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.

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.

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.

作为CSNS/RCS横向束流准直系统的关键部件,次级准直器用于吸收经主准直器散射后不在预定轨道的束晕粒子,其工作原理决定了该设备要求满足强辐射环境下的稳定性、超高真空及高定位精度等要求.基于主准直器的设计及研制经验,对次级准直器结构方案及控制系统进行详细设计.针对关键部件吸收体,结合辐射防护分析结果,考虑水冷降温的方式,设计了控制程序,通过有限元分析软件ANSYS对其进行瞬态热分析,保证吸收体设计的可行性.

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.

A new H^- ion source has been installed successfully and will be used to serve the China Spallation Neutron Source (CSNS). In this paper, we report various components of the ion source, including discharge chamber, temperature, cooling system, extraction electrodes, analyzing magnet, remote control system and so on. Compared to the previous experimental ion source, some improvements have been made to make the ion source more compact and convenient. In the present arrangement, the Penning field is generated by a pair of pole tip extensions on the analyzing magnet instead of by a separate circuit. For the remote control system, F3RP61-2L is applied to the accelerator online control system for the first time. In the running of the ion source, a stable pulse H- beam with a current of 50 mA at an energy of 50 keV is produced. The extraction frequency and pulse width is 25 Hz and 500microsecond, respectively. Furthermore, an emittance scanner has been installed and measurements are in progress.

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.

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 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.

The accelerator complex of the China Spallation Neutron Source (CSNS) consists of a H− linear accelerator (linac) and a rapid cycling synchrotron (RCS). The linac contains a Penning surface H− ion source. The designed energy and the beam current of the source are 50 keV and 20 mA respectively, with a normalized root mean square (norm. rms.) emittance of 0.2π mm mrad. The manufactures and tests of the discharge chamber are in great progress. The construction of H− ion source test stand has been completed, and the operation of the source is also in progress. Stable H− ion beams with energy of 50 keV and current up to 50 mA are attained. Emittance measurement for the H− beam is being prepared.

The Penning surface plasma source is adopted as the China Spallation Neutron Source (CSNS) H− ion source. The designed energy and beam current of the source are 50 keV and 20 mA, respectively, with a normalized root mean square (norm. rms.) emittance of 0.2 πmm·mrad. The construction of a H− ion source test stand has been completed, and the commissioning of the source is in progress. Stable H− ion beams with energy of 50 keV and current up to 50 mA are attained. Emittance measurement for the H− beam is being prepared.

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