发表机构
Tsinghua University; Physikalisch-Technische Bundesanstalt (PTB); Helmholtz-Zentrum Berlin (HZB)（清华大学; 德国联邦物理技术研究院; 柏林亥姆霍兹中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
实验验证了存储环中束团长度变化和头尾交换效应可将微波不稳定性阈值提高至经典预测的六倍，并提出相应评估方法，为极短束团存储环设计提供指导。
AI 中文摘要
微波不稳定性的经典分析建立在纵向绝热近似的基础上，该近似假设束团长度在存储环周围保持恒定。然而，在全局相位滑移较小的存储环中，束团长度可能随环位置变化，并且由于部分相位滑移和横向-纵向耦合，部分粒子可能经历头尾交换。我们的理论研究揭示，这些效应可能有利于抑制微波不稳定性。相应地，我们提出了一种新的微波不稳定性阈值评估方法，以考虑这些效应。在此，我们展示了支持我们理论分析的第一个实验证据。测量结果证实，在我们的案例中，微波不稳定性阈值相比经典预测可提高多达六倍。我们的结果还可为极短束团存储环的设计提供实用指导。
英文摘要
Classical analyses of microwave instability are built upon the longitudinal adiabatic approximation, which assumes that the bunch length remains constant around the storage ring. However, in a storage ring with small global phase slippage, the bunch length can vary around the ring and some particles can experience head-tail exchange due to the partial phase slippage and transverse-longitudinal coupling. Our theoretical study reveals that these effects can be beneficial for suppressing microwave instability. A new microwave instability threshold evaluation method has been correspondingly proposed to account for these effects. Here we present the first experimental evidence supporting our theoretical analysis. The measurements confirm that the microwave instability threshold can be increased by a factor of up to six compared to the classical prediction in our cases. Our results can also provide practical guidance for the design of extremely short bunch storage rings.
