LLRF control system for TTX

Tsinghua University Accelerator Lab has already built a Thomson scattering X-ray source (TTX),which generates X-ray with high peak brightness and ultra-short pulse duration . When scattering happens, the energy spread, size of electron bunch, and its position related to the laser beam will affect the parameters of generated X-ray, this has already been proved by theoretical research. A digital LLRF control system is under construction to limit the electron bunch energy spread and to ensure its synchronization to laser beams. Since the duration of the macro bunch pulse used is very short (1.5-4μS), TTX only permits pulse-to-pulse feedback control. With LLRF evaluation board of SNS, this frequency distribution and LLRF control system for TTX has already been accomplished.