论文标题
纵向跨界和均匀电子椭圆形的动力学，线性chirp聚焦
Longitudinal crossover and the dynamics of uniform electron ellipsoids focused by linear chirp
论文作者
论文摘要
高分辨率单发非偏见超快电子显微镜（UEM）依赖于自适应光学器件使用射频（RF）腔来压缩高强度束。我们对可用的分析方法进行了全面的讨论，以表征束动力学，因为电子束经过了RF腔后的纵向焦点，在RF腔中，空间电荷效应可能很大。从库仑爆炸文献，为UEM开发的加速器物理学文献和分析高斯模型中得出的方法，在某些情况下被比较，利用和扩展。特别是，纵向重点可能发生在两个不同的政权中，一个反弹政权和一个跨界政权。我们表征了零阳性模型中分离这些机制的临界点。将使用有效多极方法的N粒子模拟的结果与理论模型进行了比较，该模型揭示了需要扩展分析方法的特征。并讨论了散发性生长和转移的特殊机制。
High resolution single-shot non-relativistic ultrafast electron microscopy(UEM) relies on adaptive optics to compress high intensity bunches using Radio Frequency (RF) cavities. We present a comprehensive discussion of the analytic approaches available to characterize bunch dynamics as an electron bunch goes through a longitudinal focal point after an RF cavity where space charge effects can be large. Methods drawn from the Coulomb explosion literature, the accelerator physics literature and the analytic Gaussian model developed for UEM are compared, utilized and extended in some cases. In particular the longitudinal focus may occur in two different regimes, a bounce-back regime and a crossover regime; and we characterize the critical point separating these regimes in the zero-emittance model. Results from N-particle simulations using efficient multipole methods are compared to the theoretical models revealing features requiring extensions of the analytic approaches; and in particular mechanisms for emittance growth and transfer are discussed.
