Non-destructive electron bunch length measurement via the surface plasmon resonance

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13415
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Quantum beam science
• Research Institution: Japan Synchrotron Radiation Research Institute
• Principal Investigator: Okayasu Yuichi 公益財団法人高輝度光科学研究センター, 加速器部門, 研究員 (90509910)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 量子ビーム測定手法 / EO サンプリング / 表面プラズモン励起 / SPR / フェムト秒 / 電子加速器 / 有機 EO 結晶

Outline of Final Research Achievements

We developed a non-destructive and real time electron bunch charge distribution measurement system via an organic Pockels Electro-Optic (EO) sampling apart from accelerator vacuum systems. The targeted bunch length is a few tens of femto-seconds (FWHM). Coulomb fields associated with the electron bunch excite surface plasmonic resonance (SPR) through a meta-material deposited prism and the SPR is measured by the EO sampling. Structures of the meta-material layer on the SPR substrate was optimized by a numerical analysis. The substrates were assembled at Kyoto University on 2015 and 2016 and geometrical structures of meta-material layers were measured with a 3D laser microscope.
Feasibility test is demonstrated at an RF fotocathode electron gun test accelerator, however the accelerator and its control system upgrade constructions are still undergoing, thus the feasibility test is scheduled to start from December 2017.

Free Research Field

加速器科学