Characterization and control of the transverse phase space of high-brightness electron beams is required at free-electron lasers or electron diffraction experiments for emittance measurement and beam optimization as well as at advanced acceleration experiments. Dielectric laser accelerators or plasma accelerators with external injection indeed require beam sizes at the micron level and below. We present a method using nano-fabricated metallic wires oriented at different angles to obtain projections of the transverse phase space by scanning the wires through the beam and detecting the amount of scattered particles. Performing this measurement at several locations along the waist allows assessing the transverse distribution at different phase advances. By applying a novel tomographic algorithm the transverse phase space density can be reconstructed. Measurements at the ACHIP chamber at SwissFEL confirm that the transverse phase space of micrometer-sized electron beams can be reliably characterized using this method.

中文翻译：

---

使用亚微米级分辨率的纳米线扫描仪进行电子束横向相空间层析成像

在自由电子激光器或电子衍射实验中，需要进行高亮度电子束横向相空间的表征和控制，以进行发射率测量和电子束优化以及先进的加速实验。带有外部注入的介电激光加速器或等离子加速器的确需要微米级及以下的光束尺寸。我们提出了一种使用以不同角度定向的纳米加工金属线来获得横向相空间的投影的方法，该方法是通过扫描穿过光束的线并检测散射颗粒的数量来获得。在沿腰部的多个位置执行此测量可以评估不同相位超前处的横向分布。通过应用新颖的层析成像算法，可以重建横向相空间密度。