# half_life¶

plasmapy.particles.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 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

Quantity

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 MissingParticleDataError. When no isotope information is available, then this function raises a MissingParticleDataError.

Examples

>>> half_life('T')
<Quantity 3.888e+08 s>
>>> half_life('n')
<Quantity 881.5 s>
>>> half_life('H-1')
<Quantity inf s>