Most cross sections are from Arnaud & Rothenflug 1985, who present fitting formulae to data from both theory and experiments.

In general inner shells are included, however to avoid having to deal with Auger electrons the ionisation rate is taken as the total energy rate divided by the valence shell ionization potential (this leads to a slight overestimate of the ionization rate).

The cross sections are assumed to refer to collisions leaving the ion in its ground state (except for O I for which a few individual states are treated).

In general one needs to know the differential cross sections, i.e. how the remaining energy is divided between the primary and the ejected electron. These cross sections are generally not available. The code uses the differential form based on Opal, Petersen & Beaty 1971.

H I

Arnaud & Rothenflug 1985

He I

Arnaud & Rothenflug 1985

He II

Arnaud & Rothenflug 1985

C I

Arnaud & Rothenflug 1985, 2S2 and 2P2 shells (not 1S2).

C II

Arnaud & Rothenflug 1985, 2S2 and 2P shells (not 1S2).

C III *

Arnaud & Rothenflug 1985, 2S2 shell (not 1S2).

N I

Arnaud & Rothenflug 1985, 2S2 and 2P3 shells.

N II

Arnaud & Rothenflug 1985, 2S2 and 2P2 shells.

N III

Arnaud & Rothenflug 1985, 2S2 and 2P shells.

O I

Laher & Gilmore 1990, from 2S2 and 2P4 to 4 states in O II (4S0(GS), 2D0, 2P0 and the 'inner hole' state 2S2P4)

O II

Arnaud & Rothenflug 1985, 2S2 and 2P3 shells.

O III

Arnaud & Rothenflug 1985, 2S2 and 2P2 shells.

Ne I

Arnaud & Rothenflug 1985, 2S2 and 2P6 shells.

Ne II

Arnaud & Rothenflug 1985, 2S2 and 2P5 shells.

Ne III

Arnaud & Rothenflug 1985, 2S2 and 2P4 shells.

Na I

Arnaud & Rothenflug 1985, 2P6 and 3S shells.

Na II

Arnaud & Rothenflug 1985, 2S2 and 2P6 shells.

Na III

Arnaud & Rothenflug 1985, 2S2 and 2P5 shells.

Mg I

Arnaud & Rothenflug 1985, 2S2, 2P6 and 3S2 shells.

Mg II

Arnaud & Rothenflug 1985, 2S2, 2P6 and 3S shells.

Aluminium

Not included.

Si I

Arnaud & Rothenflug 1985, 3S2 and 3P2 shells.

Si II

Arnaud & Rothenflug 1985, 3S2 and 3P shells.

Si III *

Arnaud & Rothenflug 1985, 2S2, 2P6 and 3S2 shells.

Phosphurus

Not included

S I

Arnaud & Rothenflug 1985, 2S2, 3P4 shells.

S II

Arnaud & Rothenflug 1985, 2S2, 3P3 shells.

S III

Arnaud & Rothenflug 1985, 2S2, 3P2 shells.

Chlorine

Not included.

Ar I

Arnaud & Rothenflug 1985, 3S2, 3P6 shells.

Ar II

Arnaud & Rothenflug 1985, 3S2, 3P5 shells

Ar III

Arnaud & Rothenflug 1985, 3S2, 3P4 shells

Potassium

Not included

Ca I

Arnaud & Rothenflug 1985, 3S2, 3P6, 4S2 shells

Ca II

Arnaud & Rothenflug 1985, 3S2, 3P6, 4S shells

Ca III

Arnaud & Rothenflug 1985, 3S2, 3P6 shells

Scandium

Not included

Titanium

Not included

Vanadium

Not included

Chromium

Not included

Manganese

Not included

Fe I

Arnauld & Raymond 1992, 3P6, 3D6, 4S2 shells.

Fe II

Arnauld & Raymond 1992, 3P6, 3D6, 4S shells.

Fe III

Arnauld & Raymond 1992, 3P6, 3D6 shells.

Co I

Source of data unclear (not in AR85 or in AR92), 3P6, 3D7 and 4S2 shells included.

3P6 : ABCD = 69.9, -23.7, 9.5, -51.7. IP = 59 eV

3D7 : ABCD = 11.1, -3.5, 0.35, -5.35. IP = 9 eV

4S2 : ABCD = 3.9, -1.3, 0.4, -1.9. IP = 7.88 eV

Co II

Source of data unclear (not in AR85 or in AR92), 3S2, 3P6, 3D8 shells included.

3S2 : ABCD = 19.2, -5.7, 2.3, -12.7. IP : 142 eV

3P6 : ABCD = 69.9, -23.7, 9.5, -51.7. IP : 84 eV

3D8 : ABCD = 28.8, -8.8, 0.9, -13.6. IP : 17.1 eV

Co III

Source of data unclear (not in AR85 or in AR92), 3S2, 3P6, 3D7 shells included.

3S2 : ABCD = 19.2, -5.7, 2.3, -12.7. IP : 141 eV

3P6 : ABCD = 69.9, -23.7, 9.5, -51.7. IP 103 eV

3D7 : ABCD = 38.6, -12.3, 1.2, -18.7. IP 33.5eV

Ni I

Arnaud & Rothenflug 1985, 3P6, 3D8, 4S2 shells.

Ni II

Arnaud & Rothenflug 1985, 3S2, 3P6, 3D9 shells.

Ni III

Arnaud & Rothenflug 1985, 3S2, 3P6, 3D8 shells.