Purpose A 325-MHz bi-periodic on-axis coupled accelerating structure prototype which consists of two bi-periodic accelerating modules is under fabrication in the Institute of High Energy Physics,Beijing,dedicated to a...Purpose A 325-MHz bi-periodic on-axis coupled accelerating structure prototype which consists of two bi-periodic accelerating modules is under fabrication in the Institute of High Energy Physics,Beijing,dedicated to a 10-MeV/100 kW industrial linear electron accelerator.According to the beam dynamics study,the average power dissipated in the prototype cavity is about 19.1 kW.Effective cooling scheme is one of the most important issues in the high-power operation.Methods This paper mainly deals with the RF,thermal and structural coupled analyses of the accelerating structure prototype with the help of the ANSYS code.The cooling scheme is optimized to minimize the temperature rise,displacement and von Mises stresses.Results The temperature and stress distributions in the steady state are presented.The maximum von Mises stress is much lower than the yield strength limit of the corresponding material.The frequency shift caused by the thermal expansion is calculated as well,which is within the scope of the tuning range.Conclusion The coupled analyses based on the ANSYS software package are presented to design and optimize the cooling scheme of the accelerating structure.The von Mises stresses are much lower than the yield strength limit of the material.The calculation results indicate that our cooling scheme can deal with the dissipated RF power efficiently.展开更多
以整体叶盘振动抑制为目的,利用压电材料在叶盘结构不同扇区形成异周期系统,并将与压电材料连接的外部电路并联或串联形成不同形式的网络,建立该机电耦合系统的动力学方程,分析其对叶盘结构动力学特性的影响效果。研究发现,双周期压电...以整体叶盘振动抑制为目的,利用压电材料在叶盘结构不同扇区形成异周期系统,并将与压电材料连接的外部电路并联或串联形成不同形式的网络,建立该机电耦合系统的动力学方程,分析其对叶盘结构动力学特性的影响效果。研究发现,双周期压电网络对叶盘结构的频率影响很小,在本文所研究的叶盘结构模型的参数变化范围内仅对频率转向区有轻微的影响,变化最大只有2%;但是双周期压电网络会对叶盘结构的模态振型产生很大的影响,会使原各阶单一节径振型变为多节径振型,节径种类数跟双周期数有关;压电网络还会把机械位移转化为电荷位移;同时压电网络中电阻元件的引入提高了系统的模态阻尼比。这些都会对叶盘结构的振动响应起到很好的抑制效果。最后,采用修正的模态置信因子M M AC对双周期压电网络系统进行了振动抑制特性的评估,结果表明,通过对结构系统双周期数的设计能有效提高振动抑制效果。展开更多
用传输矩阵理论,研究了双周期一维光子晶体结构模型(A N B N)M的光传输特性。结果发现:当光正入射通过光子晶体时,光子禁带内有两个区域出现多条窄带透射峰,其透射率均为100%,两区域的透射峰数目可单独由周期数M来控制,且与M-1数值对应...用传输矩阵理论,研究了双周期一维光子晶体结构模型(A N B N)M的光传输特性。结果发现:当光正入射通过光子晶体时,光子禁带内有两个区域出现多条窄带透射峰,其透射率均为100%,两区域的透射峰数目可单独由周期数M来控制,且与M-1数值对应,可实现双系多通道光滤波功能;随着周期N的增大双系出现互相靠拢的趋势,同时双系透射峰会越来越锋锐,即周期数N的增大起到提高光滤波品质的作用;随着介质折射率的增大,双系透射峰带宽均变宽,而且透射峰劈裂变为振荡峰。双周期结构光子晶体的光传输特性,对设计双系多通道滤波器具有指导意义。展开更多
文摘Purpose A 325-MHz bi-periodic on-axis coupled accelerating structure prototype which consists of two bi-periodic accelerating modules is under fabrication in the Institute of High Energy Physics,Beijing,dedicated to a 10-MeV/100 kW industrial linear electron accelerator.According to the beam dynamics study,the average power dissipated in the prototype cavity is about 19.1 kW.Effective cooling scheme is one of the most important issues in the high-power operation.Methods This paper mainly deals with the RF,thermal and structural coupled analyses of the accelerating structure prototype with the help of the ANSYS code.The cooling scheme is optimized to minimize the temperature rise,displacement and von Mises stresses.Results The temperature and stress distributions in the steady state are presented.The maximum von Mises stress is much lower than the yield strength limit of the corresponding material.The frequency shift caused by the thermal expansion is calculated as well,which is within the scope of the tuning range.Conclusion The coupled analyses based on the ANSYS software package are presented to design and optimize the cooling scheme of the accelerating structure.The von Mises stresses are much lower than the yield strength limit of the material.The calculation results indicate that our cooling scheme can deal with the dissipated RF power efficiently.
文摘以整体叶盘振动抑制为目的,利用压电材料在叶盘结构不同扇区形成异周期系统,并将与压电材料连接的外部电路并联或串联形成不同形式的网络,建立该机电耦合系统的动力学方程,分析其对叶盘结构动力学特性的影响效果。研究发现,双周期压电网络对叶盘结构的频率影响很小,在本文所研究的叶盘结构模型的参数变化范围内仅对频率转向区有轻微的影响,变化最大只有2%;但是双周期压电网络会对叶盘结构的模态振型产生很大的影响,会使原各阶单一节径振型变为多节径振型,节径种类数跟双周期数有关;压电网络还会把机械位移转化为电荷位移;同时压电网络中电阻元件的引入提高了系统的模态阻尼比。这些都会对叶盘结构的振动响应起到很好的抑制效果。最后,采用修正的模态置信因子M M AC对双周期压电网络系统进行了振动抑制特性的评估,结果表明,通过对结构系统双周期数的设计能有效提高振动抑制效果。
文摘用传输矩阵理论,研究了双周期一维光子晶体结构模型(A N B N)M的光传输特性。结果发现:当光正入射通过光子晶体时,光子禁带内有两个区域出现多条窄带透射峰,其透射率均为100%,两区域的透射峰数目可单独由周期数M来控制,且与M-1数值对应,可实现双系多通道光滤波功能;随着周期N的增大双系出现互相靠拢的趋势,同时双系透射峰会越来越锋锐,即周期数N的增大起到提高光滤波品质的作用;随着介质折射率的增大,双系透射峰带宽均变宽,而且透射峰劈裂变为振荡峰。双周期结构光子晶体的光传输特性,对设计双系多通道滤波器具有指导意义。
