共查询到17条相似文献,搜索用时 453 毫秒
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中国科学院近代物理研究所设计的工作频率为325 MHz、最优β为0.52 的双柱超导Spoke 腔的电磁已经完成。详细地描述了Spoke 基部横截面形状和大小对腔体射频性能的影响,采用了跑道形来取代通常的圆形Spoke 基部截面。从归一化峰值电磁场和分路阻抗两方面出发,比较了横截面为横向跑道和纵向跑道的Spoke 基部。Spoke 基部横截面的形状为横向跑道时能得到较好的射频参数,满足中国ADS(C-ADS) 的工程需求。最后利用CST 粒子工作室对得到的腔体进行了二次电子倍增分析,在工作电压附近不存在二次电子倍增,验证了该腔体形状的可行性。The EM design of a 325 MHz β= 0.52 superconducting double Spoke cavity has been finished at Institute of Modern Physics (IMP), Chinese Academy of Sciences(CAS). In this paper, the optimization of the Spoke base is described in detail. The goal is to minimize the peak surface field and maximize the shunt impedance. The common cylinder is replaced by the racetrack shape for the Spoke base. The transverse racetrack Spoke base can offer a better RF property than the longitudinal racetrack Spoke base, which meet the requirement of the C-ADS. The simulation of multipactor finished by CST Particle Studio is also presented, which gives a promising result that there is no multipactor around working voltage. 相似文献
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中国科学院高能物理研究所一直在研究频率为325 MHz、中低β Spoke超导加速腔,以应用在加速器驱动的次临界系统(ADS)的强流质子直线加速器中。通过对超导腔设计方法和设计原则的研究,使用CST仿真软件设计了单Spoke腔、双Spoke腔、三bar Spoke腔三种Spoke腔型。其中三bar Spoke腔和双Spoke腔一样,都有着三个加速间隙,但是Spoke柱的结构不同。在腔型设计中,对三种Spoke腔的模型均作了参数化处理。然后通过CST的参数化扫描来优化腔体形状以使得峰值电场与加速梯度的比值最小,同时使峰值磁场与加速梯度的比值处于较低范围。本文对三种腔型进行了高频结构优化和参数分析,选用了双Spoke腔型作为设计方案,并对电磁场等进行了优化设计。 相似文献
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Recently multipacting (MP) recalculation of the TeV Energy Superconducting Linear Accelerator (TESLA) resonator was performed. In addition to the normal MP which occurs at a peak electric field of around 40MV/m for the TESLA cavity, another type of multipacting with resonant electron trajectory that is far from the equator is also seen.It occurs at a gradient around 60MV/m to 70MV/m. This result seems to explain some experimental observations. 相似文献
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北京大学正在设计β=0.09,频率为162.5 MHz taper型的二分之一波长射频超导谐振腔(HWR腔),这种腔针对高流强质子束(约100mA)和氘束(约50mA)的加速而设计。对于这种超导腔而言机械性能分析是十分重要的,可以通过机械性能分析来估计由于腔体的形变带来的频率偏移。用ANSYS分析了由于液氦压力不稳定造成的麦克风效应以及洛伦兹力造成的腔体失谐,并且对沿腔体轴线方向的调谐进行了分析。模拟结果显示这只腔压力敏感系数为31.1 Hz/kPa,洛伦兹力系数为-0.41Hz/(MV·m~(-1))~2。腔体的调谐范围达到±177kHz,足够补偿腔体可能的频率偏移。腔体的机械性能满足腔体正常运行的要求。 相似文献
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中国科学院近代物理研究所自主研发的ADS注入器Ⅱ第一代高频低电平(LLRF)控制系统,工作频率为162.5 MHz;LLRF系统是由基于I/Q采样的正交解调技术构成的全数字闭环反馈控制系统,其主要功能是实现超导腔腔体电压幅值稳定控制、相位稳定控制与腔体谐振频率控制;LLRF控制系统在液氦温区超导腔上进行了系统稳定度和性能的在线测试,根据实验数据计算得超导腔体电压幅度稳定度为±3.4‰,相位稳定度为±0.3°,腔体表面峰值电场(Epk)能长时间稳定在25.1 MV/m。通过实验测试,检验了LLRF控制系统的性能,并对测试过程中出现的问题进行了分析,为将来超导腔LLRF控制系统运行积累了经验。 相似文献
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A superconducting quarter-wave resonator (QWR) of frequency=162.5 MHz and β=0.085 (β =v/c) has been designed at Peking University. The multipacting (MP) simulation and analysis for the QWR with CST Particle Studio has been performed. The simulation results reveal that there is no sign of MP with its normal operating accelerating gradients in the range of 6-8 MV/m. The accelerating gradient range that may incur MP is from about 1.4 to 3.2 MV/m, and the places where MP may be encountered are mainly located at the top part of the QWR. So the effect of different top geometries on MP has also been studied in depth. Our results show that an inward convex round roof is better than other round roofs, and plane roofs have an advantage over round roofs on the suppression of MP in general. While considering the optimization of its electromagnetic (EM) design, our initial designed model is also acceptable. 相似文献
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中国散裂中子源二期束流功率升级到500 kW,直线加速器H-的能量增益由现在的80 MeV提高到300 MeV以上,其中150 ~ 300 MeV能量段采用648 MHz βg=0.60的5-cell超导椭球腔结构。超导椭球腔具有加速梯度高、结构简单、后处理容易等优点,缺点是结构强度弱、易失谐。本文主要研究该椭球腔的失谐特性。利用COMSOL Multiphysics软件进行了计算分析,在两端固定边界条件下,裸腔的氦压敏感性系数KP=–45.705 Hz/mbar(1 mbar=100 Pa),洛伦兹力失谐因子KL=1.574 Hz/(MV/m)2。增加加强环并优化其位置来改善氦压敏感性系数和洛伦兹力失谐因子,通过计算分析最终确定选择双加强环方案来减小椭球腔的失谐。两个加强环位置分别取在75和120 mm的位置,腔体失谐的改善最大,KP=6 Hz/mbar,KL=0.43 Hz/(MV/m)2。为了更准确地计算椭球腔的氦压敏感性系数和洛伦兹力失谐因子,本文引入调谐刚度边界条件进行失谐分析,在椭球腔调谐器端设置30 kN/mm边界条件,另一端固定,计算得到氦压敏感性系数为4.8 Hz/mbar,洛伦兹力失谐因子1.99 Hz/(MV/m)2,满足工程要求。另外,用CST软件对椭球腔的动态洛伦兹力失谐进行了初步分析,用软件Workbench计算了椭球腔的振动本征频率,结果显示,振动本征频率离射频脉冲重复频率及环境振动频率较远,不易发生共振失谐。 相似文献
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应用3维全电磁粒子模拟程序研究腔体的内SGEMP,作为校验,模拟计算了光电子由圆柱腔体端面向内发射的SGEMP模型,并与文献结果进行了对比;使用该程序对圆柱腔体的3维内SGEMP进行模拟研究,得出注量为100 J/m2,特征温度为2 keV的黑体谱X射线,垂直入射高为4.5 cm、半径为7.5 cm的圆柱腔体侧面时,发射电流为20 A,产生的电场最高可达150 kV/m,磁场高达3.0×10?5 T。并对不同X射线注量下的电荷和电场分布情况进行了初步研究。 相似文献
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The design of a 450 MHz β=0.2 superconducting single spoke cavity has been finished at Peking University. A theoretical model and a numerical simulation are used to study the relationship between the RF performance and the geometric parameters of the cavity. In this paper, the optimization of the spoke cavity is described in detail. The RF simulation gives the optimum parameters Epk/Eacc of 2.65 and Epk/Eacc of 5.22 mT/(MV/m). The mechanical properties of the cavity are also studied. Two stiff ribs are used to offer a credible mechanical stability. 相似文献
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《中国物理C(英文版)》2014,(7)
Twelve very low Beta superconducting single spoke cavities, whose Beta is only 0.12(Spoke012) when operating at 325 MHz, are adopted in Injector I for China-ADS linac. This type of spoke cavity is believed to be one of the key challenges for its very low geometric Beta. So far, in collaboration with Peking University and Harbin Institute of Technology, IHEP has successfully designed, fabricated, and tested the Spoke012 prototype cavity. This paper presents the details of the design, fabrication and test results for Spoke012 prototype cavity. 相似文献
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本文依据能量守恒,就RF超导腔低温测量方法和原理进行了推敲.指出:由于在超导腔中存在场致电子发射(FE)效应,高功率腔和低功率腔在测量方法上是有区别的.并系统地推导了获得超导腔物理参数,比如空载Q0、最大表面电场和最大加速梯度等的准确公式. 相似文献
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在高功率超导质子直线加速器中,束流负载效应是影响超导腔幅相稳定性的一个重要因素。本工作基于谐振腔建场模型,开发了超导腔系统束流负载效应的时域仿真程序,分析了束流负载效应对超导腔幅相稳定性的影响,并在C-ADS注入器II上通过相关实验测量对仿真结果进行了验证。利用该程序,评估了CiADS超导直线加速器脉冲束流的脉冲长度,以及前馈补偿的时序抖动和束流纹波等因素对腔中电磁场幅相稳定度的影响。仿真结果表明:在当前CiADS直线加速器设计参数下,为满足超导腔中电磁场0.1%与在高功率超导质子直线加速器中,束流负载效应是影响超导腔幅相稳定性的一个重要因素。本工作基于谐振腔建场模型,开发了超导腔系统束流负载效应的时域仿真程序,分析了束流负载效应对超导腔幅相稳定性的影响,并在C-ADS注入器II上通过相关实验测量对仿真结果进行了验证。利用该程序,评估了CiADS超导直线加速器脉冲束流的脉冲长度,以及前馈补偿的时序抖动和束流纹波等因素对腔中电磁场幅相稳定度的影响。仿真结果表明:在当前CiADS直线加速器设计参数下,为满足超导腔中电磁场0.1%与$0.1^{\circ}$ 的幅相稳定度指标,前馈时序抖动的偏差不能超过0.79 μs,束流流强的直流偏差不能超过0.9%,并且给出了束流纹波的最大抖动幅值与纹波频率之间的关系。这些结果将为CiADS超导直线加速器相关子系统技术指标的确定提供依据。 相似文献