Analysis and elimination of the distortion in electro-optic measurement of low-energy subpicosecond electron bunches

作者：Zhu Li Guo^*; Pu Yi Kang; Li Ze Ren

来源：Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment , 2009, 600(3): 673-677.

DOI：10.1016/j.nima.2009.01.004

• Electro-optic
• Electron bunch
• THz pulse
• Tikhonov regularization

Electro-optic (EO) technique is widely used to characterize longitudinal profile of electron bunches. However, electron bunches with a low energy (similar to MeV) and a short time duration (similar to subpicosecond) cannot be well resolved by EO measurement, which leads to distortion. The convolution theorem is proposed to analyze this distortion in EO measurement. And the factors leading to the distortion are discussed, among which the divergent Coulomb field of electrons is the main one. Distortion elimination and reconstruction of electron bunch profiles from detected EO signals is an ill-posed inverse problem. This paper proposes an iterative Tikhonov regularization method to solve this inverse problem and to reconstruct electron bunch profiles from the EO signals detected by the EO measurement. The feasibility of our proposal is tested and numerically verified based on subpicosecond electron bunches with several MeV energy.

• 出版日期2009-3-11
• 单位中国工程物理研究院流体物理研究所; 中国工程物理研究院; 清华大学