Study on the frequency tuning of the half-wave resonator at IMP

The RF and mechanical coupled analyses are essential in superconducting cavity design in order to predict the deformation of the cavity walls and the frequency shift caused by the deformation. In this paper, the detuning caused by both bath helium pressure and Lorentz force is analysed and a tuning system has been investigated and designed to compensate the detuning by deforming the half-wave resonator along the beam axis. The simulations performed with ANSYS code show that the tuning system can adjust and compensate the frequency drift due to external vibrations and helium pressure fluctuation during operation.     

Development of a superconducting solenoid for CADS

A superconducting focusing solenoid has been designed and developed for the China Accelerator Driven System (CADS). In order to meet the requirement of focusing strength and fringe field while minimizing the physical size of the solenoid, the novel optimizing design method based on a linear programming method was employed. In this report, the design of the solenoid including magnetic field optimization, mechanical design and quench protection will be introduced. The solenoid has been fabricated and tested. The testing results show that the central field reached 8.4 T and the stray field was lower than 50 Gauss in the cavity zone.     

ADS注入器Ⅱ热冲击损伤研究(英文)

由于束流脉冲无法控制而引起直线加速器的热冲击损伤是造成加速器无法完成聚束及偏转的主要因素,而对热冲击进行定量的热应力评估可以有效地避免RFQ、超导腔以及其他加速元件等加速器设备的损伤,这在研制强流直线加速器的过程中至关重要。本研究引用一种新颖的计算方法定量分析整个注入器的热冲击损伤并明确了三种不同材料高纯铌、无氧铜和不锈钢对应的加速器件的热冲击的特征。基于有限元方法对瞬态热应力进行分析,得出三种不同材料对应的加速器件在入射角度为90度时的温度分析结果。对于所研制的注入能量低于10 MeV的强流直线加速器来讲,得到可允许的入射时间为20μs。     

Numerical optimization and multi-particle dynamics simulation of the radial matching section of the RFQ

The ABC code is an optimization program for the development of matching channels and dynamical matchers in radio frequency quadrupole (RFQ) structures, and a new approach to this code to define the geometry of the radial matching section of the RFQ has been developed. This approach is based on the application of the numerical optimization step by step. This optimization is intended to search for the initial matching condition of a beam, the optimization of parameters of a cell of the channel on given characteristic parameters and traces of a beam in linear channels in both forward and backward directions. To further verify the results of the optimization, multi-particle beam dynamics simulations have been carried out using the BEAMPATH and TRACK codes. The result of the beam dynamics simulation shows that the optimization result of the ABC code is reasonable and this approach provides an opportunity to redesign the structure of the radial matching section of the RFQ.     

CSR60°二极C型铁磁场特性的研究

兰州重离子加速器冷却储存环主环注入线二极C型磁铁首次采用了磁极头中埋置垫补线圈调整磁场均匀度的设计.在其磁场测量中,使用了点测和积分测量的方法对其各方面特性参数进行了测量,并对积分场的测量结果以及内置垫补线圈对均匀场的垫补效果进行了详细的非线性分析.     

埋入SiO_2薄膜中纳米Ge的光学、电学性质和室温可见光致发光

用射频共溅射技术和真空退火方法，制备出埋入ＳｉＯ２基质中纳米Ｇｅ的复合膜（ｎｃＧｅ／ＳｉＯ２），通过喇曼散射、Ｘ射线衍射、室温光致发光（ＰＬ）、紫外可见光近红外吸收及电导温度关系等测量手段，较系统地研究了该复合膜的光学、电学、薄膜结构和光致发光性质，在室温情况下得到了有多个弱峰的、不对称的宽带ＰＬ谱，主峰能量约为２０５ｅＶ，这一结果同量子限制效应符合     

冷却储存环主环注入线四极磁铁测量

 介绍了兰州重离子加速器冷却储存环工程主环注入线四极磁铁谐波测磁系统和谐波磁场测量结果。分析了磁铁误差产生的原因以及磁铁加工存在的问题和注意事项。     

Adjusting the accelerating field distribution of a superconducting CH cavity

In a superconducting CH (cross bar H mode) cavity, the method of regulating the length of a drift tube is employed to adjust the distribution of the accelerating field. In this article, we simulate the electromagnetic field of a CH structure to illustrate the reason for adjusting the field distribution by varying drift tube length. Meanwhile, that the presence of the drift tube will cause a sharp rise in the maximum electric field is also shown. This phenomenon is contrary to superconducting cavity design principles in which the cavity geometry needs to be optimized to reduce the maximum electric field to avoid field emission. We propose a variable diameter superconducting CH cavity design to solve this conflict. The simulation of the variable diameter superconducting CH cavity shows that this method is feasible.     

兰州重离子加速器冷却储存环kicker磁铁设计

 介绍了兰州重离子加速器冷却储存环（HIRFL-CSR）CSRm引出kicker磁铁的物理设计、参数计算以及结构设计和加工。为了减小电感，使上升时间达到要求，CSRm引出kicker磁铁采用分布式的传输线方案，同时将无感电容与磁铁并联以满足匹配的问题。磁铁用单匝线圈和铁氧体铁芯来降低电感、减少涡流损耗，并采取两台电源成对供电、导体一端共地的结构形式消除杂散电感和轴向场，这种方式不但消除了过桥的不利影响，而且可通过调节导体间距离方便的调节磁场均匀区宽度和磁铁电感。完成设计后磁铁电感小于1 μH，在140 mm范围内磁场均匀度好于±0. 5%，最高磁场达到0.038 T，最大峰值激磁电流约为2.5 kA。     

Super-FRS超导磁体失超瞬态热应力分析

国际反质子与离子大科学工程(FAIR)项目是一个大型的国际合作项目,其中Super-FRS超导二极磁体由中国科学院近代物理研究所研制。利用ADINA有限元程序对项目中的超导Super-FRS磁体线圈的失超过程进行了模拟分析。利用C程序对ADINA程序进行二次开发以便对有限元求解器的调用和载荷的控制。分析结果显示:在失超过程中产生的最大热应力为26 MPa,可能产生的声波频率在35 Hz左右。