Space charge is typically one of the performance limitations for the operation of high intensity and high brightness beams in circular accelerators. In the Proton Synchrotron (PS) at CERN, losses are observed for vertical tunes above $Q_y=6.25$, especially for beams with large space charge tune shift. The work presented here shows that this behavior is associated to structure resonances excited by space charge due to the highly symmetric accelerator lattice of the PS, typical for first generation alternating gradient synchrotrons. Experimental studies demonstrate the dependency of the losses on the beam brightness and the harmonic of the resonance, and simulation studies reveal the incoherent nature of the resonance. Furthermore, the calculation of the resonance driving terms generated by the space charge potential shows that the operational working point of the PS is surrounded by multiple space charge driven incoherent resonances. Finally, measurements and simulations on both lattice driven and space charge driven resonances illustrate the different behavior of the beam loss depending on the source of the resonance excitation and on the beam brightness.

中文翻译：

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CERN质子同步加速器中高阶非相干空间电荷驱动的结构共振的鉴定和表征

空间电荷通常是圆形加速器中高强度和高亮度光束运行的性能限制之一。在欧洲核子研究组织（CERN）的质子同步加速器（PS）中，观察到高于垂直方向的调谐的损耗${问}_{ÿ}=6.25$，特别是对于具有大空间电荷调谐位移的光束。此处介绍的工作表明，由于PS的高度对称加速器晶格（通常是第一代交替梯度同步加速器的典型特性），这种行为与空间电荷激发的结构共振有关。实验研究证明了损耗对光束亮度和谐振谐波的依赖性，而仿真研究则揭示了谐振的不连贯性。此外，由空间电荷电势产生的谐振驱动项的计算表明，PS的工作工作点被多个空间电荷驱动的非相干谐振所包围。最后，