Effects of machine errors on the ILC main linac

For a practical linac, the beam property is affected seriously by any machine imperfections. In this paper, the effects of several main errors in the ILC main linac, such as quadrupole misalignment, magnet strength error and cavity misalignment, were studied by a theoretical method. The tolerance for each error was also obtained. Comparison with the numerical simulation result is made and the agreement is quite good.     

仪器柔度标定误差对两种压入测试方法的精度影响

针对目前最具代表性的两种压入测试方法:Oliver-Pharr方法和Ma方法,通过有限元数值模拟分析了仪器柔度标定误差对测试精度的影响.结果表明仪器柔度的标定精度直接影响压入测试结果的准确度,尤其是当材料较软且压入深度较大时更为显著;对同一材料,压入载荷越大,由仪器柔度标定误差引入的压入测试结果误差越大;在同一压入深度下,针对不同材料,由仪器柔度标定误差引入的压入测试结果误差差别不大;就测试方法而言,Ma方法具有比Oliver-Pharr方法更高的精度和更低的仪器柔度敏感性.     

单线阵CCD相机定位精度评估模型及几何误差研究

为满足单线阵CCD相机立体测绘定位的需求,研究了相机几何误差对定位精度的影响,并建立了它们之间的数值模型,为相机的几何指标分析和量化提供理论支持.首先针对单线阵立体成像特点,分析了几何标定和像点量测误差对定位结果的影响;然后以前方空间交会公式为基础,推导出定位精度评估模型.该模型给出了定位精度随几何标定和像点量测误差的...     

Drawdown in prolate spheroidal–spherical coordinates obtained via Green’s function and perturbation methods

When investigating aquifer behaviour it is important to note that there exists a close relationship between the geometrical properties of the aquifer and the behaviour of the solution. In this paper our concern is to solve the flow equation described by prolate spheroidal coordinates by means of perturbation and the Green’s function method, where the spheroid is considered to be a perturbation of a sphere. We transformed the spheroidal coordinates to spherical polar coordinates in the limit, as the shape factor tends to zero. The new groundwater flow equation is solved via an asymptotic parameter expansion and the Green’s function method. The approximate solution of the new equation is compared with experimental data from real world. To take into account the error committed while approximating, we estimate the error in the asymptotic expansion. The error functions obtained suggest that the error would be very small for the shape factor tending to zero if the first two terms of the expansion are taken as an approximation.     

光电经纬仪电控系统数据在线调试分析研究

针对光电经纬仪嵌入式电控系统便携式调试的要求,设计了一套在线调试分析系统,上位机采用ATEML公司的哈佛处理器TSC21020-20MB为核心实现嵌入式的MCU控制系统,下位机由美国Silicon Laboratories公司的新一代具有USB2.0接口的C8051F340(简称F340)单片机和普通便携式计算机(简称PC)上运行的GUI程序组成在线调试分析系统。通过下位机在线或事后数据分析,实现了参数整定,协助上位机,进而实现对运动目标的监测、搜索与捕获、精确定向和稳定跟踪。为解决调试问题提供了一种全新的思路和新颖的方法。     

Heisenberg behavior of some carbon‐beryllium compounds: How well truncated‐CI approaches work

This works tries to establish the performance of truncated CI calculations on the evaluation of magnetic coupling parameters with respect to available FCI estimates on a set of carbon‐beryllium clusters. First‐, second‐ and third‐neighbor magnetic coupling constants have been evaluated and many body effective parameters as the cyclic terms. They result from the fitting of the low‐lying states to the eigenvalues of an extended Heisenberg Hamiltonian, involving not only two‐body isotropic terms but also cyclic terms. SDCI and DDCI calculations have been carried out and their performance compared with FCI ones. The impact of the basis set choice and size‐consistency errors have been explored. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011     

平面反射元件的安装误差对光学成像质量的影响

在折转光路中,由于安装误差,平面反射元件会存在三维方向的微偏角.根据棱镜调整理论,分析了由于平面反射元件的安装误差所导致的光束转向、光轴偏离系统光轴的情况,并推导出相应的精确表达式.讨论了光轴偏离后,光斑在靶面上的漂移情况.给出了一种用于修正平面反射元件在光学安装中存在轴向偏转的调整方法,并通过实验验证了该方法的可行性...     

Interferometric tolerance determination for a Dove prism using exact ray trace

We use exact ray trace to calculate the interferometric Dove prism tolerance to manufacturing errors. We model the manufacturing errors by modifying the position of the prism vertices. The normal to the prism faces establishes the direction of the rays. We determine the prism tolerance by analyzing the optical traversed path rays. We evaluate the change in the image quality introduced by the normal deviation. When the manufacturing tolerance is maintained within ±0.35 arc sec, the maximum wave-front deviation is better than λ/10 at 633 nm. We found that a Dove prism with such tolerance introduces an OPD of two orders of magnitude lesser than a commercial Dove prism. The exact ray trace accuracy of the developed program is validated with the commercially available optical-design program OSLO™. The calculated tolerance complements a previous analysis of a Dove prism for its implementation in a rotationally shearing interferometer.     

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用SURFMN和SURFMN_TFCOIL代码计算了由HL-2M装置磁场线圈安装误差产生的误差场。根据国外托克马克装置TF和PF线圈安装误差的取值范围,以及HL-2A装置安装的经验,计算选取的TF线圈和PF线圈最大位移范围为3~8mm,最大倾斜角度为0.05~0.1°。选取9组数据计算了误差场的概率密度分布和累计概率分布。结果发现：在TF和PF线圈安装误差取值范围内,随磁场线圈最大移位增大概率密度显著变平,误差场B3-mode/BT的分布范围显著增大;磁场线圈的位移比倾斜对误差场的影响更大;当磁场线圈最大位移达到5mm时误差场大于2×10-4的概率都比较大,特别是线圈最大位移等于8mm时,误差场大于2×10-4的概率在60%以上。     

Dynamic polarization potential effects on vector analyzing powers of Li–Si elastic scattering from non-monotonic potentials

Experimental cross section (CS) and vector analyzing power (VAP) data of the ⁶Li–²⁸Si elastic scattering at 22.8 MeV are analyzed in the coupled-channels (CC) and coupled discretized continuum channels (CDCC) methods. Non-monotonic (NM) ⁶Li and α potentials of microscopic origin are employed, respectively, in the CC calculations and to generate folding potentials for the CDCC calculations. The study demonstrates that the use of central NM potentials can generate an appropriate dynamic polarization potential (DPP) required to describe both the CS and VAP   data without the necessity of renormalization. This also produces an effective spin–orbit (SO) potential to account for the iT₁₁$i{T}_{11}$ data without the requirement of an additional static SO potential at the incident energy considered.