超级陶粲装置对撞机环的光学设计
Optics design of the Super Tau-Charm Facility collider rings
AI总结：
针对STCF高亮度低能对撞中的强非线性难题，提出准两重对称磁聚焦结构并用PAMKIT多目标遗传算法优化，以提升动力学孔径、动量带宽和束流寿命。
摘要：
超级陶粲装置（STCF）是中国的下一代正负电子对撞机，其目标是在4 GeV质心系能量下实现超过5×10^34 cm^-2 s^-1的前所未有的亮度。在这一低能区，在相互作用点实现亚毫米量级垂直β函数（小于1 mm）并采用蟹腰碰撞方案，会因严重的非线性效应带来关键挑战，这些效应限制动力学孔径并降低Touschek寿命。为应对这些约束，我们提出一种新型准两重对称磁聚焦结构设计，融合若干协同特性：通过线性光学优化使环周围的H不变量最小化，从而最大化局部动量接受度（LMA）；在相互作用区实现最高三阶的局部色散校正，并结合二阶消色差弧光学，增强偏动量束流动力学；配置带有满足-I变换的交错六极铁组的FODO弧结构，在抑制三阶几何像差的同时优化Montague函数分布；先进的最终聚焦系统集成色散六极铁、蟹腰六极铁和战略性布置的八极铁，以抵消最终四极铁边缘场。此外，我们利用自主开发的工具包PAMKIT开发了多目标遗传算法，同时优化46个六极铁族，使动力学孔径和动量带宽均最大化。光学性能在误差条件下并经适当校正后进行评估，以确保稳健的束流动力学。
英文摘要：
The Super Tau-Charm Facility (STCF), China's next-generation electron-positron collider, targets an unprecedented luminosity exceeding 5x10^34 cm^-2 s^-1 at a center-of-mass energy of 4 GeV. The implementation of a submillimeter vertical beta function at interaction point (< 1 mm) and crab-waist collision scheme in this low-energy regime introduces critical challenges through severe nonlinear effects that constrain dynamic aperture and degrade Touschek lifetime. To address these constraints, we propose a novel quasi-two-fold symmetric lattice design integrating several synergistic features: Linear optics optimization minimizing the H-invariant around the ring to maximize local momentum acceptance (LMA); Up to third-order of local chromaticity correction in the interaction region combined with second-order achromatic arc optics, enhancing off-momentum beam dynamics; Configured FODO arc structure with interleaved sextupole groups satisfying -I transformation, suppressing third-order geometric aberrations while optimizing Montague function distributions; Advanced final focus system integrating chromatic sextupoles, crab sextupoles, and strategically positioned octupoles to counteract final quadrupole fringe fields. Furthermore, we develop a multi-objective genetic algorithm using the in-house toolkit PAMKIT to simultaneously optimize 46 sextupole families, maximizing both dynamic aperture and momentum bandwidth. Optics performance is evaluated under error conditions with appropriate corrections, ensuring robust beam dynamics.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
