Huang K, Esirkepov T, Koga J K, Kotaki H, Mori M, Hayashi Y, Nakanii N, Bulanov S V, Kando M
Kansai Photon Science Institute, National Institutes for Quantum and Radiological Science and Technology (QST), 8-1-7 Umemidai, Kizugawa-city, Kyoto, 619-0215, Japan.
Institute of Physics ASCR, v.v.i. (FZU), ELI BEAMLINES, Za Radnicí 835, Dolní Břežany, 252241, Czech Republic.
Sci Rep. 2018 Feb 13;8(1):2938. doi: 10.1038/s41598-018-21242-y.
Detections of the pulse durations and arrival timings of relativistic electron beams are important issues in accelerator physics. Electro-optic diagnostics on the Coulomb fields of electron beams have the advantages of single shot and non-destructive characteristics. We present a study of introducing the electro-optic spatial decoding technique to laser wakefield acceleration. By placing an electro-optic crystal very close to a gas target, we discovered that the Coulomb field of the electron beam possessed a spherical wavefront and was inconsistent with the previously widely used model. The field structure was demonstrated by experimental measurement, analytic calculations and simulations. A temporal mapping relationship with generality was derived in a geometry where the signals had spherical wavefronts. This study could be helpful for the applications of electro-optic diagnostics in laser plasma acceleration experiments.
相对论电子束脉冲持续时间和到达时间的检测是加速器物理中的重要问题。基于电子束库仑场的电光诊断具有单次测量和非破坏性的优点。我们展示了一项将电光空间解码技术引入激光尾场加速的研究。通过将一块电光晶体放置得非常靠近气体靶，我们发现电子束的库仑场具有球面波前，这与之前广泛使用的模型不一致。通过实验测量、解析计算和模拟证明了场结构。在信号具有球面波前的几何结构中推导了一个具有普遍性的时间映射关系。这项研究可能有助于电光诊断在激光等离子体加速实验中的应用。
