The input.str file header is three lines long and has the following layout
# comments # nx ny nz ncolumn nabundance # column_labels
The comments line has the purpose of describing the data. It typically contains information like: creation date; author; simulation id; mapping details (e.g. by velocity or by position). It is ignored during read-in.
ncolumn field describes the total number of columns in the file body, including cell position columns.
nabundance field describes the number of columns that describe the chemical abundances.
The input.str file body consists of one row for each grid cell and one column for each variable.
The order of variables is as follows:
1. cell position boundaries: 2 columns per dimension.
2. cell mass: 1 column. This column needs to be labeled as
3. cell electron fraction (optional): 1 column. This column needs to be labeled as
4. cell temperature (optional): 1 column. This column needs to be labeled as
5. additional optional columns, these are ignored.
6. abundances: elemental and isotope abundances. These are labeled by their element name and isotope name like in
The input electron fraction Ye is the fraction at time t=0. Based on these initial values, the electron fraction is updated with radioactive decay in every time step. If the initial electron fraction is not provided it will be calculated from the abundance data assuming solar mean atomic masses.
There are two types of abundance columns: element abundances, and isotope abundances. The element abundances together need to add up to 1 in each cell. Duplicate element or isotope names are not permitted. The list of isotopes treated in SuperNu can be found in gasmod.f or inputstrmod.f. It includes the unstable alpha-chain isotopes Ni56, Fe52, and Cr48, and the products of their decay chain. The isotope abundances are assumed to be included in the element abundances. Each isotope abundance shall not be greater than the corresponding element abundance.
Example input.str files are available in the Input/ directory.