CR超导二极磁铁线圈受力分析

采用有限元分析的方法,以CR超导二极铁为研究对象,对其进行受力分析,分别计算线圈所受到的电磁力以及在此力作用下线圈发生的应变,线圈和相邻部分降温速率不均匀引起的热应力的分布以及线圈发生的应变.最后利用所得到的数据来校对线圈和线圈盒的强度,为结构的优化设计提供依据,并为失超保护提供可参考的数据.

CR超导二极铁导线的3D有限元失超模拟

利用FEM软件ANSYS对德国GSI的FAIR项目的超导二极铁的超导线进行了失超模拟.该模拟形象地给出导线的失超过程,通过APDL编程可以得到失超传播速度,失超时导体的端电压随时间的变化.文章还进一步研究了导线的最小失超传播区域MPZ,失超段初始温度和电流对失超传播速度的影响.

CR环二极磁铁的磁场优化

FAIR项目中的CR环二极磁铁对磁场积分场的误差分布要求很高,通过削斜与加载镜像板的方法是优化磁场的主要方法,文中介绍了对二极磁铁优化方法和对它的处理方法.利用削斜的方法来改变二极磁铁积分场的误差分布,通过复杂的削斜,已将其高场的误差分布优化到±2×10~(-4).加镜像板的方法主要适合高场,而对低场的调节不明显.另外处理方法的选取对结果的影响也很大,文中对两种方法作了比较.优化模拟计算软件采用的是专门的磁场计算工具OPERA.

用CR-39对空间重离子的鉴别模型(英文)

根据重离子在CR39中能量损失率公式,建立了一个鉴别空间重离子的数学模型LET=cZdRb.通过传能线密度与剩余射程之间的关系曲线,获得了该模型的系数.在实验中发现的CR39蚀刻率与离子有限传能线密度的关系VT=A·(REL)BE<350,被用来与该数学模型相关联,并得到一等式R=A0.0455Z3.18V-1T.最终,借助于标定实验得到了离子鉴别公式Z3.18=64541.08+2.53(dR/dV-1T).

Shell model study of single-particle and collective structure in neutron-rich Cr isotopes

The structure of neutron-rich Cr isotopes is systematically investigated by using the spherical shell model. The calculations reproduce well the known energy levels for the even-even Cr52-62 and odd-mass Cr53-59 nuclei, and predict a lowering of excitation energies around neutron number N = 40. The calculated B(E2; 2(1)(+) -> 0(1)(+)) systematics shows a pronounced collectivity around N = 40; a similar characteristic behavior has been suggested for Zn and Ge isotopes. Causes for the sudden drop of the 9/2(1)(+) energy in Cr-59 and the appearance of very low 0(2)(+) states around N = 40 are discussed. We also predict a new band with strong collectivity built on the 0(2)(+) state in the N = 40 isotope Cr-64.

3D quench simulation using finite element method for CR superconducting magnet's strand

The CR superconducting magnet is a dipole of the FAIR project of GSI in Germany. The quench of the strand is simulated using FEM software ANSYS. From the simulation, the quench propagation can be visualized. Programming with APDL, the value of propagation velocity of normal zone is calculated. Also the voltage increasing over time of the strand is computed and pictured. Furthermore, the Minimum Propagation Zone (MPZ) is studied. At last, the relation between the current and the propagation velocity of normal zone, and the influence of initial temperature on quench propagation are studied.

Optimization of magnetic field for CR dipole magnet

High homogeneity of the CR (collector ring) dipole magnet for FAIR (Facility for Antiproton and Ion Research) project at GSI is essential. The two optimized and analysis methods are introduced in detail. In order to obtain an ideal integral magnetic field distribution, the complicated end chamfer has been designed. By chamfering the removable pole, the distribution tolerance of high magnetic field is optimized to +/- 2 x 10(-4). The method of adding a mirror plane is suitable for the high magnetic field and it doesn't fit the low one. The OPERA is used to optimize the dipole magnetic field.

Stress analysis of CR superferric magnet

Finite Element Method is used in this article to analyze the stress of CR superferric magnet. Magnetic force and the stress caused by this force are calculated. The thermal stress and strain of the coil caused by cooling down is also analyzed. The result will be taken as a check for the design of the coil and coilcase, and also as a reference for the optimization of further design and quench protection.

Rotation alignment in neutron-rich Cr isotopes: A probe of deformed single-particle levels across N=40

Recent experiments have reached the neutron-rich Cr isotope with N = 40 and confirmed enhanced collectivity near this subshell. The current data focus on low-spin spectroscopy only, with little information on the states where high-j particles align their spins with the system rotation. By applying the projected shell model, we show that rotation alignment occurs in neutron-rich even-even Cr nuclei as early as spin 8 (h) over bar h and, owing to shell filling, the aligning particles differ in different isotopes. It is suggested that observation of irregularities in moments of inertia is a direct probe of the deformed single-particle scheme in this exotic mass region.

SUPER-FRS/CR超导磁体力学性能分析

中国签订了为德国FAIR国际大科学工程加工SUPER-FRS/CR超导二极磁铁样机的合作备忘录。该超导二极磁铁属于常温铁芯、低温线圈的超导磁铁，该磁铁的磁场强度0.15～1.6T，偏转角度15°，偏转半径8125mm，磁场精度要求±1×10-4，磁铁总重量约50吨。磁铁铁芯采用0.5mm的硅钢片叠压成型，由中科院近代物理研究（IMP）所计算、设计制造，线圈采用4.2K液氦浸泡式超导线圈，由合肥等离子体所设计制造（IPP）。 超导磁体的力学性能分析一直是超导磁体的基础问题。本文利用有限元分析方法，借助有限分析工具ANSYS、ADINA、OPERA等，分析了超导磁体的电磁场，着重模拟计算了SUPER-FRS/CR超导二极磁铁的电磁力作用；模拟了降温过程，计算了杜瓦、线圈热应力的作用；并对SUPER-FRS/CR超导线圈进行地震载荷作用的模拟。对以上不同的受力作用所遵循的不同的机械设计准则，进行不同的分析，最后计算结果证明设计的结构是安全、可靠的。由于超导线圈的结构复杂，导致在线圈拐角的地方应力有些集中，但是并不影响结构的可靠性。 本文还介绍了超导实验线圈的一些工艺设计，例如超导线圈的绕制，低温材料的选择，电流引线的设计工艺，以及VPI工艺。并对实验磁体进行了一系列的低温性能测试，例如短样测试、降温实验等，获得了一些重要的低温实验参数。这些参数将为以后超导磁体的研制提供宝贵的依据

Cr/Al系统的离子束混合

用600kev的kr~+对Cr/Al薄膜系统进行了离子束混合研究。实验样品是在单晶硅上蒸镀约5000 A厚的铝膜，相继再上所需不同厚度的铬膜。Kr~+注入剂量范围在2.0 * 10~(15)～2.5 * 10~(16) kr~+/cm~2之间。用2.0 Mev的α粒子对注入前后的样品进行了背散射分析，发现铝谱的前沿和铬谱的后沿有明显的展宽，且随剂量的增大而加宽，Cr/Al界面原子混合扩展量的平方α~2注入剂量φ成线性关系；当注入剂量大于1.0 * 10~(16) kr~+/cm~2时，铝谱前沿和铬谱的后沿出现有明显的平坦，经理论拟合计算，发现有化合物形成，x射线衍射实验结果证明化合物形式为Al_(13)Cr_2。本文还得到了混合量Q与剂量的线性关系。最后，对混合机制进行了讨论