共查询到20条相似文献,搜索用时 15 毫秒
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Gao Jie Zhai JiYuan Pan WeiMin Li ShaoPeng Sun Yi Dai JianPing Chi YunLong Li ZhongQuan Zhao TongXian Huang TongMing Ma Qiang Ge Rui Li ChunHua Guo HaiSheng Wang GuangWei Qiu Feng Lin HaiYing Hou Mi Wang QunYao 《中国科学:物理学 力学 天文学(英文版)》2011,54(2):154-159
The 1.3 GHz superconducting radio-frequency (SRF) technology is one of the key technologies for the ILC and future XFEL and ERL projects in China. With the aim to develop 1.3 GHz SRF technology, IHEP has started a program to build an SRF Accelerating Unit. This unit contains a 9-cell 1.3 GHz superconducting cavity, a short cryomodule, a high power input coupler, a tuner and a low level RF system. This program also includes the SRF laboratory upgrade, which will permit the unit to be built and tested at IHEP. The unit will be used for the 1.3 GHz SRF system integration study, high power horizontal test and possible beam test in the future. In this paper, we report the recent R&D status of this program. The first large grain low-loss shape 9-cell superconducting RF cavity made by IHEP reached 20 MV/m in the first vertical test in July, 2010. The prototype tuner and low level RF (LLRF) system are under test. The high power input coupler and cryomodule are under fabrication. Several key SRF facilities for 9-cell cavity surface treatment and pre-tuning were successfully commissioned and are in operation. 相似文献
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In accelerator RF cavities, there exists not only the fundamental mode which is used to accelerate the beam, but also higher order modes(HOMs). The higher order modes excited by the beam can seriously affect beam quality, especially for the higher R/Q modes. 1.3 GHz low-loss 9-cell superconducting cavity as a candidate for ILC high gradient cavity, the properties of higher order mode has not been studied carefully. IHEP based on existing low loss cavity, designed and developed a large grain size 1.3 GHz low-loss 9-cell superconducting cavity(IHEP02cavity). The higher order mode coupler of IHEP02 used TESLA coupler's design. As a result of the limitation of the mechanical design, the distance between higher order mode coupler and end cell is larger than TESLA cavity.This paper reports on measured results of higher order modes in the IHEP02 1.3 GHz low-loss 9-cell superconducting cavity. Using different methods, Q e of the dangerous modes passbands have been obtained. The results are compared with TESLA cavity results. R/Q of the first three passbands have also been obtained by simulation and compared with the results of the TESLA cavity. 相似文献
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为了大幅度提高纯铌超导腔的品质因数,从而降低其使用功耗,选择对超导腔进行高温氮掺杂处理。立足国内外大型加速器的需求,中国科学院高能物理研究所首先开展了1.3 GHz 1-cell超导腔的研究,包括常规处理以及氮掺杂实验,并且对掺杂前后的结果进行了分析、对比。结果表明,通过掺氮,两只1.3 GHz 1-cell细晶粒纯铌超导腔的品质因数均获得了显著提升,同时在超导腔低温垂直测试中观察到了比较明显的反常的品质因数随加速梯度变化的曲线,即"anti-Q-slope"现象。 相似文献
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基于数字自激算法设计并实现的超导腔垂直测试系统提高了超导腔的垂直测试效率,为先进光源技术研发与测试平台(PAPS)的超导腔批量化生产提供了重要保障;垂直测试系统的射频前端和时钟分配系统采用了二次上下变频方案,可以在一定范围内灵活设置测试系统自激环路的工作频率,增大了该测试系统的工作带宽。利用此系统完成了1.3 GHz 9-cell超导腔的通带频率测试,结果表明,该测试系统能有效避免不同模式之间的串扰,具备较强的频率分辨能力(<800 kHz),保证多单元超导腔性能验证的进行。 相似文献
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The RF performance of a 1.3 GHz 9-cell superconducting niobium cavity was evaluated at cryogenic temperatures following surface processing by using the standard ILC-style recipe. The cavity is a TESLA-style 9-cell superconducting niobium cavity, with complete end group components including a higher order mode coupler, built in China for practical applications. An accelerating gradient of 28.6 MV/m was achieved at an unloaded quality factor of 4×109. The morphological property of mechanical features on the RF surface of this cavity was characterized through optical inspection. Correlation between the observed mechanical features and the RF performance of the cavity is attempted. 相似文献
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A 3+1/2cell DC-SC photo-injector for PKU-FEL facility is under development, which is an upgrade design of the successful 1+1/2cell DC-SC photo-injector. The Lorentz detuning and tuning structure for the 3+1/2cell superconducting cavity is presented in this paper. The Lorentz force detuning coefficient is 7.2 Hz/(MV/m)2 with double stiffening rings for the half cell and single stiffening rings between the adjacent TESLA cells. With the special stiffening structure, the 3+1/2cell whole cavity needs only one tuner. The influences of the tuning on frequency shift, field flatness and average gradient are discussed in this paper. The simulation results show that the stiffening rings' design is successful. 相似文献
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The Advanced Photon Source (APS) at Argonne National Laboratory is considering the development of a superconducting linac-based fourth-generation hard X-ray source to meet future scientific needs of the hard X-ray user community. This work specifically focuses on the design of an optimized 5-cell superconducting radio-frequency structure well suited for a high-energy, high-beam-current energy recovery linac. The cavity design parameters are based on the APS storage ring nominal 7 GeV and 100 mA beam operation. A high-current 5-cell cw superconducting cavity operating at 1.4 GHz has been designed. In order to achieve a high current, the accelerating cavity shape has been optimized and large end-cell beam pipes have been adopted. The beam break-up threshold of the cavity has been estimated using the code TDBBU, which predicts a high threshold beam current for a 7 GeV energy recovery linac model. A copper prototype cavity has been fabricated that uses half-cell modules, initially assembled by clamping the cells together. 相似文献
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金晓 许州 杨兴繁 蔡公和 沈旭明 邓仁培 黎明 都兴绍 杨茂荣 李正红 钱民权 蔡琳 潘清 程云 刘捷 卢和平 赵夔 张保澄 王莉芳 谢大林 郝建奎 胡克松 周传明 《强激光与粒子束》2001,13(6):769-772
光阴极超导加速器实验系统由四倍频Nd:YAG锁模激光器、Cs2Te光阴极、2+1/2微波电子枪、L波段3.5MW脉冲微波源,1.3GHz单腔超导铌腔,500W连续微波源,超导腔束管耦合器,4.2K低温恒温容器,液氦制冷系统,同步控制系统,束流参数诊断,真空系统等构成。2001年6月在中物院进行了光阴极超导加速器原理性实验,测得超导加速段能量增益0.58MeV,微脉冲束流强度0.1A,取得了预期的实验结果。 相似文献
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The physical design of the 2-cell superconducting cavity is presented.The RF parameters of the cavity and HOMs (high order modes) are reported.In this paper,we put the emphasis on the analysis of the HOMs and interaction between beam and cavity. 相似文献
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对频率和场平坦度的预调谐是9-cell超导腔耗时最多的后处理工序之一,很快将成为国内相关大科学工程9-cell腔批量生产的瓶颈。首先介绍了9-cell超导腔两种常用的预调谐方法,即DESY方法和Cornell方法的原理,建模分析和比较了两种方法的计算精度和误差来源,给出Cornell方法调谐量计算的修正。然后结合9-cell超导腔预调谐实验研究,给出了快速预调谐方法:DESY的重建算法在低场平时精度较高且收敛迅速,可作为粗调;Cornell微扰算法在高场平时精度较高且测量迅速,可作为微调。结合两种调谐方式,将预调谐分为粗调和微调两步,可有效提升9-cell超导腔预调谐的速度。 相似文献
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The physical design of the 2-cell superconducting cavity is presented. The RF parameters of the cavity and HOMs (high order modes) are reported. In this paper, we put the emphasis on the analysis of the HOMs and interaction between beam and cavity. 相似文献
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A totally home-made 9-cell TESLA type superconducting cavity is mane at Peking University. The cavity abrication is according to DESY specification. The cavity is made of high purity niobium from OTIC, Ningxia. The electron beam welding is carried out at Harbin Institute of Technology, Harbin. By the cooperation, the cavity is tested at Thomas Jefferson National Accelerator Facility, USA. The preliminary result shows the acceleration gradient Eacc is 23 MV/m without quench and has potential for improvement. 相似文献
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以常用的多单元超导腔预调谐方法为基础,搭建了一套完整的预调谐系统,并实现了超导腔预调谐测量的自动化。实验首先通过网络分析仪对超导腔进行测量,利用Labview进行数据采集,并协同控制步进电机。通过“拉小珠”的微扰法,测量沿小珠运动路径的场分布。编写了一套Java程序,通过矩阵运算,计算出9单元腔各个腔单元频率的校正量。根据计算结果对9单元腔的某个单元进行挤压或拉抻,经多次上述操作后,在较高精度范围内,可将9单元铜腔的每个腔单元调谐至预期的目标频率。 相似文献
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Tuning for the first 9-cell TESLA cavity of PKU 总被引:1,自引:0,他引:1
A method based on circuit model is used to tune the first home-made 9-cell TESLA type superconducting niobium cavity at Peking University. After tuning, a flat field profile with a final π-mode frequency within 3 kHz of target frequency is achieved. The field flatness is measured by a bead-pull method, and the relative electric field is calculated from the frequency shift perturbed by the bead stepping along the axis of the cavity. 相似文献
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Research and development of a 1.3 GHz 9-cell cavity test cryomodule were carried out by a collaboration group between IHEP (Institute of High Energy Physics) and TIPC (Technical Institute of Physics and Chemistry) in China. The cryomodule is a "test model" for the ILC cryomodule, and a key component of a superconducting accelerator test unit which will be built in the near future, also can be used as a horizontal test facility for 1.3~GHz 9-cell cavities. This paper presents the development status of the cryomodule, including structure design, cryogenic flow diagram, thermal and mechanical simulations, heat load estimation and etc. 相似文献
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CHEN Si HUANG Sen-Lin LI Yong-Ming FENG Li-Wen ZHU Feng QUAN Sheng-Wen LIU Ke-Xin CHEN Jia-Er 《中国物理C(英文版)》2013,37(8):087001-0870
Generally, the Energy Recovery Linac (ERL) needs specially designed high current superconducting RF cavities. In this paper, the threshold current of beam breakup for compact ERL facilities with 9-cell Tesla type cavities are investigated. The results show that it is feasible to adopt the 9-cell Tesla cavity for compact ERL test facilities with just a few cavities and beam current around 10 mA. 相似文献