ENDF/B-VIII.0 Change Log ======================== Author: D.A. Brown, NNDC, BNL Affiliation: NNDC, Brookhaven National Laboratory ENDF/B-VIII.0 Final (2 Feb 2018) -------------------------------- * Added smin value to H2O and D2O LEAPR inputs * Update ENDF header and distribution date in all files ENDF/B-VIII.0beta7 (16 Jan 2018) -------------------------------- * Reorganize graphite evaluations. Elaborating on the changes in beta6, "cubic graphite" is a model for coherent elastic cross sections (as implemented in NJOY) with graphite structural factors calculated using the hexagonal lattice geometry data and with a scalar Debye-Waller factor for temperature and lattice vibration correction. Given this Previously, in beta6, we have 2 graphites: tsl-reactor-graphite MAT=32, 30% porosity tsl-graphite MAT=31, 0% porosity Now we have: tsl-reactor-graphite-30P MAT=32, 30% porosity tsl-reactor-graphite-10P MAT=31, 10% porosity tsl-crystalline-graphite MAT=30, 0% porosity Note: the 10% porosity graphite is "new" ENDF/B-VIII.0beta6 (15 Dec 2017) -------------------------------- * Make "Trial B" version of light water (HinH2O) the official light water of beta6. This is suspected to be the good one, so let's just jump the gun, shall we? * Replace the hexagonal version of graphite and reactor-graphite with the cubic approximation version. The cubic versions perform nearly as good as ENDF/B-VII.1 (in some cases better) and the provided LEAPR files can be processed. Note: in this release, reactor-graphite corresponds to the 30% porosity version, arguably the upper bound for porosity seen in practice. The 10% porosity version, which performs best of the three in many tests, is NOT included in this release. ENDF/B-VIII.0beta5 (29 Sep 2017) -------------------------------- * SiC, BeO, lucite (C5O2H8): The coherent elastic xsec and the alpha, beta grid for S(a,b) are updated. * UN: The incoherent bound xsec for N in UN used to calculate the incoherent elastic xsec is updated. The coherent bound xsec of U in UN used to calculate the coherent elastic xsec is also updated. The alpha, beta grid for S(a,b) is updated. * UO2: The coherent bound xsec used to calculate the coherent elastic xsec is updated. * graphite The coherent elastic component is updated. For coherent elastic scattering (MT=2), the Debye-Waller matrix approach was used based on the same phonon spectrum implemented in the calculation of the inelastic cross section (MT=4). * reactor-graphite: The coherent elastic component and alpha, beta grid for S(a,b) are updated. For coherent elastic scattering (MT=2) the Debye-Waller matrix approach was used based on the same phonon spectrum implemented in the calculation of the inelastic cross section (MT=4). * polyethylene (CH2) The alpha, beta grid for S(a,b) is updated and temperature 5 K and 293 K are removed. * Be-metal The coherent elastic xsec (MT = 2) was generated using an 'in-house' Generalized Coherent Elastic Scattering Formulation routine ENDF/B-VIII.0beta4.1 (2 Sep 2017) -------------------------------- * Added LEAPR inputs and README's for most evaluations from NCSU, Bettis, CAB and LANL: IceIh (tsl-HinIceIh, tsl-OinIceIh), Al (tsl-013_Al_027), Fe (tsl-026_Fe_056), YH2 (tsl-HinYH2, tsl-YinYH2), D2O (tsl-DinD2O, tsl-OinD2O), H2O (tsl-HinH2O), ZrH (tsl-HinZrH, tsl-ZrinZrH), ortho-D (tsl-ortho-D), ortho-H (tsl-ortho-H), para-D (tsl-para-D), para-H (tsl-para-H), liquid methane (tsl-l-CH4), solid methane (tsl-s-CH4), Be (tsl-Be-metal), BeO (tsl-BeinBeO, tsl-OinBeO), UN (tsl-UinUN, tsl-NinUN), UO2 (tsl-OinUO2, tsl-UinUO2), SiC (tsl-CinSiC, tsl-SiinSiC), graphite (tsl-graphite), reactor grade graphite (tsl-reactor-graphite), alpha and beta phase SiO2 (tsl-SiO2-alpha, tsl-SiO2-beta), polyethylene (tsl-HinCH2), lucite (tsl-HinC5O2H8) * Heavy water: The new evaluation fixes the issues with the angular differential cross section for, which were more noticeable in O(D2O), but actually affected both oxygen and deuterium evaluations. The problem was traced to an error in the calculation of the Skold correction factors from molecular dynamics calculations by Fourier transform. * Light water: To improve the temperature behavior of the H(H2O) evaluation CAB produced two trial evaluations to be tested as candidates for beta5: ** Trial evaluation A: *** Trial evaluation A simplifies the interpolation between temperatures of the frequency spectra by adopting a common grid for all temperatures, with a step of E = 0.001265 eV, which is consistent with the spacing of 0.05 in the beta grid and LAT=1. *** The interpolation of the diffusion parameter c is improved and matches better the experimental data by Lappi. *** The evaluated point at 300K was improved by interpolation of the LEAPR parameters between 293.6 K and 350 K. Extrapolated points at 650 and 800 K are also included. ** Trial evaluation B: In addition to the improvements in Trial evaluation A, the frequency spectra in for T = 323.6, 350, 373.6, 400, 423,6 K was modified to smooth the noise introduced from individual molecular dynamics simulations at each temperature. In both trial evaluations for light water the point at room temperature (T = 293.6 K) remains the same as in ENDF/B-VIII.0-beta4. The new evaluations improve the temperature behavior of the total cross section, with Trial Evaluation B being slightly better than Trial Evaluation A. The libraries were also tested using using benchmark LEU-COMP-THERM-046 with differences of 10 - 20 pcm in 293.6 - 350 K. To test the effect of the libraries in reflection - moderation, a numerical benchmark was created with two sub-assemblies of the IPEN/MB-01 reactor separated by 6 cm of water. Differences of 20 - 30 pcm were found in 293.6 - 350 K, with Trial evaluation B being behaving better. In testing it was found that these systems are very sensitive to how the ENDF/B-VII.1 evaluation is used to obtain a baseline. Based on this, we recommend that each temperature point should be obtained from an interpolated LEAPR input instead of using cross section interpolation. Overall, we recommend using Trial evaluation B, but include both to have feedback on the different changes we introduced. * tsl-HinH2O.endf, tsl-HinH2O.leapr: Changed sigma-free to make it consistent with neutron sublibrary * tsl-DinD2O.endf, tsl-DinD2O.leapr: Changed ZAID to 1002 to comply with ENDF-102, app. C * tsl-OinD2O.endf, tsl-OinD2O.leapr: Changed MAT to 51 and ZAID to 8016 to comply with ENDF-102, app. C * tsl-graphite.endf: fix author list so it doesn't spill onto next line * Fixed revision, release, nlib for DinD20, HinH20(all), OinD20, BeinBeO, HinCh2, OinBe0 ENDF/B-VIII.0beta4 (28 Feb 2017) -------------------------------- * Revised Be(metal) file (tsl-Be-metal.endf)'s coherent elastic scatt. (LEIP LAB @ NCSU) * Two new UN files (tsl-UinUN.endf, tsl-NinUN.endf) (LEIP LAB @ NCSU) * Correct spelling of benzene ENDF/B-VIII.0beta3.1 (18 Jan 2017) ---------------------------------- * New water ice (phase Ih): tsl-HinIceIh.endf, tsl-OinIceIh.endf (NPL, Bettis) * New YH2 evaluation: tsl-HinYH2.endf, tsl-YinYH2.endf (NPL, Bettis) ENDF/B-VIII.0beta3 (1 Nov 2016) -------------------------------- * Added 300 K and 623.6 K temperatures to several evaluations: tsl-HinH2O.endf, tsl-DinD2O.endf, tsl-OinD2O.endf (CAB) * New Be(metal) file (tsl-Be-metal.endf) (LEIP LAB @ NCSU) * Two new UO2 files (tsl-OinUO2.endf and tsl-UinUO2.endf) (LEIP LAB @ NCSU) * New single graphite crystal file (tslgraphite.endf) (LEIP LAB @ NCSU) * New "reactor processed" graphite file (tsl-reactor-graphite.endf)(LEIP LAB @ NCSU) ENDF/B-VIII.0beta2 (19 Aug 2016) -------------------------------- * New polyethyline (tsl-HinCH2.endf) file from A. Hawari, Y. Zhu (LEIP LAB @ NCSU) * Two new BeO files (tsl-OinBeO.endf and tsl-BeinBeO.endf) Y. Zhu, A. Hawari (LEIP LAB @ NCSU) ENDF/B-VIII.0beta1 (25 Apr 2016) -------------------------------- * No changes since beta0 ENDF/B-VIII.0beta0 (8 Apr 2016) ------------------------------- * MAT number fixes in tsl-013_Al_027.endf, tsl-OinBeO.endf, tsl-SiO2.endf and tsl-UinUO2.endf * Add alpha and beta phase SiO2 evaluations from Holmes, Al-Qasir, Hehr, and Hawari (NCSU) * Add Silicon Carbide evaluations from A. Hawari's group (NCSU) * Set EMAX in many evaluations to 5 eV (See first paragraph of Chapter 7 in ENDF-102) * Add Lucite (tsl-HinC5O2H8.endf) from A. Hawari's group (NCSU). The library was generated using classical molecular dynamics methods using a predictive approach. The initial atomistic models were parametrized using the fundamental properties (density and glass transition temperature) of C5O2H8. * Add TSL for hydrogen bound in light water calculated with the CAB Model. * Add the TSL for deuterium and oxygen bound in heavy water calculated with the CAB Model.