Characterizing an inverse Compton X-ray source and determining its electron beam parameters using a genetic algorithm

Abstract

Inverse Compton X-ray sources are laboratory-scale devices providing quasi-monochromatic synchrotron radiation which is generated by laser photons Compton-scattering off highly relativistic electrons. Since the shape and width of the X-ray spectrum are determined by the properties of the colliding beams, these must be carefully optimised. However, device compactness limits the space for diagnostics, rendering a complete characterisation challenging, especially if an electron storage ring is combined with a laser enhancement cavity. Here, a framework for laser, electron and X-ray beam parameter determination is proposed to address this issue. First, methods for determining the laser- and X-ray parameters are presented. Knowing these, electron beam parameters are retrieved from the shape of the X-ray spectrum. To this end, an analytical physical model enabling a rapid calculation of inverse Compton scattering spectra is developed and combined with a genetic algorithm. This strategy's effectiveness is demonstrated by applying the concept at the Munich Compact Light Source, a storage ring-based inverse Compton X-ray source facility. Since the analytical model is computationally very inexpensive, the proposed framework could enable real-time monitoring of inverse Compton X-ray sources or be used as a non-invasive diagnostic based on a single spectrum for the electron beam emittance of storage rings or accelerators.