Theory of radiation and pair production based on radiation formula beyond the synchrotron approximation

应用本研究人员和Khokonov提出的标准轨迹方法，得到了强非均匀电磁场中光子产生正负电子对的简单表达式。该表达式依赖于两个参数：不变场参数和非偶极子参数。前者表示场的强度，而后者取决于产生的正电子/电子的散射角。我们的数值计算结果与实验结果很好地吻合，预测在10TeV左右产生对的速率达到最大值。至于辐射，我们发现在较小的非偶极子参数极限下，我们的辐射公式没有发散，而不是韧致辐射的Bethe-Heitler公式。这是非常重要的发现，特别是与朗道-波美兰丘克效应有关的。作为韧致辐射的另一种辐射过程，偏振辐射是重要的考虑因素。我们发展了基于偏振辐射的过程的统一处理，即切伦科夫辐射、跃迁辐射和相干偏振辐射(参数X射线辐射)。

By applying the standard trajectory method derived by the present investigator and Khokonov, a simple expression is obtained for electron-positron pair production by photons in a strong nonuniform electromagnetic field. The expression depends on two parameters : the invariant field parameter and the "non-dipole" parameter. The former represents the strength of the field while the latter depends on the scattering angle of a produced positron/electron. Our numerical calculations agree well with experimental results.It is predicted that the pair production rate reaches its maximum at about 10TeV.As for radiation, we have found that at the small non-dipole parameter limit our radiation formula has no divergence, in contrast to the Bethe-Heitler formula of bremsstrahlung. This is very important findings especially in connection with the Landau-Pomeranchuk effect.As an alternative radiation process to bremsstrahlung, polarization radiation is important to take into account. We have developed a unified treatment of polarization-radiation-based processes, i.e. the Cherenkov radiation, transition radiation, and coherent polarization radiation (parametric x-ray radiation).