Uncertainties of displacement cross-sections for iron and tungsten at neutron irradiation energies above 0.1 MeV

Uncertainty of atomic displacement cross-sections was estimated for iron and tungsten irradiated with neutrons of intermediate energy. The TALYS and ECIS codes were applied for recoil energy distribution calculations in the energy range 0.1 to 150 MeV; the CASCADE code implementing the intranuclear cascade evaporation model was used at the energies from 100 MeV to 3 GeV. The NRT model and the arc-dpa approach were applied for calculation of the number of stable defects produced under irradiation

Atomic displacement cross-sections for neutron irradiation of materials from Be to Bi calculated using the arc-dpa model

Displacement cross-sections for an advanced assessment of radiation damage rates were obtained for a number of materials using the arc-dpa model at neutron incident energies from 10−5 eV to 10 GeV. Evaluated data files, CEM03 and ECIS codes, and an approximate approach were applied for the calculation of recoil energy distributions in neutron induced reactions. Three sets of displacement cross-sections based on the use of low-energy data from JEFF-3.3, ENDF/B-VIII.0, and JENDL-4.0u were prepared. Files contain also cross-sections calculated using the standard NRT model. Special efforts were made to estimate the uncertainty of obtained displacement cross-sections

Evaluation of effective threshold displacement energies and other data required for the calculation of advanced atomic displacement cross-sections

Minimum displacement threshold energy, averaged displacement threshold energy, effective displacement energy, and parameters of arc-dpa equations were estimated for 70 materials from Li to U using available experimental data. Obtained data can be used for approximate calculation of the radiation damage rate for materials irradiated with neutrons in the different facilities

Evaluated data files for neutron irradiation of 182^{182}W and 186^{186}W at energies up to 200 MeV

New evaluated general purpose nuclear data files were prepared for 182,186W isotopes at primary neutron energy up to 200 MeV. A special version of the TALYS code implementing the geometry dependent hybrid model (GDH) supplied with models for the non-equilibrium cluster emission was applied for calculations of nuclide production and particle energy distributions. The parameters of the GDH model were properly estimated using measured data for individual tungsten isotopes. The evaluation of cross-sections was performed using results of model calculations, available experimental data, systematics of light charge particle production cross-sections, and obtained covariance information. The BEKED code package developed in KIT was used for numerical calculations. Data were formatted using the TEFAL code and the FOX code from BEKED

New evaluation of general purpose neutron data for stable W-isotopes up to 200 MeV

In the frame of the Power Plant Physics and Technology of EUROfusion, new evaluations of general purpose neutron cross-section data were performed for the 180,182,183,184,186W isotopes covering the neutron energy up to 200 MeV. A special version of the TALYS nuclear model code implementing the geometry dependent hybrid model supplied with models for the non-equilibrium cluster emission was applied for calculations of the nuclide production and the energy distribution of the emitted particles. The parameters of the GDH model were properly estimated using measured data for individual tungsten isotopes. The neutron cross-sections were evaluated making use of available experimental data, systematics including estimated A-dependence of components of gas production cross-sections, and covariance information produced as part of the evaluation process. The BEKED code package, developed at KIT, was applied for calculations of co-variances using a dedicated Monte Carlo method. The evaluated data were processed into standard ENDF data format using the TEFAL code and the FOX module of the BEKED system. The evaluated data files were checked for errors and inconsistencies, processed with the NJOY code into ACE data format, and benchmarked against available integral experiments with MCNP neutron transport calculations

Evaluated data file for neutron irradiation of Ta-181 at energies up to 200 MeV

New evaluated data file for 181Ta irradiated with neutrons at energies up to 200 MeV has been prepared. The data evaluation has been done using the results of calculations, measured data, systematics predictions, and covariance information. Calculations have been performed using a special version of the TALYS code implementing the geometry dependent hybrid model and models for the non-equilibrium light cluster emission. The TEFAL code and the FOX code from the BEKED package have been used for the formatting of the data

Uncertainty assessment for the number of defects calculated using the NRT damage model

The work concerns the estimation of the uncertainty of the number of defects calculated using the NRT model. The impact of spread of nuclear stopping power, electronic stopping power, and threshold displacement energy was examined. The results were obtained for aluminum, iron, zirconium, and tungsten

IOTA-2017: a code for the simulation of ion transport in materials

The report describes a new version of the IOTA code elaborated to study primary radiation defects in composite materials irradiated with ions. The code is used for the calculation of the total number of primary defects created in materials, displacement cross-sections, and spatial defect distributions. The calculations apply analytical expressions for the differential cross-section for the transfer of the kinetic energy from the moving ion to a lattice atom and tabulated stopping power data. The simulation is based on the binary collision approximation and the Monte Carlo method. Using the results of molecular dynamics calculations or the arc-dpa model, the IOTA code is applied for joint BCA-MD or BCA-arc-dpa simulations. The code can be downloaded on https://goo.gl/DXFqMn or https://bwsyncandshare.kit.edu/dl/fiVD4QCZgWtqzFacULdvJ6MN/iota_2017.zip