Adjoint Monte-Carlo method with fictitious scattering in deep penetration and long-distance detector calculations

The failure tree and J-M model method are lack of analysis of the importance of each component model, which leads to the low reliability of the analysis results. In view of this problem, a Monte Carlo method based on the shape of the English long-distance robot is proposed. In view of the configuration of the robot, the realization process of the robot shape fluid dynamics system is analyzed. The frequency of accident is determined by Monte Carlo simulation, which is used as the reliability index of the system. In MATLAB, the reliability of the shape fluid dynamic system of robot is analyzed by Monte Carlo method. The system importance name and parameters are determined. The parameter conforms to the statistical function of random variables of each corresponding probability distribution function. According to the parameters, the function of the structure is established. The system is divided into reliable state, failure state and limit state with 0 as the dividing point, and the actual failure probability of the system is calculated. The numerical solution of log domain is simulated by the method of statistical calculation of random variables, and the actual failure probability is expressed by normal distribution function. The experimental results show that the actual failure probability of the method is lower than 5% under any working load, and the reliability of the analysis results is high.

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Application of Monte Carlo to PWR Cavity Radiation Streaming Calculation

Volume 7: Fuel Cycle, Decontamination and Decommissioning, Radiation Protection, Shielding, and Waste Management; Mitigation Strategies for Beyond Design Basis Events ◽

10.1115/icone25-67831 ◽

2017 ◽

Author(s):

Han Jingru ◽

Liu Qiaofeng ◽

Chen Haiying ◽

Zhang Chunming

Keyword(s):

Monte Carlo ◽

Monte Carlo Method ◽

Variance Reduction ◽

Complex Geometry ◽

Deep Penetration ◽

Monte Carlo Code ◽

Discrete Ordinate Method ◽

Discrete Ordinate ◽

The Monte Carlo Method ◽

Cavity Radiation

The cavity streaming is the neutron beam from the reactor core through the tunnel, which is between the external surface of the pressure vessel and the shield inner surface. Reactor cavity streaming calculation is a typical deep penetration problem with complex geometry. The accurate calculation of neutron radiation streaming is a key problem to the reactor shielding calculation, for which the Monte Carlo method and the discrete ordinate method are two popular methods. The speed of discrete ordinate method calculation is fast, but it is hard to describe the complex pile of cavity; the Monte Carlo method can accurately describe the complex geometry, it has a high calculation precision, but with a low direct simulation efficiency. Based on a pressurized water reactor nuclear power plant, this paper presents a detailed model realized by Monte Carlo code, with continuous energy points cross section libraries. The neutron flux density distribution of PWR reactor cavity streaming can directly be calculated by a three-dimensional simulation. For such an actual deep penetration problem, a variety of variance reduction techniques are studied, an effective variance reduction technique is used to obtain results with small statistic errors for a Monte Carlo simulation, which effectively solves the problem of large-scale deep penetrating convergence difficulty, the cavity radiation streaming calculation and analysis are completed. The result shows that the Monte Carlo method can be used as a powerful tool to solve the problem of cavity streaming leakage.

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Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

International Astronomical Union Colloquium ◽

10.1017/s0252921100034035 ◽

1974 ◽

Vol 22 ◽

pp. 307 ◽

Cited By ~ 3

Author(s):

Zdenek Sekanina

Keyword(s):

Monte Carlo ◽

Monte Carlo Method ◽

Interplanetary Space ◽

Porous Matrix ◽

Maximum Diameter ◽

Expansion Velocity ◽

Solid Constituent ◽

Meteoric Material ◽

Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

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Structures and crystallization of vacuum-deposited amorphous Se and Sb films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100173832 ◽

1990 ◽

Vol 48 (4) ◽

pp. 140-141

Author(s):

Makoto Shiojiri ◽

Toshiyuki Isshiki ◽

Tetsuya Fudaba ◽

Yoshihiro Hirota

Keyword(s):

Monte Carlo ◽

Electron Microscope ◽

Monte Carlo Method ◽

Computer Program ◽

Radial Distribution ◽

Film Formation ◽

Amorphous State ◽

Two Dimensional ◽

Amorphous Films ◽

Binding Condition

In hexagonal Se crystal each atom is covalently bound to two others to form an endless spiral chain, and in Sb crystal each atom to three others to form an extended puckered sheet. Such chains and sheets may be regarded as one- and two- dimensional molecules, respectively. In this paper we investigate the structures in amorphous state of these elements and the crystallization.HRTEM and ED images of vacuum-deposited amorphous Se and Sb films were taken with a JEM-200CX electron microscope (Cs=1.2 mm). The structure models of amorphous films were constructed on a computer by Monte Carlo method. Generated atoms were subsequently deposited on a space of 2 nm×2 nm as they fulfiled the binding condition, to form a film 5 nm thick (Fig. 1a-1c). An improvement on a previous computer program has been made as to realize the actual film formation. Radial distribution fuction (RDF) curves, ED intensities and HRTEM images for the constructed structure models were calculated, and compared with the observed ones.

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