反应堆上产生强流放射性核束的模拟实验装置

正研制了一台反应堆上产生强流放射性核束的模拟实验装置。模拟装置示于图1,模拟装置真空室与反应堆中子管道尺寸一致。模拟装置由真空系统、真空室、加热系统、离子源、导向器、四极透镜、束测单元等元件组成。离子源阴极采用LaB6材料,由加热元件加热发射电子,电子在阴极和阳极之间加速获得能量后在阳极内与原子碰撞将原子电离。离子源位于20kV的电位上,离子通过引出电极引出加速获得20keV的能量。紧跟着离子源,布置了一套XY导向器,然后是两组四极     

快堆主容器内氩气空间传热实验原理及分析

本文研究了池式快堆主容器内氩气空间模拟实验的模拟准则及原理.根据模拟准则和对流换热方程组,研究了模拟实验装置需满足的物理相似和边界相似的条件,并对氩气空间的换热状况进行了计算,确定了实验装置的设计参数范围,从理论上解决了池式实验快堆钠池覆盖气体--氩气空间模拟实验装置的模拟问题.     

实验快堆自然循环模拟实验装置的模拟原理及其参数计算

研究了池式快堆自然循环模拟实验的模拟准则，根据模拟准则和自然循环守衡方程式，对池式实验快堆自然循环模拟实验装置，在各种模拟准则条件下的几何与热工设计参数进行了计算。研究了模型比例，事故冷却器一次侧进出口温差和阻力系数等对相似准则数的影响，并且确定了模拟实验装置的设计参数范围，从理论上解决了池式实验快堆自然循环模拟实验装置的模拟问题。     

改进的激光多步共振电离实验技术

描述了一套改进了的利用于激光多步共振电离谱学研究的实验装置和技术.在此技术中,利用加热蒸发的方式产生高温难熔元素的原子流;对激光功率和中性原子流进行实时监测,对测量结果作归一化处理;采用V-F变换器对堆积了的光信号和离子信号作瞬时变换,企图得到堆积的事件个数; CAMAC多道定标获取系统与其联合操作实现原子流强度、共振电离生成的离子数和激光功率等参数的同步获取.通过离线数据分析,能够得到更精确的实验数据.     

等离子体与石墨及其涂层相互作用实验研究

等离子体与表面相互作用(PSI)是聚变研究领域中重要课题之一。本项目应用LAS-2000质谱分析设备、射频离子源设备及HL-1M装置,对等离子体与石墨及其涂层的相互作用进行了系统研究。研究表明:(1)D~ 束辐照HL-1M装置第一壁用SMF-800石墨在770中K处有化学腐蚀高峰,而石墨原位硼化、硅化涂层可以有效地抑制石墨的化学溅射(降低80％～90％);H~ 辐射SiC的溅射产额为0.5原子/H~ ,为石墨的1/3;原位硼化涂层热解释过程中未见硼氢化合物的释放,其释放成分主要是碳氢化合物,通过它可减少a-C:H成分,提高涂层性能;(2)原位涂层几乎完全抑制了HL-1M装置放电中重金属杂质,而碳、氧杂质则分别降低70％、90％以     

热离子转换器中添加氧的研究

添加并控制电极间隙内氧的含量对提高热离子转换器（TIC）的能量转换效率和功率密度具有关键作用,因此本文针对TIC中氧的不同添加途径及其对转换性能的影响进行系统研究。吸附氧后的电极在吸附Cs后的功函数较单吸附Cs更低,从而提高了TIC的输出功率密度和转换效率。TIC中氧的添加途径主要有两种：一是利用蒸气源添加,即直接将氧或氧化物以气态的形式添加至电极间隙内;二是利用接收极添加,即通过释放接收极上氧化物的氧或活性过渡金属材料内溶解的氧为电极间隙内供氧。对比分析认为,采用活性金属作为接收极能得到性能更优异、可靠性更高、寿命更长的TIC,因此选择或设计一种新型的接收极材料可作为含氧TIC的一个发展方向。     

生物样品与有机物质在化学分析前的灰化预处理技术(二)

2.低温干灰化:低温干灰化即低温等离子体灰化法(以下简称低温灰化)。所谓等离子体即在高频电场中氧气分子和原子被分解,其中除含中性原子外,还含有阳离子和数量相等的阴离子和电子,其整体呈中性状态,此时的气体称为等离子体(Plasma)。低温灰化是利用无电极的高频电场产生的灼热放电使通至反应器中的氧气被激活产生激发态氧原子,它具有很强的氧化能力。以此氧化分解有机物质。氧等离子体灰化有机物质的机理:氧等离子体中的激活态氧原子作用于样品的表层     

单节热离子二极管堆内试验

本试验的目的是验证装置设计的合理性和研究二极管电输出特性。在270小时试验中,电极最大比功率和效率分别为5.7瓦/厘米~2和8.1%。本文介绍装置结构、制备工艺、采用的电特性测量方法、试验结果及讨论。     

原子电池

原子电池是以原子核辐射能转变为电能的原理而制成的电池。原子电池一般可按辐射能转变成电能的方式分成两大类。 Ⅱ.将辐射能直接转变为电能 这类原子电池又可按不同转变方法分成三种: 1.直接充电法 利用由于核衰变所产生的带电辐射(即高能电子),从一含有放射性物质的电极出发,而被和它绝缘的另一电极所吸收。这样,前者因失去电子而带正电(阳极),后者     

利用14MeV快中子对蓝色氧化钨中氧钨原子比的测定

双钨丝生产工艺中要求分析蓝色氧化钨的氧钨原子比。本方法用14MeV快中子活化氧测定氧/钨原子比。加速器产生的14MeV快中子轰击氧,发生核反应形成的~(16)N放出γ射线能量为6.13和7.13MeV,用3"×3"Nal(Tl)探测器以及相连的多道分析器或单道分析器测量其强度。以纯三氧化钨作标准,并在相同条件下进行活化测量。通过所测量的γ射线的相对     

The calculation of oxygen potentials

We consider the calculation of the oxygen potential of the mixed oxide (U,Pu)O₂ and show how a new model, taking account of the short-range ordering between the defects, can give reasonable agreement with the experimental data.     

Erosion of thin hydrogenated carbon films in oxygen,oxygen/hydrogen and water plasmas

The erosion of amorphous hydrogenated carbon films in oxygen, oxygen/hydrogen and water electron cyclotron resonance plasmas was investigated by in situ ellipsometry. The erosion was measured as a function of the energy of the impinging ions and the substrate temperature. Erosion is most effective in pure oxygen plasmas. The erosion rate rises with increasing ion energy and substrate temperature, in the latter case however only at low ion energies. The reaction layer at the surface of the eroded film is further analyzed by X-ray photoelectron spectroscopy (XPS). The C 1s peak of the XPS spectra shows, that oxygen is implanted in the films and forms double and single bonds to the carbon atoms. This modification, however, is limited to a few atomic layers.     

Interaction between uranium sulphides and oxygen

Study of the oxidation of uranium monosulphide shows that certain phenomena occur at three temperatures: 350–380, 480, and 720°C. In the temperature range 350–380°C, an intensive incorporation of oxygen begins, accompanied by loss of SO₂ and S. Simultaneously UO_2+0.45 and UO₂SO₄ are formed. As the temperature increases, the amount of sulphur remains constant and only oxygen is incorporated. At 540°C the X-ray pattern of the product corresponded to that of U₃O₈, but the composition was UO_3.50 + UO₂SO₄. At higher temperatures the remaining sulphur was burnt and U₃O₈ was obtained. The reaction between uranium disulphide and oxygen proceeds in a similar way, except that at 345°C preferential oxidation of sulphur occurs. Investigation of the isothermal oxidation of US and US₂ at temperatures 250–305° C and under an oxygen pressure of 400 Torr showed that the rate law was initially exponential (lateral growth of oxide film), and that it later became parabolic (diffusion of oxygen through the oxide layer).     

Fundamental data: Solubility of nickel and oxygen and diffusivity of iron and oxygen in molten LBE

Experiments for determining nickel solubility limit and iron diffusion coefficient are presented and their results are discussed. Nickel solubility limit is determined by two methods: ex situ by solid sampling followed by ICP-AES analysis and in situ by Laser Induced Breakdown Spectroscopy and their results are compared. The iron diffusion coefficient is obtained using the technique of rotating specimen dissolution.Also a method to determine the oxygen solubility and diffusivity in LBE is developed and results at 460, 500 and 540 °C are presented. It is based on the following electrochemical cell: O₂ (reference mixture), Pt //YSZ//O₂ (LBE) which can work as an oxygen sensor or as a coulometric pump.     

Impurities and oxygen control in lead alloys

The control of the impurities is of major interest for ensuring adequate and safe operation of lead alloys facilities from the viewpoint of the corrosion phenomenon. Specific methods have to be implemented for effective control of the liquid lead-bismuth eutectic quality to the required specifications, as for instance: dissolved oxygen monitoring, dip sampling system, analytical techniques for impurities measurement. Even though the oxygen control in the static facility BIP proved difficult, a better knowledge of kinetics behaviour of the oxygen is acquired. Oxygen sensors gave results in agreement with the theory during the tests achieved on the BIP and on the COLIMESTA facilities. The dip sampler was validated on static device: it allows an effective sampling of the liquid metal melt and an easy separation of the melt from the sampling device when cold. The set of analytical techniques for the measurements of metallic impurities is efficient as well, except for the nickel element, for which the method of analysis with atomic absorption spectroscopy coupled with spiking method should allow the lower detection limit to be decreased below the 5 μg/g as for the iron impurity.