利用集体模和色噪声产生增强束晕
Production of Enhanced Beam Halos via Collective Modes and Colored Noise
摘要：
我们研究如何集体模式和色噪声合谋产生一个光束晕与更大的幅度比可以单独产生的现象。集体模式是最低阶径向本征模计算自洽的配置对应于直流，圆柱对称，温暖的流体Kapchinskij-Vladimirskij平衡。色噪声来自于不可避免的机器误差，并影响内部空间电荷力。它的存在通过不断地将统计上罕见的粒子踢回与集体模式振荡同相，迅速将它们发射到不断增长的振幅。对于纯径向轨道和最初纯方位角轨道，晕幅基本上是相同的;轨道角动量在统计上没有显著的影响。确实有影响的因素包括集体模式的振幅以及色噪声的强度和自相关时间。由于噪声破坏了Kolmogorov-Arnol 'd-Moser环面，否则将限制光束，因此潜在的动力学增强。这些环面是脆弱的;即使是非常微弱的噪音最终也会打破它们，尽管它们解体的时间尺度取决于噪音的强度。因此，集体模式和噪声是非常重要的，在真实光束中的晕形成的动力学。
英文摘要：
We investigate how collective modes and colored noise conspire to produce a beam halo with much larger amplitude than could be generated by either phenomenon separately. The collective modes are lowest-order radial eigenmodes calculated self-consistently for a configuration corresponding to a direct-current, cylindrically symmetric, warm-fluid Kapchinskij-Vladimirskij equilibrium. The colored noise arises from unavoidable machine errors and influences the internal space-charge force. Its presence quickly launches statistically rare particles to ever-growing amplitudes by continually kicking them back into phase with the collective-mode oscillations. The halo amplitude is essentially the same for purely radial orbits as for orbits that are initially purely azimuthal; orbital angular momentum has no statistically significant impact. Factors that do have an impact include the amplitudes of the collective modes and the strength and autocorrelation time of the colored noise. The underlying dynamics ensues because the noise breaks the Kolmogorov-Arnol'd-Moser tori that otherwise would confine the beam. These tori are fragile; even very weak noise will eventually break them, though the time scale for their disintegration depends on the noise strength. Both collective modes and noise are therefore centrally important to the dynamics of halo formation in real beams.
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。
