# Basic Nuclear Data – pyne.data¶

This module provides a top-level interface for a variety of basic nuclear data needs. This aims to provide quick access to very high fidelity data. Usually values are taken from the nuc_data.h5 library.

All functionality may be found in the data module:

from pyne import data


## Atomic Mass¶

pyne.data.atomic_mass()

Finds the atomic mass of a nuclide in [amu].

Parameters
nucint or str

Input nuclide.

Returns
massfloat

Atomic mass of this nuclide [amu].

Notes

If the nuclide is not found, the A-number is returned as a float.

pyne.data.atomic_mass_map

A mapping from zzaaam-nuclides to their mass weights. This is used by atomic_mass() under the hood.

## Natural Abundance Ratios¶

pyne.data.natural_abund()

Finds the natural abundance of a nuclide.

Parameters
nucint or str

Input nuclide.

Returns
abundfloat

Natural abundance of this nuclide.

Notes

pyne.data.natural_abund_map

A mapping from zzaaam-nuclides to their mass weights. This is used by natural_abund() under the hood.

## Atomic Data¶

pyne.data.calculate_xray_data()

Calculates X-ray intensities for a given atom with k and l conversion intensities

Parameters
nucint or str

Input nuclide.

k_convfloat

k electron converion coefficient arbitrary units

l_convfloat

l electron converion coefficient arbitrary units

Returns
arrvector of pairs

Vector of pairs containing the four primary X-rays and their intensities: Ka1, Ka2, Kb, L

## Decay Data¶

pyne.data.half_life()

Finds the half-life of a nuclide in [seconds].

Parameters
nucint or str

Input nuclide, if metastable is false this uses state_id

use_metastablebool

Assume state of input nuc_id refers to metastable state. Defaults to True.

Returns
hlfloat

Half-life of this nuclide [seconds].

Notes

Half life reported for a level in ENSDF level data.

pyne.data.decay_const()

Finds the decay constant of a nuclide in [1/seconds].

Parameters
nucint or str

Input nuclide, if metastable is false this uses state_id

use_metastablebool

Assume state of input nuc_id refers to metastable state. Defaults to True.

Returns
dcfloat

Decay constant of this nuclide [1/seconds].

Notes

If the nuclide is not found, the nuclide is assumed to be stable.

pyne.data.branch_ratio()

Finds a branch ratio for a from -> to nuclide pair [fraction].

Parameters
from_nucint or str

Parent nuclide, if metastable is false this uses state id

to_nucint or str

Child nuclide, if metastable is false this uses state id

use_metastablebool

Assume state of input nuc_id refers to metastable state. Defaults to True.

Returns
brfloat

Branch ratio of this nuclide pair [fraction].

Notes

If this pair is not found, it is assumed to be impossible, and the branch ratio is set to zero.

Branch ratio reported for a reaction in ENSDF level data. This is not necessarily equivalent to the value reported in a decay dataset by decay_branch_ratio but it should be.

pyne.data.state_energy()

Finds the excitation energy [MeV] of a nuclide in a given state.

Parameters
nucint or str

Input nuclide, if metastable is false this uses state id

use_metastablebool

Assume state of input nuc_id refers to metastable state. Defaults to True

Returns
sefloat

Excitation energy of this nuclide [MeV].

Notes

If the nuclide is not found, the nuclide is assumed to be stable.

pyne.data.decay_children()

Finds the decay children of a nuclide.

Parameters
nucint or str

Input nuclide, if metastable is false this uses state id

use_metastablebool

Assume state of input nuc_id refers to metastable state. Defaults to True

Returns
dcset of ints

Decay children in id form.

Notes

If the nuclide is not found or is stable, the empty set is returned.

pyne.data.id_from_level()

return the state_id for input energy level

Parameters
nucint

Input nuclide

leveldouble

energy level of state

specialstr

special level denotation. This is a single A-Z character corresponding to a group of levels and associated gammas with no reference to the GS

Returns
——-
nucint

state_id of state

pyne.data.metastable_id()

return the nuc_id of a metastable state

Parameters
nucint

Input nuclide

levelint

integer metastable state

Returns
nucint or None

state_id of metastable state or None if the metastable state can not be found.

pyne.data.decay_half_life()

Returns the half life from ENSDF decay dataset parent data

Parameters
from_nucint

parent nuclide in state_id form

to_nucint

child nuclide in state_id form

Returns
half_lifedouble

half life in seconds

errordouble

Error in seconds

pyne.data.decay_half_life_byparent()

Returns a list half lives from ENSDF decay dataset parent data

Parameters
parentint

parent nuclide in state_id form

Returns
half_livesarray of pairs

An array of half lives and their errors for a given parent nuclide

pyne.data.decay_branch_ratio()

Returns the branch ratio from ENSDF decay dataset data

Parameters
from_nucint

parent nuclide in state_id form

to_nucint

child nuclide in state_id form

Returns
ratiodouble

branching ratio

pyne.data.decay_branch_ratio_byparent()

Returns a list branching ratios from ENSDF decay dataset data for a given parent.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of half lives and their errors for a given parent nuclide

pyne.data.decay_photon_branch_ratio()

Returns the photon branch ratio from ENSDF decay dataset data

Parameters
from_nucint

parent nuclide in state_id form

to_nucint

child nuclide in state_id form

Returns
ratiodouble

photon branching ratio

pyne.data.decay_photon_branch_ratio_byparent()

Returns a list of photon branch ratios from ENSDF decay dataset parent data

Parameters
parentint

parent nuclide in state_id form

Returns
half_livesarray of pairs

An array of photon branching ratios and their errors for a given parent nuclide

pyne.data.decay_beta_branch_ratio()

Returns the branch ratio from ENSDF decay dataset data

Parameters
from_nucint

parent nuclide in state_id form

to_nucint

child nuclide in state_id form

Returns
ratiodouble

branching ratio

pyne.data.decay_beta_branch_ratio_byparent()

Returns a list of beta branch ratios from ENSDF decay dataset parent data

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of pairs

An array of beta branching ratios and their errors for a given parent nuclide

pyne.data.gamma_energy()

Returns a list of gamma ray energies from ENSDF decay dataset from a given parent

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of pairs

An array of gamma ray energies and errors

pyne.data.gamma_photon_intensity()

Returns a list of gamma ray photon intensities from ENSDF decay dataset from a given parent

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of pairs

An array of gamma ray photon intensities and errors

This intensity is just the relative intensity for different photons in the same dataset. It needs to be multiplied by the output of decay_photon_branch_ratio() to give the percentage of parent decays.

pyne.data.gamma_conversion_intensity()

Returns a list of gamma ray conversion intensities from ENSDF decay dataset from a given parent

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of pairs

An array of gamma ray conversion intensities and errors

pyne.data.gamma_total_intensity()

Returns a list of gamma ray total intensities from ENSDF decay dataset from a given parent

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of pairs

An array of gamma ray total intensities and errors

pyne.data.gamma_from_to_byparent()

Returns a list of gamma ray level pairs from ENSDF decay dataset from a given parent. This makes it possible to calculate coincidence rates.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of pairs

An array of gamma ray level pairs in state_id form

pyne.data.gamma_from_to_byen()

Returns a list of gamma ray level pairs from ENSDF decay dataset based on gamma-ray energy.

Parameters
endouble

gamma ray energy in keV

enerrordouble

gamma ray energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of pairs

An array of gamma ray level pairs in state_id form

pyne.data.gamma_parent()

Returns a list of gamma ray parents from ENSDF decay dataset based on gamma-ray energy.

Parameters
endouble

gamma ray energy in keV

enerrordouble

gamma ray energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of ints

An array of gamma ray parents in state_id form

pyne.data.gamma_xrays()

Returns an array of arrays of xrays associated with the gamma rays from an input parent nuclide

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of arrays

This returns an array of length 4 arrays containing pairs of energies and intensities of the following X-rays: Ka1, Ka2, Kb, L

pyne.data.alpha_energy()

Returns a list of alpha energies from ENSDF decay dataset from a given parent

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of alpha energies

pyne.data.alpha_intensity()

Returns a list of alpha intensities from ENSDF decay dataset from a given parent

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of alpha intensities

pyne.data.alpha_parent()

Returns a list of alpha parents from ENSDF decay dataset based on alpha energy.

Parameters
endouble

alpha energy in keV

enerrordouble

alpha energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of ints

An array of alpha parents in state_id form

pyne.data.alpha_child_byen()

Returns a list of alpha children from ENSDF decay dataset based on alpha energy.

Parameters
endouble

alpha energy in keV

enerrordouble

alpha energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of ints

An array of alpha children in state_id form

pyne.data.alpha_child_byparent()

Returns a list of alpha children from ENSDF decay dataset based on alpha parent.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of ints

An array of alpha children in state_id form

pyne.data.beta_endpoint_energy()

Returns a list of beta endpoint energies from ENSDF decay dataset based on parent nuclide.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of beta endpoint energies

pyne.data.beta_average_energy()

Returns a list of beta average energies from ENSDF decay dataset based on parent nuclide.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of beta average energies

pyne.data.beta_intensity()

Returns a list of beta intensities from ENSDF decay dataset based on parent nuclide.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of beta intensities

pyne.data.beta_parent()

Returns a list of beta minus parents from ENSDF decay dataset based on beta energy.

Parameters
endouble

beta- energy in keV

enerrordouble

beta- energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of ints

An array of beta minus parents in nuc_id form

pyne.data.beta_child_byen()

Returns a list of beta minus children from ENSDF decay dataset based on beta energy.

Parameters
endouble

beta- energy in keV

enerrordouble

beta- energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of ints

An array of beta minus children in nuc_id form

pyne.data.beta_child_byparent()

Returns a list of beta minus children from ENSDF decay dataset based on parent.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of ints

An array of beta- children in state_id form

pyne.data.ecbp_endpoint_energy()

Returns a list of beta plus endpoint energies from ENSDF decay dataset from a given parent.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of beta plus endpoint energies

pyne.data.ecbp_average_energy()

Returns a list of beta plus average energies from ENSDF decay dataset from a given parent.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of beta plus average energies

pyne.data.ec_intensity()

Returns a list of electron capture intensisities from ENSDF decay dataset from a given parent.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of pairs

An array of electron capture intensisities and errors

pyne.data.beta_plus_intensity()

Returns a list of beta plus intensities from ENSDF decay dataset from a given parent.

Parameters
parentint

parent nuclide in state_id form

Returns
ratiosarray of doubles

An array of beta plus intensities

pyne.data.ecbp_parent()

Returns a list of beta plus/electron capture parents from ENSDF decay dataset based on beta energy.

Parameters
endouble

beta- energy in keV

enerrordouble

beta- energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of ints

An array of beta plus/electron capture children in nuc_id form

pyne.data.ecbp_child_byen()

Returns a list of beta plus/electron capture parents from ENSDF decay dataset based on beta energy.

Parameters
endouble

beta- energy in keV

enerrordouble

beta- energy error (range which you want to search) this defaults to 1% of the energy if it is not provided

Returns
ratiosarray of ints

An array of beta plus/electron capture children in state_id form

pyne.data.ecbp_child_byparent()

Returns a list of beta plus children from ENSDF decay dataset based on parent.

Parameters
parentint

parent nuclide in nuc_id form in state_id form

Returns
ratiosarray of ints

An array of beta+ children in state_id form

pyne.data.ecbp_xrays()

Returns an array of arrays of xrays associated with the electron capture and beta plus decays from an input parent nuclide

Parameters
parentint

parent nuclide

Returns
ratiosarray of arrays

This returns an array of length 4 arrays containing pairs of energies and intensities of the following X-rays: Ka1, Ka2, Kb, L

## Neutron Scattering Lengths¶

pyne.data.b()

Finds the bound scattering length of a nuclide in [cm].

Parameters
nucint or str

Input nuclide.

Returns
bfloat

Bound scattering length of nuc [cm].

Notes

If nuc is not found, the value for a nuclide with the same A-number is used instead. If still no value is found, the an isotope of the same element as nuc is used. If still no values are found, zero is returned.

This value is computed from the coherent and incoherent scattering lengths as follows:

$b = \sqrt{\left| b_{\mbox{coh}} \right|^2 + \left| b_{\mbox{inc}} \right|^2}$
pyne.data.b_map

A mapping from zzaaam-nuclides to their bound neuton scattering lengths. This is used by b() under the hood.

pyne.data.b_coherent()

Finds the coherent bound scattering length of a nuclide in [cm].

Parameters
nucint or str

Input nuclide.

Returns
bccomplex

Coherent bound scattering length of nuc [cm].

Notes

If nuc is not found, the value for a nuclide with the same A-number is used instead. If still no value is found, the an isotope of the same element as nuc is used. If still no values are found, zero is returned.

pyne.data.b_coherent_map

A mapping from zzaaam-nuclides to their bound coherent neuton scattering lengths. This is used by b_coherent() under the hood.

pyne.data.b_incoherent()

Finds the incoherent bound scattering length of a nuclide in [cm].

Parameters
nucint or str

Input nuclide.

Returns
bicomplex

Incoherent bound scattering length of nuc [cm].

Notes

If nuc is not found, the value for a nuclide with the same A-number is used instead. If still no value is found, the an isotope of the same element as nuc is used. If still no values are found, zero is returned.

pyne.data.b_incoherent_map

A mapping from zzaaam-nuclides to their bound incoherent neuton scattering lengths. This is used by b_coherent() under the hood.