EVALUATION OF SEVERAL ENDF/B-2 CROSS-SECTION SETS USING MONTE CARLO SLOWING- DOWN AGE CALCULATIONS.

A way to generate the few-group cross sections for fast reactor calculation is presented in this paper. It is based on the three steps computational scheme. In the first step, the ultrafine method is used to solve the slowing down equation based on the ultrafine group cross section generated by NJOY. Optional 0D or 1D calculation is used to collapse energy group into broad energy groups. In the second step, the 2D RZ calculation using SN method is performed to obtain the space dependent neutron spectra to collapse broad energy groups into few groups. The anisotropic scattering is well handled by the direct SN calculation. Finally, the full core calculation is performed by using the 3D SN nodal method. The results are compared with continuous energy Monte-Carlo calculation. Both the cross section generated in the first step and the final keff in the last step are compared. The results match well between the three steps calculation and Monte-Carlo calculation.

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Monte Carlo simulation of electron passage through matter using the effective differential cross section for elastic scattering of electrons by atoms and the continuous slowing-down approximation

Physica Scripta ◽

10.1088/0031-8949/84/02/025705 ◽

2011 ◽

Vol 84 (2) ◽

pp. 025705 ◽

Cited By ~ 1

Author(s):

E G Sheikin

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Elastic Scattering ◽

Differential Cross Section ◽

Cross Section ◽

Differential Cross ◽

Slowing Down

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IMPROVEMENT OF SCALE-XSProc MULTIGROUP CROSS SECTION PROCESSING BASED ON THE CENTRM POINTWISE SLOWING DOWN CALCULATION

EPJ Web of Conferences ◽

10.1051/epjconf/202124702011 ◽

2021 ◽

Vol 247 ◽

pp. 02011

Author(s):

Seog Kim Kang ◽

Andrew M. Holcomb ◽

Friederike Bostelmann ◽

Dorothea Wiarda ◽

William Wieselquist

Keyword(s):

Monte Carlo ◽

Cross Section ◽

Cross Sections ◽

Reaction Rate ◽

Neutron Transport ◽

Energy Structure ◽

Reactor Physics ◽

Slowing Down ◽

Monte Carlo Calculations ◽

Scattering Matrices

The SCALE-XSProc multigroup (MG) cross section processing procedure based on the CENTRM pointwise slowing down calculation is the primary procedure to process problem-dependent self-shielded MG cross sections and scattering matrices for neutron transport calculations. This procedure supports various cell-based geometries including slab, 1-D cylindrical, 1-D spherical and 2-D rectangular configurations and doubly heterogeneous particulate fuels. Recently, this procedure has been significantly improved to be applied to any advanced reactor analysis covering thermal and fast reactor systems, and to be comparable to continuous energy (CE) Monte Carlo calculations. Some reactivity bias and reaction rate differences have been observed compared with CE Monte Carlo calculations, and several areas for improvement have been identified in the SCALE-XSProc MG cross section processing: (1) resonance self-shielding calculations within the unresolved resonance range, (2) 10 eV thermal cut-off energy for the free gas model, (3) on-the-fly adjustments to the thermal scattering matrix, (4) normalization of the pointwise neutron flux, and (5) fine MG energy structure. This procedure ensures very accurate MG cross section processing for high-fidelity deterministic reactor physics analysis for various advanced reactor systems.

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MONTE CARLO SIMULATION OF SOIL MOISTURE EFFECTS ON ANTI-TANK LANDMINES DETECTION BY NEUTRON BACKSCATTERING TECHNIQUE

International Journal of Modern Physics B ◽

10.1142/s0217979209049735 ◽

2009 ◽

Vol 23 (32) ◽

pp. 5907-5913

Author(s):

ALI ASGHAR MOWLAWI ◽

MAJED YAZDANI

Keyword(s):

Monte Carlo ◽

Soil Moisture ◽

Cross Section ◽

Landmine Detection ◽

Fast Neutrons ◽

Explosive Detection ◽

Direct Measure ◽

Slowing Down ◽

Explosive Materials ◽

Moisture Effects

The detection of landmines using available technologies is a time consuming, expensive, and extremely dangerous job, so that there is a need for technological breakthroughs in this field. One of the safest and most effective technologies to landmine and explosive detection is the neutron backscattering technique. The slowing-down of fast neutrons to the thermal energy is a direct measure of the concentration of hydrogen, one of the main elements present in explosive materials. The elastic scattering of fast neutrons is affected by the strong resonances in the cross-section of the three other elements of explosives: nitrogen, oxygen, and carbon. In this work, Monte Carlo estimations of the soil moisture effects on landmine detection are presented.

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Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164854 ◽

1996 ◽

Vol 54 ◽

pp. 478-479

Author(s):

Matthew T. Johnson ◽

Ian M. Anderson ◽

Jim Bentley ◽

C. Barry Carter

Keyword(s):

Monte Carlo ◽

Quantitative Analysis ◽

Monte Carlo Simulations ◽

Cross Section ◽

Spatial Resolution ◽

Low Voltage ◽

Magnesium Ferrite ◽

X Ray ◽

Interaction Volume ◽

Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

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