【作者】 常玮；

【导师】 何源；

【作者基本信息】 中国科学院研究生院（近代物理研究所） ， 核技术及应用， 2014， 博士

【摘要】 低beta超导腔体主要应用于质子或重离子超导直线加速器，是超导直线加速器的加速元件。在超导腔体上线运行之前，测试其性能非常重要，因此本论文主要研究低beta超导腔体的测试系统、测试方法以及分析物理现象。首先，低beta超导腔体的测试离不开腔体的设计、加工以及表面处理。超导腔体纵向加速电场、峰值电场等诸多测量参数依赖于腔体电磁仿真设计参数。良好的加工以及表面处理工艺也是测试顺利进行的必要条件。因此论文首先阐述了低beta超导腔体的工作原理，介绍了设计、加工以及表面处理方法以及必要基础设施的设计理念。其次，低beta超导腔体测试属于射频测量的范畴。所以论文从射频测量基础出发逐步解释说明超导腔体的测试原理。测试原理中最重要的部分是压控振荡器锁相环（VCO-PLL）技术，利用该技术可以锁定超导腔体的本征频率，使测量顺利进行。论文从锁相环原理出发，对整个锁频系统进行建模仿真，验证了该技术的使用条件。接下来，本论文详细描述了整套低beta超导腔体测试平台的设计。整个设计包括基础设施，外围设备，硬件设计，软件设计以及保护设计。论文的第五章详细解释了超导腔体测试前耦合天线的射频测量选取，线缆校准方法，腔体参数df/dp、Q0、Epk以及洛仑兹失谐量的测量方法，并给出了IMP-HWR010-S超导腔体的实际测量结果。论文的最后一章分析了低beta超导腔体在低温测试中出现的各种物理现象，特别分析了超导腔体的受迫振动效应。该效应的现象是频谱分析设备上出现令人困惑的两条频率峰。本论文从受迫振动的数学模型出发并借助仿真工具解释该现象，此项工作也成为了本论文的创新点。最后，针对测试中的各种物理现象，讨论了低beta超导腔体的射频锻炼技术。更多还原

【Abstract】 The low beta superconducting cavity is used for a proton or a heavy ionsuperconducting linac as the accelerating part. Before the low beta superconductingcavity online operation, testing the performance of the cavity is essential. So the mainresearch issue of this thesis is the testing of low beta superconducting cavities.First of all, the testing of low beta superconducting cavities is inseparable from thedesign, the machining and the surface treatment of the cavity. Many measurementparameters, such as the average accelerating field, the peak electric field, etc., dependon electromagnetic simulation parameters of the cavity design. Good machining andsurface processing of the cavity are also necessary conditions for testing successfully.So the thesis expounds the working principle of the low beta superconducting cavity,introduces the design, the machining, the surface processing, and the design concept ofessential fundamental infrastructures in the beginning.Secondly, the testing of low beta superconducting cavities belongs to the RFmeasurement domain. So the thesis bases on the principle of the RF measurement,explains the theory of the superconducting cavity testing. The VCO-PLL (voltagecontrolled oscillator phase lock loop) is the most important technique. It can be used tolock the eigen frequency of the superconducting cavity. Based on the theory of the PLL,the application condition is verified by the modeling and the simulation.After that, the thesis describes the design of the test plant for low beta cavities indetail. It includes fundamental infrastructures, accessory equipments, hardwares, softwares, and protecting interlocks.The chapter five of the thesis explains the choice method of the coupling antennalength through the RF measurement. It also explains the method of the cable calibrationand measuring parameters such as df/dp, Q0, Epkand Lorentz detuning in detail. It alsoshows the test result of IMP-HWR010-S superconducting cavities.The last chapter of the thesis analyses various physical phenomena which haveemerged in the low temperature test of low beta superconducting cavities. This chapterespecially analyses the forced vibration effect of the superconducting cavity. Thephenomenon of this effect in the superconducting cavity is that perplexing twofrequency peaks appear on the spectrum analyzer. The thesis explains this phenomenonby mean of the math of the forced vibration and simulation tools. And this researchbecame an innovative point of the thesis. Finally, contraposing various physicalphenomena in the test, RF conditioning techniques of the low beta superconductingcavities have been discussed.更多还原