中国散裂中子源(CSNS)靶站质子束窗位于环到靶站输运线(RTBT)与靶站交接面,起到隔离加速器高真空和靶站氦气环境的作用.随着束流功率提高,目前质子束窗单层膜结构形式已无法满足CSNS-Ⅱ 500 kW的高功率需求,因此开展CSNS-Ⅱ质子束窗研制,设计出双层膜中间通水的冷却结构,完成质子束窗双层膜的薄膜半径、薄膜厚度、水冷槽长度与宽度、对流换热系数等各参数对质子束窗温升与热应力的影响分析.通过冷却水需求分析得出,冷却水流速需大于 15 L/min.通过质子束窗主体的流固耦合分析,消除箱体内部死水区域.最终优化后质子束窗薄膜位置最高温度 47.8℃,薄膜位置最高热应力 30.758 MPa.通过FLUKA软件对质子束窗材料的辐照损伤性能进行分析,在每年 5000 h工作时长、500 kW高功率束流的辐照下,辐照损伤DPA计算值为 1.285 DPA,质子束窗的安全使用寿命在 7 年以上.

束流准直器作为加速器的关键部件,用于吸收不在预定轨道的束晕粒子.因良好的电导率和良好的准直效率,铜被广泛应用于准直器中作为挡块材料.通常,挡块位于超高真空环境中,承受高功率束流载荷冲击,其不同表面处理工艺直接影响传热性能及放气率.为评估无氧铜表面处理工艺对相关性能的影响,分别对其进行表面化学腐蚀发黑处理、高温氧化处理以及仅机械加工处理,结果表明:无氧铜表面发黑处理后,其热辐射系数明显增加,同时也伴随着放气率的明显增加;而通过高温氧化处理后的铜块,其表面热辐射系数与仅机械加工后的铜块差异不大,放气率有一定程度的增加.以散裂中子源二期项目中的动量准直器为研究对象,在一定的束流载荷作用下,挡块选用发黑无氧铜,可将其最高温度控制在 125℃以下,同时增加两台离子泵可使该准直器所在区域真空度满足运行要求.

陶瓷真空盒作为中国散裂中子源(CSNS)快循环同步加速器(RCS)真空系统的关键部件,能避免RCS二极、四极交流磁铁因快速变化的磁场而产生的涡旋电流.因安装空间限制,RCS陶瓷真空盒支架固定在磁铁线圈上.在CSNS/RCS交流磁铁长时间加电测试中,出现陶瓷真空盒断裂、真空破坏的情况.为避免后期出现类似问题,从磁铁发热进而引起陶瓷真空盒不均匀升温的角度出发,对陶瓷真空盒的热特性进行了分析,同时基于双目视觉测量技术,对陶瓷真空盒的振动情况进行了监测,针对部分真空盒水平方向振动异常的问题,确定其影响因素为快卸链条的磁导率超标.最后开展了陶瓷真空盒的支架减振技术研究.

Based on thermal stability and vibration stability, an ultra stability structure of rigid support is designed and optimized. Through the finite element modal analysis of ANSYS, the thermal expansion variation and the characteristic frequency of the support is verified. The support is fixated to the ground by using the method of concrete grouting and then the characteristic frequency is tested. The test results show that the characteristic frequency of the support reaches up to 61.9 Hz and the vibration amplitude is less than 30 nm, both of which meet the design requirements. Finally, the method of dynamic stiffness testing is adopted to obtain the stiffness value of the concrete grouting, and the accuracy of the optimization results of the support is further verified.

Accelerating tube is one kind of important acceleration equipment of linear accelerator. It is often made up of oxygen free copper with long tubular structure. It’s easy to suffer from deformation. Based on support requirements, the reasonable structure of the girder was obtained. Four supporting blocks were installed on the top surface of aluminium profile with the uniform distribution along the beam direction. The support strength with static condition and different working conditions were checked by ANSYS simulation calculation to ensure the stable operation of the girder. The two-layer girder can be used as a reference for other similar slender part for its simple structure and reliable support. INSTRUCTIONS Accelerating tube is often applied to the linear accelerator to speed up the beam. Based on the functional requirements, it’s manufactured as long tubular structure with oxygen free copper. It’s easy to suffer from deformation for its special structure and material. So it’s necessary to design a two-layer girder for accelerating tube to decrease deformation. SUPPORTING STRUCTURE Structural Plan To meet the functional requirements, the accelerating tube was designed as tubular structure with a length of three meters. Four supporting blocks with the same height were used to support the tube, which were installed on the same foundation. Meanwhile, the located block and sleeve were applied to locate the tube together. A standard pipe was applied to adjust the four blocks in the same line. And two locating pins were applied to ensure the position for the repeated installation. According to the supporting requirements and the disc size, the supporting blocks were set in the middle of the disc with the uniform distribution along the beam. The following figures showed the detailed plan. Figure 1 illustrated the supporting position and Fig. 2 showed the structure of the girder. Figure 1: Supporting position. Figure 2: Structure of the girder. strained XY movement and rotation. Figure 3 showed the detailed analysis. Figure 3: Locating analysis of the girder. STRENGTH ANALYSIS Related mechanical parameters were listed as Table 1, which were from www.matweb.com [1]. Table 1: Mechanical Properties Parameters Material  E   S  Cu 8940 115 0.31 17 195 Al 2830 70.3 0.33 21 296 ___________________________________________ † niexj@ihep.ac.cn Locating Analysis Flat surfaces and arc curved surface were used to restrain the tube position. The top surface of the located block restrained Z rotation. The front surface of located sleeve restrained Z movement. And the arc curved surface reS Note: Cu-Oxygen free copper Al-Duralumin aluminum alloy  Density [kg/m3 ] E Modulus of elasticity [MPa]  Poisson ratio  Line infl ation coefficient [μm/m °C]  yield limit [MPa ] Strength Analysis of Supporting Block Gravity of the tube was loaded on the supporting block surface with the fixed bottom surface. According to the area of supporting surface, the value of the load was calculated and then the final result was achieved accordingly 12th Int. Particle Acc. Conf. IPAC2021, Campinas, SP, Brazil JACoW Publishing ISBN: 978-3-95450-214-1 ISSN: 2673-5490 doi:10.18429/JACoW-IPAC2021-WEPAB397 WEPAB397 C on te nt fr om th is w or k m ay be us ed un de rt he te rm s of th e C C B Y 3. 0 lic en ce (© 20 21 ). A ny di st ri bu tio n of th is w or k m us tm ai nt ai n at tr ib ut io n to th e au th or (s ), tit le of th e w or k, pu bl is he r, an d D O I 3636 MC7: Accelerator Technology T31 Subsystems, Technology and Components, Other [2, 3]. The maximal stress was 0.45 MPa and the maximal deformation was 5.3*10^-4 mm. The result was acceptable. Figure 4 showed the analytic results. (a) Stress (b) Deformation Figure 4: Analytic results of supporting block. Strength Analysis of Accelerating Tube The gravity of the tube and the atmospheric pressure outside the tube were loaded with the bottom surface of supporting blocks fixed and the stress and deformation were calculated. The results showed as Figs. 5 and 6. The maximal stress was 4.39 MPa and the maximal deformation was 1.4E-6 mm. Both of the results were acceptable. Figure 5: Distribution of stress for the tube. Figure 6: Distribution of deformation for the tube. Strength Analysis Under Different Temperature According to evaluation, the normal working temperature of the tube is about 30 °C. But some special cases might happen occasionally. For example, the air-conditioner in the tunnel is broken suddenly in summer or winter. Here assumed the abnormal temperature as 0 °C and 40 °C. The stress of tube was evaluated under the three temperatures. The bottom surface of the girder was fixed and tube was bundled with the first supporting block. The other three blocks were kept as contact constraint. Meanwhile, the atmospheric pressure, gravity and temperature difference with normal condition were loaded when the strength was calculated. The result showed as Table 2 and Figs. 7 and 8. Here just one case was listed; the other two cases were similar. Table 2: Margin Specifications W T E T T  max  max  30 0 -30 9.35 1.19 30 25 -5 2.24 0.24 30 40 10 3.91 0.71 Note: TW Working temperature [°C] TE Environmental temperature [°C] E Difference of temperature [°C] max Maximal stress [MPa] max  Maximal deformation [mm] Figure 7: Distribution of stress for the girder (just case 2). Figure 8: Distribution of deformation for the girder (just case 2). According to above analysis, we can conclude that the girder can work normally even under some abnormal conditions. CONCLUSION The structure of the two-layer girder was decided based on the accelerating tube structure. The supporting strength and its self-deformation were calculated by ANSYS. The stress and deformation of the tube under different temperature were also evaluated at the same time. The analytic result showed that the strength of the girder is enough. It can still meet working requirement even under some abnormal conditions. ACKNOWLEDGEMENTS The authors would like to express their appreciation to all the colleagues who have contributed to this project. REFERENCES [1] [DB/OL], http://www.matweb.com [2] Chaohui Zhang, ANSYS 12.0 structural analysis of engineering application examples, Beijing, China: Machinery Industry Press, 2010, pp. 95-107. [3] Fang Hu et al., “Analysis of the Structure of the Rail Beam Support Based on ANSYS”, Metallurgical Equipment, vol. 262, pp. 36-38, 2020. 12th Int. Particle Acc. Conf. IPAC2021, Campinas, SP, Brazil JACoW Publishing ISBN: 978-3-95450-214-1 ISSN: 2673-5490 doi:10.18429/JACoW-IPAC2021-WEPAB397 MC7: Accelerator Technology T31 Subsystems, Technology and Components, Other WEPAB397 3637 C on te nt fr om th is w or k m ay be us ed un de rt he te rm s of th e C C B Y 3. 0 lic en ce (© 20 21 ). A ny di st ri bu tio n of th is w or k m us tm ai nt ai n at tr ib ut io n to th e au th or (s ), tit le of th e w or k, pu bl is he r, an d D O I

Chinese spallation neutron source (CSNS) rapid circulation synchrotron (RCS) of the dipole magnets by 25 Hz sinusoidal alternating current (AC) with dc bias field, because the magnet will produce eddy current effect caused by the vibration, this safe and reliable operation of the long-term impact of magnets, so need to CSNS/RCS dipole magnets, support system for dynamic characteristic research and the performance of vibration isolation design. In this paper, the mechanical model of ac dipole magnet and support system is first established, and ANSYS modal analysis are carried out. On this basis, vibration isolation parameters of the four-point support system are studied. The theoretical analysis and the experimental results of modal parameters are consistent, which shows that the ANSYS analysis model is correct and reliable. The dynamic system parameter design method established in this paper can be applied to various equipment of AC power accelerator. The final experimental verification shows that the total displacement amplitude of the isolator to the Y direction of the magnet on the magnetic support decreases by 62.3%. Conclusions: Simulation results of the four-point support model and experimental modal extraction experiments and vibration response tests verify that the proposed model is effective [1-9].

并联六自由度主动减振平台可有效隔离外界低频微振动对加速器BPM及光束线站等精密设备的影响,由于并联六自由度主动减振平台具有很强的耦合特性,需对平台的耦合特性进行分析研究.本文以压电陶瓷驱动器构建并联六自由度主动减振平台,在平台运动学的基础上,采用Newton-Euler法建立了平台的动力学模型.分析了平台各通道间的耦合特性,设计了一种通用的平台解耦控制策略.搭建了实验验证平台,开展次级通道参数测量与减振实验研究.实验结果表明,设计的多通道解耦控制策略是有效的,平台对低频微振动有良好的减振效果.

With the development of synchrotron radiation source technology, some beamline stations require the sample positioning platform to have a large sample scanning stroke while adjusting the resolution at nanometer level. In order to meet this requirement, a six degree of freedom positioning platform is studied. The key technologies such as coordinate parameter transformation, kinematics analysis and adjustment decoupling algorithm of 6-DOF sample positioning platform are mainly studied. The six degree of freedom platform driven by stepping motor is designed and manufactured, and6-DOF sample positioning platform control system based on bus control is developed, and the adjustment accuracy test is completed. The three-dimensional moving repeat positioning accuracy of the platform is 0.019mm, and the three-dimensional rotating repeat positioning accuracy is 0.012 degrees. The test results verify the correctness of the theoretical analysis and the rationality of the mechanism design. The research of motion algorithm and control system has important reference value for the development of 6-DOF large stroke nano positioning platform. PREFACE With the development of synchrotron radiation source, the fourth generation of high energy synchrotron radiation source has more stringent requirements on the space size, pose adjustment and positioning accuracy of the sample positioning platform. Some beam line stations require the sample adjustment platform to have centimeter level scanning stroke and nanometer level positioning accuracy [1, 2]. At present, the sample adjustment platform of synchrotron radiation source beamline station mainly adopts two structural forms: (1) the superposition combination of multi-layer adjustment platform [3]; (2) the parallel six degree of freedom platform based on Stewart Structure. For the nano parallel 6-DOF sample stage, the adjustment stroke can only stay at the submillimeter level due to the travel limit of the piezoelectric actuator. The traditional nano positioning method adopts the combination of stepping motor adjusting platform and piezoelectric ceramic adjusting platform, but it takes up a large space and has low stability. STRUCTURE DESIGN This paper mainly studies the attitude adjustment algorithm of platform. Considering the convenience of experimental measurement and the cost of platform construction, a 6-DOF platform with micron level adjustment accuracy is built by using the stepper motor mobile components (as shown in Fig. 1) for testing to verify the feasibility of structure scheme. The structural form of the platform is shown in Fig. 2 below. The position and posture of the upper loading plate is determined by three support points (ball center of the bearing), and the position of the support points is moved by three groups of adjusting units. Each adjusting unit is composed of two stepper motor moving components. The bottom stepper motor realizes the radial movement of the support point, and the middle stepper motor realizes the tangential movement of the support point. The top cross roller guide is an adaptive layer to realize the height adjustment of support points. Figure 1: Stepper motor moving stage. Figure 2: 6-DOF Platform driven by stepping motor. Ball joint bearing

本文以压电陶瓷促动器构建并联六自由度减振平台,采用NI Compact-RIO实时控制系统和Fx-LMS自适应控制算法进行振动主动控制,对次级通道辨识方法和主动控制算法进行了模拟仿真,并搭建主动减振控制系统进行实验验证.仿真与实验结果表明,设计的主动减振控制系统对于7～50 Hz范围内的低频微振动有很好的控制效果.

The fast extraction kicker system is one of the most important accelerator components and the main source of impedance in the Rapid Cycling Synchrotron of the China Spallation Neutron Source. It is necessary to understand the kicker impedance before its installation into the tunnel. Conventional and improved wire methods are employed in the impedance measurement. The experimental results for the kicker impedance are explained by comparison with simulation using CST PARTICLE STUDIO. The simulation and measurement results confirm that the window-frame ferrite geometry and the end plate are the important structures causing coupling impedance. It is proved in the measurements that the mismatching from the power form network to the kicker leads to a serious oscillation sideband of the longitudinal and vertical impedance and the oscillation can be reduced by ferrite absorbing material.

China Spallation Neutron Source is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts an H- linac and a rapid cycling synchrotron. The RCS accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25Hz. The dipole of the CSNS RCS is operated at a 25 Hz sinusoidal alternating current which causes severe vibrate. The vibration will influence the long term safety and reliable operation of the magnet. The dipole of the CSNS RCS is an active vibration equipment which is different from the ground vibration accelerator. It is very important to design and study the dynamic characteristics of the dipole girder system. This paper takes the dipole and girder as a specific model system, a method for studying the dynamic characteristics of the system is put forward by combining theoretical calculation with experimental testing. The modal parameters with and without vibration isolator of the dipole girder system are obtain through ANSYS simulation and testing. Then the dynamic response of the system is calculated with modal analysis and vibration testing data. The dipole girder takes four-point support system which maybe appears over constrained in the progress of adjustment. The dynamic characteristics and dynamic response of the three point girder system were studied with the same method.

China Spallation Neutron Source (CSNS) is a high intensity proton accelerator-based facility. Its accelerator complex includes two main parts: an H- linac and a rapid cycling synchrotron (RCS). The RCS accumulates an 80 MeV proton beam and accelerates it to 1.6 GeV, with a repetition rate of 25 Hz. The AC dipole of the CSNS/RCS is operated at a 25 Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. The CSNS/RCS AC dipole-girder system takes vibration isolator to decrease the vibratory force and the vibration amplitude of the dipole. For the long-term safety and reliable operation of the dipole, it is very important to study the dynamic characteristics of the dipole-girder system. This paper takes the dipole-girder as a specific model system. A method for studying the dynamic characteristics of the system is put forward by combining theoretical calculation with experimental testing. The modal parameters with and without vibration isolator of the dipole-girder system are obtained through ANSYS simulation and testing. Then, the dynamic response of the system is calculated with modal analysis and vibration testing data. With the simulation and testing method, the dynamic characteristics of the AC dipole-girder are studied.

以中国散裂中子源(China Spallation Neutron Source,CSNS)/快循环同步加速器(Rapid Cycling Synchrotron,RCS)主准直器为对象,研究从合肥某工厂通过公路运输到位于东莞的CSNS装置地运输过程中的振动情况.整个主准直器装置中,最薄弱的部位是刮束器的薄钨片,其质地硬而脆,运输途中的振动可能导致其发生破坏.考虑到装置造价高,制造周期长,现场无条件修复,对运输过程的安全进行评估很有必要.文中运用Matlab/Simulink建立卡车模型,仿真运输过程得到振动信号,通过试验测得实际运输过程的振动信号,将两种情况下获得的振动激励加载到ANSYS中的主准直器模型中,由此获得薄钨片在虚拟运输过程中因振动而产生的应力.通过仿真和试验,验证了仿真模型的有效性,得到了安全运输的指导车速.对加速器设备的运输振动安全评估具有实际意义.

China spallation neutron source(CSNS) is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts: an H- linac and a rapid cycling synchrotron(RCS). The rcs accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25 Hz. The AC dipole of the RCS is operated at a 25Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. The dipole magnet of RCS is active vibration equipment which is different with ground vibration accelerator. It is very important to design and research the dynamic characteristic of the dipole-girder system. This paper takes the dipole and girder as a specific model system, a method for researching the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. The ansys simulation method plays a very important role in the girder structure design stage. With the method the mechanical resonance phenomenon was avoided in the girder design time. At the same time the dipole vibratory force will influence the other equipment through the girder. It is necessary to isolate and decrease the dipole vibration. So a new isolator was designed to isolate the vibratory force and decrease the vibration amplitude of the magnet.

The quadrupole magnet of the China Spallation Neutron Source (CSNS) Rapid-cycling Synchrotron (RCS) is operated at a 25 Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the quadrupole magnet. By taking the quadrupole magnet and girder as specific model system, a method for analyzing and studying the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. The theoretical modal analysis results coincide with the experimental testing results. It shows that the dynamic characteristic parameters of the structure can be obtained by modal analysis which will provide a theoretical basis for the further study and the magnet girder optimal design of CSNS/RCS.

The proton beam window (PBW) is one of the key devices of China Spallation Neutron Source (CSNS). It is the boundary between transport line and target. This paper will present a new PBW structure and detailed thermal-stress analysis. The energy deposition and scattering effect need to be low when the beam passes through the PBW, so proper selection of material and structure is important. According to the study of energy deposition, A5083-O is selected as the PBW material. A single-double layer structure is first proposed based on the study of cooling structures. Thermal analysis and structural optimization are discussed, and transient analysis is done to show the effect of the beam pulse. Besides, safety is confirmed for cases of cooling tunnel blockage, beam profile shrinkage, or centroid orbit offset. All these analyses show the newly designed PBW structure can meet the requirements of the CSNS well.

The dipole magnet of the China Spallation Neutron Source Rapid-cycling Synchrotron (RCS) will be operated at a 25 Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. By taking the magnet and magnetic measurement girder as a specific model system, a method for analysing and studying the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. And the active vibration of magnet is different with passive vibration which was causes by ground vibration, so a new isolator was designed to decrease the vibratory force and avoid the resonance phenomenon. INTRODUCTION The CSNS-I accelerators consist of an 80 MeV H linac and a rapid cycling synchrotron of 1.6 GeV [1]. The RCS ring is a four-folded symmetrical topological structure which consist four arc zones and four line segments. There are 24 sets dipoles uniformly distributed in the whole RCS ring, and the AC dipoles will be operated at a 25 Hz rate sinusoidal alternating current. The magnetic core and coils made severe vibration especially at the frequency 25 Hz. At the same time the vibration influenced other equipment through the magnetic measurement girder. Dipole magnet girder system with complex structure and high-precision adjustment is one of the most important equipment of the CSNS/RCS. Because of the self-excited vibration, the comprehensive technical index of requirement is different than other accelerator which vibration was caused by the ground vibration [2, 3]. So it is necessary to study the dynamic characteristic and reduce the vibration of the system [4]. After that a new isolator was designed to improve the dynamic characteristic of the system, decrease the vibratory force and avoid the resonance phenomenon. This paper adopts the AC dipole & magnetic measurement girder system as research object. The theoretical and testing methods are used to study the dynamic characteristic of the system. VIBRATION TESTING OF THE DIPOLE CSNS dipole magnet will be operated at a 25 Hz sinusoidal alternating current of 1100 DC with 816 AC which causes severe vibration. The acceleration sensor will be used to measure vibration of the dipole and the testing project and results are shown in Fig. 1. The maximum amplitude is 7.16 um at the vertical direction(Y). The main amplitude is at 25 Hz and the frequency doubling of 50 Hz and 75 Hz are much less than exciting frequency. At the same time the vibration influenced the other equipment through the magnetic measurement girder. Figure 1: The dipole magnet vibration test of CSNS. ___________________________________________ *Work supported by China Spallation Neutron Source Project liurh@ihep.ac.cn Sensor

The dipole magnet of the China Spallation Neutron Source (CSNS) Rapid-cycling Synchrotron (RCS) will be operated at a 25 Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the dipole magnet. By taking the dipole magnet and magnetic measurement girder as specific model system, a method for analyzing and studying the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. This paper established the mechanical model of the system, and the top six step natural frequency and vibration mode were obtained through theoretical modal analysis (ANSYS). Then according to testing modal analysis, the natural frequency, damping ratios and vibration mode of the system structure were obtained too. The theoretical modal analysis results coincide with the experimental testing results. Besides, the 6th step natural frequency is close to the exciting frequency of the magnet, so the resonance phenomenon may take place at the actual working conditions. The dynamic characteristic data of the structure can provide an analysis basis for the further study and the formal dipole magnet girder optimal design of RCS.

STRUCTURE DESIGN AND MOTION ANALYSIS OF 6-DOF SAMPLE POSITIONING PLATFORM BASED ON SPACEFAB STRUCTURE WANG Guangyuan1,2,LIU Renhong1,2,ZHANG Junsong1,2,KANG Ling1,2,YU Jiebing1,2,WANG Anxin1,2,CHEN Jiaxin1,2,NING Changjun1,2,YU Yongji1,2,LIU lei1,2 1 Institute of High Energy Physics, Chinese Academy of Sciences(CAS),Beijing 100049, China 2 Dongguan Neutron Science Center, No. 1, Zhongziyuan Road, Dalang, Dongguan[523803], China THPAB300