#include <deformednucleus.h>

DeformedNucleus: Child of nucleus for deformed nuclei.

All options from the nucleus will still apply. The deformed nucleus adds new or updated features which are outlined below.

Definition at line 27 of file deformednucleus.h.

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Public Member Functions
	DeformedNucleus (const std::map< PdgCode, int > &particle_list, int nTest)
	Constructor for DeformedNucles which takes a particle list and the number of testparticles. More...

	DeformedNucleus (Configuration &config, int nTest)
	Constructor for DeformedNucleus, that needs the configuration parameters from the inputfile and the number of testparticles. More...

double	deformed_woods_saxon (double r, double cosx) const
	Return the deformed Woods-Saxon probability for the given position. More...

ThreeVector	distribute_nucleon () override
	Deformed Woods-Saxon sampling routine. More...

void	set_deformation_parameters_automatic ()
	Sets the deformation parameters of the radius according to the current mass number. More...

void	set_deformation_parameters_from_config (Configuration &config)
	Set parameters for spherical deformation of the nucleus from the values specified in the configuration file. More...

void	rotate () override
	Rotates the nucleus according to members nucleus_polar_angle_ and nucleus_azimuthal_angle_ and updates nucleon positions. More...

void	generate_fermi_momenta () override
	Does not allow to generate Fermi-momenta for a deformed nucleus. More...

double	y_l_0 (int l, double cosx) const
	Spherical harmonics Y_2_0 and Y_4_0. More...

void	set_beta_2 (double b2)
	Set deformation coefficient for Y_2_0. More...

void	set_beta_4 (double b4)
	Set deformation coefficient for Y_4_0. More...

void	set_polar_angle (double theta)
	Set the nucleus polar angle. More...

void	set_azimuthal_angle (double phi)
	Set the nucleus azimuthal angle. More...

Public Member Functions inherited from smash::Nucleus
	Nucleus ()=default
	default constructor More...

	Nucleus (Configuration &config, int nTest)
	Constructor for Nucleus, that needs the configuration parameters from the inputfile and the number of testparticles. More...

	Nucleus (const std::map< PdgCode, int > &particle_list, int nTest)

virtual	~Nucleus ()=default

double	mass () const

double	woods_saxon (double x)
	Woods-Saxon distribution. More...

void	arrange_nucleons ()
	Sets the positions of the nucleons inside a nucleus. More...

virtual void	set_parameters_automatic ()
	Sets the deformation parameters of the Woods-Saxon distribution according to the current mass number. More...

virtual void	set_parameters_from_config (Configuration &config)
	Sets the parameters of the Woods-Saxon according to manually added values in the configuration file. More...

void	boost (double beta_scalar)
	Boosts the nuclei into the computational frame, such that the nucleons have the appropriate momentum and the nuclei are lorentz-contracted. More...

void	fill_from_list (const std::map< PdgCode, int > &particle_list, int testparticles)
	Adds particles from a map PDG code => Number_of_particles_with_that_PDG_code to the nucleus. More...

void	shift (double z_offset, double x_offset, double simulation_time)
	Shifts the nucleus to correct impact parameter and z displacement. More...

void	copy_particles (Particles *particles)
	Copies the particles from this nucleus into the particle list. More...

size_t	size () const
	Number of numerical (=test-)particles in the nucleus: More...

size_t	number_of_particles () const
	Number of physical particles in the nucleus: More...

FourVector	center () const
	Calculate geometrical center of the nucleus. More...

void	align_center ()
	Shifts the nucleus so that its center is at (0,0,0) More...

std::vector< ParticleData >::iterator	begin ()
	For iterators over the particle list: More...

std::vector< ParticleData >::iterator	end ()
	For iterators over the particle list: More...

std::vector< ParticleData >::const_iterator	cbegin () const
	For const iterators over the particle list: More...

std::vector< ParticleData >::const_iterator	cend () const
	For const iterators over the particle list: More...

void	set_diffusiveness (double diffuse)
	Sets the diffusiveness of the nucleus. More...

double	get_diffusiveness () const

void	set_saturation_density (double density)
	Sets the saturation density of the nucleus. More...

double	get_saturation_density () const

double	default_nuclear_radius ()

void	set_nuclear_radius (double rad)
	Sets the nuclear radius. More...

double	get_nuclear_radius () const

Private Attributes
double	beta2_ = 0.0
	Deformation parameter for angular momentum l=2. More...

double	beta4_ = 0.0
	Deformation parameter for angular momentum l=4. More...

Angles	nuclear_orientation_
	Nucleus orientation (initial profile in xz plane) in terms of a pair of angles (theta, phi) More...

Additional Inherited Members
Protected Attributes inherited from smash::Nucleus
std::vector< ParticleData >	particles_
	Particles associated with this nucleus. More...

Constructor & Destructor Documentation

smash::DeformedNucleus::DeformedNucleus	(	const std::map< PdgCode, int > &	particle_list,
		int	nTest
	)

Constructor for DeformedNucles which takes a particle list and the number of testparticles.

This constructor is only used for testing purposes.

Parameters

[in]	particle_list	Map with PDGCode and number of particles which make up the nucleus
[in]	nTest	number of testparticles

Example: Configuring a deformed nucleus

To configure a fixed target heavy-ion collision with deformed nuclei, whose spherical deformation is explicitly declared, it can be done according to the following example. For explanatory (and not physics) reasons, the projectile's Woods Saxon distribution is initialized automatically and it's spherical deformation manually, while the target nucleus is configured just the opposite.

Modi:
    Collider:
        Projectile:
            Particles:    {2212: 29, 2112: 34}
            Deformed:
                # Manually set deformation parameters
                Automatic: False
                Beta_2: 0.1
                Beta_4: 0.3
                Theta: 0.8
                Phi: 0.02
        Target:
            Particles:    {2212: 29, 2112: 34}
            # manually set woods saxon parameters
            Saturation_Density: 0.1968
            Diffusiveness: 0.8
            Radius: 2.0
            Deformed:
                # Automatically set deformation parameters
                Automatic: True
        E_kin: 1.2
        Calculation_Frame: "fixed target"

Definition at line 96 of file deformednucleus.cc.

98 : Nucleus(particle_list, nTest) {}

smash::Nucleus::Nucleus

Nucleus()=default

default constructor

smash::DeformedNucleus::DeformedNucleus	(	Configuration &	config,
		int	nTest
	)

Constructor for DeformedNucleus, that needs the configuration parameters from the inputfile and the number of testparticles.

Parameters

[in]	config	contains the parameters from the inputfile on the numbers of particles with a certain PDG code
[in]	nTest	number of testparticles

Definition at line 100 of file deformednucleus.cc.

     : Nucleus(config, nTest) {
   if (config.has_value({"Deformed", "Automatic"}) &&
       config.take({"Deformed", "Automatic"})) {
     set_deformation_parameters_automatic();
   } else {
     set_deformation_parameters_from_config(config);
   }
 }

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Member Function Documentation

double smash::DeformedNucleus::deformed_woods_saxon	(	double	r,
		double	cosx
	)		const

Return the deformed Woods-Saxon probability for the given position.

Parameters

[in]	r	The radius at which to sample
[in]	cosx	The cosine of the polar angle at which to sample

Returns: The Woods-Saxon probability

Definition at line 110 of file deformednucleus.cc.

                                                                         {
   return Nucleus::get_saturation_density() /
          (1 + std::exp((r - Nucleus::get_nuclear_radius() *
                                 (1 + beta2_ * y_l_0(2, cosx) +
                                  beta4_ * y_l_0(4, cosx))) /
                        Nucleus::get_diffusiveness()));
 }

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ThreeVector smash::DeformedNucleus::distribute_nucleon ( )

overridevirtual

Deformed Woods-Saxon sampling routine.

Returns: Spatial position from uniformly sampling the deformed woods-saxon distribution

Reimplemented from smash::Nucleus.

Definition at line 118 of file deformednucleus.cc.

                                                 {
   double a_radius;
   Angles a_direction;
   // Set a sensible maximum bound for radial sampling.
   double radius_max =
       Nucleus::get_nuclear_radius() / Nucleus::get_diffusiveness() +
       Nucleus::get_nuclear_radius() * Nucleus::get_diffusiveness();
 
   // Sample the distribution.
   do {
     a_direction.distribute_isotropically();
     // sample r**2 dr
     a_radius = radius_max * std::cbrt(random::canonical());
   } while (random::canonical() >
            deformed_woods_saxon(a_radius, a_direction.costheta()) /
                Nucleus::get_saturation_density());
 
   // Update (x, y, z) positions.
   return a_direction.threevec() * a_radius;
 }

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void smash::DeformedNucleus::set_deformation_parameters_automatic ( )

Sets the deformation parameters of the radius according to the current mass number.

The deformation parameters are taken from Moller:1993ed. Corrections to the deformation parameter beta2 in Uranium come from Kuhlman:2005ts. For finite nucleon size corrections to the nuclear density and radius for copper and gold, see Hirano:2009ah, and Hirano:2010jg for uranium.

Definition at line 139 of file deformednucleus.cc.

                                                            {
   // Set the deformation parameters extracted from \iref{Moller:1993ed}.
   switch (Nucleus::number_of_particles()) {
     case 238:  // Uranium
       set_beta_2(0.28);
       set_beta_4(0.093);
       break;
     case 208:  // Lead
       set_beta_2(0.0);
       set_beta_4(0.0);
       break;
     case 197:  // Gold
       set_beta_2(-0.131);
       set_beta_4(-0.031);
       break;
     case 63:  // Copper
       set_beta_2(0.162);
       set_beta_4(-0.006);
       break;
     default:
       throw std::domain_error(
           "Mass number not listed for automatically setting deformation "
           "parameters. Please specify at least \"Beta_2\" and \"Beta_4\" "
           "manually and set \"Automatic: False.\" ");
   }
 
   // Set a random nuclear rotation.
   nuclear_orientation_.distribute_isotropically();
 }

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void smash::DeformedNucleus::set_deformation_parameters_from_config ( Configuration & config )

Set parameters for spherical deformation of the nucleus from the values specified in the configuration file.

Parameters

config The configuration for the deformation of this nucleus (projectile or target).

Definition at line 169 of file deformednucleus.cc.

                            {
   // Deformation parameters.
   if (config.has_value({"Deformed", "Beta_2"})) {
     set_beta_2(static_cast<double>(config.take({"Deformed", "Beta_2"})));
   }
   if (config.has_value({"Deformed", "Beta_4"})) {
     set_beta_4(static_cast<double>(config.take({"Deformed", "Beta_4"})));
   }
   if (config.has_value({"Deformed", "Theta"})) {
     set_polar_angle(static_cast<double>(config.take({"Deformed", "Theta"})));
   }
   if (config.has_value({"Deformed", "Phi"})) {
     set_azimuthal_angle(static_cast<double>(config.take({"Deformed", "Phi"})));
   }
 }

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void smash::DeformedNucleus::rotate ( )

overridevirtual

Rotates the nucleus according to members nucleus_polar_angle_ and nucleus_azimuthal_angle_ and updates nucleon positions.

Reimplemented from smash::Nucleus.

Definition at line 186 of file deformednucleus.cc.

                              {
   for (auto &particle : *this) {
     /* Rotate every vector by the nuclear azimuth phi and polar angle
      * theta (the Euler angles). This means applying the matrix for a
      * rotation of phi about z, followed by the matrix for a rotation
      * theta about the rotated x axis. The third angle psi is 0 by symmetry.*/
     ThreeVector three_pos = particle.position().threevec();
     three_pos.rotate(nuclear_orientation_.phi(), nuclear_orientation_.theta(),
                      0.);
     particle.set_3position(three_pos);
   }
 }

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void smash::DeformedNucleus::generate_fermi_momenta ( )

overridevirtual

Does not allow to generate Fermi-momenta for a deformed nucleus.

Exceptions

domain_error if this function is ever called

Reimplemented from smash::Nucleus.

Definition at line 199 of file deformednucleus.cc.

                                              {
   throw std::domain_error(
       "Fermi momenta currently not implemented"
       " for a deformed nucleus.");
 }

double smash::DeformedNucleus::y_l_0	(	int	l,
		double	cosx
	)		const

Spherical harmonics Y_2_0 and Y_4_0.

Parameters

[in]	l	Angular momentum value (2 and 4 are supported)
[in]	cosx	Cosine of the polar angle

Returns: Value of the corresponding spherical harmonic

Exceptions

domain_error if unsupported l is encountered

Definition at line 205 of file deformednucleus.cc.

                                                       {
   if (l == 2) {
     return (1. / 4) * std::sqrt(5 / M_PI) * (3. * (cosx * cosx) - 1);
   } else if (l == 4) {
     return (3. / 16) * std::sqrt(1 / M_PI) *
            (35. * (cosx * cosx) * (cosx * cosx) - 30. * (cosx * cosx) + 3);
   } else {
     throw std::domain_error(
         "Not a valid angular momentum quantum number in"
         "DeformedNucleus::y_l_0.");
   }
 }

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void smash::DeformedNucleus::set_beta_2 ( double b2 )

inline

Set deformation coefficient for Y_2_0.

Parameters

[in] b2 deformation coefficient for l=2

Definition at line 108 of file deformednucleus.h.

108 { beta2_ = b2; }

smash::DeformedNucleus::beta2_

double beta2_

Deformation parameter for angular momentum l=2.

Definition: deformednucleus.h:131

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void smash::DeformedNucleus::set_beta_4 ( double b4 )

inline

Set deformation coefficient for Y_4_0.

Parameters

[in] b4 deformation coefficient for l=4

Definition at line 113 of file deformednucleus.h.

113 { beta4_ = b4; }

smash::DeformedNucleus::beta4_

double beta4_

Deformation parameter for angular momentum l=4.

Definition: deformednucleus.h:133

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void smash::DeformedNucleus::set_polar_angle ( double theta )

inline

Set the nucleus polar angle.

Parameters

[in] theta Polar angle of position inside nucleus

Definition at line 118 of file deformednucleus.h.

                                             {
     nuclear_orientation_.set_theta(theta);
   }

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void smash::DeformedNucleus::set_azimuthal_angle ( double phi )

inline

Set the nucleus azimuthal angle.

Parameters

[in] phi Azimuthal angle of position inside nucleus

Definition at line 125 of file deformednucleus.h.

                                               {
     nuclear_orientation_.set_phi(phi);
   }

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Member Data Documentation

double smash::DeformedNucleus::beta2_ = 0.0

private

Deformation parameter for angular momentum l=2.

Definition at line 131 of file deformednucleus.h.

double smash::DeformedNucleus::beta4_ = 0.0

private

Deformation parameter for angular momentum l=4.

Definition at line 133 of file deformednucleus.h.

Angles smash::DeformedNucleus::nuclear_orientation_

private

Nucleus orientation (initial profile in xz plane) in terms of a pair of angles (theta, phi)

Definition at line 138 of file deformednucleus.h.

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

src/include/smash/deformednucleus.h
src/deformednucleus.cc

Public Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

Example: Configuring a deformed nucleus

Member Function Documentation

Member Data Documentation