Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China.
Phys Rev Lett. 2015 Mar 20;114(11):114801. doi: 10.1103/PhysRevLett.114.114801.
High quality electron beams with flat distributions in both energy and current are critical for many accelerator-based scientific facilities such as free-electron lasers and MeV ultrafast electron diffraction and microscopes. In this Letter, we report on using corrugated structures to compensate for the beam nonlinear energy chirp imprinted by the curvature of the radio-frequency field, leading to a significant reduction in beam energy spread. By using a pair of corrugated structures with orthogonal orientations, we show that the quadrupole wakefields, which, otherwise, increase beam emittance, can be effectively canceled. This work also extends the applications of corrugated structures to the low beam charge (a few pC) and low beam energy (a few MeV) regime and may have a strong impact in many accelerator-based facilities.
具有平坦能谱和电流分布的高质量电子束对于许多基于加速器的科学设施至关重要，如自由电子激光、兆电子伏特超快电子衍射和显微镜。在这篇快报中，我们报告了使用波纹结构来补偿由射频场曲率引起的束非线性能量啁啾，从而显著降低了束能散度。通过使用一对具有正交取向的波纹结构，我们表明，否则会增加束发射度的四极尾场可以被有效地抵消。这项工作还将波纹结构的应用扩展到低束电荷（几个皮库）和低束能量（几个兆电子伏特）的范围，并可能对许多基于加速器的设施产生重大影响。
