.. _io_nuclear_data: ========================= Nuclear Data File Formats ========================= --------------------- Incident Neutron Data --------------------- **/** :Attributes: - **filetype** (*char[]*) -- String indicating the type of file - **version** (*int[2]*) -- Major and minor version of the data **//** :Attributes: - **Z** (*int*) -- Atomic number - **A** (*int*) -- Mass number. For a natural element, A=0 is given. - **metastable** (*int*) -- Metastable state (0=ground, 1=first excited, etc.) - **atomic_weight_ratio** (*double*) -- Mass in units of neutron masses - **n_reaction** (*int*) -- Number of reactions :Datasets: - **energy** (*double[]*) -- Energies in [eV] at which cross sections are tabulated **//kTs/** K is the temperature in Kelvin, rounded to the nearest integer, of the temperature-dependent data set. For example, the data set corresponding to 300 Kelvin would be located at `300K`. :Datasets: - **K** (*double*) -- kT values in [eV] for each temperature TTT (in Kelvin) **//reactions/reaction_/** :Attributes: - **mt** (*int*) -- ENDF MT reaction number - **label** (*char[]*) -- Name of the reaction - **Q_value** (*double*) -- Q value in eV - **center_of_mass** (*int*) -- Whether the reference frame for scattering is center-of-mass (1) or laboratory (0) - **n_product** (*int*) -- Number of reaction products - **redundant** (*int*) -- Whether reaction is redundant **//reactions/reaction_/K/** K is the temperature in Kelvin, rounded to the nearest integer, of the temperature-dependent data set. For example, the data set corresponding to 300 Kelvin would be located at `300K`. :Datasets: - **xs** (*double[]*) -- Cross section values tabulated against the nuclide energy grid for temperature TTT (in Kelvin) :Attributes: - **threshold_idx** (*int*) -- Index on the energy grid that the reaction threshold corresponds to for temperature TTT (in Kelvin) **//reactions/reaction_/product_/** Reaction product data is described in :ref:`product`. **//urr/K/** K is the temperature in Kelvin, rounded to the nearest integer, of the temperature-dependent data set. For example, the data set corresponding to 300 Kelvin would be located at `300K`. :Attributes: - **interpolation** (*int*) -- interpolation scheme - **inelastic** (*int*) -- flag indicating inelastic scattering - **other_absorb** (*int*) -- flag indicating other absorption - **factors** (*int*) -- flag indicating whether tables are absolute or multipliers :Datasets: - **energy** (*double[]*) -- Energy at which probability tables exist - **table** (*double[][][]*) -- Probability tables **//total_nu/** This special product is used to define the total number of neutrons produced from fission. It is formatted as a reaction product, described in :ref:`product`. **//fission_energy_release/** :Datasets: - **fragments** (:ref:`function <1d_functions>`) -- Energy released in the form of fragments as a function of incident neutron energy. - **prompt_neutrons** (:ref:`function <1d_functions>`) -- Energy released in the form of prompt neutrons as a function of incident neutron energy. - **delayed_neutrons** (:ref:`function <1d_functions>`) -- Energy released in the form of delayed neutrons as a function of incident neutron energy. - **prompt_photons** (:ref:`function <1d_functions>`) -- Energy released in the form of prompt photons as a function of incident neutron energy. - **delayed_photons** (:ref:`function <1d_functions>`) -- Energy released in the form of delayed photons as a function of incident neutron energy. - **betas** (:ref:`function <1d_functions>`) -- Energy released in the form of betas as a function of incident neutron energy. - **neutrinos** (:ref:`function <1d_functions>`) -- Energy released in the form of neutrinos as a function of incident neutron energy. - **q_prompt** (:ref:`function <1d_functions>`) -- The prompt fission Q-value (fragments + prompt neutrons + prompt photons - incident energy) - **q_recoverable** (:ref:`function <1d_functions>`) -- The recoverable fission Q-value (Q_prompt + delayed neutrons + delayed photons + betas) -------------------- Incident Photon Data -------------------- **/** :Attributes: - **filetype** (*char[]*) -- String indicating the type of file - **version** (*int[2]*) -- Major and minor version of the data **//** :Attributes: - **Z** (*int*) -- Atomic number :Datasets: - **energy** (*double[]*) -- Energies in [eV] at which cross sections are tabulated **//bremsstrahlung/** :Attributes: - **I** (*double*) -- Mean excitation energy in [eV] :Datasets: - **electron_energy** (*double[]*) -- Incident electron energy in [eV] - **photon_energy** (*double[]*) -- Outgoing photon energy as fraction of incident electron energy - **dcs** (*double[][]*) -- Bremsstrahlung differential cross section at each incident energy in [mb/eV] - **ionization_energy** (*double[]*) -- Ionization potential of each subshell in [eV] - **num_electrons** (*int[]*) -- Number of electrons per subshell, with conduction electrons indicated by a negative value **//coherent/** :Datasets: - **xs** (*double[]*) -- Coherent scattering cross section in [b] - **integrated_scattering_factor** (:ref:`tabulated <1d_tabulated>`) -- Integrated coherent scattering form factor - **anomalous_real** (:ref:`tabulated <1d_tabulated>`) -- Real part of the anomalous scattering factor - **anomalous_imag** (:ref:`tabulated <1d_tabulated>`) -- Imaginary part of the anomalous scattering factor **//compton_profiles/** :Datasets: - **binding_energy** (*double[]*) -- Binding energy for each subshell in [eV] - **num_electrons** (*double[]*) -- Number of electrons in each subshell - **pz** (*double[]*) -- Projection of the electron momentum on the scattering vector in units of :math:`me^2 / \hbar` where :math:`m` is the electron rest mass and :math:`e` is the electron charge - **J** (*double[][]*) -- Compton profile for each subshell in units of :math:`\hbar / (me^2)` **//heating/** :Datasets: - **xs** (*double[]*) -- Total heating cross section in [b-eV] **//incoherent/** :Datasets: - **xs** (*double[]*) -- Incoherent scattering cross section in [b] - **scattering_factor** (:ref:`tabulated <1d_tabulated>`) -- **//pair_production_electron/** :Datasets: - **xs** (*double[]*) -- Pair production (electron field) cross section in [b] **//pair_production_nuclear/** :Datasets: - **xs** (*double[]*) -- Pair production (nuclear field) cross section in [b] **//photoelectric/** :Datasets: - **xs** (*double[]*) -- Total photoionization cross section in [b] **//subshells/** :Attributes: - **designators** (*char[][]*) -- Designator for each shell, e.g. 'M2' **//subshells//** :Attributes: - **binding_energy** (*double*) -- Binding energy of the subshell in [eV] - **num_electrons** (*double*) -- Number of electrons in the subshell :Datasets: - **transitions** (*double[][]*) -- Atomic relaxation data - **xs** (*double[]*) -- Photoionization cross section for subshell in [b] tabulated against the main energy grid :Attributes: - **threshold_idx** (*int*) -- Index on the energy grid of the reaction threshold ------------------------------- Thermal Neutron Scattering Data ------------------------------- **/** :Attributes: - **version** (*int[2]*) -- Major and minor version of the data **//** :Attributes: - **atomic_weight_ratio** (*double*) -- Mass in units of neutron masses - **energy_max** (*double*) -- Maximum energy in [eV] - **nuclides** (*char[][]*) -- Names of nuclides for which the thermal scattering data applies to **//kTs/** K is the temperature in Kelvin, rounded to the nearest integer, of the temperature-dependent data set. For example, the data set corresponding to 300 Kelvin would be located at `300K`. :Datasets: - **K** (*double*) -- kT values (in eV) for each temperature TTT (in Kelvin) **//elastic/K/** K is the temperature in Kelvin, rounded to the nearest integer, of the temperature-dependent data set. For example, the data set corresponding to 300 Kelvin would be located at `300K`. :Datasets: - **xs** (:ref:`function <1d_functions>`) -- Thermal elastic scattering cross section for temperature TTT (in Kelvin) :Groups: - **distribution** -- Format for angle-energy distributions are detailed in :ref:`angle_energy`. **//inelastic/K/** K is the temperature in Kelvin, rounded to the nearest integer, of the temperature-dependent data set. For example, the data set corresponding to 300 Kelvin would be located at `300K`. :Datasets: - **xs** (:ref:`function <1d_functions>`) -- Thermal inelastic scattering cross section for temperature TTT (in Kelvin) :Groups: - **distribution** -- Format for angle-energy distributions are detailed in :ref:`angle_energy`. .. _product: ----------------- Reaction Products ----------------- :Object type: Group :Attributes: - **particle** (*char[]*) -- Type of particle - **emission_mode** (*char[]*) -- Emission mode (prompt, delayed, total) - **decay_rate** (*double*) -- Rate of decay in inverse seconds - **n_distribution** (*int*) -- Number of angle/energy distributions :Datasets: - **yield** (:ref:`function <1d_functions>`) -- Energy-dependent yield of the product. :Groups: - **distribution_** -- Formats for angle-energy distributions are detailed in :ref:`angle_energy`. When multiple angle-energy distributions occur, one dataset also may appear for each distribution: :Datasets: - **applicability** (:ref:`function <1d_functions>`) -- Probability of selecting this distribution as a function of incident energy .. _1d_functions: ------------------------- One-dimensional Functions ------------------------- Scalar ------ :Object type: Dataset :Datatype: *double* :Attributes: - **type** (*char[]*) -- 'constant' .. _1d_tabulated: Tabulated --------- :Object type: Dataset :Datatype: *double[2][]* :Description: x-values are listed first followed by corresponding y-values :Attributes: - **type** (*char[]*) -- 'Tabulated1D' - **breakpoints** (*int[]*) -- Region breakpoints - **interpolation** (*int[]*) -- Region interpolation codes .. _1d_polynomial: Polynomial ---------- :Object type: Dataset :Datatype: *double[]* :Description: Polynomial coefficients listed in order of increasing power :Attributes: - **type** (*char[]*) -- 'Polynomial' Coherent elastic scattering --------------------------- :Object type: Dataset :Datatype: *double[2][]* :Description: The first row lists Bragg edges and the second row lists structure factor cumulative sums. :Attributes: - **type** (*char[]*) -- 'CoherentElastic' Incoherent elastic scattering ----------------------------- :Object type: Dataset :Datatype: *double[2]* :Description: The first value is the characteristic bound cross section in [b] and the second value is the Debye-Waller integral in [eV\ :math:`^{-1}`]. :Attributes: - **type** (*char[]*) -- 'IncoherentElastic' Sum of functions ---------------- :Object type: Group :Attributes: - **type** (*char[]*) -- "Sum" - **n** (*int*) -- Number of functions :Datasets: - ***func_** (:ref:`function <1d_functions>`) -- Dataset for the i-th function (indexing starts at 1) .. _angle_energy: -------------------------- Angle-Energy Distributions -------------------------- Uncorrelated Angle-Energy ------------------------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'uncorrelated' :Datasets: - **angle/energy** (*double[]*) -- energies at which angle distributions exist - **angle/mu** (*double[3][]*) -- tabulated angular distributions for each energy. The first row gives :math:`\mu` values, the second row gives the probability density, and the third row gives the cumulative distribution. :Attributes: - **offsets** (*int[]*) -- indices indicating where each angular distribution starts - **interpolation** (*int[]*) -- interpolation code for each angular distribution :Groups: - **energy/** (:ref:`energy distribution `) .. _correlated_angle_energy: Correlated Angle-Energy ----------------------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'correlated' :Datasets: - **energy** (*double[]*) -- Incoming energies at which distributions exist :Attributes: - **interpolation** (*double[2][]*) -- Breakpoints and interpolation codes for incoming energy regions - **energy_out** (*double[5][]*) -- Distribution of outgoing energies corresponding to each incoming energy. The distributions are flattened into a single array; the start of a given distribution can be determined using the ``offsets`` attribute. The first row gives outgoing energies, the second row gives the probability density, the third row gives the cumulative distribution, the fourth row gives interpolation codes for angular distributions, and the fifth row gives offsets for angular distributions. :Attributes: - **offsets** (*double[]*) -- Offset for each distribution - **interpolation** (*int[]*) -- Interpolation code for each distribution - **n_discrete_lines** (*int[]*) -- Number of discrete lines in each distribution - **mu** (*double[3][]*) -- Distribution of angular cosines corresponding to each pair of incoming and outgoing energies. The distributions are flattened into a single array; the start of a given distribution can be determined using offsets in the fifth row of the ``energy_out`` dataset. The first row gives angular cosines, the second row gives the probability density, and the third row gives the cumulative distribution. Kalbach-Mann ------------ :Object type: Group :Attributes: - **type** (*char[]*) -- 'kalbach-mann' :Datasets: - **energy** (*double[]*) -- Incoming energies at which distributions exist :Attributes: - **interpolation** (*double[2][]*) -- Breakpoints and interpolation codes for incoming energy regions - **distribution** (*double[5][]*) -- Distribution of outgoing energies and angles corresponding to each incoming energy. The distributions are flattened into a single array; the start of a given distribution can be determined using the ``offsets`` attribute. The first row gives outgoing energies, the second row gives the probability density, the third row gives the cumulative distribution, the fourth row gives Kalbach-Mann precompound factors, and the fifth row gives Kalbach-Mann angular distribution slopes. :Attributes: - **offsets** (*double[]*) -- Offset for each distribution - **interpolation** (*int[]*) -- Interpolation code for each distribution - **n_discrete_lines** (*int[]*) -- Number of discrete lines in each distribution N-Body Phase Space ------------------ :Object type: Group :Attributes: - **type** (*char[]*) -- 'nbody' - **total_mass** (*double*) -- Total mass of product particles - **n_particles** (*int*) -- Number of product particles - **atomic_weight_ratio** (*double*) -- Atomic weight ratio of the target nuclide in neutron masses - **q_value** (*double*) -- Q value for the reaction in eV Coherent Elastic ---------------- This angle-energy distribution is used specifically for coherent elastic thermal neutron scattering. :Object type: Group :Attributes: - **type** (*char[]*) -- "coherent_elastic" :Hard link: - **xs** -- Link to the coherent elastic scattering cross section Incoherent Elastic ------------------ This angle-energy distribution is used specifically for incoherent elastic thermal neutron scattering (derived from an ENDF file directly). :Object type: Group :Attributes: - **type** (*char[]*) -- "incoherent_elastic" :Datasets: - **debye_waller** (*double*) -- Debye-Waller integral in [eV\ :math:`^{-1}`] Incoherent Elastic (Discrete) ----------------------------- This angle-energy distribution is used for discretized incoherent elastic thermal neutron scattering distributions that are present in ACE files. :Object type: Group :Attributes: - **type** (*char[]*) -- "incoherent_elastic_discrete" :Datasets: - **mu_out** (*double[][]*) -- Equiprobable discrete outgoing angles for each incident neutron energy tabulated Incoherent Inelastic -------------------- This angle-energy distribution is used specifically for (continuous) incoherent inelastic thermal neutron scattering. :Object type: Group :Attributes: - **type** (*char[]*) -- "incoherent_inelastic" :Datasets: The datasets for this angle-energy distribution are the same as for :ref:`correlated angle-energy distributions `. Incoherent Inelastic (Discrete) ------------------------------- This angle-energy distribution is used specifically for incoherent inelastic thermal neutron scattering where the distributions have been discretized into equiprobable bins. :Object type: Group :Attributes: - **type** (*char[]*) -- "incoherent_inelastic_discrete" :Datasets: - **energy_out** (*double[][]*) -- Distribution of outgoing energies for each incoming energy. - **mu_out** (*double[][][]*) -- Distribution of scattering cosines for each pair of incoming and outgoing energies. - **skewed** (*int8_t*) -- Whether discrete angles are equi-probable (0) or have a skewed distribution (1). Mixed Elastic ------------- This angle-energy distribution is used when an evaluation specifies both coherent and incoherent elastic thermal neutron scattering. :Object type: Group :Attributes: - **type** (*char[]*) -- "mixed_elastic" :Groups: - **coherent** -- Distribution for coherent elastic scattering. The format is given in :ref:`angle_energy`. - **incoherent** -- Distribution for incoherent elastic scattering. The format is given in :ref:`angle_energy`. .. _energy_distribution: -------------------- Energy Distributions -------------------- Maxwell ------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'maxwell' - **u** (*double*) -- Restriction energy in eV :Datasets: - **theta** (:ref:`tabulated <1d_tabulated>`) -- Maxwellian temperature as a function of energy Evaporation ----------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'evaporation' - **u** (*double*) -- Restriction energy in eV :Datasets: - **theta** (:ref:`tabulated <1d_tabulated>`) -- Evaporation temperature as a function of energy Watt Fission Spectrum --------------------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'watt' - **u** (*double*) -- Restriction energy in eV :Datasets: - **a** (:ref:`tabulated <1d_tabulated>`) -- Watt parameter :math:`a` as a function of incident energy - **b** (:ref:`tabulated <1d_tabulated>`) -- Watt parameter :math:`b` as a function of incident energy Madland-Nix ----------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'watt' - **efl** (*double*) -- Average energy of light fragment in eV - **efh** (*double*) -- Average energy of heavy fragment in eV Discrete Photon --------------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'discrete_photon' - **primary_flag** (*int*) -- Whether photon is a primary - **energy** (*double*) -- Photon energy in eV - **atomic_weight_ratio** (*double*) -- Atomic weight ratio of target nuclide in neutron masses Level Inelastic --------------- :Object type: Group :Attributes: - **type** (*char[]*) -- 'level' - **threshold** (*double*) -- Energy threshold in the laboratory system in eV - **mass_ratio** (*double*) -- :math:`(A/(A + 1))^2` Continuous Tabular ------------------ :Object type: Group :Attributes: - **type** (*char[]*) -- 'continuous' :Datasets: - **energy** (*double[]*) -- Incoming energies at which distributions exist :Attributes: - **interpolation** (*double[2][]*) -- Breakpoints and interpolation codes for incoming energy regions - **distribution** (*double[3][]*) -- Distribution of outgoing energies corresponding to each incoming energy. The distributions are flattened into a single array; the start of a given distribution can be determined using the ``offsets`` attribute. The first row gives outgoing energies, the second row gives the probability density, and the third row gives the cumulative distribution. :Attributes: - **offsets** (*double[]*) -- Offset for each distribution - **interpolation** (*int[]*) -- Interpolation code for each distribution - **n_discrete_lines** (*int[]*) -- Number of discrete lines in each distribution