endfio - ENDF-6 I/O Library for Rust

ENDF-6 is the standard format for distribution of nuclear data files. endfio aims to be a small library to allow reading, modifying and creating the nuclear data files in that format.

Each ENDF file is considered a Tape, which can contain multiple Materials, which are a collection of Files, which finally store Sections. Only at the level of section is the actual data stored as a sequence of Records.

At the moment endfio supports reading and writing the following records:

• TEXT record
• CONT record
• HEAD record
• DIR record
• LIST Record
• TAB1 Record
• TAB2 Record
• INTG Record

Format Warnings

Ambigious 'Record' meaning in MF=1 MT=451

Header section of each Material (MF=1 MT=451) terminates with a 'Directory entry', which lists the contents in a format like e.g.:

                                1        451        164          3
                               23        501        677          3
                               23        502        124          3
                             <mf>       <mt>       <nc>     <nmod>

Where:

• <mf> - The number specifying type of a file
• <mt> - The number specifying type of a section (e.g. reaction type)
• <nc> - Number of Records in the section
• <nmod> - Number of times the data in the section was changed since originally published

Historically the ENDF files seem to interpret Records in the context of <nc> as the 'number of lines'. However, since a single ENDF record can span multiple lines (TAB1, TAB2, LIST, INTG), it can be argued that this interpretation is incorrect. In fact, some recently added sections in e.g.: ENDF/B VIII.0(e.g. MF=33 of H-1), seem to interpret Record as 'ENDF Record'.

To resolve this problem endfio will read the files with the stricter interpretation of Record in <nc> without error, but will use the historical 'number of lines' interpretation on output.

HSUB Overture

ENDF-6 format requires that first three lines of the text comment section of the Material header (MF=1 MT=451) follow special format:

---<Library Name>      MATERIAL <MAT>      REVISION <N>
----<Descriptive sub-library name>
-----ENDF-6

There is a bit of ambiguity regarding the format of different entries. endfio makes the following assumptions:

• <Library Name> contains name from NLIB number and arabic version e.g. JEFF 3 or ENDF/B 8.
• REVISION keyword is present if release number if not 0. E.g. JEFF 3.3. will contain REVISION 3.
• Descriptive Sub-Library names are altered wrt. to manual to be easier to generate automatically: E.g. endfio will use Incident-Photon Data instead of Photo-Nuclear Data
• 3rd line does not contain FORMAT keyword (it is not mentioned in the ENDF Manual)

Note that the overture is only generated by endfio for Materials that are created from scratch. If the MaterialHeader was loaded from an existing file the overture will not be changed when re-printed!