gridfire::rates::weak::WeakReaction Class Reference

Concrete Reaction representing a single weak process (beta±, e−/e+ capture). More...

#include <weak.h>

Inheritance diagram for gridfire::rates::weak::WeakReaction:

Collaboration diagram for gridfire::rates::weak::WeakReaction:

Classes
class	AtomicWeakRate
	CppAD atomic that wraps weak-rate interpolation for AD evaluation. More...
struct	constants

Public Member Functions
	WeakReaction (const fourdst::atomic::Species &species, WeakReactionType type, const WeakRateInterpolator &interpolator)
	Construct a WeakReaction for a specific weak channel and parent species.
double	calculate_rate (double T9, double rho, double Ye, double mue, const std::vector< double > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const override
	Scalar weak reaction rate λ(T9, rho, Ye, μe) in 1/s.
CppAD::AD< double >	calculate_rate (CppAD::AD< double > T9, CppAD::AD< double > rho, CppAD::AD< double > Ye, CppAD::AD< double > mue, const std::vector< CppAD::AD< double > > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const override
	AD-enabled weak reaction rate λ(T9, rho, Ye, μe) in 1/s.
std::string_view	id () const override
	Unique identifier string for the weak channel.
const std::vector< fourdst::atomic::Species > &	reactants () const override
	Reactants list (parent nuclide only).
const std::vector< fourdst::atomic::Species > &	products () const override
	Products list (daughter nuclide only).
bool	contains (const fourdst::atomic::Species &species) const override
	Check if a species participates in this weak reaction.
bool	contains_reactant (const fourdst::atomic::Species &species) const override
	Check if a species is the reactant (parent).
bool	contains_product (const fourdst::atomic::Species &species) const override
	Check if a species is the product (daughter).
std::unordered_set< fourdst::atomic::Species >	all_species () const override
	Set of both parent and daughter species.
std::unordered_set< fourdst::atomic::Species >	reactant_species () const override
	Singleton set containing only the parent species.
std::unordered_set< fourdst::atomic::Species >	product_species () const override
	Singleton set containing only the daughter species.
size_t	num_species () const override
	Number of unique species involved (always 2 for weak reactions).
std::unordered_map< fourdst::atomic::Species, int >	stoichiometry () const override
	Full stoichiometry map: parent -1, daughter +1.
int	stoichiometry (const fourdst::atomic::Species &species) const override
	Stoichiometric coefficient for a species: -1 (parent), +1 (daughter), 0 otherwise.
uint64_t	hash (uint64_t seed) const override
	Content-based 64-bit hash for this reaction.
double	qValue () const override
	Q-value (MeV) based on nuclear mass differences and channel.
double	calculate_energy_generation_rate (double T9, double rho, double Ye, double mue, const std::vector< double > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const override
	Net energy generation rate (MeV/s) for this weak reaction.
CppAD::AD< double >	calculate_energy_generation_rate (const CppAD::AD< double > &T9, const CppAD::AD< double > &rho, const CppAD::AD< double > &Ye, const CppAD::AD< double > &mue, const std::vector< CppAD::AD< double > > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const override
	AD-enabled net energy generation rate (MeV/s).
double	calculate_log_rate_partial_deriv_wrt_T9 (double T9, double rho, double Ye, double mue, const fourdst::composition::Composition &composition) const override
	Logarithmic temperature sensitivity of the rate at the given state.
reaction::ReactionType	type () const override
	Reaction type tag for runtime dispatch.
std::unique_ptr< Reaction >	clone () const override
	Polymorphic deep copy.
bool	is_reverse () const override
	Weak reactions are parameterized in the forward sense (never reverse).
const WeakRateInterpolator &	getWeakRateInterpolator () const
	Access the underlying rate interpolator used by this reaction.
std::optional< std::vector< reaction::RateCoefficientSet > >	getRateCoefficients () const override
size_t	countReactantOccurrences (const fourdst::atomic::Species &species) const override
size_t	countProductOccurrences (const fourdst::atomic::Species &species) const override
Public Member Functions inherited from gridfire::reaction::Reaction
virtual	~Reaction ()=default
	Virtual destructor for correct polymorphic cleanup.

Private Member Functions
template<IsArithmeticOrAD T>
T	calculate_rate (T T9, T rho, T Ye, T mue, const std::vector< T > &Y, const std::unordered_map< size_t, fourdst::atomic::Species > &index_to_species_map) const
	Internal unified implementation for scalar/AD rate evaluation.
double	get_log_rate_from_payload (const WeakRatePayload &payload) const
	Extract the channel-specific log10(rate) from an interpolated payload. Mapping: β−→log_beta_minus, β+→log_beta_plus, e− capture→log_electron_capture, e+ capture→log_positron_capture.
double	get_log_neutrino_loss_from_payload (const WeakRatePayload &payload) const
	Extract the channel-specific log10(neutrino loss) from a payload. Mapping: β−/e+ capture→log_antineutrino_loss_bd; β+/e− capture→log_neutrino_loss_ec.

Private Attributes
const constants	m_constants
fourdst::atomic::Species	m_reactant
fourdst::atomic::Species	m_product
std::vector< fourdst::atomic::Species >	m_reactants
std::vector< fourdst::atomic::Species >	m_products
size_t	m_reactant_a
size_t	m_reactant_z
size_t	m_product_a
size_t	m_product_z
std::string	m_id
WeakReactionType	m_type
const WeakRateInterpolator &	m_interpolator
AtomicWeakRate	m_atomic

Detailed Description

Concrete Reaction representing a single weak process (beta±, e−/e+ capture).

Wraps interpolation logic for tabulated weak rates and provides both scalar and AD interfaces for rate and energy generation. The reactants/products are the parent/daughter nuclei of the weak process.

the product nucleus is resolved from (A,Z) and channel via simple charge-changing rules (β−: Z+1; β+: Z−1; e− capture: Z−1; e+ capture: Z+1). The reaction ID is formatted like "Parent(channel)Product" with ν/ν̄ decorations, and an internal CppAD atomic (AtomicWeakRate) is prepared for AD energy calculations.

Constructor & Destructor Documentation

WeakReaction()

gridfire::rates::weak::WeakReaction::WeakReaction ( const fourdst::atomic::Species &  species, WeakReactionType  type, const WeakRateInterpolator &  interpolator  )

explicit

Construct a WeakReaction for a specific weak channel and parent species.

Parameters

species	Parent nuclide undergoing the weak process.
type	The weak reaction channel (beta−, beta+, e− capture, e+ capture).
interpolator	Reference to a WeakRateInterpolator providing tabulated data.

Precondition

The product nuclide must be resolvable for the given (species, type).

Postcondition

Object is ready to compute rates using the provided interpolator.

Exceptions

std::runtime_error

If the product species cannot be resolved for the channel (product resolution uses the charge-changing rules described above).

Member Function Documentation

all_species()

std::unordered_set< fourdst::atomic::Species > gridfire::rates::weak::WeakReaction::all_species ( ) const

overridevirtual

Set of both parent and daughter species.

Implements gridfire::reaction::Reaction.

calculate_energy_generation_rate() [1/2]

CppAD::AD< double > gridfire::rates::weak::WeakReaction::calculate_energy_generation_rate ( const CppAD::AD< double > &  T9, const CppAD::AD< double > &  rho, const CppAD::AD< double > &  Ye, const CppAD::AD< double > &  mue, const std::vector< CppAD::AD< double > > &  Y, const std::unordered_map< size_t, fourdst::atomic::Species > &  index_to_species_map  ) const

overridevirtual

AD-enabled net energy generation rate (MeV/s).

Uses an internal CppAD atomic to compute two outputs at once: the rate λ and the neutrino loss ν_loss at (T9, log10(rho*Ye), μe). Returns λ · (Q − ν_loss). The atomic throws on interpolation failure.

Exceptions

std::runtime_error

If the atomic rate evaluation fails to interpolate.

Reimplemented from gridfire::reaction::Reaction.

calculate_energy_generation_rate() [2/2]

double gridfire::rates::weak::WeakReaction::calculate_energy_generation_rate ( double  T9, double  rho, double  Ye, double  mue, const std::vector< double > &  Y, const std::unordered_map< size_t, fourdst::atomic::Species > &  index_to_species_map  ) const

overridevirtual

Net energy generation rate (MeV/s) for this weak reaction.

Interpolates once to obtain both the log10(rate) and the appropriate log10(neutrino-loss) for the channel, converts to linear values, computes E_deposited = Q − ν_loss, and returns λ · E_deposited. Throws on interpolation failure.

Channel mapping for neutrino-loss column:

• β− decay and e+ capture: use log_antineutrino_loss_bd
• β+ decay and e− capture: use log_neutrino_loss_ec

Parameters

T9	Temperature in GK.
rho	Density in g cm^-3.
Ye	Electron fraction.
mue	Electron chemical potential (MeV).
Y	Composition vector (unused for weak channels).
index_to_species_map	Index-to-species map (unused for weak channels).

Returns

Energy generation rate in MeV/s.

Exceptions

std::runtime_error

On interpolation failure.

Example

double eps = rxn.calculate_energy_generation_rate(3.0, 1e7, 0.5, 2.0, {}, {});

Reimplemented from gridfire::reaction::Reaction.

calculate_log_rate_partial_deriv_wrt_T9()

double gridfire::rates::weak::WeakReaction::calculate_log_rate_partial_deriv_wrt_T9 ( double  T9, double  rho, double  Ye, double  mue, const fourdst::composition::Composition &  composition  ) const

overridevirtual

Logarithmic temperature sensitivity of the rate at the given state.

Implementation status: requests derivative tables from the interpolator and throws on failure; otherwise the function is not yet implemented and does not return a value. Avoid calling until implemented.

Parameters

T9	Temperature in GK.
rho	Density in g cm^-3.
Ye	Electron fraction.
mue	Electron chemical potential (MeV).
composition	Composition context (not used by weak channels presently).

Returns

d ln λ / d ln T9.

Exceptions

std::runtime_error

On interpolation failure.

Implements gridfire::reaction::Reaction.

calculate_rate() [1/3]

CppAD::AD< double > gridfire::rates::weak::WeakReaction::calculate_rate ( CppAD::AD< double >  T9, CppAD::AD< double >  rho, CppAD::AD< double >  Ye, CppAD::AD< double >  mue, const std::vector< CppAD::AD< double > > &  Y, const std::unordered_map< size_t, fourdst::atomic::Species > &  index_to_species_map  ) const

overridevirtual

AD-enabled weak reaction rate λ(T9, rho, Ye, μe) in 1/s.

Current implementation returns 0.0. AD support is provided for the energy-generation overload below using an internal CppAD atomic that evaluates both the rate and neutrino loss consistently. A future implementation may mirror that atomic here and return the AD rate.

Parameters

T9	Temperature in GK (AD type).
rho	Mass density (g cm^-3, AD type).
Ye	Electron fraction (AD type).
mue	Electron chemical potential (MeV, AD type).
Y	Composition vector (unused for weak channels).
index_to_species_map	Index-to-species map (unused for weak channels).

Returns

Reaction rate (1/s) as CppAD::AD<double> (currently 0.0).

Example

using AD = CppAD::AD<double>;
AD lambda_ad = rxn.calculate_rate(AD(3.0), AD(1e7), AD(0.5), AD(2.0), {}, {});

Implements gridfire::reaction::Reaction.

calculate_rate() [2/3]

double gridfire::rates::weak::WeakReaction::calculate_rate ( double  T9, double  rho, double  Ye, double  mue, const std::vector< double > &  Y, const std::unordered_map< size_t, fourdst::atomic::Species > &  index_to_species_map  ) const

overridevirtual

Scalar weak reaction rate λ(T9, rho, Ye, μe) in 1/s.

Performs a single interpolation of the weak-rate tables at (T9, log10(rho*Ye), μe). If the selected log10(rate) is ≤ sentinel (-60), returns 0; otherwise returns 10^{log10(rate)}. On interpolation failure, throws with a message including (A,Z) and the state point.

Parameters

T9	Temperature in GK (1e9 K).
rho	Mass density (g cm^-3).
Ye	Electron fraction.
mue	Electron chemical potential (MeV).
Y	Composition vector (unused for weak channels).
index_to_species_map	Index-to-species map (unused for weak channels).

Returns

Reaction rate (1/s).

Exceptions

std::runtime_error

On interpolation failure.

Example

double lambda = rxn.calculate_rate(2.0, 1e8, 0.4, 1.5, {}, {});

Implements gridfire::reaction::Reaction.

calculate_rate() [3/3]

template<IsArithmeticOrAD T>

T gridfire::rates::weak::WeakReaction::calculate_rate ( T  T9, T  rho, T  Ye, T  mue, const std::vector< T > &  Y, const std::unordered_map< size_t, fourdst::atomic::Species > &  index_to_species_map  ) const

private

Internal unified implementation for scalar/AD rate evaluation.

Template Parameters

T	double or CppAD::AD<double>.

Parameters

T9,rho,Ye,mue	Thermodynamic state.
Y	Composition vector (unused for weak channels).
index_to_species_map	Index-to-species map (unused for weak channels).

Returns

Reaction rate (1/s) as T. For double, performs table interpolation and returns 0 when the tabulated log10(rate) ≤ sentinel; for AD, calls the atomic and returns the first output.

Precondition

T9 > 0, rho > 0, 0 < Ye <= 1.

Postcondition

No persistent state is modified.

Exceptions

std::runtime_error

If interpolation fails (double path) or the atomic fails (AD path).

clone()

std::unique_ptr< reaction::Reaction > gridfire::rates::weak::WeakReaction::clone ( ) const

overridevirtual

Polymorphic deep copy.

Implements gridfire::reaction::Reaction.

contains()

bool gridfire::rates::weak::WeakReaction::contains ( const fourdst::atomic::Species &  species ) const

overridevirtual

Check if a species participates in this weak reaction.

Implements gridfire::reaction::Reaction.

contains_product()

bool gridfire::rates::weak::WeakReaction::contains_product ( const fourdst::atomic::Species &  species ) const

overridevirtual

Check if a species is the product (daughter).

Implements gridfire::reaction::Reaction.

contains_reactant()

bool gridfire::rates::weak::WeakReaction::contains_reactant ( const fourdst::atomic::Species &  species ) const

overridevirtual

Check if a species is the reactant (parent).

Implements gridfire::reaction::Reaction.

countProductOccurrences()

size_t gridfire::rates::weak::WeakReaction::countProductOccurrences ( const fourdst::atomic::Species &  species ) const

overridevirtual

Implements gridfire::reaction::Reaction.

countReactantOccurrences()

size_t gridfire::rates::weak::WeakReaction::countReactantOccurrences ( const fourdst::atomic::Species &  species ) const

overridevirtual

Implements gridfire::reaction::Reaction.

get_log_neutrino_loss_from_payload()

double gridfire::rates::weak::WeakReaction::get_log_neutrino_loss_from_payload ( const WeakRatePayload &  payload ) const

private

Extract the channel-specific log10(neutrino loss) from a payload. Mapping: β−/e+ capture→log_antineutrino_loss_bd; β+/e− capture→log_neutrino_loss_ec.

get_log_rate_from_payload()

double gridfire::rates::weak::WeakReaction::get_log_rate_from_payload ( const WeakRatePayload &  payload ) const

private

Extract the channel-specific log10(rate) from an interpolated payload. Mapping: β−→log_beta_minus, β+→log_beta_plus, e− capture→log_electron_capture, e+ capture→log_positron_capture.

getRateCoefficients()

std::optional< std::vector< reaction::RateCoefficientSet > > gridfire::rates::weak::WeakReaction::getRateCoefficients ( ) const

inlineoverridevirtual

Implements gridfire::reaction::Reaction.

getWeakRateInterpolator()

const WeakRateInterpolator & gridfire::rates::weak::WeakReaction::getWeakRateInterpolator

(

)

const

Access the underlying rate interpolator used by this reaction.

hash()

uint64_t gridfire::rates::weak::WeakReaction::hash ( uint64_t  seed ) const

overridevirtual

Content-based 64-bit hash for this reaction.

Implements gridfire::reaction::Reaction.

id()

std::string_view gridfire::rates::weak::WeakReaction::id ( ) const

overridevirtual

Unique identifier string for the weak channel.

Returns

A stable string view (e.g., "Fe52(e-,ν)Mn52").

Implements gridfire::reaction::Reaction.

is_reverse()

bool gridfire::rates::weak::WeakReaction::is_reverse ( ) const

overridevirtual

Weak reactions are parameterized in the forward sense (never reverse).

Implements gridfire::reaction::Reaction.

num_species()

size_t gridfire::rates::weak::WeakReaction::num_species ( ) const

overridevirtual

Number of unique species involved (always 2 for weak reactions).

Implements gridfire::reaction::Reaction.

product_species()

std::unordered_set< fourdst::atomic::Species > gridfire::rates::weak::WeakReaction::product_species ( ) const

overridevirtual

Singleton set containing only the daughter species.

Implements gridfire::reaction::Reaction.

products()

const std::vector< fourdst::atomic::Species > & gridfire::rates::weak::WeakReaction::products ( ) const

overridevirtual

Products list (daughter nuclide only).

Returns

Vector with the daughter species.

Implements gridfire::reaction::Reaction.

qValue()

double gridfire::rates::weak::WeakReaction::qValue ( ) const

overridevirtual

Q-value (MeV) based on nuclear mass differences and channel.

Computes Q = (M_parent − M_daughter) c^2 converted to MeV. For β+ decay subtract 2 m_e c^2, for e+ capture add 2 m_e c^2; for β− and e− capture it is just the nuclear mass difference. Neutrino rest mass is ignored.

Implements gridfire::reaction::Reaction.

reactant_species()

std::unordered_set< fourdst::atomic::Species > gridfire::rates::weak::WeakReaction::reactant_species ( ) const

overridevirtual

Singleton set containing only the parent species.

Implements gridfire::reaction::Reaction.

reactants()

const std::vector< fourdst::atomic::Species > & gridfire::rates::weak::WeakReaction::reactants ( ) const

overridevirtual

Reactants list (parent nuclide only).

Returns

Vector with the parent species.

Implements gridfire::reaction::Reaction.

stoichiometry() [1/2]

std::unordered_map< fourdst::atomic::Species, int > gridfire::rates::weak::WeakReaction::stoichiometry ( ) const

overridevirtual

Full stoichiometry map: parent -1, daughter +1.

Implements gridfire::reaction::Reaction.

stoichiometry() [2/2]

int gridfire::rates::weak::WeakReaction::stoichiometry ( const fourdst::atomic::Species &  species ) const

overridevirtual

Stoichiometric coefficient for a species: -1 (parent), +1 (daughter), 0 otherwise.

Implements gridfire::reaction::Reaction.

type()

reaction::ReactionType gridfire::rates::weak::WeakReaction::type ( ) const

overridevirtual

Reaction type tag for runtime dispatch.

Implements gridfire::reaction::Reaction.

Member Data Documentation

m_atomic

AtomicWeakRate gridfire::rates::weak::WeakReaction::m_atomic

mutableprivate

m_constants

const constants gridfire::rates::weak::WeakReaction::m_constants

private

m_id

std::string gridfire::rates::weak::WeakReaction::m_id

private

m_interpolator

const WeakRateInterpolator& gridfire::rates::weak::WeakReaction::m_interpolator

private

m_product

fourdst::atomic::Species gridfire::rates::weak::WeakReaction::m_product

private

m_product_a

size_t gridfire::rates::weak::WeakReaction::m_product_a

private

m_product_z

size_t gridfire::rates::weak::WeakReaction::m_product_z

private

m_products

std::vector<fourdst::atomic::Species> gridfire::rates::weak::WeakReaction::m_products

private

m_reactant

fourdst::atomic::Species gridfire::rates::weak::WeakReaction::m_reactant

private

m_reactant_a

size_t gridfire::rates::weak::WeakReaction::m_reactant_a

private

m_reactant_z

size_t gridfire::rates::weak::WeakReaction::m_reactant_z

private

m_reactants

std::vector<fourdst::atomic::Species> gridfire::rates::weak::WeakReaction::m_reactants

private

m_type

WeakReactionType gridfire::rates::weak::WeakReaction::m_type

private

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The documentation for this class was generated from the following files:

• src/include/gridfire/reaction/weak/weak.h
• src/lib/reaction/weak/weak.cpp