Design and application of multimegawatt X-band deflectors for femtosecond electron beam diagnostics
Design and application of multimegawatt X-band deflectors for femtosecond electron beam diagnostics
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DOI：
10.1103/physrevstab.17.102801
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发表时间：
2014-10-02
影响因子：
--
通讯作者：
Xiang, Dao
中科院分区：
文献类型：
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作者：
Dolgashev, Valery A.;Bowden, Gordon;Xiang, Dao
X 射线自由电子激光器直线加速器相干光源 (LCLS) 和高级加速器实验测试设施 (FACET) 的性能取决于其极短电子束的特性。 LCLS 和 FACET 中的多 GeV 电子束长度均小于 100 fs。光束特性的优化和对自由电子激光操作的理解需要时间分辨率约为 10 fs 的电子束诊断。我们设计、建造和调试了一套高频 X 波段偏转器，可以测量束流纵向空间电荷分布和切片能量分布，在全 LCLS 能量 (14 GeV) 下分辨率优于 10 fs，在全 FACET 能量 (20 GeV) 下分辨率优于 70 fs。这些设备中高频和高梯度的使用使它们能够达到前所未有的性能。我们报告了 SLAC 当前使用的 X 波段偏转器系统的物理动机、设计考虑、操作配置、冷测试和典型结果。
Performance of the x-ray free electron laser Linac Coherent Light Source (LCLS) and the Facility for Advanced Accelerator Experimental Tests (FACET) is determined by the properties of their extremely short electron bunches. Multi-GeV electron bunches in both LCLS and FACET are less than 100 fs long. Optimization of beam properties and understanding of free-electron laser operation require electron beam diagnostics with time resolution of about 10 fs. We designed, built and commissioned a set of high frequency X-band deflectors which can measure the beam longitudinal space charge distribution and slice energy spread to better than 10 fs resolution at full LCLS energy (14 GeV), and with 70 fs resolution at full FACET energy (20 GeV). Use of high frequency and high gradient in these devices allows them to reach unprecedented performance. We report on the physics motivation, design considerations, operational configuration, cold tests, and typical results of the X-band deflector systems currently in use at SLAC.