Binary collisions of charged particles in a magnetic field.
Binary collisions of charged particles in a magnetic field.
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DOI：
10.1103/physreve.79.066405
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发表时间：
2008-12
期刊：
影响因子：
--
通讯作者：
H. Nersisyan;G. Zwicknagel
中科院分区：
文献类型：
--
作者：
H. Nersisyan;G. Zwicknagel
在一个经典的二阶摄动理论中考虑了外加磁场中带电粒子之间的二元碰撞，即，从粒子的无扰动螺旋运动开始，直到二元相互作用中的二次贡献。计算是在改进的二元碰撞处理的帮助下完成的，该处理对任何强度的磁场都有效，其中二阶能量和速度传递在傅里叶空间中表示为任意相互作用势。本文明确地计算了一个正则化和屏蔽势的能量传递，该势在原点处具有有限范围和非奇异性，其极限情况包括德拜势（即屏蔽势）和库仑势。详细考虑了两种不同的情况：(i)两个相同的粒子（例如，电子-电子）的碰撞，（ii）磁化的电子和均匀移动的重离子之间的碰撞。能量传递涉及电子回旋运动的所有谐波。通过与经典轨迹蒙特卡罗计算的比较，评价了微扰处理的有效性，该方法也允许在低速下研究具有大能量和速度传递的强碰撞。另一方面，对于大的初始速度，只发生小的速度传递。在那里，非微扰数值经典轨迹蒙特卡洛结果与微扰处理的预测结果非常吻合。
Binary collisions between charged particles in an external magnetic field are considered within a classical second-order perturbation theory, i.e., up to contributions which are quadratic in the binary interaction, starting from the unperturbed helical motion of the particles. The calculations are done with the help of an improved binary collisions treatment which is valid for any strength of the magnetic field, where the second-order energy and velocity transfers are represented in Fourier space for arbitrary interaction potentials. The energy transfer is explicitly calculated for a regularized and screened potential which is both of finite range and nonsingular at the origin, and which involves as limiting cases the Debye (i.e., screened) and Coulomb potential. Two distinct cases are considered in detail: (i) the collision of two identical (e.g., electron-electron) particles, and (ii) the collision between a magnetized electron and a uniformly moving heavy ion. The energy transfer involves all harmonics of the electron cyclotron motion. The validity of the perturbation treatment is evaluated by comparing with classical trajectory Monte Carlo calculations which also allows to investigate the strong collisions with large energy and velocity transfer at low velocities. For large initial velocities on the other hand, only small velocity transfers occur. There the nonperturbative numerical classical trajectory Monte Carlo results agree excellently with the predictions of the perturbative treatment.