Particle Naming Conventions

Transport physics codes like MCNP, Fluka, Geant4 etc each identify particles, in their own unique way, MCNP for example uses single letter mneumonics like ‘n’ for neutron, Fluka uses the full name of the particle or its own particle id number like ‘NEUTRON’. The particle class aims to have a single unified naming scheme, a Camel Case like name for humans, like “MuonNeutrino”, the fundamental particles map to Berkley Particle Data Center numbering schemes, and some physics codes allow the scoring of so called ‘Heavy Ions’, which is handled using the pyne nucname module. So the particle identification methods use:

  1. name: The human readable Camel Case form of the name.

  2. id: The PDC id number.

Thus by using either the particle name or the PDC number, you can be guarenteed to map to the same particle. There are also helper functions like, is_valid to determine if your partice id is a valid one.

Valid particle names can be output using the code specific output functions, if unknown so an invalid particle name is generated:

  1. mcnp: The MCNP4/5 equivalent of the particle name, if unknown returns ‘?’

  2. mcnp6: The MCNP6 equivalent of the particle name, if unknown returns ‘?’

  3. fluka: The Fluka equiavlent of the particle name, if unknown returns


  1. geant4: The Geant4 equivalent of the particle name, if unknown returns


Examples of Use

In [1]: from pyne import particle

In [2]:'Proton')
Out[2]: Proton

In [3]:'Hydrogen')
Out[3]: Proton

In [4]:'Protium')
Out[4]: Proton

In [5]:'Neutron')
Out[5]: Neutron

In [6]: particle.is_valid('AM242M')
Out[6]: True

In [7]: particle.is_valid['Clearly not a particle name']
Out[7]: False

In [8]: particle.is_heavy_ion['AM242M]
Out[8]: True

In [9]: particle.is_heavy_ion('Hydrogen')
Out[9]: False

In [10]: x ='Hydrogen')
In [11]: print x.mcnp()
Out[11]: ?

Further information on the particle module may be seen in the library reference Particle Names – pyne.particle.