Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
Department of Engineering Physics, Tsinghua University, Beijing 100084, China and University of California Los Angeles, Los Angeles, California 90095, USA.
Phys Rev Lett. 2014 Jan 24;112(3):035003. doi: 10.1103/PhysRevLett.112.035003. Epub 2014 Jan 23.
The evolution of beam phase space in ionization injection into plasma wakefields is studied using theory and particle-in-cell simulations. The injection process involves both longitudinal and transverse phase mixing, leading initially to a rapid emittance growth followed by oscillation, decay, and a slow growth to saturation. An analytic theory for this evolution is presented and verified through particle-in-cell simulations. This theory includes the effects of injection distance (time), acceleration distance, wakefield structure, and nonlinear space charge forces, and it also shows how ultralow emittance beams can be produced using ionization injection methods.
使用理论和粒子模拟研究了电离注入等离子体尾流中的束相空间演化。注入过程涉及纵向和横向相混合，最初导致发射度迅速增长，随后发生振荡、衰减，然后缓慢增长至饱和。提出了一种用于此演化的分析理论，并通过粒子模拟进行了验证。该理论包括注入距离（时间）、加速距离、尾流结构和非线性空间电荷力的影响，还展示了如何使用电离注入方法产生超低发射度束。
