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.

    IsotopeSource of Previous Data

    *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.


    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


    NEWXSD can be downloaded either as a zip file or as a compressed tarball

    • newxsd.tgz (sha512 888d6f612f96c5ba491b8968ccf37a32aa7d98dd7f7de874386c44ff59b6da92c22fac06ce8edb9e66d48570cba221d7e31422b6e4cfe0a99b3d146c59e80393)
    • (sha512 92c5da72bfc2e21895df6acdb6b78ef40a64ce2bc8595997bd7202f6d5ec732564922127fb8d8fe225cc4917be210793e43fbbad481f130f8a1f2fb42e39f794)

    If further information is required contact a member of the Data Team by e-mail at