IPAC'23 - Student Poster Session Guide

IPAC’23 / STUDENT POSTER SESSION GUIDE 10 Student Poster Session The LHC particle-physics program requires that the delivered luminosity be measured to an ab- solute accuracy in the 1% range. To this effect, the absolute luminosity scale at each interaction point (IP) is calibrated by scanning the beams across each other according to the van der Meer method. During such scans, the orbit and the shape of the colliding bunches are significantly distorted by their mutual electromagnetic interaction; the resulting biases, if left uncorrected, would absorb a major fraction of the systematic-uncertainty budget on the luminosity calibra- tion. The present report summarizes recent studies of such biases in the single-IP configura- tion, and generalizes it to the more typical case where bunches collide not only at the scanning IP, but also experience additional head-on encounters at up to 3 locations around the ring. Simulations carried out with the COherent-Multibunch Beam-beam Interaction multiparticle code (COMBI) are used to characterize the dependence of beam--beam-induced luminosity-cal- ibration biases on the phase advance between IPs, and to derive scaling laws that relate the multi-IP case to the simpler and better understood single-IP configuration. SUPM006 Problems and Considerations about the Injection Philosophy and Timing Structure for CEPC Dou Wang, Meng Li (Chinese Academy of Sciences) , Xiaohao Cui (Institute of High Energy Physics). Cai Meng, Chenghui Yu, Gang Li, Ge Lei, Jinhui Chen, Tianmu Xin, Zusheng Zhou (Institute of High En- ergy Physics), Jie Gao, Jingru Zhang, Jiyuan Zhai, Xiaoping Li, Yuhui Li (Chinese Academy of Sciences), Yuan Zhang (University of Chinese Academy of Sciences). In this paper we will show the injection philosophy and the design of timing and lling scheme for high luminosity CEPC scheme under di erent energy modes. It is found that the RF fre- quency choice in CDR cannot meet the injection requirements for the bunch number at Z pole. A modi ed scheme was proposed to support the design luminosity,which basically meets our current design requirements and retains more flexibility for future high luminosity upgrade. SUPM007 Tunable Monochromatic Gamma Ray Source Design Using Inverse Compton Scattering at Daresbury Laboratory Alex Morris (Cockcroft Institute) . Hywel Owen (Science and Technology Facilities Council), Joe Crone, Laura Corner, Peter Williams (Cockcroft Institute). Inverse Compton Scattering (ICS) is an ideal source of tunable monochromatic gamma rays. These gammas have uses for Nuclear Resonance Fluorescence, and production of novel med- ical radioisotopes. The gamma energy can be tuned by changing the electron energy. An ICS source can be made quasi-monochromatic by using low energy spread electron and laser beams, and using a collimator. Currently ICS gammas are only available from large synchrotron driven electron sources. These sources suffer from a smaller fux in the desired bandwidth than ERLs or linacs. A new planned gamma source is under consideration as part of the proposed UK-XFEL project, this would in- volve part of the XFEL linac being enabled for an energy recovery mode.