Sigma Basic Retrieval Help

The Basic Retrieval search form allows to retrieve data stored in ENDF format from 4 different libraries: ENDF/B-VII.0 (USA, 2006), JEFF 3.1 (Europe, 2005), JENDL 3.3 (Japan, 2003) and ENDF/B-VI.8 (USA, 2001).

This form has been designed for simple retrievals and for users not familiar with the ENDF format. More complex retrievals can be accomodated with the Advanced Retrieval page.

Users can specify the target using the "Target", "Z" and "A" inputs. For instance, 232Th can be determined as:

  • , or
  • , or

The retrieval for 2 or more target nuclei can be achieved using "," (comas) or ";" (semicolons) to separate the nuclei names. For instance, a retrieval for 236U and 238Pu is performed using:

The following examples explain how ranges can be specified:

  • Search for Th isotopes:
    • , or


  • Search for A=240 isotobars:

  • Search for Z=90 to Z=94 isotopes:

  • Search for A=230 to A=244 isotopes:

Following the Target/Z/A inputs, one finds two panels, the left one is devoted to neutron-induced reactions, while the right one includes additional topics that are part of the libraries. Finally, the libraries can be selected with the check boxes at the bottom of the form. The following examples will illustrate a few typical retrievals:

  • Neutron capture cross sections on Pb isotopes from the ENDF/B-VII.0 and JEFF 3.1 libraries:
  • Neutron cross sections standards, note that because there are so few of them, one can leave the Target/Z/A inputs empty:

    For similar reasons, the target doesn't have to be specified when searching for covariances, nu-bars and fission yields.
  • Proton cross sections from ENDF/B-VII.0 in the Z=20-40 range:

If you have questions about Sigma, please don't hesitate to contact us.