒性分析.