@misc{oai:repo.qst.go.jp:00066805,
 author = {黄, 開 and Timur, Esirkepov and Kevin, Koga James and Kotaki, Hideyuki and Mori, Michiaki and Hayashi, Yukio and Nakanii, Nobuhiko and Bulanov, Sergey and Kando, Masaki and 黄 開 and エシロケポフ ティムル and コーガ ジェームズ and 小瀧 秀行 and 森 道昭 and 林 由紀雄 and 中新 信彦 and ブラノフ セルゲイ and 神門 正城},
 month = {Apr},
 note = {Detections of the pulse durations and arrival timings of relativistic electron beams are important issues for accelerators. Electro-optic diagnostics on the Coulomb fields of electron beams have the advantages of single shot and non-destructive characteristics.1,2 We present a study of introducing the electro-optic spatial decoding technique3 to laser wakefield acceleration (LWFA)4. 
To determine the time scale of the observed signal, a temporal mapping relationship is necessary.  By placing an electro-optic crystal very close to a gas target, we discovered that the Coulomb field of the electron bunch possessed a spherical structure that was inconsistent with the previously widely used model. The field structure was demonstrated by experimental measurement, analytic calculations and simulations. A new temporal mapping relationship with generality was derived in a geometry where the signals had spherical wavefronts5. This study could be helpful for the applications of electro-optic diagnostics in laser plasma acceleration experiments.
    This work was funded by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan)., HEDS2018},
 title = {Electro-optic spatial decoding on the spherical-wavefront Coulomb fields of plasma electron sources},
 year = {2018}
}