Transport barrier for the radial diffusion due to the ExB drift motion of guiding centers in cylindrical confinement geometry

The slow collisional ExB ion drift characterized as the major instability mechanism of a poorly magnetized plasma column with an inward-directed radial electric field

The low-frequency instability of a cylindrical poorly magnetized plasma with an inward-directed radial electric field is studied changing the gas pressure and the ion cyclotron frequency. The unstable frequency always decreases when the gas pressure is increased indicating collisional effects. At a fixed pressure, the unstable frequency increases with the magnetic field when the B-field is low and decreases at larger magnetic field strength. We find that the transition between these two regimes is obtained when the ion cyclotron frequency equals the ion-neutrals collision frequency. This is in…

部分磁化ExB等离子体中二维大尺度相干结构的基准测试——社区协作与经验教训

Benchmark for two-dimensional large scale coherent structures in partially magnetized ExB plasmas -- Community collaboration & lessons learned

本研究通过十七个国际代码对部分磁化ExB潘宁放电进行基准测试，验证了旋转辐条频率及关键等离子体特性的一致性，并总结了未来基准测试与模拟软件开发的实践经验。

关于引导中心问题的李变换微扰方法的奇异性研究

On the singularity of Lie-transform perturbation approach to the guiding-center problem

针对引导中心李变换微扰中生成向量确定方程的固有奇异性难题，提出交错确定生成向量的新方案，通过回旋角显式积分自然得到规范函数，无高阶误差，并推导了含强ExB剪切与电磁涨落效应的统一引导中心变换形式体系。

直接激光加速：圆柱形引导结构壁面电子注入的模型

Direct laser acceleration: A model for the electron injection from the walls of a cylindrical guiding structure

本文通过解析模型与粒子模拟，揭示了直接激光加速中电子主要从圆柱形等离子体通道壁界面释放的机制，并验证了释放电荷和通道内电子密度的定量预测。

Shearless bifurcations in particle transport for reversed shear tokamaks

Some internal transport barriers in tokamaks have been related to the vicinity of extrema of the plasma equilibrium profiles. This effect is numerically investigated by considering the guiding-center trajectories of plasma particles undergoing ExB drift motion, considering that the electric field has a stationary nonmonotonic radial profile and an electrostatic fluctuation. In addition, the equilibrium configuration has a nonmonotonic safety factor profile. The numerical integration of the equations of motion yields a symplectic map with shearless barriers. By changing the parameters of the sa…

Hybrid guiding-centre/full-orbit simulations in non-axisymmetric magnetic geometry exploiting general criterion for guiding-centre accuracy

To identify under what conditions guiding-centre or full-orbit tracing should be used, an estimation of the spatial variation of the magnetic field is proposed, not only taking into account gradient and curvature terms but also parallel currents and the local shearing of field-lines. The criterion is derived for general three-dimensional magnetic equilibria including stellarator plasmas. Details are provided on how to implement it in cylindrical coordinates, and in flux coordinates that rely on the geometric toroidal angle. A means of switching between guiding-centre and full-orbit equations a…