Validation and Verification of the Evaluated Electron Data Library in FRENSIE

Abstract

Verification and validation tests have been performed for the single scattering Evaluated Electron Data Library (EEDL) implemented in the Framework for Research in Nuclear ScIence and Engineering (FRENSIE). Tests compared simulation results with experimental results for electron multiple scattering and low-energy backscattering coefficients as well as simulation results from MCNP6.2. Several bivariate grid policies (unit base, correlated, and unit base correlated) and elastic scattering implementations (coupled versus decoupled) were tested. FRENSIE showed good agreement with MCNP6.2 when using the same grid policy and elastic implementation. Logarithmic-logarithmic grid policies were found to best match experimental results. For multiple scattering, an increase in accuracy was seen when using coupled elastic scattering. When using correlated or unit-base-correlated grid policies, computational results matched the experimental measurements of Hanson et al. [Phys. Rev., Vol.  84, p. 634,(1951)] for the peak amplitude of the angular distribution to within 7% and for ${\theta }_{1/e}$ to within $2\mathrm{\%}$, but the unit-base grid policy showed error up to 38% and 24%, respectively. For backscattering coefficients, all results below 1 keV showed large error caused by insufficiencies in the data at that energy range. The correlated and unit-base-correlated grid policies overestimated the backscattering coefficient experimental results above 1 keV, but the unit-base grid policy was in the range of the measured experimental backscattering coefficients.

Keywords:

• Monte Carlo
• electron transport
• FRENSIE
• FACEMC, EEDL

Acknowledgments

This work was partially supported by U.S. Nuclear Regulatory Commission Fellowship grants NRC-38-10-954, NRC-HQ-12-G-38-0012, NRC-38-09-944, NRC-HQ-13-G-38-0031, NRC-HQ-8414-G-0030, and NRC-HQ-84-15-G-0040 and Domestic Nuclear Detection Office Academic Research Initiative grant 2015-DN-0077-ARI095.

We give special thanks to members of the Radiation Effects Theory Department of Sandia National Laboratories for their aid and advice in implementing the EEDL in FRENSIE. Additionally, we would like to acknowledge the MCNP Team at Los Alamos National Laboratory for use of the beta version of MCNP6.2.