blike_jl96#al8j.dat

• Spontaneous Emission: Al⁺⁸(i) → Al⁺⁸(j) + hv
• Electron Impact Excitation: Al⁺⁸(i) + e → Al⁺⁸(j) + e

-----------------------------------------------------------------------------
 ENERGY LEVELS AND IONISATION POTENTIAL
 The ionisation potential is from Kelly (J Phys Chem Ref Data 16, 
 Suppl 1, 1987). The energies are from Edlen (Phys Scripta 28, 483, 
 1983). The ordering of the levels is as given in the work used for 
 the effective collision strengths. There are differences in energy
 of up to 68 cm-1 with the data from the NIST discs.

 TRANSITION PROBABILITIES
 For the transition between the 1/2 and 3/2 levels of the ground term 
 the multiconfiguration Hartree-Fock Breit-Pauli result of C Froese 
 Fischer (J Phys B 16, 157 1983) is used (1.04 s-1). The
 multiconfiguration Dirac-Fock calculations of Cheng, Kim and 
 Desclaux (ADNDT 24, 111, 1979) yielded 1.17 s-1.
 
 The results of of Merkelis, Vilkas, Gaigalas and Kisielius were 
 adopted. (Phys Scripta 51, 233, 1995). Their calculation employed 
 the stationary second order many-body perturbation theory, the 
 relativistic corrections being included using the Breit-Pauli 
 approximation. They say that for 12<=Z<=20 their results are 
 more accurate than the multiconfiguration Hartree-Fock with 
 Breit-Pauli correction results of Dankwort and Trefftz (Astron 
 Astrophys 65, 93, 1978). For allowed E1 transitions their 
 results obtained in intermediate LSJ-coupling are close to those
 determined by  Cheng et al, Dankwort and Trefftz not giving 
 results for this ion.

 EFFECTIVE COLLISION STRENGTHS
 In their assessment of effective collision strengths for the B-like 
 sequence Sampson, Zhang and Fontes (ADNDT 57, 98, 1994) review the 
 available results. No close coupling results were then available
 for this ion. However, Sampson et al anticipated the R-matrix close
 coupling calculations of Zhang, Graziana and Pradhan (Astron 
 Astrophys 283, 319,1994) for the 105 fine structure transitions 
 among the 15 levels of the 2s2 2p, 2s 2p2 and 2p3 configurations.
 These results are adopted here. The data were obtained 
 electronically and processed into ADF04 format.

 J Lang
 A Lanzafame         May 1996
-----------------------------------------------------------------------------
---------------------------------------------------------------------------------
---------------------------------------------------------------------------------

Contributors

• Jim Lang
• Hong Zhang
• Douglas Sampson
• Alessandro Lanzafame