Thermal analysis and tests of W/Cu brazing for primary collimator scraper in CSNS/RCS

To the transverse beam collimation system in a rapid cycling synchrotron,an important component is the primary collimator,which improves emittance of the beam halo particles such that the particles outside the predefined trajectory can be absorbed by the secondary collimators.Given the material properties and power deposition distribution,the beam scraper of the primary collimator is a0.17 mm tungsten foil on a double face-wedged copper block of 121.5 mm x 20 mm.The heat is transferred to the outside by a φ34 mm copper rod.In this paper,for minimizing brazing thermal stress,we report our theoretical analysis and tests on brazing the tungsten and copper materials which differ greatly in size.We show that the thermal stress effect can be controlled effectively by creating stress relief grooves on the copper block and inserting a tungsten transition layer into the copper block.This innovation contributes to the successful RD of the primary collimator.And this study may be of help for working out a brazing plan of similar structures.     

Collimation method of measurement of linear magnitudes

Principles for the construction and transformations of signals in optoelectronic collimation devices used in the measurement of linear displacements are considered. Translated from Izmeritel’naya Tekhnika, No. 10, pp. 23–26, October, 2008.     

Detection System for the Fuel Assembly Nondestructive Testing

Fuel assemblies are the central components of a reactor. The core fuel pellets in the fuel pins will swell and deform and the fuel cladding may even break under the complex environment of high temperature, high pressure and intense neutron radiation field, which threats the safety of the reactor. To better understand the changes in the behavior of the fuel assembly in the reactor and study the central void formations and deformations of fuel pins in fuel assemblies to high burn-up, high-energy X-ray non-destructive testing is an effective technical means. Irradiated nuclear fuel assembly has a strong radioactivity, it is necessary to optimize the design of the detector system and the collimator to reduce the effect from gamma rays emitted from the irradiated fuel assembly during detection system designing phase. Through modeling, estimating and optimization, the optimal size of the detector unit is obtained and the collimator design is optimized which can lay the foundation to improve the quality of the reconstructed images of the fuel assembly nondestructive system.     

一种大长度轨道直线度的测量方法和装置

以起重机轨道作为研究对象,研究了一种高精度、可自动化测量和实时在线分析的大长度轨道直线度的测量方法和装置。该方法利用准直激光束作为直线基准,携带光斑位置探测装置的小车行走于轨道上并根据激光光斑位置确定轨道测量点的偏差参数。光斑位置探测装置由一个接收屏、光路成像系统和一个二维PSD组成。针对300m长的起重机轨道的直线度测量,分析了装置的测量原理、数据处理方法,以及控制系统结构。并通过精度分析和误差评估证明了该方法和装置的可行性,仿真计算结果表明其原理误差仅为10-5mm数量级,完全符合大长度轨道的测量要求。     

光学瞄具冲击系统弹性阻尼设计仿真

通过简化光学瞄具冲击系统,对轻武器光学瞄具强度射击模拟系统建立了数学模型,对以板弹簧作为模拟系统的弹性阻尼进行了设计,并用m atlab软件simu link工具箱对冲击系统进行了仿真,通过仿真系统所得曲线与实际实验所得曲线的对比分析证明了弹性阻尼设计的合理性,为实际设计提供了一定的理论基础。     

CCD传感器用于球面光学零件参数测量的新装置及方法

为了实现球面光学零件的数字化测量,介绍了一种用高性能CCD代替人眼,结合测量软件自动测量的新方法。可测量的参数包括正负透镜的焦距、球面曲率半径、中心偏等,具有精度高和重复性好的优点。数字化测量减轻了测量劳动强度,提高了工作效率。     

准直光束高斯特征对直写光斑强度的影响

通过建立非理想准直光束残余高斯特征的功率密度模型,阐述了光束准直效果与功率密度的关系,借助光束通光比例系数对直写光斑强度分布影响的分析,以光斑主瓣、旁瓣的强度和宽度为主要特征,讨论了直写光斑强度及强度分布与光束准直效果的变化规律,确定了合理选取激光直写系统中准直扩束比例系数的原则.通过仿真不仅系统阐述了理想准直光束与非理想准直光束所形成的直写光斑形状的差异,还描述了理想准直光束近似计算光斑强度分布时的误差形式,这一结论为激光直写机准直系统设计提供了理论依据.     

14 MeV快中子照相准直屏蔽系统的设计与优化

基于强流氘氚中子源科学装置HINEG设计了一套快中子照相准直屏蔽系统。采用中子输运设计与安全评价软件系统SuperMC和ENDF/B-Ⅶ.0数据库计算了准直中子束的中子能谱及注量率、γ射线能谱及注量率、直射中子注量率与γ射线注量率比值（φ_d/φ_γ）、直射与散射中子注量率比值（φ_d/φ_s）、准直束中子注量率的不均匀度等特性参数,并采用MCNP5程序进行了对比验证。研究了准直屏蔽系统的内衬材料、尺寸等对特性参数的影响规律,并通过优化获取了最优设计方案。计算结果显示,在同等计算条件下,SuperMC计算结果与MCNP计算结果相对偏差小于1%,准直屏蔽系统的φ_d/φ_γ为50.1,φ_d/φ_s为5.7,在Φ30 cm视野范围内的中子注量率为4.80×10⁷ cm^-2•s^-1,其中直射中子注量率为4.09×10⁷ cm^-2•s^-1,中子注量率不均匀度为5.8%,满足快中子照相对准直束特性参数的要求。     

基于高速相机的多叶光栅机械性能测试方法研究

基于高速相机搭建了多叶光栅机械性能测试平台,进行了实验测试和数据处理,研究了高速相机图像分辨率、采集速度及图像处理方法对机械性能测试精度的影响。结果表明,采用视野分区的形式,在40 mm×40 mm区域视野中,选用高速相机在单方向图像分辨率4000、帧率500帧/s时,对叶片运动速度不高于250 mm/s的多叶光栅进行机械性能测试,测量精度可以达到0.01 mm。     

高能闪光照相中陡坡准直体成像性能实验研究

在针对FTO样品的高能闪光照相实验中,比较了一般准直体与陡坡准直体对FTO样品的成像性能。结果表明,陡坡准直体对降低散射及缩小照射量量程非常有效,可得到层次分明的底片图像;采用一般准直体则无法得到有意义的样品图像。对实验进行了蒙卡模拟,模拟结果与实验结果一致。