LHC俘获腔高次模阻抗及抑制研究

为研究LHC俘获腔高次模阻抗的抑制结果,将频域和时域的方法应用于此腔的高次模阻抗的计算中,对装有4个磁耦合高次模抑制器LHC俘获腔(三维情况)做了抑制前后高次模阻抗的计算,得到了详细的腔的高次模频谱和阻抗抑制结果,由此可判断高次模吸收器的吸收效果和是否满足束流稳定性要求以及证实其设计的合理性.同时,模拟结果也显示引入高次模抑制器后腔中仍有一些阻抗值较高、具有潜在危险的高次模,这已引起高度重视并为今后的实验研究提供了重要信息.本文详细论述了用于LHC俘获腔的高次模阻抗计算的三维方法和高次模抑制的计算结果.

Higher Order Modes Impedance and Damping Study for the LHC Capture Cavity

To investigate the higher order mode (HOM) damping in the LHC 200MHz capture cavity when using four HOM couplers, simulations have been done by both frequency domain and time domain methods. Using these methods the impedance spectra of the higher order modes in the cavity before and after damping has been obtained. From this, detailed information about the HOM coupler's contribution to HOM damping can be obtained. The distribution and magnitude of some potentially dangerous higher order modes in the LHC capture cavity have been found.