half_life¶
-
plasmapy.particles.atomic.
half_life
(particle: plasmapy.particles.particle_class.Particle, mass_numb: Optional[numbers.Integral] = None) → astropy.units.quantity.Quantity¶ Return the half-life in seconds for unstable isotopes and particles, and numpy.inf in seconds for stable isotopes and particles.
Parameters: Returns: half_life_sec – The half-life of the isotope or particle in units of seconds.
Return type: Raises: Notes
Accurate half-life data is not known for all isotopes. Some isotopes may have upper or lower limits on the half-life, in which case this function will return a string with that information and issue a
MissingAtomicDataWarning
. When no isotope information is available, then this function raises aMissingAtomicDataError
.Examples
>>> half_life('T') <Quantity 3.888e+08 s> >>> half_life('n') <Quantity 881.5 s> >>> half_life('H-1') <Quantity inf s>