In addition to the class, the plasmapy.particles subpackage has a functional interface.
Several functions in plasmapy.particles return string representations of particles, including , , , and .
>>> from plasmapy.particles import * >>> atomic_symbol('alpha') 'He' >>> isotope_symbol('alpha') 'He-4' >>> ionic_symbol('alpha') 'He-4 2+' >>> particle_symbol('alpha') 'He-4 2+' >>> element_name('alpha') 'helium'
The full symbol of the particle can be found using .
>>> particle_symbol('electron') 'e-'
The and functions are analogous to the corresponding attributes in the class.
>>> atomic_number('iron') 26 >>> mass_number('T+') 3
Charge information may be found using and .
>>> charge_number('H-') -1 >>> electric_charge('muon antineutrino') <Quantity 0. C>
These functions will raise a for elements and isotopes that lack explicit charge information.
>>> electric_charge('H') Traceback (most recent call last): ... plasmapy.particles.exceptions.ChargeError: Charge information is required for electric_charge.
The standard atomic weight for the terrestrial environment may be accessed using .
>>> standard_atomic_weight('Pb').to('u') <Quantity 207.2 u>
The mass of a particle may be accessed through the function.
>>> particle_mass('deuteron') <Quantity 3.34358372e-27 kg>
The relative isotopic abundance of each isotope in the terrestrial environment may be found using .
>>> isotopic_abundance('H-1') 0.999885 >>> isotopic_abundance('D') 0.000115
A list of all discovered isotopes in order of increasing mass number can be found with .
>>> known_isotopes('H') ['H-1', 'D', 'T', 'H-4', 'H-5', 'H-6', 'H-7']
The isotopes of an element with a non-zero isotopic abundance may be found with .
>>> common_isotopes('Fe') ['Fe-56', 'Fe-54', 'Fe-57', 'Fe-58']
All stable isotopes of an element may be found with .
>>> stable_isotopes('Pb') ['Pb-204', 'Pb-206', 'Pb-207', 'Pb-208']
The function returns True for stable particles and False for unstable particles.
>>> is_stable('e-') True >>> is_stable('T') False
The function returns the particle's half-life as a in units of seconds, if known.
>>> half_life('n') <Quantity 881.5 s>
For stable particles (or particles that have not been discovered to be unstable), returns seconds.
>>> half_life('p+') <Quantity inf s>
If the particle's half-life is not known to sufficient precision, then returns a str with the estimated value while issuing a .
The function is useful in cases of two-body collisions.
>>> reduced_mass('e-', 'p+') <Quantity 9.10442514e-31 kg> >>> reduced_mass('D+', 'T+') <Quantity 2.00486597e-27 kg>