Module inelastic 

Inelastic electron scattering from dielectric-function models.

The simplest model is the single-pole Penn algorithm (penn): from a user-supplied optical energy-loss function (crate::electron::data::OpticalElf) it builds the momentum-dependent loss function, the differential inverse inelastic mean free path (DIIMFP), the inelastic mean free path and the stopping power, with nonrelativistic kinematics. sum_rules checks an optical ELF against the f-sum and perfect-screening sum rules, bethe gives the nonrelativistic Bethe stopping the model must approach at high energy, and drude is an analytic Drude-Lorentz ELF with closed-form sum rules, used as a synthetic fixture by the tests, examples and benchmarks.

No optical data is committed for this module (docs/data-provenance.md): the valence ELF comes from the caller.

inner_shell resolves the losses into a valence channel and inner-shell ionization channels (secondary energy ω - B), each from its own optical ELF, and the optional Born-Ochkur ExchangeCorrection makes the primary and the struck electron indistinguishable at low energy. shell_elf builds the inner-shell ELFs of the K, L1, L2 and L3 subshells from the hydrogenic photoionization formulas and a subshell binding-energy table; other shells come from the caller.

table builds the inelastic energy-loss CrossSectionTable and a momentum-transfer sampler from the model.

The full Penn algorithm (full_penn) expands the same optical ELF over the Lindhard dielectric functions of free-electron gases (lindhard_gas) and costs about a second per energy where the single pole costs milliseconds; model selects either per material and gives the string to record in the metadata of derived tables.

The Mermin-ELF model (mermin, mermin_fit) fits a sum of Mermin oscillators to the optical ELF (the MELF-GOS approach: amplitudes constrained non-negative, fit residuals and sum rules reported) and extends it to finite momentum with the Mermin relaxation-time dielectric function; it is the third option of model beside the single pole and the full Penn algorithm.

Relativistic kinematics are later work.

Re-exports

pub use drude::DrudeLorentz;

pub use drude::DrudeLorentzOscillator;

pub use full_penn::DiimfpEvaluation;

pub use full_penn::DiimfpGrid;

pub use full_penn::FullPenn;

pub use full_penn::ImfpEvaluation;

pub use full_penn::LossFunctionEvaluation;

pub use full_penn::DEFAULT_FULL_TOLERANCE;

pub use full_penn::OMEGA_P_INTERVAL_BUDGET;

pub use inner_shell::Channel;

pub use inner_shell::ChannelDiimfp;

pub use inner_shell::ChannelInverseImfp;

pub use inner_shell::InnerShell;

pub use inner_shell::ShellResolvedChannels;

pub use lindhard_gas::LindhardGas;

pub use lindhard_gas::LindhardPlasmon;

pub use mermin::MerminGas;

pub use mermin::MerminPenn;

pub use mermin::DEFAULT_MERMIN_TOLERANCE;

pub use mermin_fit::fit_mermin_oscillators;

pub use mermin_fit::FitWeighting;

pub use mermin_fit::MerminFit;

pub use mermin_fit::MerminFitOptions;

pub use mermin_fit::MAX_OSCILLATORS;

pub use model::PennAlgorithm;

pub use model::PennInelastic;

pub use penn::born_ochkur_factor;

pub use penn::ExchangeCorrection;

pub use penn::InelasticPoint;

pub use penn::SinglePolePenn;

pub use penn::DEFAULT_RELATIVE_TOLERANCE;

pub use shell_elf::hydrogenic_2p_oscillator_strength_density_per_ev;

pub use shell_elf::hydrogenic_2s_oscillator_strength_density_per_ev;

pub use shell_elf::hydrogenic_k_oscillator_strength_density_per_ev;

pub use shell_elf::hydrogenic_shell_elf;

pub use shell_elf::hydrogenic_shell_elfs;

pub use shell_elf::ShellElfGrid;

pub use sum_rules::SumRuleReport;

Modules

bethe

Nonrelativistic Bethe stopping, the high-energy reference for the dielectric models.

drude

An analytic Drude-Lorentz energy-loss function with closed-form sum rules.

full_penn

The full Penn algorithm (FPA): the optical energy-loss function expanded over the Lindhard loss functions of free-electron gases, and the DIIMFP, inelastic mean free path and stopping power built from it.

inner_shell

Inner-shell ionization channels from shell-resolved loss functions.

lindhard_gas

The Lindhard dielectric function of a free-electron gas at zero temperature (random-phase approximation), in Hartree atomic units (m_e = e = ħ = 1), and the loss-function integrals built from it.

mermin

The Mermin dielectric function of a free-electron gas, and the Mermin-ELF inelastic model built from a fit of oscillators to an optical ELF.

mermin_fit

Fitting Mermin oscillators to an optical energy-loss function (the MELF-GOS fit).

model

Choosing the ELF-extension model per material.

penn

The single-pole Penn algorithm: the momentum-dependent energy-loss function, the differential inverse inelastic mean free path (DIIMFP), the inelastic mean free path (IMFP) and the stopping power, built from an optical ELF.

shell_elf

Inner-shell optical ELFs built from the hydrogenic K-shell (1s) and L-subshell (2s, 2p) photoionization formulas, for ShellResolvedChannels.

sum_rules

Sum rules of an optical energy-loss function.

table

Inelastic sampling tables from the single-pole Penn DIIMFP (issue #94): an electron::data::CrossSectionTable with SamplingAxis::InelasticEnergyLoss (the inverse mean free path and the inverse CDF of the energy loss W at every energy of a caller-chosen grid), and a sampler of the momentum transfer q given (E, W), from which the deflection angle follows.