Electro-optic spatial decoding on the spherical-wavefront Coulomb fields of plasma electron sources

• Published in: Scientific reports Vol. 8; no. 1; pp. 2938 - 10
• Main Authors: Huang, K., Esirkepov, T., Koga, J. K., Kotaki, H., Mori, M., Hayashi, Y., Nakanii, N., Bulanov, S. V., Kando, M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.02.2018; Nature Publishing Group
• Subjects: 639/766/1960/1135; 639/766/1960/1137; Electric fields; Electrons; Experiments; Geometry; Humanities and Social Sciences; Lasers; multidisciplinary; Plasma; Propagation; Radiation; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-21242-y

Detections of the pulse durations and arrival timings of relativistic electron beams are important issues in accelerator physics. Electro-optic diagnostics on the Coulomb fields of electron beams have the advantages of single shot and non-destructive characteristics. We present a study of introducing the electro-optic spatial decoding technique to laser wakefield acceleration. By placing an electro-optic crystal very close to a gas target, we discovered that the Coulomb field of the electron beam possessed a spherical wavefront and was inconsistent with the previously widely used model. The field structure was demonstrated by experimental measurement, analytic calculations and simulations. A temporal mapping relationship with generality was derived in a geometry where the signals had spherical wavefronts. This study could be helpful for the applications of electro-optic diagnostics in laser plasma acceleration experiments.