Radiation-dominated particle and plasma dynamics
Radiation-dominated particle and plasma dynamics
复制标题
辐射主导的粒子和等离子体动力学
作者：
A. Gonoskov;M. Marklund
我们考虑带电粒子在任意配置的强电磁场中运动的一般问题，并发现一个普遍的行为：对于足够高的场强，辐射损失导致的一般趋势的电荷移动沿着的方向，局部产生零横向加速度。根据辐射反应的经典和量子描述，相对论运动沿着这样的方向不会导致辐射损失。我们发现，这样的无辐射方向（RFD）存在于任意电磁场的每一点，而接近这个方向的时间尺度随着场强的增加而减小。因此，在足够强的电磁场的情况下，在空间的每个点处，电荷主要沿着沿着局部RFD移动并形成电流，而它们的运动与RFD的偏差可以被计算以解释它们的非相干发射。这形成了对强电磁场中粒子和等离子体动力学的一般描述，后者可以由最先进的激光器或天体物理环境产生。
We consider the general problem of charged particle motion in a strong electromagnetic field of arbitrary configuration and find a universal behaviour: for sufficiently high field strengths, the radiation losses lead to a general tendency of the charge to move along the direction that locally yields zero lateral acceleration. The relativistic motion along such a direction results in no radiation losses, according to both classical and quantum descriptions of radiation reaction. We show that such a radiation-free direction (RFD) exists at each point of an arbitrary electromagnetic field, while the time-scale of approaching this direction decreases with the increase of field strength. Thus, in the case of a sufficiently strong electromagnetic field, at each point of space, the charges mainly move and form currents along local RFD, while the deviation of their motion from RFD can be calculated in order to account for their incoherent emission. This forms a general description of particle, and therefore plasma, dynamics in strong electromagnetic fields, the latter can be generated by state-of-the-art lasers or in astrophysical environments.