The NEWXSD Discrete Cross Section Library

Released: 1986-07-25

The newxsd library is a discrete version of the newxs library. The newxs library contains LANL based evaluations based off of previous libraries such as ENDL85, ENDF/B-V, and Group T-2. The isotopes adjusted and source of data can be seen in the table below.

Isotope	Source of Previous Data
5-B-11	LANL*
63-Eu-151	ENDF/B-V
63-Eu-153	ENDF/B-V
67-Ho-165	ENDL85
79-Au-197	ENDF/B-V

*See "n+11B Gamma-Ray Production Evaluation"

Discrete neutron cross-section tables are equivalent to continuous-energy tables except that all cross sections have been averaged over 262 energy bins, creating a histogram structure for the cross sections. These are not multigroup data tables, as the secondary energy and angular distribution data remains completely continuous.

Discrete libraries were a useful concept when computer memory and speed were significant issues. We maintain them primarily for backwards compatibility, and recommend against their use unless a specific reason for doing so can be provided.

Documentation

1. "Improved Cross Sections from Group T-2 for 11B, 151Eu, 153Eu, and 165Ho," Little, R.C., Seamon, R.E., (1986) LA-UR-21-27725
2. "Processing the Latest 197Au Evaluation from Group T-2," Little, R.C., (1986), LA-UR-21-27680
3. "n+11B Gamma-Ray Production Evaluation," Little, R.C., Seamon, R.E., (1984) LA-UR-21-27080