Several transverse noise sources, such as power supply ripple, can potentially act as an important limiting mechanism for the luminosity production of the Large Hadron Collider (LHC) and its future High-Luminosity upgrade (HL-LHC) [High Luminosity Large Hadron Collider (HL-LHC): Technical Design Report V0.1, CERN-2017-007-M [http://cds.cern.ch/record/782076?ln=en]]. In the presence of non-linearities, depending on the spectral components of the power supply ripple spectrum and the nature of the source, such a mechanism can increase the tune diffusion of the particles in the distribution through the excitation of sideband resonances in the vicinity of the resonances driven by the lattice nonlinearities. For the HL-LHC, due to the reduction of the beam size in the interaction points (IP) of the high luminosity experiments (IP1 and 5), increased sensitivity to power supply ripple is anticipated for the quadrupoles of the inner triplets. The modulation that may arise from the power supply ripple will be combined with the tune modulation that intrinsically emerges from the coupling of the transverse and longitudinal plane for off-momentum particles through chromaticity. This paper aims to study the impact of tune modulation effects on the transverse beam motion resulting from the interplay between quadrupolar power supply ripple and synchro-betatron coupling in the presence of strong head-on and long-range beam-beam interactions. A power supply ripple threshold for acceptable performance is estimated with single-particle tracking simulations by investigating the impact of different modulation frequencies and amplitudes on the dynamic aperture. The excitation of sideband resonances due to the tune modulation is demonstrated with frequency maps and the higher sensitivity to specific modulation frequencies is explained. Finally, a power supply ripple spectrum consisting of several tones is considered to determine whether their presence will limit the luminosity production in the HL-LHC era.

中文翻译：

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高光度强子对撞机中碰撞光束的音调调制效果

几个横向噪声源（例如电源纹波）可能会成为大型强子对撞机（LHC）的发光度及其未来的高光度升级（HL-LHC）[高光度大强子对撞机（ HL-LHC）：技术设计报告V0.1，CERN-2017-007-M [http://cds.cern.ch/record/782076?ln=en]。在存在非线性的情况下，根据电源纹波频谱的频谱分量和信号源的性质，这种机制可以通过激发附近的边带共振来增加分布中粒子的调谐扩散。由晶格非线性驱动的共振。对于HL-LHC，由于减小了高光度实验（IP1和5）的相互作用点（IP）中的光束大小，内三联体的四极杆有望提高对电源纹波的敏感性。由电源纹波引起的调制将与调谐调制结合在一起，调谐调制是通过色度从横向和纵向平面的耦合中产生的，用于非动量粒子。本文旨在研究在强的正面和远距离束流相互作用下，四极电源纹波和同步倍增管耦合之间的相互作用对调谐调制效果的影响。通过研究不同调制频率和幅度对动态孔径的影响，通过单粒子跟踪仿真可以估算出可接受性能的电源纹波阈值。用频率图说明了由于调谐调制而引起的边带谐振的激励，并说明了对特定调制频率的更高灵敏度。最后，考虑由几个音调组成的电源纹波频谱，以确定它们的存在是否会限制HL-LHC时代的发光度产生。