Coherent transition radiation (CTR) is a widely used approach to characterize the electron beam in accelerator science and technology. Characterization of the CTR with an efficient, versatile and compact setup is in considerable demand for a wide range of applications such as free electron lasers, electron storage rings and other related scientific researches. In this article, we report on spatial-temporal electric field measurements of CTR using the single-shot electro-optic spatial decoding method. A quasi-half-cycle temporal waveform of the THz pulse with peak electric field strength of $\sim 42\mathrm{MV}/\mathrm{m}$ has been measured. A symmetrical field profile across the transverse center and the distorted wave front of CTR THz pulses near the focal plane were demonstrated. Moreover, timing jitters of the ultrashort electron beams are also monitored via this method with tens of femtosecond accuracy. This comprehensive method provides the temporal waveform and the one-dimensional spatial imaging of THz fields simultaneously, showing it has the potential for single-shot diagnostics of ultrashort electron beams.

中文翻译：

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相干过渡辐射产生的太赫兹脉冲的单次时空电场测量

相干过渡辐射（CTR）是加速器科学和技术中表征电子束特征的一种广泛使用的方法。高效，通用和紧凑的装置对CTR进行表征，对诸如自由电子激光器，电子存储环和其他相关科学研究之类的广泛应用具有相当大的需求。在本文中，我们报告了使用单次电光空间解码方法对CTR进行时空电场测量的情况。峰值电场强度为的THz脉冲的准半周期时间波形$〜42\mathrm{MV}/\mathrm{米}$已被测量。证明了在焦平面附近横切中心和CTR THz脉冲的畸变波前对称的场分布。此外，通过该方法还可以以数十飞秒的精度监视超短电子束的定时抖动。这种全面的方法可同时提供THz场的时间波形和一维空间成像，表明它具有用于超短电子束单次诊断的潜力。