Development of New Capability for Inverse Compton Scattering Simulation and Application to Diagnostics

Researchers requiring X-ray analysis may soon opt for accelerator-based Inverse Compton Sources (ICS) that collide laser-pulsed photons with a relativistic electron beam, producing tunable X-rays. The Old Dominion University/Jefferson Lab group has been developing a code, called STARS, that simulates Inverse Compton Scattering, aiming to provide a diagnostic tool for arbitrary ICS. STARS currently models the electron beam energy distribution function as Gaussian, but real laboratory distributions are more complex. The latest capability update aims to allow STARS to simulate Inverse Compston Scattering using any model of electron energies, enabling detailed exploration of the effects of the distribution on the X-ray spectrum. To do this, a parameter was added that, when set to one, tells STARS to read in and use a dataset of energies and their probabilistic frequencies generated by the user to model their phase space. Then, the simulated spectra produced by STARS were fitted to an experimental spectrum through an algorithm that varies the parameter values controling the shape of this external distribution to reverse-engineer the experimental beam structure. Tests show the spectra from the old and new versions of STARS match, indicating that the update maintains accuracy. Additionally, a strong fits between the experimental data and the simulated data was achieved, providing a diagnosis of the beam shape. With this new capability, STARS can serve arbitrary ICS and empower users to employ STARS as a diagnostic tool, providing clarity to experimental uncertainties.