11
sum of all ionization rates
out
of He-like, weighted by the appropriate He-like initial state
populations, and summed over all final states in the H-like ion. The averaging over initial states
is completed by dividing the above sum by the total population of the He-like ion.
α
tot
for the
He-like ion is the sum of all recombination rates out of He-like, weighted by the appropriate He-
like initial state populations, and summed over all final states in the Li-like ion.
The averaging
over initial states is completed by dividing the above sum by the total population of the He-like
ion.
With these definitions, we can define a set of ionization rate equations.
In the case of the
He-like ion, we write:
dn
(
He
)
dt
=
α
tot
(
H
)
n
(
H
)
-
[
α
tot
(
He
)
+S
tot
(
He
)
]
n
(
He
)
+S
tot
(
Li
)
n
(
Li
)
.
Units of
<S
tot
>
and
<
α
tot
>
are 1/sec.
In
section 4
, the
energy_levels
section, the following quantities are requested:
<Nbound>
Identifies the ionization stage to which this energy level belongs.
As always,
this quantity is the number of bound electrons in the level.
<level>
A sequential level number within this ionization stage.
This index begins at 1
within each ionization stage for use as a label in model comparisons.
The
ground state of each ion stage will be identified by locating the state of lowest
energy within the ion stage.
<stwt>
The statistical weight of this energy level.
<energy>
The energy of the level relative to the overall model. Ionization potentials will
be obtained by subtraction of successive ground state energies.
Units are in
eV. The overall energy reference is the ground state of the most neutral ion in
the problem.
<population>
The
normalized
ion density of this level.
Sum of all level populations over all
ions is unity
.
<
Γ
tot
>
The
total
population flux out
of this level. Units are 1/sec.
<f_
Γ
collBB
>
The
fractional
contribution of electron collision excitation/de-excitation
processes to
<
Γ
tot
>
.
<f_
Γ
photoBB
>
The
fractional
contribution of bound-bound radiation processes to
<
Γ
tot
>
.
<f_
Γ
collBF
>
The
fractional
contribution of electron collision ionization-recombination
processes to
<
Γ
tot
>
.
<f_
Γ
photoBF
>
The
fractional
contribution of photo-ionization-recombination to
<
Γ
tot
>
.
<f_
Γ
auto
>
The
fractional
contribution of auto-ionization/dielectronic recombination
processes to
<
Γ
tot
>
.
<
Θ
tot
>
The
total
population flux into
this level.
For steady-state condition
<
Θ
tot
> =
-<
Γ
tot
>.
Units are 1/sec.