Simulation study of intra-beam scattering effect in the HALF storage ring with Piwinski model

The Hefei Advanced Light Facility (HALF) will be a VUV and soft X-ray diffraction-limited storage ring (DLSR), and its high density of electron bunches makes the intra-beam scattering (IBS) effect very serious.

An IBS module used in the IMPACT code is developed, where the scattering process of IBS is described by the Piwinski model in Monte Carlo sampling. In the IMPACT code with IBS module, the macroparticle beam in storage ring is numerically tracked, including motion under external electromagnetic field and the IBS scattering process. And the long-term tracking results of macroparticle beam are statistically analyzed.

The results of IBS effect in the HALF storage ring studied by this new code are presented. For benchmarking, the IMPACT code with IBS module is compared with the ELEGANT code and a semi-analytic code using Bane’s model, and the results agree well with each other. With various countermeasures, the IBS impact can be controlled to a certain extent, and the expected beam emittance is approximately 59 pm·rad.