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(nuc)

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

Parameters:

nuc : int or str

Input nuclide.
Returns:

mass : float

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(nuc)

Finds the natural abundance of a nuclide.

Parameters:

nuc : int or str

Input nuclide.
Returns:

abund : float

Natural abundance of this nuclide.

Notes

If the nuclide is not found, abundance is 0.

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(nuc, k_conv, l_conv)

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

Parameters:

nuc : int or str

Input nuclide.

k_conv : float

k electron converion coefficient arbitrary units

l_conv : float

l electron converion coefficient arbitrary units
Returns:

arr : vector of pairs

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

Decay Data

pyne.data.half_life(nuc)

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

Parameters:

nuc : int or str

Input nuclide, if metastable is false this uses state_id

use_metastable : bool

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

hl : float

Half-life of this nuclide [seconds].

Notes

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

Half life reported for a level in ENSDF level data.

pyne.data.decay_const(nuc)

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

Parameters:

nuc : int or str

Input nuclide, if metastable is false this uses state_id

use_metastable : bool

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

dc : float

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(from_nuc, to_nuc, use_metastable=True)

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

Parameters:

from_nuc : int or str

Parent nuclide, if metastable is false this uses state id

to_nuc : int or str

Child nuclide, if metastable is false this uses state id

use_metastable : bool

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

br : float

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(nuc, use_metastable=True)

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

Parameters:

nuc : int or str

Input nuclide, if metastable is false this uses state id

use_metastable : bool

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

se : float

Excitation energy of this nuclide [MeV].

Notes

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

pyne.data.decay_children(nuc, use_metastable=True)

Finds the decay children of a nuclide.

Parameters:

nuc : int or str

Input nuclide, if metastable is false this uses state id

use_metastable : bool

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

dc : set 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(nuc, level, special=”“)

return the state_id for input energy level

Parameters:

nuc : int

Input nuclide

level : double

energy level of state

special : str

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

——-

nuc : int

state_id of state
pyne.data.metastable_id(nuc, level=1)

return the nuc_id of a metastable state

Parameters:

nuc : int

Input nuclide

level : int

integer metastable state
Returns:

nuc : int

state_id of metastable state
pyne.data.decay_half_life(from_nuc, to_nuc)

Returns the half life from ENSDF decay dataset parent data

Parameters:

from_nuc : int

parent nuclide in state_id form

to_nuc : int

child nuclide in state_id form
Returns:

half_life : double

half life in seconds

error : double

Error in seconds
pyne.data.decay_half_life_byparent(parent)

Returns a list half lives from ENSDF decay dataset parent data

Parameters:

parent : int

parent nuclide in state_id form
Returns:

half_lives : array of pairs

An array of half lives and their errors for a given parent nuclide
pyne.data.decay_branch_ratio(from_nuc, to_nuc)

Returns the branch ratio from ENSDF decay dataset data

Parameters:

from_nuc : int

parent nuclide in state_id form

to_nuc : int

child nuclide in state_id form
Returns:

ratio : double

branching ratio
pyne.data.decay_branch_ratio_byparent(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of half lives and their errors for a given parent nuclide
pyne.data.decay_photon_branch_ratio(from_nuc, to_nuc)

Returns the photon branch ratio from ENSDF decay dataset data

Parameters:

from_nuc : int

parent nuclide in state_id form

to_nuc : int

child nuclide in state_id form
Returns:

ratio : double

photon branching ratio
pyne.data.decay_photon_branch_ratio_byparent(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

half_lives : array of pairs

An array of photon branching ratios and their errors for a given parent nuclide
pyne.data.decay_beta_branch_ratio(from_nuc, to_nuc)

Returns the branch ratio from ENSDF decay dataset data

Parameters:

from_nuc : int

parent nuclide in state_id form

to_nuc : int

child nuclide in state_id form
Returns:

ratio : double

branching ratio
pyne.data.decay_beta_branch_ratio_byparent(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of pairs

An array of beta branching ratios and their errors for a given parent nuclide
pyne.data.gamma_energy(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of pairs

An array of gamma ray energies and errors
pyne.data.gamma_photon_intensity(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array 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(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of pairs

An array of gamma ray conversion intensities and errors
pyne.data.gamma_total_intensity(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of pairs

An array of gamma ray total intensities and errors
pyne.data.gamma_from_to_byparent(parent)

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:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of pairs

An array of gamma ray level pairs in state_id form
pyne.data.gamma_from_to_byen(en, enerror=None)

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

Parameters:

en : double

gamma ray energy in keV

enerror : double

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

ratios : array of pairs

An array of gamma ray level pairs in state_id form
pyne.data.gamma_parent(en, enerror=None)

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

Parameters:

en : double

gamma ray energy in keV

enerror : double

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

ratios : array of ints

An array of gamma ray parents in state_id form
pyne.data.gamma_xrays(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array 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(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of alpha energies
pyne.data.alpha_intensity(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of alpha intensities
pyne.data.alpha_parent(en, enerror=None)

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

Parameters:

en : double

alpha energy in keV

enerror : double

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

ratios : array of ints

An array of alpha parents in state_id form
pyne.data.alpha_child_byen(en, enerror=None)

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

Parameters:

en : double

alpha energy in keV

enerror : double

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

ratios : array of ints

An array of alpha children in state_id form
pyne.data.alpha_child_byparent(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of ints

An array of alpha children in state_id form
pyne.data.beta_endpoint_energy(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of beta endpoint energies
pyne.data.beta_average_energy(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of beta average energies
pyne.data.beta_intensity(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of beta intensities
pyne.data.beta_parent(en, enerror=None)

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

Parameters:

en : double

beta- energy in keV

enerror : double

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

ratios : array of ints

An array of beta minus parents in nuc_id form
pyne.data.beta_child_byen(en, enerror=None)

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

Parameters:

en : double

beta- energy in keV

enerror : double

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

ratios : array of ints

An array of beta minus children in nuc_id form
pyne.data.beta_child_byparent(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of ints

An array of beta- children in state_id form
pyne.data.ecbp_endpoint_energy(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of beta plus endpoint energies
pyne.data.ecbp_average_energy(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of beta plus average energies
pyne.data.ec_intensity(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of pairs

An array of electron capture intensisities and errors
pyne.data.beta_plus_intensity(parent)

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

Parameters:

parent : int

parent nuclide in state_id form
Returns:

ratios : array of doubles

An array of beta plus intensities
pyne.data.ecbp_parent(en, enerror=None)

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

Parameters:

en : double

beta- energy in keV

enerror : double

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

ratios : array of ints

An array of beta plus/electron capture children in nuc_id form
pyne.data.ecbp_child_byen(en, enerror=None)

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

Parameters:

en : double

beta- energy in keV

enerror : double

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

ratios : array of ints

An array of beta plus/electron capture children in state_id form
pyne.data.ecbp_child_byparent(parent)

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

Parameters:

parent : int

parent nuclide in nuc_id form in state_id form
Returns:

ratios : array of ints

An array of beta+ children in state_id form
pyne.data.ecbp_xrays(parent)

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

Parameters:

parent : int

parent nuclide
Returns:

ratios : array 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(nuc)

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

Parameters:

nuc : int or str

Input nuclide.
Returns:

b : float

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(nuc)

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

Parameters:

nuc : int or str

Input nuclide.
Returns:

bc : complex

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(nuc)

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

Parameters:

nuc : int or str

Input nuclide.
Returns:

bi : complex

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.