Exact Doppler Broadening of Tabulated Cross Sections

1976 ◽  
Vol 60 (3) ◽  
pp. 199-229 ◽  
Author(s):  
Dermott E. Cullen ◽  
Charles R. Weisbin
Keyword(s):  
Cross Sections ◽  
Doppler Broadening

Neutron Up-Scattering Effect in Refined Energy Group Structure

2016 ◽  
Author(s):  
Qingming He ◽  
Hongchun Wu ◽  
Yunzhao Li ◽  
Liangzhi Cao ◽  
Tiejun Zu
Keyword(s):  
Cross Sections ◽  
Group Structure ◽  
Scattering Matrix ◽  
The Self ◽  
Shielding Effect ◽  
Doppler Broadening ◽  
Fuel Temperature ◽  
Energy Group ◽  
Scattering Effect ◽  
Mc Method

Aiming at generating a 361-group library, this paper investigated neutron up-scattering effect in the 361-group Santamarina-Hfaiedh Energy Mesh (SHEM). Firstly, the Doppler Broadening Rejection Correction (DBRC) method is implemented to consider the neutron up-scattering effect in Monte Carlo (MC) method. Then the MC method is employed to prepare resonance integral table and scattering matrix for afterward calculation. Numerical results show that the neutron up-scattering affects kinf by ∼200 pcm at most for UO2 pin cell problems in the 361-group SHEM, while the fuel temperature coefficient (FTC) is also influenced by 12∼13%. It has also been found that both of the above two influences acts through scattering matrix rather than self-shielded absorption cross sections. In addition, the self-shielding effect of cladding is studied and it’s been found that it affects kinf by 30∼70 pcm.

Effect of Mg Contents on Trapping Efficiency in Al-Mg System Using PAS

2007 ◽  
Vol 265 ◽  
pp. 7-11
Author(s):  
N.A. Kamel
Keyword(s):  
Cross Sections ◽  
Mg Alloys ◽  
Trapping Efficiency ◽  
Thickness Reduction ◽  
Doppler Broadening ◽  
Degree Of Deformation ◽  
S Parameter ◽  
Mean Lifetime ◽  
The Mean ◽  
Al Mg Alloys

PLT and the Doppler broadening S-parameter were used to characterize the Al-Mg alloys, AA5005, AA5051, AA5052 and AA5083. The trapping efficiencies of these alloys were estimated to be 2.42 x 109, 2.29 x 109, 2.24 x 109 and 2.27 x 109 s-1 cm3, respectively, and the corresponding trapping cross-sections were estimated to be 2.66 x 10-16, 2.14 x 10-16, 2.10 x 10-16 and 3.51 x 10-16 cm2. It was found to be very clear that the mean lifetime and S-parameter exhibited the same behaviour as a function of the degree of deformation, and that they saturated at the same degree of thickness reduction.

scholarly journals Study of Doppler broadening Compton scattering and cross section determination for the elements Fe, Zn, Ag, Au and Hg

2019 ◽  
Vol 14 (29) ◽  
pp. 145-157
Author(s):  
Wrood K. Abood
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Photon Energy ◽  
Cross Sections ◽  
Scattered Photon ◽  
Doppler Broadening ◽  
Mass Energy ◽  
Resolution Function ◽  
Electron Momentum ◽  
Momentum Resolution

To assess the contribution of Doppler broadening and examine theCompton profile, the Compton energy absorption cross sections aremeasured and calculated using formulas based on a relativisticimpulse approximation. The Compton energy-absorption crosssections are evaluated for different elements (Fe, Zn, Ag, Au and Hg)and for a photon energy range (1 - 100 keV). With using these crosssections,the Compton component of the mass–energy absorptioncoefficient was derived, where the electron momentum prior to thescattering event caused a Doppler broadening of the Compton line.Also, the momentum resolution function was evaluated in terms ofincident and scattered photon energy and scattering angle. The resultsof cross sections for the coherent and incoherent processes arecompared with theoretical values and reported values of otherresearchers. The present results are in agreement with the theoreticalvalues.

scholarly journals On-the-fly Doppler broadening of unresolved resonance region cross sections

2017 ◽  
Vol 101 ◽  
pp. 444-460 ◽  
Author(s):  
Jonathan A. Walsh ◽  
Benoit Forget ◽  
Kord S. Smith ◽  
Forrest B. Brown
Keyword(s):  
Cross Sections ◽  
Resonance Region ◽  
Doppler Broadening

scholarly journals GPU ACCELERATION OF DOPPLER BROADENING FOR NEUTRON TRANSPORT CALCULATIONS1

2021 ◽  
Vol 247 ◽  
pp. 04017
Author(s):  
Paul E. Burke ◽  
Kyle E. Remley ◽  
David P. Griesheimer
Keyword(s):  
Monte Carlo ◽  
Cross Section ◽  
Cross Sections ◽  
Radiation Transport ◽  
Neutron Transport ◽  
Processing Unit ◽  
Complex Data ◽  
Doppler Broadening ◽  
Central Processing ◽  
Monte Carlo Transport

In radiation transport calculations, the effects of material temperature on neutron/nucleus interactions must be taken into account through Doppler broadening adjustments to the microscopic cross section data. Historically, Monte Carlo transport simulations have accounted for this temperature dependence by interpolating among precalculated Doppler broadened cross sections at a variety of temperatures. More recently, there has been much interest in on-the-fly Doppler broadening methods, where reference data is broadened on-demand during particle transport to any temperature. Unfortunately, Doppler broadening operations are expensive on traditional central processing unit (CPU) architectures, making on-the-fly Doppler broadening unaffordable without approximations or complex data preprocessing. This work considers the use of graphics processing unit (GPU)s, which excel at parallel data processing, for on-the-fly Doppler broadening in continuous-energy Monte Carlo simulations. Two methods are considered for the broadening operations – a GPU implementation of the standard SIGMA1 algorithm and a novel vectorized algorithm that leverages the convolution properties of the broadening operation in an attempt to expose additional parallelism. Numerical results demonstrate that similar cross section lookup throughput is obtained for on-the-fly broadening on a GPU as cross section lookup throughput with precomputed data on a CPU, implying that offloading Doppler broadening operations to a GPU may enable on-the-fly temperature treatment of cross sections without a noticeable reduction in cross section processing performance in Monte Carlo transport codes.

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