论文标题
在CERN质子同步器中的高阶不连贯空间驱动结构共振的识别和表征
Identification and characterization of high order incoherent space charge driven structure resonances in the CERN Proton Synchrotron
论文作者
论文摘要
空间电荷通常是圆形加速器中高强度和高亮度梁操作的性能限制之一。在CERN的质子同步加速器（PS）中，观察到以上$ q_y = 6.25 $的垂直曲调的损失，尤其是对于具有较大空间电荷调动的光束。此处介绍的工作表明，由于PS高度对称的加速器晶格，这种行为与空间电荷激发的结构共振有关，这是第一代交替梯度同步性的典型的。实验研究表明，损失对梁亮度和共振的谐波的依赖性，模拟研究揭示了共振的不连贯性质。此外，由空间电荷电位产生的共振驾驶项（RDT）的计算表明，PS的操作工作点被多个空间电荷驱动的不一致的共振包围。最后，对晶格驱动和空间电荷驱动的共振的测量和模拟说明了光束损耗的不同行为，具体取决于共振激发的源和梁的亮度。
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 behaviour 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 (RDT) 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 behaviour of the beam loss depending on the source of the resonance excitation and on the beam brightness.
