A 4D Monte Carlo laser-Compton scattering simulation code for the characterization of the future energy-tunable SLEGS

For the full determination of the characteristics of laser-Compton X/γ-ray source, a four-dimensional (three-dimensional time and frequency-domain) Monte Carlo laser-Compton scattering simulation code has been developed with Geant4 toolkit. The code has the capability to calculate the spatial, spectral and temporal characteristics of the LCS X/γ-ray source with slanting collision configuration. This capability is crucial for both the design of successful LCS X/γ-ray source, as well as future experiments and applications utilizing this kind of sources. In this paper, the algorithm of the code and its benchmark processes are presented in detail. To benchmark the code, the X/γ-ray data taken from the worldwide and typical LCS facilities, such as HIγS at Duke University and PLEIADES at LLNL are compared to the simulated results. The benchmark processes show that the simulated results are consistent with the measurements. Utilizing the code, partial characteristics of Shanghai laser electron gamma source (SLEGS) are studied as well. The SLEGS is expected to be an energy tunable γ-ray source with its maximum energy adjustable from tens MeV to hundreds MeV and its photon flux of 105-106 photons/s if a 1-mJ/pulse, 1-kHz Ti:Sa laser system is employed.