Tritium Released from Mantle Source: Implications for Natural Nuclear Fusion in the Earth’s Interior

This paper summarizes the observation results of mantle tritium (³H) in two volcanic lakes, Lakes Nemrut (Turkey) and Laacher (Germany). The presence of excess ³H in the lakes can be explained as material released from mantle source because of the correlation of excess ³H with mantle ³He and ⁴He. We conclude that excess ³H in these two lakes, after the origin of the excess ³H from atmosphere and conventional nuclear reactions are excluded and the correlation of the excess ³H and mantle ³He is considered, might be from a mantle source and produced by nuclear fusion (d–d reaction) in the deep Earth. We have also investigated helium isotopes in the hydrothermal vent fluids at Mid-Ocean Ridge (MOR). The results show nearly constant ³He/⁴He ratio (³He/⁴He = 1.12 ± 0.13 × 10⁻⁵) and approximately constant ³He/heat ratios ((5–10) × 10⁻¹⁸ mol/J). The correlation of ³He with ⁴He and heat suggests that it is reasonable to suppose ³He is produced by nuclear fusion (d–d reaction) and ⁴He from α-decay of U and Th in the deep Earth. Based on that, ³He/⁴He ratios for 10 hydrothermal vent fluids are calculated. The results agree with the measurement at hydrothermal vent fluids and Mid-Ocean Ridge Basalts (MORB) on the average. We concludes that the narrow distribution of ³He/⁴He ratio peaked at ∼8 R_A in MORB can be explained by the hypothesis that ³He is produced in nuclear fusion.     

Probing the density dependence of the symmetry energy with central heavy ion collisions

An improved isospin dependent Boltzmann Langevin model, in which the inelastic channels and momentum dependent interactions are incorporated, is used to investigate the high-density behavior of nuclear symmetry energy. By taking several forms of nuclear symmetry energy, we calculate the time evolutions of neutron over proton ratio, π ultiplicity and π-/π＋ ratio, and the kinetic energy and transverse momentum spectra of π-/π＋ ratio in the heavy ion collisions at 400A MeV. It is found that the neutron over proton ratio and π-/π＋ ratio are very sensitive to the nuclear symmetry energy, and the π- is more sensitive to the nuclear symmetry energy than the π＋. A supersoft symmetry energy results in a larger π-/π＋ ratio.     

Probing nucleon effective mass splitting with light particle emission

The main objective of this study was to investigate the impact of effective mass splitting on heavy-ion-collision observables.We first analyzed correlations between different nuclear matter parameters obtained from 119 effective Skyrme interaction sets.The values of the correlation coefficients illustrate that the magnitude of effective mass splitting is crucial for tight constraints on the symmetry energy via heavy-ion collisions.The ⁸⁶ Kr+²⁰⁸ Pb system at beam energies ra...     

新型充Ar靶丸设计

从惯性约束聚变实验物理诊断需求出发,提出并分析了利用聚碳硅烷空心微球作为DT燃料容器实现扩散法充氩的可行性。初步实验研究表明,聚碳硅烷微球有望替代玻璃微球作为DT燃料容器用于内爆物理研究。     

Photoactivation of Rare Earth Elements with 20 MeV Bremsstrahlung

The oxides of scandium, yttrium and all elements from lanthanum through lutetium, except promethium, were irradiated for 1hr with bremsstrahlung γ-rays converted from a 20MeV electron beam, and the radioactive species produced as a result have been examined on the basis of photonuclear reactions, their yields, and their applicability to activation analyses. The sensitivity and selectivity of the proposed method are discussed from the data thus obtained.

The (γ,n) reaction was predominant for most elements, and at least 28 product nuclides have been identified. A number of other (γ,2n) reactions have also been observed.

The yields of the (γn) reactions have been estimated for the lanthanide rare earths through measurement of the resultant activity to be about 10⁷mole·R and somewhat more than 10% smaller for the corresponding (γ,2n) reaction. Reactions with charged particle emission contributed only a small fraction in the observed radioactivity.

Extraneous activity arising from neutron capture was also measured; these activities could be reduced considerably by encasing the sample in boron.

The lower limits of detection averaged about 1 μg for most of the rare earth elements.     

用PS作探针研究化学反应中间态及中间过程

介绍了一种奇特原子－正电子素的基本性质及作为探针研究化学反应历程、探测中间产物的实用性。为了检验这种应用的可能性，选用Ｒｈ（Ⅲ）与乙烯作用制备Ｒｈ（Ｉ）催化剂的合成反应．根据观测到的正电子素湮没寿命及强度随反应时间的异常变化讨论了中间态的Ｒｈ（Ⅱ）的形成及反应机理。     

铀铌合金表面热氧化膜结构研究

采用X射线光电谱分析技术、结合Ar离子枪溅射,研究了大气环境、不同温度(室温、100、200和300℃)条件下铀铌合金样品表面氧化膜结构的变化情况。实验结果表明:随温度升高,氧化膜厚度增大,氧化膜结构发生明显变化。不同温度热氧化处理后,铀铌合金初始表面Nb主要以Nb2O5形式存在,在Nb2O5与金属Nb之间,总存在一定厚度的NbO及少量其他价态氧化物NbOx(0x1,1x2)的混合层。室温～200℃热氧化合金样品表面铀均以含间隙氧的UO2+x(P型)存在,其U4f7/2结合能较UO2低约0.7eV。室温条件下,氧化膜成分主要为UO2;100、200℃热氧化后,氧化膜中除UO2外,还含有少量P型UO2+x,其U4f5/2卫星峰的结合能为396.6eV。300℃热氧化后的合金样品表面为铀的高价氧化物(U3O8或UOx,2x3),U4f特征峰的结合能分别为381.8和392.2eV;氧化层为UO2和金属铀的混合物。热氧化过程中,温度对铀氧化的影响较对Nb的明显得多。     

氧化钆中稀土和非稀土杂质元素的ICP－AES法测定

本文介绍了电感耦合等离子体原子发射光谱法测定氧化钆中１８种元素。经对元素光谱干扰和基体效应的探讨发现：当溶液中氧化钆浓度为５ｍｇ·ｍＬ－１时，本法测定下限在６×１０－５～１×１０－３μｇ（ｇ·Ｇｄ２Ｏ３）－１之间，加入回收率在８２％～１０９％之间；相对标准偏差优于±６．９％。     

Probing Density Dependence of Symmetry Energy with Angular Distribution of Light Particles in HICs

正The nuclear symmetry energy plays a crucial role for understanding not only nuclear structure and reaction but also astrophysics phenomena.However,theoretical predictions on the density dependence of symmetry energy of nuclear matter show large uncertainties away from the normal density.Lot of efforts have been devoted to     

钍资源的核能利用问题探讨

分析了钍/铀燃料循环特点,评估了国际上钍资源利用研究开发现状和发展趋势,并试图按照科学发展观提出了我国钍资源核能利用的战略思考和钍/铀燃料循环前瞻性研究开发课题.     

Crystalline Phase in Surface Layers of Glass Waste Form

An integral test of γ-ray production data of iron in the latest version of Japanese Evaluated Nuclear Data Library (JENDL-3.2) has been performed by means of a shielding benchmark analysis of KfK leakage neutron and γ-ray spectrum measurements from iron spheres with a ²⁵²Cf source in the center. Two comprehensive systems which consist of a continuous-energy Monte Carlo method and a multi-group Sn transport method have been adopted in this benchmark analysis. For comparison, analyses with JENDL-3.1, FENDL-1 and ENDF/B-IV have been also carried out. The calculation using JENDL-3.2 showed a good agreement with the experiment. It has been concluded that the γ-ray production data of iron in JENDL-3.2 were applicable for use of shielding designs and analyses of the fission neutron source problem.     

A Particle-in-Cell Simulation of Double Layers and Ion-Acoustic Waves

Double layers and ion-acoustic waves are investigated by using a one-dimensional electrostatic particle-in-cell simulation code. Our results show that double layers can be formed even when the drift velocity between electrons and ions is less than the electron thermal velocity. Electron and ion density depressions were clearly seen. Electrons gradually developed a distribu- tion comprising both background and beam components. In fact, as the initial electron-ion drift velocity was less than the electron thermal velocity, intense ion-acoustic waves could be found only at the places where the electron beam was located, suggesting that they are excited by the self-consistently developed electron beam. Besides the Langmuir waves and ion-acoustic waves, the beam mode excited by electron beams produced in our simulation has been clearly found.     

Measurements of the Thermal Neutron Macroscopic Absorption Cross Section for Neutron Absorbing Layers

Objective of this study is measuring the macroscopic cross section of a neutron absorbing layer for thermal neutrons. For this purpose a neutron source and BF ₃ detector have been applied. For measuring macroscopic cross section of thermal neutrons by the \( I = BI_{0} e^{{ - \sum\nolimits_{tot} t}} \) Formula, it is necessary to provide suitable geometric conditions in order to assume the production and build-up coefficient to be the unit value (=1). To fulfill required conditions for this assumption, surface of the detector is covered with a 2 mm thick layer of cadmium. Radiation window of the detector has a 3 cm diameter, situated directly in front of the source. By placing the cadmium cover over the detector, variation of \( Ln{\frac{{I_{0}^{{}} }}{I}} \) values verses thickness of absorbent layer, renders linear function behavior, making it possible to measure the macroscopic cross section. The next stage is applying the MCNP code by simulating F1 tally and cosine-cards for calculating Total Macroscopic Cross-Section. Validation of this study is achieved through comparison of simulation by the MCNP code and results rendered by experiment measurements.     

模型泵内部流场的数值模拟

采用雷诺时均N-S方程和标准k-ε湍流模型,应用三维非结构四面体网格建模,选用旋转流体机械模型中的多重参考坐标系模型(MRF),对设计工况下反应堆主冷却剂泵模型泵的三维不可压缩湍流流场进行了数值模拟,模拟结果较好地揭示了内部流场的特点.本文分析了流场内总的压力分布和速度分布,描述了叶轮、导叶和球壳各个部分的内部流场特征,并探讨了造成这些特征的原因.研究结果可用于反应堆主冷却剂泵的性能预测,并为其水力优化设计提供有益参考.     

Superfluidity in the Solar Interior: Implications for Solar Eruptions and Climate

Efforts to understand unusual weather or abrupt changes in climate have been plagued by deficiencies of the standard solar model (SSM) [1]. Although it assumes that our primary source of energy began as a homogeneous ball of hydrogen (H) with a steady, well-behaved H-fusion reactor at its core, observations instead reveal a very heterogeneous, dynamic Sun. As examples, the upward acceleration and departure of H⁺ ions from the surface of the quiet Sun and abrupt climatic changes, including geomagnetic reversals and periodic magnetic storms that eject material from the solar surface are not explained by the SSM. The present magnetic fields are probably deep-seated remnants of very ancient origin. These could have been generated from two mechanisms. These are (1) Bose-Einstein condensation [2] of iron-rich, zero-spin material into a rotating, superfluid, superconductor surrounding the solar core and/or (2) superfluidity and quantized vortices in nucleon-paired Fermions at the core [3].     

废放射源整备用封装管的设计与检测

研制废放射源整备封装管,使整备后废放射源满足处置或者长期贮存要求,是废放射源管理的重要组成部分。本文针对不同活度、不同核素的废放射源,设计制造了不同的封装管,并对其中的螺纹封装管进行了跌落性、抗冲击性、耐热性等一系列检测。检测结果表明,本研究设计的封装管,满足封装废放射源的要求。     

Calculation of Distribution Ratios of Rare Earth Elements in Multistage Counter Current Extraction with HDEHP

Extraction of rare earth elements with di (2-ethylhexyl) phosphoric acid (HDEHP) - tributyl-phosphate (TBP)-n-paraffin system was studied as functions of concentrations of the quantity of H⁺ released into aqueous phase. The ratio of rare earth elements extracted into organic phase was found to depend on the initial composition of the aqueous solution. The ratios determined for various concentrations of rare earth elements and acid were shown as a linear function of the concentrations of acid in aqueous phase and that of rare earth elements in organic phase after extraction. The acid concentration in aqueous phase after extraction can be estimated from any initial concentrations of acid and rare earth elements in aqueous solution by this equation. Also a graphic process of experimental results could give approximate values of distribution ratio for various initial concentrations of rare earth elements and nitric acid. For calculation of the distribution ratio of each stage in multi-stage counter current extraction, a computation code was programmed on the basis of the graphical process. The calculated values agreed well with those obtained experimentally in multistage extraction.     

双单元建筑物的换气速度和内部流动的测量

采用示踪气体稀释法对选定的双单元建筑物的换气速度和内部流动进行了测量,以期建立一种实际测量的方法,同时获得一些有用的数据。测量结果表明,选定的建筑物具有令人满意的换气速度,内部流通良好,可满足室内空气质量的要求,但对污染事故的屏蔽能力较差。本工作可以为研究室内空气质量和建筑物屏蔽因子提供一些借鉴。