Function `adas.r8ecip`

def r8ecip(iz, xi, energy)

Evaluates the ECIP (exchange classical impact parameter) electron impact ionization cross section.

Parameters

iz : int: recombined ion charge.
xi : float: effective ionization potential (eV).
energy : float: evaluate the cross section at these energies (eV).

Returns

sigma : float: ionization rate cross section (cm2)

Notes

Pure python code but calls some functions which depend on complied code.

This function returns the cross section. For the rate use the unfortunately similarly named r8necip function. Note that the units for xi in this function are eV and not Rydbergs.

References

The primary references are two internal laboratory reports and a journal article: A Burgess, AERE R-4818 (1964) H P Summers, Appleton Laboratory IM-367 (1974) A Burgess and H P Summers, Mon. Not. T. Astron. Soc., 174, p345 (1976)

Version History

Martin O'Mullane, 02-08-2022
- First version

Example

Calculate the ionization cross section from n=3 level of neutral hydrogen.

>>> import adas as adas
>>> import numpy as np
>>> xi = (109679.0 - 97492.3) / 8066.0
>>> energy = np.geomspace(13.6, 500.0, 4)
>>> adas.r8ecip(0, xi, energy)
array([2.09688024e-15, 9.68722430e-16, 3.65417749e-16, 1.26294046e-16])