Establishment of neutron dose calibration fields based on a ²⁵²Cf source by Monte-Carlo method

2021 ◽  
Vol 6 (2) ◽  
pp. 15-20
Author(s):  
Van Nguyen Hoang ◽  
Huu Thang Ho ◽  
Ngoc Toan Tran ◽  
Xuan Hai Nguyen
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Neutron Dose ◽  
Neutron Spectra ◽  
Irradiation System ◽  
Neutron Moderator ◽  
Calculation Results

This paper presents calculation results based on Monte-Carlo method to select an appropriate neutron moderator and design four configurations for a 252Cf irradiation system. These configurations provide six neutron spectra with the various average energies (1.04 MeV, 1.38 MeV, 1.69 MeV, 2.05 MeV, 2.46 MeV and 2.93 MeV) suitable for the calibration of neutron survey meters and personal dosimeters.

On the slowing down of 14 MeV neutrons

2020 ◽  
Vol 22 (2-3) ◽  
pp. 249-256
Author(s):  
D. Flammini ◽  
R. Bedogni ◽  
F. Moro ◽  
A. Pietropaolo
Keyword(s):  
Monte Carlo ◽  
Neutron Generator ◽  
Experimental Measurements ◽  
Experimental Procedure ◽  
Neutron Spectra ◽  
Slowing Down ◽  
Thermal Peak ◽  
Monte Carlo Calculations ◽  
Neutron Moderator ◽  
Set Up

An experimental procedure is assessed to obtain moderated neutron fields starting from almost monochromatic 14 MeV neutrons generated by means of an accelerator-driven D-T source. The use of a metallic pre-moderator and a standard hydrogen-containing moderator is effective in producing neutron spectra featuring a thermal peak and an epithermal slowing down tail extending up to 14 MeV. The performance of proposed moderation system was investigated by means of MCNP Monte Carlo calculations, benchmarked against experimental measurements using an explorative set up, assembled at the Frascati Neutron Generator. The benchmarked calculations allow at making predictions about the brilliance of a 14 MeV neutron moderator in view of possible applications in neutron science.

Using Monte Carlo Method and Adaptive Sampling to Estimate the Limit Surface

2021 ◽  
Author(s):  
Lixuan Zhang ◽  
Zhijian Zhang ◽  
He Wang ◽  
Yuhang Zhang ◽  
Dabin Sun
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Adaptive Sampling ◽  
Nuclear Power ◽  
Power Plants ◽  
Safety Margin ◽  
Model Parameters ◽  
Limit Surface ◽  
Calculation Results ◽  
Low Efficiency

Abstract In the research on the risk-informed safety margin characterization (RISMC) methodology, how to estimate the limit surface is important. Using the reduced Order Models (ROMs) to simulate calculations can obtain results more quickly and estimate the limit surface. For example, we use ROMs instead of Complex simulation model, Parameters that are critical to the safety of nuclear power plants, such as the peak temperature of the fuel cladding, can be calculated relatively quickly. Using Monte Carlo method to analyze nuclear accident is low efficiency and poor accuracy. To get relatively accurate results, a large amount of simulation experiments is needed. Based on adaptive sampling, the samples which will cause failure will be acquired more easily. Adaptive sampling uses the calculation results of the previous step to guide the next step of sampling, which can quickly obtain the samples points near the failure edge. This article will introduce the definition of the limit surface and use the Monte Carlo method and the adaptive sampling to estimate the limit surface through ROMs. And compare the calculation results of the two methods and the number of samples required. The two methods are verified by a case.

Analysis of the relationship between neutron dose and Cerenkov photons under neutron irradiation through Monte Carlo method

2016 ◽  
Vol 93 ◽  
pp. 35-40 ◽  
Author(s):  
Diyun Shu ◽  
Xiaobin Tang ◽  
Fada Guan ◽  
Changran Geng ◽  
Haiyan Yu ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Neutron Irradiation ◽  
Neutron Dose ◽  
The Relationship

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

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
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.

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

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.

Sign in / Sign up

Export Citation Format

Share Document