celeritas::UUNuclearFormFactor Class Reference

Uniform-uniform folded nuclear form factor. More...

#include <NuclearFormFactors.hh>

Inheritance diagram for celeritas::UUNuclearFormFactor:

Public Member Functions
CELER_FUNCTION	UUNuclearFormFactor (AtomicMassNumber a_mass)
	Construct from atomic mass number.
CELER_FUNCTION real_type	operator() (MomentumSq target_momsq) const
	Calculate the uniform-uniform folded form factor by calculating momentum.
CELER_FUNCTION real_type	operator() (Momentum target_mom) const
	Calculate the uniform-uniform folded form factor.

Static Public Member Functions
static CELER_CONSTEXPR_FUNCTION FFType	ff_type ()
	Form factor type corresponding to this distribution.
Static Public Member Functions inherited from celeritas::NuclearFormFactorTraits
static CELER_CONSTEXPR_FUNCTION InvMomentum	fm_par_hbar ()
	Momentum transfer prefactor: 1 fm / hbar.

Additional Inherited Members
Public Types inherited from celeritas::NuclearFormFactorTraits
using	AtomicMassNumber = AtomicNumber
using	Momentum = units::MevMomentum
using	MomentumSq = units::MevMomentumSq
using	InvMomentum = RealQuantity< UnitInverse< Momentum::unit_type > >
using	InvMomentumSq = RealQuantity< UnitInverse< MomentumSq::unit_type > >
using	FFType = NuclearFormFactorType

Detailed Description

Uniform-uniform folded nuclear form factor.

This nuclear form factor corresponds NuclearFormFactorType::flat and assumes a uniform nuclear charge at the center with a smoothly decreasing charge at the surface. From leroy-2016 Eq. 2.265, this leads to a form factor:

\[ F(q) = F'(x(R_0, q)) F'(x(R_1, q)) \]

where \( x \equiv q R / \hbar \) uses the effective nuclear radius \( R_0 = 1.2 A^{1/3} \,\mathrm{fm} \) and nuclear surface skin \( R_1 = 2.0 \,\mathrm{fm} \), and

\[ F'(x) = \frac{3}{x^3} ( \sin x - x \cos x) \]

is the form factor for a uniformly charged sphere.

Warning

This form factor suffers from catastrophic numerical cancellation for small radii and momenta so should only be used for large nuclei or large momentum transfers.

See also helm-scattering-1956, fernandez-msc-1993

---

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

• NuclearFormFactors.hh