首尾模空间电荷阻尼的电抗性阻抗增强
Enhancement of space-charge induced damping due to reactive impedances for head-tail modes
摘要：
朗道阻尼的头-尾模式在聚束由于扩展的调移可以是一个决定性因素的光束稳定性。我们表明，由于电抗性阻抗的相干调谐移位可以增强空间电荷引起的阻尼和改变的稳定性阈值（在这里，电抗性阻抗意味着两个符号的阻抗的虚部）。例如，在强空间电荷下的高阻尼率或$k=0$模式的阻尼是可能的。它示出并解释，如何负电抗阻抗（导致负相干调谐位移类似于空间电荷的效果）可以增强朗道阻尼，而正相干调谐位移具有相反的效果。它示出的阻尼率是在非相干谱中的相干模式的位置的函数，根据集体模式与共振粒子的相互作用的概念。我们提出了一个分析模型，它允许定量预测的阻尼阈值为不同的头-尾模式，为任意的空间电荷和相干调谐移位条件，因为它是使用粒子跟踪模拟验证。
英文摘要：
Landau damping of head-tail modes in bunches due to spreads in the tune shift can be a deciding factor for beam stability. We demonstrate that the coherent tune shifts due to reactive impedances can enhance the space-charge induced damping and change the stability thresholds (here, a reactive impedance implies the imaginary part of the impedance of both signs). For example, high damping rates at strong space-charge, or damping of the $k=0$ mode, can be possible. It is shown and explained, how the negative reactive impedances (causing negative coherent tune shifts similarly to the effect of space-charge) can enhance the Landau damping, while the positive coherent tune shifts have an opposite effect. It is shown that the damping rate is a function of the coherent mode position in the incoherent spectrum, in accordance with the concept of the interaction of a collective mode with resonant particles. We present an analytical model, which allows for quantitative predictions of damping thresholds for different head-tail modes, for arbitrary space-charge and coherent tune-shift conditions, as it is verified using particle tracking simulations.
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。
