FISPACT-II to decay source (fisdef)

Command line tool to convert FISPACT-II JSON results to decay sources.

Usage: fisjson <path> [options]

Arguments:
  <path>                 Path to fispact JSON file
  [idx]                  Indices of time steps (optional)

Options:
  -v, --verbose...       Verbose logging (-v, -vv)
  -q, --quiet            Supress all logging
  -h, --help             Print help (see more with '--help')

Data options:
  -r, --rad <type>       Type of decay radiation
  -s, --sort <property>  Sort records by property ['energy', 'intensity']
      --fetch            Query IAEA directly rather than pre-fetched data

Output files:
  -o, --output <name>    Prefix for output files
  -t, --text             Text based table
  -j, --json             JSON output format
  -m, --mcnp             MCNP SDEF card
  -i, --id <num>         Starting MCNP distribution number

Note: --help shows more information and examples

Help is printed with the -h flag, and --help will show default values, examples, and any important behaviour.

Overview

This tool takes the FISPACT-II nuclides for any number of calculation steps and matches them to known decay data from the IAEA chart of nuclides.

fisdef therefore supports all IAEA decay data types:

Decay radiation type	IAEA symbol
alpha	a
beta plus	bp
beta minus	bm
gamma	g
electron	e
x-ray	x

Note that selecting 'gamma' will provide all photon data, including X-rays. This is consistent with the data retrieved via the horrible IAEA API.

Install

Download and unpack the latest binary executable release here for running in a terminal/powershell.

Linux/MacOS

Unpack the relevant executable from the latest release.

# Linux
tar -xjf fisdef-x86_64-unknown-linux-gnu.tar.xz  # Generic linux
tar -xjf fisdef-aarch64-unknown-linux-gnu.tar.xz # ARM64 Linux

# MacOS
tar -xjf fisdef-x86_64-apple-darwin.tar.xz       # Intel macOS
tar -xjf fisdef-aarch64-apple-darwin.tar.xz      # Apple Silicon macOS

And either run from there or add the executable to your $PATH.

./fisdef -h

Windows

Extract fisdef-x86_64-pc-windows-msvc.zip from the latest release.

Navigate to this folder and run from powershell.

.\fisdef.exe -h

This may be set as an alias for convenience.

Set-Alias -Name fisdef -Value C:\Path\To\Folder\fisdef.exe

Examples

Summary of available calculation steps

This is always printed for reference, and when no arguments are provided this will be the default.

# Print a summary of intervals
fisdef /path/to/results.json

Choosing specific intervals

If no intervals are defined, a source definition will be generated for every calculation step.

There are several input methods included for convenience. For example, if there were 5 calculation steps:

[idx] argument	Expanded	Note
1	[1]
0-2	[0, 1, 2]	Inclusive of upper
"1 3 4"	[1, 3, 4]	Must be in quotation
all	[0, 1, 2, 3, 4]
left blank	[0, 1, 2, 3, 4]	[default]

Any indices out of bounds are ignored.

# Choose specific steps (e.g. 5 total steps):
fisdef results.json    1
fisdef results.json   0-2
fisdef results.json "1 3 4"
fisdef results.json   all
fisdef results.json

Choosing output formats

The following output formats are supported:

Output format	Flag
Utf-8 text file	-t/--text
JSON	-j/--json
MCNP SDEF	-m/--mcnp
OpenMC	work in progress

For example:

# Equivalent: creates 'step_2.i', 'step_2.json', 'step_2.txt'
fisdef results.json 2 --mcnp --json --text
fisdef results.json 2 -m -j -t
fisdef results.json 2 -mjt

The --text and --json files contain relevant nuclides with activity and energy/intensity decay data. For example:

The --mcnp flag writes a source distribution of decay data for each nuclide, and an overall activity-based distribution to sample from. For example:

Note that for MCNP SDEF, the distribution cards need an id. These are generated sequentially from the value passed to --id. Defaults to 100.

# Start from SI/SP 20 instead of 100
fisdef results.json 2 --mcnp --id 20

Choosing output file prefix/name

Prefix for output files defaults to step.

Files are named <name>_<n>.<ext> where <n> is the index of the fispact time interval, and <ext> the appropriate extension.

For example:

# Change the prefix to myname
fisdef results.json 2 --mcnp --text --output myname

This generates myname_2.i/mynmame_2.txt instead of step_2.i/step_2.txt.

Choosing decay data type

fisdef supports all IAEA decay data types.

The default is "gamma", however this may be changed using the --rad/-r argument.

# Choose radiation type:
fisdef results.json --rad gamma        [default]
fisdef results.json --rad xray
fisdef results.json --rad alpha
fisdef results.json --rad beta-plus
fisdef results.json --rad beta-minus
fisdef results.json --rad electron

For example, --rad gamma:

Note that the IAEA API returns any photon emission for gamma, including X-rays. For X-ray data only, use --rad x-ray. For gamma-only, take it up with the IAEA.

For example, --rad beta-minus electrons:

Choosing decay data order

By default, all decay data are ordered by energy.

To order by relative intensity (descending), use the --sort/-s argument.

For example:

# Choose output data sorting:
fisdef results.json --sort energy        [default]
fisdef results.json --sort intensity

IAEA data options

It is strongly recommended to use the pre-compiled decay data (default).

If the absolute latest data are required and performance is not a concern, the data may be fetched directly from the IAEA chart of nuclides API with the -f/--fetch flag.

For example:

# Force decay data to be fetched direct from the IAEA chart of nuclides API
fisdef results.json --fetch ...

This obviously requires an internet connection.