Chung and Everhart

Presentation

This is a model for emission energy distribution of SEs [CE74]. It does not take into account incidence angle of PEs.

Input files

You must provide an emission energy distribution at normal incidence. Currently, the fitting on several emission distribution files at different PE energies is not supported.

	Emission Yield	Emission energy distribution	Emission angle distribution
“True” secondaries	❌	❌	❌
Elastically backscattered	❌	❌	❌
Inelastically backscattered	❌	❌	❌
Total	❌	✅	❌

Definitions

Emission energy distribution is given by:

\[f(E_\mathrm{SE}) = \frac{E_\mathrm{SE}}{\left( E_\mathrm{SE} + W_f \right)^4}\]

\(W_f\) is the material work function in \(\mathrm{eV}\). In order to set it’s maximum to unity, we scale it by \(256W_f/27\).

Model parameters

The parameters list is dynamically created here: Chung and Everhart API documentation.

To-do list

Todo

Allow fitting on several distribution files with different PE energy.
Set up tests.