Temperature dependence of total cold neutron cross section in light water and benzene

Stepanov, S. B.; Zhitarev, V. E.; Zelenyuk, F.M.; Krasil'nikov, V. Ya.

doi:10.1007/bf01666642

Cited by 9 publications

(2 citation statements)

References 3 publications

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“…To test the behavior of our model with temperature, we compared our calculations with the cold neutron measurements performed by Stepanov and Zhitarev [23,24] at the IRT reactor of the Moscow Engineering Physics Institute. Stepanov published a series of measurements of the total cross section of liquid water at high temperatures for a fixed set of incident energies.…”

Section: Total Cross Sectionmentioning

confidence: 99%

New Thermal Neutron Scattering Kernels for Light and Heavy Water Based on Molecular Dynamics Simulations

2014

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Calculations of moderators require scattering kernels that are accurate in both the energetics and angular distribution of outgoing neutrons. Currently, scattering cross sections available in ENDF format to be used in Monte Carlo and deterministic calculations rely on water models that do not utilize the up-to-date knowledge of its structure and dynamics.In this work we present a new model to compute the scattering kernels for light and heavy water based on molecular dynamics simulations. Using the molecular dynamics program GROMACS and a flexible TIP4P model we obtained the frequency spectra of hydrogen, deuterium and oxygen, bound in light and heavy water. With those spectra we computed the scattering laws using the LEAPR module of NJOY, which uses the incoherent approximation. Scattering laws for D and O in D2O are corrected using the Skld approximation and partial structure factors obtained by Soper.Using those kernels we computed double differential and integral cross sections over a wide range of neutron energies (10 −5 1 eV). These results represent an improvement over existing models when compared with experimental values, especially for low incident neutron energies.

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Section: Total Cross Sectionmentioning

confidence: 99%

New Thermal Neutron Scattering Kernels for Light and Heavy Water Based on Molecular Dynamics Simulations

2014

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“…Likewise, experimental thermal scattering data for water at elevated ܶ is very sparse. The little data available is either for cold neutrons (< 1 meV) [12,13,14] of marginal interest in reactor applications or for limited select ܶ [15,16,17]. Not surprisingly, light-water TSL performance has been thoroughly validated at RT, but comprehensive non-proprietary validation across the full range of ܶ of interest in reactor applications is lacking.…”

Section: Introductionmentioning

confidence: 99%

Validation of Thermal Scattering Laws for Light Water at Elevated Temperatures With Diffusion Experiments

2021

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Light water is the most important neutron moderator in many reactor applications. Thermal neutron scattering kernels for H bound in H2O are represented by ENDF-format thermal scattering laws (TSLs) evaluated at discrete temperatures T. Nuclear data evaluations are conventionally validated utilizing a combination of critical benchmarks and experimental cross section data. Existing public critical benchmarks may be inadequate for testing water TSLs over the full range of T of interest in reactor applications, and experimental thermal scattering cross section data for water is sparse at elevated T. In this work, MC21 is used to simulate the decay of the equilibrium thermal neutron flux in light-water spheres of several radii. The fundamental-mode time eigenvalue α is calculated at 22 °C and 227 °C (at saturation pressure) for each sphere using three different H-H2O TSLs. Fitting α to a polynomial function of geometric buckling allows calculation of the thermal neutron diffusion length L. Extrapolation lengths are treated as a function of the transport mean free path and geometry. Experimental L data from 25 publications at 49 temperatures (from 10 °C to 295 °C), computed by several different time-dependent and space-dependent decay methods, is used to develop an empirical fit of L vs. T. The MC21-calculated L for the TSLs tested are within ±1% of the predicted values at 22 °C and 227 °C. This validation approach, which may be repeated at arbitrary T, constitutes an integral benchmark specific to and characterizing the detailed physics of the thermal scattering kernel applied.

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Total cross section for interaction of cold neutrons with liquid and gaseous benzene

Zhitarev¹,

Stepanov²

1978

At Energy

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Temperature dependence of total cold neutron cross section in light water and benzene

Cited by 9 publications

References 3 publications

New Thermal Neutron Scattering Kernels for Light and Heavy Water Based on Molecular Dynamics Simulations

New Thermal Neutron Scattering Kernels for Light and Heavy Water Based on Molecular Dynamics Simulations

Validation of Thermal Scattering Laws for Light Water at Elevated Temperatures With Diffusion Experiments

Total cross section for interaction of cold neutrons with liquid and gaseous benzene

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