共查询到19条相似文献,搜索用时 662 毫秒
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《核化学与放射化学》2007,29(4):225-225
本发明涉及一种利用中子及了射线技术进行物料动态在线水分测量的装置和方法。装置上由于增加了了射线电离室探测器,使原来对皮带输送机中部物料一点测量变为对物料整个横断面测量,更有利于矫正物料形状对水分测量的影响,同时将慢中子探测器与快中子发生器放在同一平面上,变已有的透射式为散射式,提高探测区域慢中子通量,提高水分测量的准确度及灵敏度;在测量方法上合理的探测器布局及数学模型可使得水分测量不受物料密度、厚度、形状变化的影响,提高测量精确度。检测水分误差小于0.5%。利用检测到的水分值去控制生产设备,实现生产过程中物料水分的自动调节,可以保证产品质量,提高生产效率,给用户带来显著的经济效益。 相似文献
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本工作对以压缩作为处理放射性固体废物的方法进行了实验研究,分析了压缩过程中影响各类物料压缩减容倍数的因素。实验结果表明,高压压缩处理物料的范围广,对物料的分类要求不严格;在压力为600kN压缩下,依据物料的性质和装填密度不同,各种物料的减容倍数在2.3~11之间,压缩后各类物料压缩的平均物料密度在1 200~3 900kg/m3之间;对于某些软物料、有孔硬物料和弹性物料,压缩后物料的平均密度大于物料的物理密度;不同装填密度的废物,高压压缩后物料的平均密度基本相同,物料的压缩减容倍数与物料本身的性质、装填密度等有关。弹性物料压缩后反弹明显,甚至破坏压饼,其他物料反弹在20%以内。 相似文献
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《中国原子能科学研究院年报(英文版)》2018,(0)
正层析γ扫描(TGS)技术是当前核材料非破坏性分析(NDA)技术中重要的分析技术之一。它专用于准确测量中低密度非均匀分布介质中的放射性核素及其含量,是核设施中可回收物料及核废物测量分析的主要方法之一。 相似文献
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有源符合中子法测量材料中的高浓铀 总被引:5,自引:3,他引:2
研究了有源符合中子法测量不同试样中高浓铀的方法和技术。将1个高计数率符合中子计数器改装为有源井型符合中子计数器装置,测量由Am-Li中子源发射的中子诱发物料中的235U裂变时产生的裂变中子,以确定物料中235U含量。用U3O8粉末工作样品进行了探测效率刻度,在500gU3O8粉末范围内,以快中子方式测量的刻度曲线近似线性。实测了含铀粉末不同形态、氧化程度各异的多种试样,给出了试样的形态、密度、碳含量及轴向和径向分布不均匀性等因素引起的各种误差,并进行了实验校正。实验结果表明:测量误差在4%—11%之间,大部分数据与常规重量法在9%内符合。试样中碳含量对测量结果影响较大。 相似文献
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核子秤利用低能γ射线透过物料时被物料吸收衰减的规律来测量物料重量,是一种非接触式的连续计量装置,具有结构简单、运行可靠等优点.LabVIEW作为一种图形化的编程语言,是一种标准的数据采集和仪器控制软件,论文针对核子秤测量原理和特点,利用LabVIEW编程环境设计了一种核子秤计量系统监控软件,软件构架主要由监控软件、数据库和Web服务三大基本模块组成,实现了对核子秤计量数据采集、状态监控、数据管理及远程监控的功能. 相似文献
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一个动态不连续物料的在线中子测水系统 总被引:4,自引:1,他引:3
介绍了一个用γ密度计作密度补偿的用于测量在传送带上处于运动状态的一块一块不连续物料中水分的在线中子测水系统。来自中子、γ射线及电子秤探测器的实测数据均通过一个计数卡输入到PC机中,由微机作数据处理、记录和显示,并用表格和图形给出各时刻的瞬时湿度及某段时间间隔内通过传送带的物料的总重量、干料量和水分量。 相似文献
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研究了采用低能γ射线穿透方法检测蓄电池液密度的可行性.设计和制作了样机.密度的测量范围为1.000~1.300g/cm3,在线测量的绝对值误差好于±0.005g/cm3. 相似文献
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A. D. Galanin 《Atomic Energy》1961,9(2):591-600
This article presents a consistent theory of heterogeneous reactors with cylindrical lumps of a finite, but small, radius. The density of thermal neutrons inside a lump and in the moderator is described by taking into account the azimuthal dependence. The diffusion theory is applied to the entire reactor volume. Simple expressions for the diffusion length in the parallel and perpendicular directions with an accuracy to the first power of the lump surface to cell surface ratio are obtained. It is shown that the average scattering length for the perpendicular direction depends on the lump shape. A simple method for determining the diffusion tensor for the case of weak absorption and large spacing between the lumps is considered in section 4.The author is indebted to B. I. Il'ichev, N. I. Laletin, and Ya. V. Shevelev for the discussion of this paper. 相似文献
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周志成 《核电子学与探测技术》1990,10(2):76-81
本文描述一个线性变化电压非线性系数的测量方法。利用采样脉冲对线性变化电压进行采样,测量采样后脉冲的幅度分布密度,经过最小二乘法拟合,便可求出非线性系数。文中还提出了决定采样脉冲频率的方法。 相似文献
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V.A. Kuzminikh A.D. Pogrebnyak S.A. Vorobiev 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1984,4(1):23-33
Using the multiple-step method for calculation of transmission of charged particles through matter, the density distributions of thermalized positrons in a number of materials (6 ? Z ? 42) have been obtained under irradiation by monoenergetic positrons and positrons from 22Na and 58Ga sources. Fluctuations of energy losses, absorber boundaries, annihilation of positrons have been taken into account. Elastic scattering of the positrons was calculated according to Mott's theory. One can use the obtained data when constructing similar theoretical distributions and when determining the positron annihilation probabilities for a wide range of materials involving compounds. 相似文献
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V. V. Seliverstov 《Atomic Energy》2002,93(3):718-726
The basic elements of a method of numerical simulation of processes based on prompt and delayed neutrons in multiplying systems are presented. The method is based on predicting the contribution of the instantaneous state of the system to its state at subsequent definite times and summing the predicted contribution as a systematic transition is made to a new moment in time. The key element of the method is determining the initiation functions – the probabilities that a neutron emitted by a source in a prescribed volume of the system initiates a prompt fission neutron in a definite volume of the system sometime after emission. A procedure is proposed for determining the initiation functions; this procedure is based on the first-collision probability method and uses the standard stationary computer codes. The material presented in this paper comprises the basic results of the first stage in the development of the numerical model for full-scale simulation of the dynamics of the subcritical blanket of an experimental accelerator-driven subcritical system under construction at the Institute of Theoretical and Experimental Physics. It is noted that the model being developed can be used to analyze many important processes in other types of multiplying systems. 相似文献
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The accuracy of static neutronic parameters in the nuclear reactors depends upon the determination of group constants of the diffusion equation in the desired geometry. Although several methods have been proposed for calculating these parameters, there is still the need for more reliable methods. In this paper a powerful and innovative method based on Spatial Homogenization and Temperature Variation (SHTV) of physical properties of a WWER-1000 nuclear reactor core for calculating the relative power distribution of Fuel Assemblies (FA) and the hot fuel rod, is presented. The method is based on replacing the heterogeneous lattices of materials with different properties by an equivalent homogeneous mixture of these material for determining the few group constants, while the effect of temperature variation in the fuel and coolant density along the axial core direction is considered. All calculations are performed using WIMS and CITATION codes. The obtained results are compared with the results of Final Safety Analysis Report (FSAR) prepared by the designer, and good agreement between the two results is shown. 相似文献
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Álvaro Bernal Jose E. Roman Damián Ginestar Gumersindo Verdú 《Journal of Nuclear Science and Technology》2016,53(8):1212-1223
Heterogeneous nuclear reactors require numerical methods to solve the neutron diffusion equation (NDE) to obtain the neutron flux distribution inside them, by discretizing the heterogeneous geometry in a set of homogeneous regions. This discretization requires additional equations at the inner faces of two adjacent cells: neutron flux and current continuity, which imply an excess of equations. The finite volume method (FVM) is suitable to be applied to NDE, because it can be easily applied to any mesh and it is typically used in the transport equations due to the conservation of the transported quantity within the volume. However, the gradient and face-averaged values in the FVM are typically calculated as a function of the cell-averaged values of adjacent cells. So, if the materials of the adjacent cells are different, the neutron current condition could not be accomplished. Therefore, a polynomial expansion of the neutron flux is developed in each cell for assuring the accomplishment of the flux and current continuity and calculating both analytically. In this polynomial expansion, the polynomial terms for each cell were assigned previously and the constant coefficients are determined by solving the eigenvalue problem with SLEPc. A sensitivity analysis for determining the best set of polynomial terms is performed. 相似文献
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N. Kawachi T. Katabuchi M. Yamaguchi Y. Tagishi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2002,190(1-4):195-198
We propose a method for real-time measurement of the density of implanted deuterons in solid materials during deuterium implantation. In this method, the density of implanted deuterons is measured by detecting the emitted protons from the deuteron fusion reaction between the incident deuterons and the implanted deuterons. A negative deuterium beam with an energy of 90 keV is used both for the implanted atoms and a probe beam to measure the implanted deuterons. The density of the implanted deuterium atoms was observed to be drastically different between the single crystal and poly-crystal in Ta. 相似文献
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