中子活化法测定肿瘤小鼠脏器中的元素含量

用仪器中子活化法在微型反应堆上对小鼠的毛、脑、心肝、肾、肺、肌肉、肿瘤等８种组织中Ｂｒ、Ｃａ、Ｃｌ、Ｃｕ、Ｉ、Ｋ、Ｍｇ、Ｍｎ、Ｎａ、Ｓ和Ｖ等１１种元素进行了测定。其中铜的分析利用６５Ｃｕ（ｎ，γ）６６Ｃｕ反应，通过测定６６Ｃｕ的１０３９．６ｋｅＶγ射线强度进行定量。方法可靠性用ＮＢＳ－１５７７（牛肝）、ＩＡＥＡ－Ｈ４（肌肉）、虾粉等标准物质核对，测定值与推荐值相一致。     

多群蒙特卡罗方法在中子测井数值模拟中的应用

讨论了多群蒙特卡罗(MC)程序——MORSE在中子测井数值模拟中的应用。对不同孔隙度和不同岩性(砂岩、灰岩和白云岩)的简化球体地层模型与单一地层介质的井壁中子测井基准问题进行了模拟计算。计算结果与MC方法大型程序的计算结果吻合得很好。实践表明,用MC方法分群近似计算中子测井问题是可行的。应用MORSE程序进行中子测井数值模拟与MCNP等大型程序相比有占用计算机内存少、节省机时和使用方便等优点。     

自成靶陶瓷中子管及其应用

采用自成靶和陶瓷绝缘外壳的中子管具有长寿命，耐高温，工作稳定等特点，已实际应用于Ｃ／Ｏ石油测井和辐照养虾等。一支管子可测井６０口，实际测井工作寿命螺计达４００ｈ；地面使用平均寿命超过５００ｈ。     

HL—1聚变装置中子发射实验研究

采用ＺｎＳ（Ａｇ）闪烁计数器，经标准中子源刻度校正后，测量ＨＬ－１（中国环流器一号）聚变装置的中子演化和中子产额；同时用活化箔法（１１５Ｉｎ）和原子核乳胶法测量中子产额。在真空室充氘和电子回旋共振加热（ＥＣＲＨ）时，３种方法同时测量，确证ＨＬ－１每放电１次发射中子数平均为（３．４１±０．５０）×１０１０。得到欧姆加热、ＥＣＲＨ、改进约束放电（ＩＯＣ）和弹丸注入等放电实验中的中子演化。在分子束注入和偏压电极（ＥＰＰ）放电实验中，产生中子较少或很少。观察部分放电方式产生的中子产额Ｎ和硬Ｘ射线产额ＨＸ间有线性关系Ｎ＝ａＨＸ－ｂ，其中，ａ和ｂ是与装置运行方式有关的常数。     

A framework for understanding fast-neutron induced defects in SiO2 MOS structures

Neutron radiation damage in solids results from nuclear collisions and reactions that produce energetic recoil atoms. The recoiling atoms slow down in the host material through nuclear and electronic collisions. During a nuclear collision, energy is transferred to translatory motion of another atom, whereas during an electronic collision, energy is transferred to atomic electrons, leading to electronic excitation or ionization. Nuclear collisions may result in displacing additional host atoms from their lattice sites if the energy received by the host atom is greater than the displacement threshold energy. As neutrons pass through the thin thermally grown gate oxide of a MOSFET device, they produce both silicon and oxygen primary knock-on atoms (PKAs). These PKAs can produce significant displacement damage regions in the bulk oxide which become potential hole traps or mobile ionic charge traps similar to the condition at the SiO₂/Si interface. It is also suspected that these PKAs may deposit part of their energies into plasmons, which will eventually decay to electron-hole pairs causing charge buildup at the interface, when the MOSFET device is in operation. Since the gate oxide region is susceptible to electronic effects, it is important to know the amount of damage from individual neutron interactions in the oxide layer. A key to a theoretical study is provided in this paper. Analytical and direct-simulation estimates are made of the neutron damage.     

Analysis of DR testing blind zone of spherical fuel elements for 10 MW high-temperature gas-cooled reactor

Spherical fuel elements technology is a main innovation of high-temperature gas-cooled reactors (HTGRs), which effectively improves the safety of the reactors for higher stability at high temperature, and their quality is crucial for the safety and reliability of HTDRs. According to a spherical fuel element's structure, the coated fuel particles are not permitted to enter the fuel-free zone and the elements with escaped fuel particles must be removed during the fuel elements' quality control. In this paper, we first introduce a DR imaging system for spherical fuel elements testing applied in Chinese 10 MW high-temperature gas-cooled reactor (HTR-10). Then the blind zone where escaped particles exist is analyzed under the continuous and concrete circular scanning trajectories and the cone-beam imaging geometrical configuration. The dominant scanning parameters determining the size of the blind zone are the rotation step angle and the distance from X-ray source to the tested object. An optimal method of designing the two parameters to decrease the size of the blind zone is proposed so as to satisfy the testing requirements. Finally, the optimal method is verified by computer simulation and some practical identification results are presented.     

核数据理论计算程序处理系统的研制

研制了核数据理论计算程序处理系统，其中包括光学模型自动调参程序系统及ＵＮＦ程序输入数据的自动填充和输出结果的自动绘图程序系统。系统安装在中国核数据中心的ＭＩＣＲＯ－ＶＡＸ－Ⅱ上。简要地描述了系统的主要功能并给出使用实例。     

The performance of a multiplexing three-axis spectrometer

A novel multiplexing three-axis spectrometer for thermal neutrons has been tested for single-crystal spectroscopy. Measuring the entire 2D dispersion manifold in the bc plane of the spin-Peierls compound CuGeO₃, we demonstrate that the spectrometer fascilitates investigations of large volumes in (Q,ω)-space from small single crystals. The performance of this multi-analyser spectrometer at a steady-state source compares well to an existing time-of-flight spectrometer at a pulsed source.     

Lattice dynamics of LuPO4

Lutetium orthophosphate is an important nonmagnetic host material for rare-earth activated luminescence applications. We have measured the LuPO₄ phonon density of states and dispersion curves along the [ξ00], [ξξ0] and [00ξ] symmetry directions by neutron spectroscopy using polycrystalline and single crystal samples. A quantitative analysis of the neutron results was carried out using a lattice dynamic shell model.     

组件燃耗对堆芯裂变中子源参数的影响

在中子输运计算中，准确的裂变中子源是保证计算结果可靠性的前提和基础：随着组件燃耗的加深．^235U等核素不断消耗，^239Pu、^240Pu、^241Pu等核素不断积累，导致每次裂变产生的平均中子数v和裂变释放的平均能量E也随之变化，裂变中子源的归一化因子随燃耗增加而增加。因此，在中子输运计算中，必须考虑组件燃耗对堆芯的裂变中子源参数的影响。