openmc.data.decay_constant

openmc.data.decay_constant(isotope: str, chain_file: Literal[False] | None | PathLike | Chain = False) → float[source]

Return decay constant of isotope in [s^-1]

Decay constants are based on half-life values from the half_life() function. When the isotope is stable, a decay constant of zero is returned.

Added in version 0.13.1.

Changed in version 0.15.4: Added the chain_file argument.

Parameters:

isotope (str) – Name of isotope, e.g., ‘Pu239’
chain_file (False, None, PathLike, or openmc.deplete.Chain, optional) – Source of half-life values. If False, only ENDF/B-VIII.0 data is used. If None, the chain specified by openmc.config['chain_file'] is used when available. If a path or openmc.deplete.Chain is given, that chain is used. For None or an explicit chain, nuclides absent from the chain fall back to ENDF/B-VIII.0 data.

Returns:

Decay constant of isotope in [s^-1]

Return type:

float