This notebook is an interactive way to see what data is available to MCNP. It is a modern version of the Listing of Available ACE Data Tables (LA-UR-17-20709). It parses the XSDIR on your machine and shows the data that is available to you.
If you are concerned about what this does you are free to examine the code yourself. It is available as an Open Source project on GitHub at https://github.com/NuclearData/DataListing.
In the table below are given the different kinds of data, generally they are referred to by the incident particle. Each type is a link to a notebook where the details can be explored. In the table below lists the different types of data and the associated lib_type, the one- or two-letter extension of the full ZAID.
The order of the elements in the listing tables is important; it is the same order as in the XSDIR file. When MCNP looks for data from the material card, it scans the XSDIR file---starting at the top---until it finds the first matching ZAID (or partial ZAID). Thus, the order of the XSDIR file is important and it is reflected in the order of the listing tables.
| Type | lib_type |
|---|---|
| Continuous-Energy Neutron | c or nc |
| Thermal Scattering S(⍺,ß) Neutron | t |
| Discrete-Energy Neutron | d |
| Coupled Discrete-Energy Neutron-Photon | m |
| Photoatomic | p |
| Photonuclear | u |
| Dosimetry | y |
| Electron | e |
| Charged-Particle | varied |
In may of the notebooks linked above, you'll find a table of reaction types after the listing of the data. The reaction types are identified using the ENDF MT numbers. These numbers uniquely define a specific reaction. For example, MT 102,
The MT numbers can be used in MCNP with the tally multiplier card, FM. The FM card multiplies any tallied quantity (flux, current) by the specified cross section to produce reaction rates. The MT numbers are also used to identify reactions when plotting cross sections. In addition to the ENDF MT numbers, MCNP also defines FM numbers that are similar to the MT numbers. Note: MT numbers are always positive, while FM numbers are always negative. In each of the table of reation types, both the MT and FM numbers are given.
For more information about tallying reaction rates, see the MCNP manual.