合肥同步辐射装置U26光束线45-115nm波段高次谐波抑制系统设计

为抑制合肥同步辐射装置U26光束线掠入射单色仪真空紫外波段的高次谐波,在45-115nm波段研究了Si和Al的反射率特性,结果表明:确定的入射角下,Si和Al的反射率随波长的变化有明显的截止,截止波长随入射角减小不断变大.以Si为反射镜材料,设计了两镜高次谐波抑制系统,核心由四组两两平行的平面反射镜组成,确定了每组反射镜的最佳入射角,并给出了该装置详细的结构设计参数.对该系统的高次谐波抑制效率进行计算表明,45-115nm波段的高次谐波抑制比均大于100.     

软X射线磁性圆二色光束线的调试和实验

合肥国家同步辐射实验室二期工程建立了基于软X射线吸收的光束线和实验站。光束线采用了平面变线距光栅单色器,可以提供100—1000eV的单色光,在1000eV处当分辨本领为1000时,光子通量可以超过108s-1。光束线的焦点尺寸是3mm×1mm。在该设备上已经获得软X射线磁性圆二色吸收谱和C、N、O的K吸收边的近边吸收谱。     

微通道板在软X射线能区的绝对标定

在北京同步辐射装置(Beijing synchrotron radiation facility,BSRF)的3W1B软X射线光束线上利用Si光电二极管传输标准探测器对微通道板(Microchannel plate,MCP)探测器进行了能量响应效率的绝对标定.给出了能量范围在50-250eV的能量响应的标定结果,并给出了标定的不确定度.利用标定后的MCP对同步辐射光束线能谱及偏振特性进行了测量,得到了理想的结果.     

基于B/S的光束线站控制系统数据库设计与实现

介绍了基于B/S的光束线站控制系统数据库的设计与实现。该系统通过建立一个合理而有效的数据共享平台,存储了控制设备的静态属性和光束线运行状态的历史记录,为工程人员提供了光束线站控制系统的管理和数据检索平台。     

NSRL软X射线磁性圆二色光束线

本文对合肥同步辐射（NSRL）二期工程软X射线磁性圆二色光束线进行了介绍。束线主要包括斩波器系统、前置镜系统、单色器系统、后置镜系统、真空系统、软件及电子学系统。光束线的预期指标为：光通量10^8s^-1,实验站的波长范围为100-1000eV,圆偏振度0．6-0．8（随波长变化而变化）,在1000ev处的能量分辨率为1000,在实验站的焦点处光斑大小为水平方向3mm,垂直方向1mm。     

国家同步辐射实验室原子分子物理光束线气体滤波器的研制、安装和调试

为有效消除波荡器产生的高次谐波的影响,并维持光束线及储存环超高真空环境,根据原子分子物理光束线实际情况,采用二级差分抽气系统及大抽速的差分泵设计了气体滤波器系统.调试结果表明,在滤波气氩气压强Par<1.333×103 Pa时,光束线真空度维持在<4.933×10-7Pa,高次谐波滤波率>99.975%,满足了实验要求.     

变间距光栅刻线密度测试系统的性能评价

在国家同步辐射实验室二期工程光束线的建设中,建立了一套变间距光栅刻线密度的测试系统。该系统采用衍射测量法测量光栅间距的变化,可以对光栅长度为100 mm的平面和凹面光栅的刻线密度进行测量。样品测量结果表明,该系统的测量精度△N/N<2×10~(-4),满足光束线工程的要求,可以作为NSRL进口的变间距光栅的验收工具。     

北京同步辐射1W2B生物大分子光束线兼用模式

模拟并优化了北京同步辐射1W2B生物大分子光束线兼用模式下的光束性能。通过实际测量光束的性能参数,并与专用模式进行对比,验证了1W2B光束线兼用模式的可行性,即在兼用模式条件下,1W2B光束线依然满足生物大分子晶体多波长反常散射等实验要求,大幅增加了北京同步辐射生物大分子晶体学实验的机时,提高了该光束线的利用效率。     

北京同步辐射软X射线偏振测量装置及其应用

在北京同步辐射装置(BSRF)设计建造了-套基于多层膜偏振元件的软X射线偏振测量分析装置,可工作在双反、双透、前反后透和前透后反四种工作模式,既可作为偏振测量装置,用于同步辐射光束线和多层膜偏振元件偏振特性测量,也可作为通用反射率计,用于多层膜和薄膜的反射或透射率测量,又可用于磁性材料的磁光效应研究等.利用自行研制的装置和光学元件对BSRF的3W1B光束线的偏振特性进行了系统的测量.测量结果指出,在206 eV时,输出光的线偏振度从起偏前的O.585上升到起偏后的0.995,同步光的线偏振度得到极大改善.利用非周期宽带Mo/Si多层膜开展了铁磁性材料的磁光法拉第效应测量,获得了Ni薄膜3p边附近(60-70 eV)的法拉第旋转角度,最大偏转角度在65.5 eV和68 eV分别为1.85±0.19°和-0.75±0.09°.     

同步辐射光学元件的粘弹性减振方法

同步辐射光束线光学元件的振动不稳定性将影响样品处的光斑位置,将粘弹性减振器安装在光学元件上可以减弱地面微振动对机构影响。研究设计了粘弹性减振器,对粘弹性材料的剪切储能模量和损耗模量进行共享参数的非线性拟合,得到Prony级数各项系数;通过有限元软件模拟了粘弹性减振器的动力学性能,并以某长反射镜为例,对安装减振器后的结构系统进行谐响应分析、瞬态动力学分析以及静力学分析,并且比较了减振器安装位置对减振效果的影响。结果表明:粘弹性减振器能有效控制地面微振动对光学元件长反射镜振动稳定性的影响;减振器安装在光学元件底板下靠近两端减振效果更好,能显著提高元件的振动稳定性。该项研究对光束线其他光学元件的振动稳定性研究具有参考意义。     

Li2B4O7:Cu,In的热释光晒退特性研究

制得一系列不同烧结温度的Li2B4O7Cu,In样品,以X光衍射(XRD)、热释光(TL)、光释光(OSL)等手段研究样品的热释光陷阱的晒退特性.烧结温度对热释光陷阱的晒退特性影响较大,实验表明750℃烧结样品的热释光不易晒退.结合XRD和OSL的结果解释了烧结温度对晒退特性的影响.     

Quantitative Measurement of the Proportions of High-Order Harmonics for the 4B7B Soft-X-Ray Source at Beijing Synchrotron Radiation Facility

A transmission grating coupled with an X-ray charge coupled device(CCD)is used to quantitatively measure the proportion of high-order harmonics of the soft-X-ray source of beam line 4B7B.The results show that the monochromatic X-ray has third-order and second-order harmonics.The proportion of second-order harmonic of 4B7B is less than 9.0%and the thirdorder harmonic is below 0.7%when no suppressing method is applied.When suppression methods are used,the proportion of second-order harmonic is less than 1.7%and the third-order harmonic is ignorable.     

Fluid-to-fluid modeling of critical heat flux in 4 × 4 rod bundles

Fluid-to-fluid modeling of critical heat flux (CHF) is to simulate the CHF behaviors for water by employing low cost modeling fluid, and the flow scaling factor is the key to apply the technique to fuel bundles. The CHF experiments in 4×4 rod bundles have been carried out in Freon-12 loop in equivalent nuclear reactor water conditions (P=10.0–16.0 MPa, G=488.0–2100.0 kg/m² s, X_cr=−0.20–0.30). The models in fluid-to-fluid modeling of CHF is verified by the CHF data for Freon-12 obtained in the experiment and the CHF correlation for water obtained by Nuclear Power Institute of China (NPIC) in the same 4×4 rod bundles. It has been found that the S.Y. Ahmad Compensation Distortion model, the Lu Zhongqi model, the Groeneveld model and Stevens–Kirby model overpredict the bundles CHF values for water. Then an empirical correlation of flow scaling factor is proposed. Comparison of the CHF data in two kinds of test sections for Freon-12, in which the distance of the last grid away the end of heated length is different, shows that the spacer grid, which is located at 20 mm away from the end of the heated length, has evidently influenced on the CHF value in the 4×4 rod bundles for Freon-12. This is different from that for water, and the need for further work is required.     

MCNP4B程序可视化运行平台开发

成功开发了一套基于Windows98系统的MCNP程序可视化运行平台McnpClient，它界面美观，操作简便，易学易用，将会获得不熟悉MCNP程序和蒙特卡罗方法的物理工作者的欢迎，有利于MCNP程序的推广应用。     

通气式B4C屏蔽棒的辐照考验

介绍了中国试验快堆屏蔽组件采用的通气式B4C屏蔽棒的结构与辐照考验结果。在BOP-60快中子反应堆对屏蔽棒的辐照考验表明:在508~580℃下,经383个有效辐照天后,最大快中子注量达0.38×1023cm-2(En>0.1 MeV),包壳材料的最大辐照损伤剂量为18.6 dpa(原子离位次数),10B平均燃耗约10.2%,最大燃耗约19.4%。屏蔽棒的结构完整,尺寸无明显变化,40个芯块中,有17个块保持原状和完整性,其余的损坏成两块或更多的小块,不可能从通气孔中逃逸,B4C芯块的最大肿胀值为ΔV/V≈4.2%。包壳的机械特性能保持足够高的水平,在最大损伤剂量部位的屈服强度增加了30%~40%,在500℃下屈服强度为760 MPa。均匀伸长率在辐照后减少了25%~30%,在500℃下为1.4%。B4C吸收元件在达到的辐照参数下表现出高的辐照稳定性,可以用在CEFR反应堆的B4C屏蔽组件中。     

Scattering of 14.1 MeV Neutrons by 6Li, 7Li, 9Be, 10B and 11B

Using a time-of-flight spectrometer, the differential cross sections were measured for the elastic and inelastic scattering of 14.1 MeV neutrons by ⁶Li, ⁷Li, ⁹Be, ¹⁰B and ¹¹B. In the case of elastic scattering by ⁷Li and ¹⁰B, correction was applied to subtract the contribution of inelastic scattering from the unresolved first excited state, after which, the elastic scattering data were compared with predictions based on the optical model. The potential parameters derived with a seven-parameter search yielded angular distributions agreeing with the present experimental data. The expressions for these parameters are presented as a function of mass number.

The experimental data on inelastic scattering were analyzed with the distorted wave Born approximation. The deformation parameters were estimated to be nearly equal to or larger than unity for these nuclei.     

碳化硼锆合金可燃毒物中空芯块制备工艺研究

以氢化锆粉与碳化硼粉为原料,用橡胶模成型方法成型,真空烧结炉中脱氢;在800¹100℃下保温1 h,制得碳化硼锆合金可燃毒物中空芯块烧结体;用浸渍法测量芯块的致密度和开孔率,研究烧结温度和碳化硼含量对烧结体致密度的影响;用扫描电镜分析坯体与烧结体的微观结构。结果表明,碳化硼锆合金烧结体的致密度随烧结温度的升高而增加,随碳化硼含量的增加而降低,碳化硼颗粒在锆合金中分布比较均匀,当碳化硼质量分数为0.5%,烧结温度在1000℃以上时,烧结体致密度达到95%以上,开孔率低于1%。     

Neutron Irradiation Effect on Isotopically Tailored 11B4C

The present investigation was carried out to elucidate the effects of neutron irradiation on the dimensional change and thermal conductivity of isotopically tailored ¹¹B₄C. The specimens used in the present investigation are 99% ¹¹B-enriched ¹¹B₄C, 91% ¹⁰B-enriched ¹⁰B₄C, and β-SiC. ¹⁰B₄C was sampled from an irradiated material used as a neutron absorber in a “JOYO” MK-II control rod. The ¹¹B₄C and SiC specimens were irradiated in the experimental fast reactor “JOYO” to fluences of 1:94 × 10²⁶ n/m² (E > 0:1 MeV) at 530°C and 3:12 × 10²⁶ n/m² (E > 0:1 MeV) for ¹⁰B₄C, with a ¹⁰B burnup of 47:3 × 10²⁶ cap/m³. Measurements on changes in dimensions and thermal conductivity, as well as postirradiation annealing up to 1400°C, were carried out. The results of such measurements indicated that the changes in the dimensions and thermal conductivity of neutron-irradiated ¹¹B₄C were substantially smaller than those of ¹⁰B₄C and SiC. Postirradiation annealing measurements for ¹¹B₄C showed that the thermal conductivity was almost completely recovered at 1400°C. The changes in thermal conductivity by annealing were analyzed in terms ofphonon scattering theory. The onset of recovery of the thermal conductivity of ¹¹B₄C agreed well withirradiation temperature; however, the recovery of length did not coincide with irradiation temperature.     

X射线与半导体探测器相互作用过程的仿真研究

采用MCNP4B仿真了能量为1～100keY的单能X射线与硅半导体探测器发生相互作用的过程。仿真结果表明，当X射线能量较低时，在探测器的硅半导体上沉积能量较低，随着X射线光子能量升高，沉积能量增大，但是在探测器的整个能量段，沉积能量并非线性增加，而是有一定的涨落，经检验，5个探测器在其工作能段范围内探测效率呈正态分布。     

掺Dy与Mn的硼酸镁热释光发光谱

本文制备了掺Dy和Mn的MgB4O7的磷光体,并测量其热释光发光谱。测量结果表明,MgB4O7:Mn的热释光发光峰位于180℃和300℃左右,其发光波长分布较宽,中心约为580nm;而MgB4O7:Dy的热释光发光峰位于200℃和350℃,发光波长由Dy3+离子的能级跃迁决定,位于480、580、680和750nm左右。当两者共掺时,只改变Mn的浓度,测量结果发现,随着Mn掺杂浓度的增加,480nm和680nm左右的发光受到抑制,并且低温峰也受到强烈抑制,而580nm的高温峰逐渐增强并且发光谱变宽。