Technique for Extracting Initial Parameters of Longitudinal Phase Space of Freshly Injected Bunches in Storage Rings, and Its Applications

This paper presents a technique for extracting the initial parameters of the longitudinal phase space of freshly injected bunches in an electron storage ring. This technique combines simulation of single-bunch longitudinal phase space evolution with a bunch-by-bunch data acquisition and processing system, enabling high-precision determination of initial phase space parameters during electron storage ring injection—including the initial phase, initial bunch length, initial energy offset, initial energy spread, and initial energy chirp. In our experiments, a high-speed oscilloscope captured beam injection signals, which were then processed by the bunch-by-bunch data acquisition system to extract the evolution of the injected bunch’s phase and length. Additionally, a single-bunch simulation software package was developed, based on mbtrack2 and PyQt5, that is capable of simulating the phase space evolution of bunches under different initial parameters after injection. By employing a genetic algorithm to iteratively align simulation results with experimental data, the remaining initial phase space parameters of the injected bunch can be accurately determined.