Advanced beam diagnostics with electro-optic effect and its application to laser plasma acceleration

We established electro-optic (EO) sampling techniques adequate for the diagnostics of electron temporal information in laser wakefield acceleration (LWFA). For the investigation of electron timing jitter and injection process, EO spatial decoding on the electron Coulomb field was performed. The spherical wavefront of the Coulomb field and plasma-density-dependent electron emission timing were discovered. For the determination of electron bunch durations, EO spatial decoding on the coherent transition radiation (CTR) produced when electrons passing through a metal foil was conducted. Electron beam timing fluctuation of 7 fs and peak current over 1 kA had been demonstrated.This research not only showed the capability of EO sampling serving as a real-time electron temporal diagnostic for laser-driven sources but also demonstrated the ultra-fast and high-brightness nature of laser-driven electron sources for various applications.日本物理学会第77回年次大会 ビーム物理 若手奨励賞 記念講