The Method of Measuring Electron Beam Parameters Based on Laser Compton Scattering

Abstract: Abstract [Background]: The indirect non-destructive measurement of accelerator electron beam parameters has been a challenge, and the traditional methods using X-ray pinhole imaging on a storing ring or slit diffraction on a linear accelerator have their own shortcomings. Laser Compton Scattering (LCS) device is a new type of a light source producing a high-energy γ beam by the interaction of relativistic electrons and low-energy photons. [Purpose]: To extract the SSRF electron beam parameters based on the LCS techniques. [Method]: This study aims to search for the simulated spectrum, reconstructed by the Monte Carlo simulation program based on Geant4, that best matches the experimental energy spectrum. Then the corresponding parameters are extracted, which include the horizontal beam size, energy, and emittance. The consistency of the gamma energy spectrum at different colliding angles measured on the Shanghai Laser Electron Gamma Source (SLEGS) beamline station of Shanghai Synchrotron Radiation Facility (SSRF) is verified. [Results]: The extracted electron beam parameters of the Shanghai Light Source storing ring are in good agreement with the theoretical values. [Conclusion]: It proves that Laser Compton scattering to be an effective and non-destructive way to determine the electron beam parameters indirectly and lays a stable foundation for the extraction of other parameters of the  electron beam.