Lumpkin A H, LaBerge M, Rule D W, Zgadzaj R, Hannasch A, Zarini O, Bowers B, Irman A, Couperus Cabadağ J P, Debus A, Köhler A, Schramm U, Downer M C
Accelerator Division, Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
Physics Department, University of Texas-Austin, Austin, Texas 78712, USA.
Phys Rev Lett. 2020 Jul 3;125(1):014801. doi: 10.1103/PhysRevLett.125.014801.
We report observations of coherent optical transition radiation interferometry (COTRI) patterns generated by microbunched ∼200-MeV electrons as they emerge from a laser-driven plasma accelerator. The divergence of the microbunched portion of electrons, deduced by comparison to a COTRI model, is ∼9× smaller than the ∼3 mrad ensemble beam divergence, while the radius of the microbunched beam, obtained from COTR images on the same shot, is <3 μm. The combined results show that the microbunched distribution has estimated transverse normalized emittance ∼0.4 mm mrad.
我们报告了对由微聚束的约200 MeV电子从激光驱动的等离子体加速器出射时产生的相干光跃迁辐射干涉测量（COTRI）图样的观测结果。通过与COTRI模型比较推导得出，微聚束电子部分的发散角约为9倍小于约3毫弧度的总体束发散角，而从同一次测量的COTR图像获得的微聚束束半径小于3微米。综合结果表明，微聚束分布的横向归一化发射度估计约为0.4毫米毫弧度。
