上海同步辐射装置储存环注入冲击磁铁的设计

 开展了上海同步辐射装置储存环注入冲击磁铁的结构和脉冲电源的技术设计,并进行了磁场分布和励磁电流波形的模拟计算。还给出了陶瓷真空盒镀膜的设计参数,提出了计算陶瓷真空盒镀膜接受同步光功率的公式,研究了防止镀膜和波纹管受到同步光照射的机械布局设计。     

Eddy current septum magnets for injection and extraction at SSRF

There are 6 in-vacuum eddy current septum magnets used for booster injection,extraction,and storage ring injection in SSRF.Special attention was paid to coils and their support designs because of the shock force they bear in the magnetic fields and the high heat which is hard to be dissipated in vacuum environment.For the storage ring magnets,good transverse homogeneity in the gap was achieved by careful design,precise machining and accurate assembly;and an extremely low leakage field on the stored beam is another key feature thanks to the high permeability Mu metal.Magnetic field measurement was conducted with both a point coil and a long integral coil,and the results agree well with the OPERA-2d/3d simulations.An inner tube is added to keep the continuity of impedance for the circulating beam with two RF finger flanges at each end.There is no vacuum separation between the inner tube and the magnet chamber.Sputter ion pumps integrated with NEG are used to acquire the UHV for the chamber.     

Kicker magnet modulator in the 2-GeV Pohang light source

The 2.0-GeV Pohang light source (PLS) is a third-generation synchrotron light source that is the first such facility in Korea and the fifth in the world. The PLS mainly consisted of a full-energy injection linac and a storage ring. Four kicker magnets are installed in the storage ring tunnel to move the stored beam orbit in the storage ring closer to the injected beam from the beam transfer line. The injected beam then falls into the storage ring beam dynamic aperture. A kicker magnet modulator drives all four kicker magnets to maintain field balance and synchronized kick of the beam. Specification of the kicker magnet modulator is ~6.0-μs-full width, 200-ns flattop width with ±0.2% regulation, ~24-kA peak current, and 10-Hz repetition rate. Two thyratron switches (EEV CX-1536AX) are used in the system. As the inverse voltage is dangerous to thyratron operation, a new surge suppression circuit was developed. The kicker modulator has been operated very reliably since its installation in August 1995. In this article, design, simulation, and experimental results of the kicker magnet modulator are discussed. In addition, measurement result of spatial B-field distribution in the kicker magnet and maximum operating range of kicker magnet are discussed     

电子储存环中闭合轨道和色散函数的校正

电子储存环中,由磁铁元件制造误差和安装误差导致的闭合轨道和色散函数的畸变,通常会引起一系列的负面效应,介绍了以合肥光源储存环为模型,用响应矩阵的奇值分解法对闭合轨道和色散函数进行校正的可行性研究结果.     

Design and Construction of a New Type Kicker Magnet for Injection of BEPCⅡ Storage Ring

For the severe requirements of BEPCⅡ injecting kicker magnets, the two schemes of low impedance kicker magnets used in other accelerator labs in the world are not adaptive to the BEPCII storage ring. A new scheme of kicker magnets proposed in this article solves the difficult problem of BEPCII kicker magnet design. And the successful construction of a prototype has demonstrated that the new scheme of kicker magnets is viable and the design of the kicker magnet structure is reasonable.     

Special-purpose radiation sources based on the Siberia-2 storage ring

Synchrotron radiation (SR) generated by homogeneous magnetic fields of bending magnets is now employed at the Siberia-2 electron storage ring. It is planned that, in the near future, most of the storage ring’s free straight sections will be equipped with insertion devices (undulators and wigglers). Two projects of specialized radiation sources based on the Siberia-2 stor age ring are discussed. The first source is a vacuum milliundulator intended for generation of extremely bright X-ray beams. An X-ray source with vertically limited diffraction is shown to be feasible when the vertical emittance of an electron beam is equal to the diffraction emittance of photons with an energy of 2 keV. The second source uses edge radiation (ER) generated at the ends of bending magnets of the storage ring. Calculations show that, in the infrared and ultraviolet spectral regions, the ER intensity must exceed the intensity of standard SR formed by the homogeneous field of a bending magnet.     

基于LOCO的上海光源储存环线性光学参数校正

 为了测量和校正线性光学参数,在上海光源储存环调束过程当中使用了基于响应矩阵的线性光学参数分析(LOCO)的方法。介绍了应用LOCO进行计算和校正的过程,包括：数值模拟得到束流位置探测器的测量精度对拟合结果的影响,调整四极铁电源电流强度来校正工作点和beta函数周期性的恢复。测量结果表明,在四极铁强度调整幅度在1.5%以内的情况下,储存环的束流光学参数成功地恢复到和设计值相当接近的状态,beta函数和色散函数畸变小于1%。通过束流光学参数的校正,使得在今后的工作当中可以轻松地控制储存环的工作模式。     

Orbit response matrix analysis and lattice periodicity restoration of the SSRF storage ring

In this paper, we present numerically and experimentally the linear beam-optics distortion in the SSRF storage ring and the correction of optics by using a number of quadrupole magnets installed in the storage ring. The measured orbit-response matrices were fitted to the model-response matrices to obtain the β and the dispersion functions in the storage ring. By readjusting the currents of quadrupole-magnet power supplies, we were able to successfully restore the optics parameters to values very close to the design ones, with rms deviations around 1%. This periodicity restoration is verified with the β function measurement,     

上海光源增强器动态升能过程分析

上海光源增强器采用FODO型磁聚焦结构, 由28个FODO单元组成, 周长180m, 可将直线加速器引出的100MeV的电子束加速至3.5GeV, 用于储存环的注入, 重复频率为2Hz. 增强器的动态升能过程将直接影响到储存环的注入效率. 报告上海光源增强器动态升能过程中磁铁磁场、高频电压的上升过程、涡流效应及影响以及束流参数的变化等.     

CSRe储存环等时性模式转变能洛伦兹因子曲线的测量与校正

综述了兰州冷却储存环CSRe上转变能洛伦兹因子的测量与校正的最新进展,详细阐述了基于等时性质谱仪实验数据测量储存环的转变能洛伦兹因子的方法,以及利用CSRe二极、四极、六极磁铁校正转变能洛伦兹因子曲线的结果。实验结果表明,二极磁铁和四极磁铁可以平移转变能洛伦兹因子曲线,六极磁铁可以旋转转变能洛伦兹因子曲线。通过校正CSRe的转变能洛伦兹因子曲线,将CSRe对目标离子的质量分辨能力R=m/△m=3.15（9）×104（FWHM）（回旋周期相对误差σT/T=7.3（2）×10-6）提高到1.72（4）×105（FWHM）（σT/T=1.34（3）×10-6）。     

用模拟退火法进行纯永磁波荡器磁块组合优化

 纯永磁波荡器由多个磁块组成,磁块的剩磁离散性会引起波荡器磁场误差,从而影响储存环工作状态和自发辐射谱质量。在波荡器磁块安装之前,使用模拟退火法对磁块进行组合排序优化,可以使峰值场强误差降低到10 ^-4量级以下,磁场一次积分降低到10^-6 T·m量级,二次积分降低到10 ^-6 T·m ²量级,优化结果不依赖于初始状态的选择。给出优化的详细过程,提出了根据磁块剩磁快速计算波荡器峰值场强误差和积分场的方法。     

冷却储存环主环磁铁的准直测量

 采用激光跟踪仪及配套带软件Insight对兰州重离子加速器冷却储存环主环磁铁进行了安装和准直。首先建立全局坐标系，用来确定从源体到实验环各子系统的理论原点的位置；而各个子系统又分别以各自的理论原点为基础建立局部坐标系，用来安装定位本系统内的各个元件；对各个子系统中的每一个元件还采用了元件坐标系。准直测量时，先在每块磁铁上焊接8个测量基准；然后对磁铁上的基准进行测量，以确定其在元件坐标系中的位置；再架设激光跟踪仪，测量主环控制网点，恢复主环局部坐标系，根据元件在主环局部坐标系中的位置及理论坐标，计算出相关的变换参数；转入元件坐标系，采用激光跟踪仪及Insight 软件显示实时测量坐标及其与理论值之差，其精度达到0.15 mm。     

一种新的永久周期磁铁聚焦的高功率宽带放大器

提出了一种新的高功率宽带放大器，它由速调管和自由电子脉塞组成，用永久周期磁铁聚焦。研究了这种器件的电子束聚焦、群聚和辐射。在速调管提供一阶调制系数为30%，波导管的半径1.51cm，摇摆器的磁场振幅0.16T，周期7.92cm，电子束的电压490kV，电流50A和半径0.368cm的条件下，预估这种器件的辐射波频率为11.4GHz，输出辐射功率为18MW，输出辐射带宽为44%。     

高温超导磁悬浮轴承悬浮力数值分析

高温超导磁悬浮轴承已经被广泛应用到飞轮储能系统之中,它的主要结构是由高温超导体和永磁体组成。本论文基于有限元法(FEM)和临界态模型,对高温超导推力轴承的悬浮力和刚度等参数进行模拟仿真,并且在SCML-02测试装置上进行测试,计算结果与测试结果得到很好的吻合。并且进一步对环形永磁体推力轴承进行计算模拟,为进一步的轴承结构参数优化做好基础。     

Preliminary study of EEHG-based superradiant undulator radiation at the HLS-Ⅱ storage ring

We investigate storage ring-based Echo-Enabled Harmonic Generation(EEHG) superradiant undulator radiation as a possible scheme to obtain shorter wavelengths at the HLS-Ⅱ(Hefei Light Source-Ⅱ) storage ring. In this paper we give the designation of the storage ring based EEHG up to the 26 th harmonic, where 31 nm vacuum ultraviolet light is radiated from an 800 nm seeded laser. The novelty of our design is that both the two dispersion sections of EEHG are realized by the storage ring's own magnet structure. In particular, the whole ring is used as the first dispersion section, and two modulators of the traditional EEHG can be done with the same undulator. These two dispersion sections are realized by changing the superperiod of the present lattice structure, and more precisely by changing the focusing strengths of the present structure. Since no additional magnets and chicanes are used,the beam circulates around the storage ring repeatedly, and thus this storage ring-based EEHG can have a higher repetition rate than a linac-based EEHG.     

Numerical simulation study about spin resonant depolarization due to spin—orbit coupling

Spin polarization phenomenon in lepton circular accelerators had been known for many years. It gives new approach for physicists to study about spin feature of fundamental particles and dynamics of spin-orbit coupling, such as spin resonances. We use numerical simulation to study the feature of spin under the modulation of orbital motion in electron storage ring. The various cases of depolarization due to spin-orbit coupling through emitting photon and misalignment of magnets in the ring are discussed.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

磁铁边缘场对注入束流的影响

在兰州重离子加速器冷却储存环工程(HIRFL–CSR)实验环的注入设计过程中,通过对束流在侧面边缘场作用下运动的反向数值跟踪,得到注入束流通过二极磁铁和四极透镜边缘场的传输矩阵,并同理想场对束流的作用进行了比较.通过改变注入束流中心轨道及对磁铁的重新设计,将磁铁边缘场对注入束流的影响减小到可以控制的范围.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility (SSRF)booster ring, a full energy injector for the storage ring, is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping. Closed orbit distortion (COD) caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting. Considering the affections of random errors in measurement, both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5 is given as the final installation sequence of the booster bending magnets in this paper.     

上海同步光源定时系统物理设计

正在建造中的上海光源(SSRF)设计为一台能量为3.5GeV的第三代同步辐射光源, 其定时系统的物理设计使其能够满足储存环的不同运行模式, 如单束团模式、多束团模式、混合模式及Top-up运行模式, 定时系统具有高的稳定性和低的时间晃动. 基于EPICS控制系统的定时系统可提供精确的可编程序事件驱动信号序列, 根据不同需求提供电子枪、调制器、增强器和储存环高频, 注入引出及束测等设备的触发信号.