环-靶站输运线末端准直器的研究

环-靶站输运线(RTBT)末端的准直器是中国散裂中子源(CSNS)工程中的关键部件之一,因其靠近靶站,辐射剂量大,维护困难,故设计可靠性极为重要。根据准直器的工作原理,及CSNS物理设计要求,对比国外同类加速器的设计经验,设计完成准直器设备。在设计过程中兼顾了热沉积、功率损耗和材料性能等方面的严格要求,并逐一阐述了具体方案。利用Bethe-Bloch公式计算与SRIM软件模拟的结果比较,确定了模拟工具和模拟方法的可靠性,根据ANSYS有限元软件模拟的结果,验证了准直器结构设计的可靠性。     

基于模态匹配法的接触刚度

提出一种间接测量平面接触刚度的方法，准确量化粗糙表面的接触刚度，使得整个支架系统的固有频率模拟与测试结果得到良好的匹配。基于接触刚度模型、ANSYS有限元模拟方法以及模态测试方法，以地脚螺栓固定方式的测试件为例，验证了间接测量方法的准确性，使接触刚度得到准确量化。该方法可以为提高加速器磁铁支架系统的整体刚度提供依据。     

电沉积法制备石墨烯纸-金属复合材料的初步研究

石墨烯纸具有优良的导电导热性能,但强度和硬度较低。为了获得良好的综合力学性能以提高石墨烯纸的实用价值,本文提出了制备石墨烯纸-金属复合材料的构想,从实验上初步研究了电沉积法制备石墨烯纸-金属复合材料的可行性,并探究了石墨烯纸与电沉积金属界面结合情况。采用两种常见镀层金属Cu、Cr,在实验室使用电沉积法制备了石墨烯纸-Cu,石墨烯纸-Cr两种复合镀层材料。利用扫描电镜对复合材料的表面形貌和横截面进行了表征,结果显示石墨烯纸-Cr复合材料的界面结合相对紧密。本文首次将二维错配度应用到石墨烯纸与金属镀层界面结合力分析中,通过计算分析,常温下C 的（0001）面与Cr的（110）面的二维错配度为7.26%,晶格匹配度良好. 随温度升高,C-Cr界面错配度值减小,即晶格匹配度增加,另外C-Cr二元相图显示C与Cr发生反应生成的碳化物将进一步增强其界面结合。     

Thermal analysis and optimization of proton beam window for the CSNS

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.     

Modal analysis of AC quadrupole magnet system for CSNS/RCS

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.     

Vibration research of the AC dipole-girder system for CSNS/RCS

The 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 the 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 dipole magnet of 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 AC 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 ANSYS simulation method plays a very important role in the girder structure design stage. With this 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. Since it is necessary to isolate and decrease the dipole vibration, a new isolator was designed to isolate the vibratory force and decrease the vibration amplitude of the magnet.     

Study of the dynamic characteristics of the AC dipole-girder system for CSNS/RCS

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.