Abstract base class for models of gamma-ray strength functions. More...

#include <GammaStrengthFunctionModel.hh>

Inheritance diagram for marley::GammaStrengthFunctionModel:

Public Types
enum class	TransitionType { electric , magnetic , unphysical }
	Electromagnetic transitions in nuclei may be classified by their multipolarity (electric vs. magnetic multipole radiation) More...

Public Member Functions
	GammaStrengthFunctionModel (int Z, int A)

virtual double	strength_function (TransitionType type, int l, double e_gamma)=0
	Returns the gamma-ray strength function (MeV^{–2 \(\ell\)–1}) for the requested gamma energy and multipolarity.

virtual double	transmission_coefficient (TransitionType type, int l, double e_gamma)=0
	Returns the gamma-ray transmission coefficient (dimensionless) for the requested gamma energy and multipolarity.

Static Protected Member Functions
static void	check_multipolarity (int l)
	Check that l > 0 and throw a marley::Error if it is not.

Protected Attributes
int	A_
	Mass number.

int	Z_
	Atomic number.

Detailed Description

Abstract base class for models of gamma-ray strength functions.

Classes derived from GammaStrengthFunctionModel may be used to simulate gamma-ray emission in situations where nuclear level data are unavailable. In particular, the HauserFeshbachDecay class uses instances of GammaStrengthFunctionModel to model the competition between gamma-ray emission and particle evaporation for highly-excited nuclear states.

Definition at line 30 of file GammaStrengthFunctionModel.hh.

Member Enumeration Documentation

◆ TransitionType

enum class marley::GammaStrengthFunctionModel::TransitionType

strong

Electromagnetic transitions in nuclei may be classified by their multipolarity (electric vs. magnetic multipole radiation)

Definition at line 43 of file GammaStrengthFunctionModel.hh.

43{ electric, magnetic, unphysical };

Constructor & Destructor Documentation

◆ GammaStrengthFunctionModel()

marley::GammaStrengthFunctionModel::GammaStrengthFunctionModel	(	int	Z,
		int	A )

Parameters

Z	Atomic number of the desired nuclide
A	Mass number of the desired nuclide

Definition at line 25 of file GammaStrengthFunctionModel.cc.

26 : Z_(Z), A_(A) {}

marley::GammaStrengthFunctionModel::Z_

int Z_

Atomic number.

Definition GammaStrengthFunctionModel.hh:74

marley::GammaStrengthFunctionModel::A_

int A_

Mass number.

Definition GammaStrengthFunctionModel.hh:75

References A_, and Z_.

Referenced by marley::StandardLorentzianModel::StandardLorentzianModel(), and marley::WeisskopfSingleParticleModel::WeisskopfSingleParticleModel().

Member Function Documentation

◆ check_multipolarity()

void marley::GammaStrengthFunctionModel::check_multipolarity ( int l )

staticprotected

Check that l > 0 and throw a marley::Error if it is not.

Todo: Improve error message

Definition at line 28 of file GammaStrengthFunctionModel.cc.

                                                                {
  if (l < 1) throw marley::Error( "Invalid multipolarity "
    + std::to_string(l) + " given for gamma ray strength"
    " function calculation" );
}

Referenced by marley::WeisskopfSingleParticleModel::strength_function().

◆ strength_function()

virtual double marley::GammaStrengthFunctionModel::strength_function	(	TransitionType	type,
		int	l,
		double	e_gamma )

pure virtual

Returns the gamma-ray strength function (MeV^{–2 \(\ell\)–1}) for the requested gamma energy and multipolarity.

Parameters

type	Electric or magnetic transition
l	Multipolarity of the transition
e_gamma	Gamma-ray energy (MeV)

Implemented in marley::StandardLorentzianModel, and marley::WeisskopfSingleParticleModel.

◆ transmission_coefficient()

virtual double marley::GammaStrengthFunctionModel::transmission_coefficient	(	TransitionType	type,
		int	l,
		double	e_gamma )

pure virtual

Returns the gamma-ray transmission coefficient (dimensionless) for the requested gamma energy and multipolarity.

The gamma-ray transmission coefficient and strength function are related via \(\text{T}_{\text{X}\ell}(\text{E}_\gamma) = 2\pi f_{\text{X}\ell}(\text{E}_\gamma)\text{E}_\gamma^{(2\ell + 1)},\) where X is the type of transition (electric or magnetic), \(\ell\) is the multipolarity, \(\text{T}_{\text{X}\ell}\) is the transmission coefficient, \(f_{\text{X}\ell}\) is the strength function, and \(\text{E}_\gamma\) is the gamma-ray energy.

Parameters