charge_number

plasmapy.particles.atomic.charge_number(particle: plasmapy.particles.particle_class.Particle) numbers.Integral

Return the charge number of a particle.

Parameters

particle (str) – String representing a particle.

Returns

Z – The charge as a multiple of the elementary charge.

Return type

int

Raises
  • InvalidParticleError – If the argument does not correspond to a valid particle or contradictory information is provided.

  • ChargeError – If charge information for the particle is not available.

  • AtomicWarning – If the input represents an ion with a charge number that is less than or equal to -3, which is unlikely to occur in nature.

Notes

This function supports two formats for charge number information.

The first format is a string that has information for the element or isotope at the beginning, a space in between, and the charge number information in the form of an integer followed by a plus or minus sign, or a plus or minus sign followed by an integer.

The second format is a string containing element information at the beginning, following by one or more plus or minus signs.

Examples

>>> charge_number('Fe-56 2+')
2
>>> charge_number('He -2')
-2
>>> charge_number('H+')
1
>>> charge_number('N-14++')
2