Ar XV - VERSION 4.0

The CHIANTI database consists of 4 primary ASCII files for each ion in the database.

• ar_15.elvlc (energy levels)

  contains the energy levels in cm^(-1) It includes both experimental data and theoretical values of the levels energies.

  References:

  %energy levels (n=2): Fuhr, J.R., Kelleher, D.E., Martin, W.C., Musgrove, A., 
                        Sugar, J., Wiese, W.L., Dalton, G.R., Dragoset, R.A., 
                        Mohr, P.J., Olsen, K., Reader, J., Saloman, E.B., Sansonetti, C.J., 
                        Wiersma, G., "NIST Atomic Spectra Database" Ver. 2.0 March 1999. 
                        NIST Physical Reference Data.
  %energy levels (n=3): Khardi et al, 1994, Physica Scripta, 49, 571
  %Theoretical energy levels (n=2): Zhang, Sampson, ADNDT, 1992 , 52, 143
  %theoretical energy levels (n=3): Sampson, D.H., Goett, S.J., Clark, R.E.H., 1984, ADNDT, 30, 125
  %produced as part of the Arcetri/Cambridge/NRL atomic data base collaboration
  %
  % K.P.Dere (n=3 levels June 97); E.Landi Mar 2001 (n=2 levels)
  

  
  

• ar_15.wgfa (radiative data)

  contains wavelengths, gf and A values for each transition. Wavelengths are based on experimental level energies where available; wavelengths calculated from theoretical energies are less accurate and are given as negative values.

  References:

  %energy levels (n=2): Fuhr, J.R., et al. 1999 "NIST Atomic Spectra Database" 
      Ver. 2.0 March 1999.  NIST Physical Reference Data.
  %energy levels (n=3): Khardi et al, 1994, Physica Scripta, 49, 571
  %theoretical energy levels (n=2): Sampson, D.H., Goett, S.J., Clark, R.E.H., 1984, ADNDT, 30, 125.
  %Allowed transitions oscillator strengths (n=2): Zhang, Sampson, ADNDT, 1992 , 52, 143
  %Allowed transitions oscillator strengths (n=3): Sampson, Goett, Clark, 1984, ADNDT, 30, 125
  %comment:transitions 1-4, 3-4, 3- 10 have been interpolated from
           the data of Be-like ions in Muhlethaler, Nussbaumer, A&A, 1976, 48, 109
  %comment:  gf values for transitions 19-26 and 23-26 were simply taken to be
     equal to the O V gf values reported by Hibbert, 1980, J. Phys. B, 13, 1721.
     The A values were obtained from the gf values by using the wavelengths listed.
  %produced as part of the Arcetri/Cambridge/NRL 'CHIANTI' atomic data base collaboration CHIANTI
  %
  %  E.Landi Mar 2001 (n=2);  n=3 levels added by K.P. Dere Jun 1996
  

  
  

• ar_15.splups (electron collision data)

  contains the spline fits to the electron collision strengths scaled according to Burgess and Tully (1992). Accurate replication of the temperature averaged collision strength over a wide range of temperatures can be accomplished with the data in this file.

  References:

  
  %filename: ar_15.splups
  %oscillator strengths (n=2): Zhang, Sampson, 1992, ADNDT, 52, 143
  %oscillator strengths (n=3): Sampson, Goett, Clark, 1984, ADNDT, 30, 125
  %Effective collision strengths (n=2): Keenan, F.P., 1988, Phys.Scripta, 37, 57
  %collision strengths (n=3): Sampson, D.H., Goett, S.J., Clark, R.E.H., 1984, ADNDT, 30, 125
  %comment: Have derived the upsilon data from Table VII of Keenan et al.
     The Delta-E's have been taken from the observed values in the .elvlc
     file. The gf values are from the .wgfa file.
     The upsilons have been created for logT=5.7-7.3 in 0.1 dex intervals.
  %produced as part of the Arcetri/Cambridge/NRL 'CHIANTI' atomic data base collaboration
  %
  % Enrico Landi March 2001 (n=2), K.P.Dere Jun 1996 (n=3)
  

  
  

• ar_15.psplups (electron collision data)

  contains the spline fits to the scaled proton collision strengths.

  References:

  
  %file: ar_15.psplups
  %rates: Ryans R.S.I., Foster-Woods V.J, Copeland F., Keenan F.P., Matthews A., Reid R.H.G., 1998, ADNDT 70, 179-229
  %energies: Bhatia A.K., Feldman U., Seely J.F., 1986, ADNDT 35, 449-472
  %comment: Fits valid for temperatures 8e5 to 1.75e8 K.
  %produced as part of the Arcetri/Cambridge/NRL 'CHIANTI' atomic data base collaboration
  %
  % Peter Young  24-Oct-00