University of Michigan, Centre of Ultrafast Optical Sciences, Ann Arbor, Michigan 48109, USA.
Phys Rev Lett. 2010 Nov 26;105(22):220407. doi: 10.1103/PhysRevLett.105.220407. Epub 2010 Nov 24.
High intensity colliding laser pulses can create abundant electron-positron pair plasma [A. R. Bell and J. G. Kirk, Phys. Rev. Lett. 101, 200403 (2008)], which can scatter the incoming electromagnetic waves. This process can prevent one from reaching the critical field of quantum electrodynamics at which vacuum breakdown and polarization occur. Considering the pairs are seeded by the Schwinger mechanism, it is shown that the effects of radiation friction and the electron-positron avalanche development in vacuum depend on the electromagnetic wave polarization. For circularly polarized colliding pulses, these effects dominate not only the particle motion but also the evolution of the pulses. For linearly polarized pulses, these effects are not as strong. There is an apparent analogy of these cases with circular and linear electron accelerators to the corresponding constraining and reduced roles of synchrotron radiation losses.
高强度碰撞激光脉冲可以产生丰富的正负电子对等离子体[A. R. 贝尔和 J. G. 柯克，物理评论快报 101，200403（2008）]，可以散射入射的电磁波。这个过程可以防止达到量子电动力学的临界场，在这个场中会发生真空击穿和极化。考虑到对是由施温格机制产生的，结果表明辐射摩擦的影响和真空中的电子-正电子雪崩发展取决于电磁波的偏振。对于圆偏振碰撞脉冲，这些影响不仅主导着粒子的运动，而且还主导着脉冲的演化。对于线性偏振脉冲，这些影响就不那么强烈。这些情况与圆形和线性电子加速器的对应情况明显类似，其中同步辐射损耗的约束和减小作用也是如此。
