darkhistory.physics.coll_ion_xsec

darkhistory.physics.coll_ion_xsec(eng, species=None, method='old')

e-e collisional ionization cross section in cm².

For the ‘old’ method, see 0906.1197. For the ‘MEDEA’ method, see Mon. Not. R. Astron. Soc. 422, 420–433 (2012). For the ‘new’ method, TBD.

Parameters:

eng : float or ndarray

Abscissa of kinetic energies.

species : {‘HI’, ‘HeI’, ‘HeII’}

Species of interest. if method == ‘MEDEA’,

see Mon. Not. R. Astron. Soc. 422, 420–433 (2012);

if method == ‘AcharyaKhatri’

see arXiv:1910.06272;

if method == ‘new’, same as MEDEA for collisional ionization, if method == ‘eff’, same as ‘new’.

Returns:

float or ndarray

e-e collisional ionization cross section.

Notes

Returns the Arnaud and Rothenflug rate if method == ‘old’.