# blike_jl96#c1j.dat

## Resolved Specific Ion Data Collections

Ion
C1+
Temperature Range
0.086 eV → 3.447 eV

Filename
blike_jl96#c1j.dat
Full Path
• Spontaneous Emission: C+1(i) → C+1(j) + hv
• Electron Impact Excitation: C+1(i) + e → C+1(j) + e
 2s2 2p 2P0.5 0.0 cm-1 2s2 2p 2P1.5 63.4 cm-1 2s1 2p2 4P0.5 43003.3 cm-1 2s1 2p2 4P1.5 43025.3 cm-1 2s1 2p2 4P2.5 43053.6 cm-1 2s1 2p2 2D2.5 74930.1 cm-1 2s1 2p2 2D1.5 74932.6 cm-1 2s1 2p2 2S0.5 96493.7 cm-1 2s1 2p2 2P0.5 110624.0 cm-1 2s1 2p2 2P1.5 110666.0 cm-1 2s2 3s 2S0.5 116538.0 cm-1 2s2 3p 2P0.5 131724.0 cm-1 2s2 3p 2P1.5 131736.0 cm-1 2p3 4S1.5 142027.0 cm-1 2p3 2D2.5 150462.0 cm-1 2p3 2D1.5 150467.0 cm-1 2p3 2P0.5 168730.0 cm-1 2p3 2P1.5 168748.0 cm-1
 + 1         6         2    196664.7
-----------------------------------------------------------------------------
FILE: blike_jl96#c1.dat

ENERGY LEVELS and IONISATION POTENTIAL
These are taken from the book 'Tables of Spectra of H, C, N and O
Atoms and Ions', C. E. Moore , ed. J. W. Gallagher (CRC Press).
The energy levels  differ by less than one cm-1 from those given in
the NIST data discs. The levels up to 14 inclusive are the 14 lowest
energy levels. The levels are ordered by increasing energy. Only levels
with n=2 or n=3 below the first ionisation potential are included.
The work of Edlen (Physica Scripta, 28, 483, 1983) did not include CII.

TRANSITION PROBABILITIES
For allowed transitions, Yan, Taylor and Seaton (J Phys B, 20, 6399,
987) have published calculations done for the Opacity Project using
the Opacity Project close-coupling method. They point out that
Nussbaumer and Storey (Astron. Astrophys. 96,91 1981) used the same
formalism as the UCL method. All results obtained are in good
agreement with each other. That and other comparisons give confidence
that the results are unlikely to be in error due coding mistakes or
numerical problems. Since Yan et al do not give fine structure
resolved results but Nussbaumer and Storey do, the results of
Nussbaumer and Storey are adopted here. One small difference is that
the fine-structure resolved results from Nussbaumer and Storey are
only obtained in the SuperStructure (SS) case. Comparisons of the gf
values from both these calculations for transitions involving n=2
levels are given below. Also included are results from the earlier
(not so comprehensive for this ion) work  of Dankwort and Treffetz
(Astron. Astrophys. 65, 93, 1978) and from two more recent
calculations by Lennon et al (Astrophy. J 294, 200, 1985, CIV3 code)
and Froese-Fischer (Physica Scripta 49, 323, 1994, MCHF in Breit-
Pauli approx.).

2s22p - 2s2p2   Exp       D+T    FF     Lennon  Yan    N+S(CC) (SS)
2P       2D    0.762     0.773  0.816  0.758   0.768  0.759   0.779
2P       2S    0.732(5%) 0.769  0.696  0.750   0.750  0.742   0.748
2P       2P    2.94(4%)  2.908  2.994  3.063   3.06   3.028   3.085

2s2p2 - 2p3     D+T    FF     Yan    N+S(CC)  (SS)
4P      4S     2.116  2.076  2.124  2.095    2.158
2D      2D     1.325         1.270  1.251
2D      2P                   1.68   1.664
2S      2P                          4.688-3
2P      2D     0.609         0.504  0.5079
2P      2P                   0.872  0.851

The highest transition for which Nussbaumer and Storey give transition
probabilities is 11-14. Their data are used for the following
1-7, 1-8, 1-9, 1-10, 2-6, 2-7, 2-8, 2-9, 2-10, 3-4, 3-5, 3-11, 3-12,
3-14, 4-5, 4-11, 4-12, 4-14, 5-12, 5-14, 6-13, 6-14, 7-12, 7-13, 7-14,
8-12, 8-13, 8-14, 9-11, 9-12, 9-13, 9-14, 10-11, 10-12, 10-13, 10-14,
11-12, 11-13, 11-14.
Note that this list includes some intercombination lines as well as
values for transitions within the 2s2 2p 4P term.

For the remaining allowed transitions the data from the NIST discs were
used. These data for the half dozen values cross checked appear to be
from Wiese, Smith and Glennon (NSRDS NBS 4, 1966) and are given on the
discs as having accuracy C or worse (25% or worse).
Their data are used for the following:
1-11, 1-15, 2-11, 6-15, 6-16, 6-18, 7-15, 7-16, 7-17, 7-18,
9-16, 10-15, 10-16.

Considering now the forbidden transitions, for the transition 1-2,
between the 1/2 and 3/2 levels of the ground 2P term, Nussbaumer and
Storey give a value of 2.29-6 s-1 while more recently Froese Fischer
(J Phys B, 16, 157, 1983) has published a value of 2.049-6 s-1 from a
multi-configuration Hartree-Fock Breit-Pauli calculation. The latter
value is used here. Note that Keenan et al (Astron. Astroph. 300, 534,
1995) say they used the result from Lennon et al to help predict a
value for Ne VI but Lennon et al don't actually quote a value.

A values for the intercombination 2s2 2p2P - 2s 2p2 4P transition have
et al and Froese Fischer whose 1994 paper was written after the
publication of measurements of the decay rates (Fang et al, Phys. Rev.
48A, 114, 1993).
The following is an adaptation of a table from the Froese Fischer paper.

Decay rates (s-1) of 2s2p2 4P levels

4P1/2            4P3/2            4P5/2
Fang et al          146.4+8.3/-9.2   11.6+0.08/-1.7   51.2+2.6/-3.5

Froese Fischer      132.2            10.9             46.1
Lennon et al        152.2            14.1             53.9
Nussbaumer+Storey   120.8             6.95            43.2
Dankwort+Treffetz    82.7             9.12            34.4

Using agreement with experiment as a criterion, the Lennon et al values
are adopted for the decay of the 4P1/2 (ie 1-3 and 2-3 transitions) and
for the decay of the 4P5/2 (2-5 transition) while the Froese Fischer
value is adopted for the decay of the 2P3/2 level (1-4 and 2-4
transitions).

EFFECTIVE COLLISION STRENGTHS
For collisions involving transitions between the 18 levels comprising
the 14 lowest levels and levels 17, 18, 22 and 23 the results of Blum
and Pradhan (Astrophys. J. SS 80, 425, 1992) are adopted. These were
scanned into a file which was then processed into ADF04 format.
At an assessment meeting (Sampson, Zhang and Fontes, ADNDT 44, 97, 1994)
there was no consensus whether the Blum and Pradhan results were more
accurate than the results of Lennon et al which only included 2s2 2p and
2s 2p2 terms. However, it was agreed that they were certainly not less
accurate.
The transitions 8-14 and 11-14 are given as having 0 effective collision
strength.

J Lang
A C Lanzafame            March 1996

Original data set energy level reduced to include only these with collision
rate coefficients.  Level indexing and annotation modified accordingly.

H P Summers              12 June 1996
-----------------------------------------------------------------------------
---------------------------------------------------------------------------------
---------------------------------------------------------------------------------


### Contributors

• Jim Lang
• Hong Zhang
• Douglas Sampson
• Alessandro Lanzafame
• Hugh Summers
• Processes
• States