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J/A+AS/97/443     Fluorescence for Be to Zn                      (Kaastra+ 1993)
X-ray emission from thin plasmas. I.
Multiple Auger ionisation and fluorescence processes for Be to Zn.
     Kaastra J.S., Mewe R.
    <Astron. Astrophys. Suppl. Ser. 97, 443 (1993)>
    =1993A&AS...97..443K
ADC_Keywords: Atomic physics

Keywords: atomic data


Abstract:
    The  basic physical processes responsible for X-ray emission from thin
    plasmas  are considered.  Collisional ionization or photoionization of
    inner shells of  neutral atoms  and ions  leads to  the creation  of a
    vacancy in one of the inner shells of the ion or atom, which is filled
    by a cascade of  radiative  (fluorescent)   and  nonradiative  (Auger)
    transitions.   The net result is the ejection of several electrons and
    photons, leaving the atom in a multiply ionized state.  In this paper,
    the  distribution of the number of emitted photons and electrons after
    the creation of a hole in  an  inner  shell  of  an  atom  or  ion  is
    calculated for all  ions from  H to  Zn.  The  method consists  of two
    stages:  the calculation of transition  rates  for  a  given  electron
    configuration, and calculation of probabilities of the several cascade
    sequences using these transition rates.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table2            76     1090   Electron distribution
table3            30    11732   Fluorescence yields


Byte-by-byte Description of file: table2

   Bytes Format  Units   Label    Explanations

   1-  2  I2     ---     Z        Atomic number
   3-  5  I3     ---     st       Ionisation stage of ion BEFORE ionisation
                                    (neutral=1 etc.)
   6-  7  I2     ---     s        Shell number of primary vacancy
                                    (1-7 correspond to K L1 L2 L3 M1 M2 M3)
   8- 14  F7.1   eV      I        Ionisation energy of the primary vacancy 
                                    in eV (from Lotz)
  15- 21  F7.1   eV      EA       Energy that goes into Auger electrons, in eV
  22- 25  I4     10-3    epsilon  Correction factor defined in equation 6 of
                                    the paper
  27- 31  I5     10-4    PrEj1    Probability that a photo-ionisation leads to
                                    ejection of 1 electron (1)
  32- 36  I5     10-4    PrEj2    Probability of 2 electrons photoionisation (1)
  37- 41  I5     10-4    PrEj3    Probability of 2 electrons photoionisation (1)
  42- 46  I5     10-4    PrEj4    Probability of 2 electrons photoionisation (1)
  47- 51  I5     10-4    PrEj5    Probability of 2 electrons photoionisation (1)
  52- 56  I5     10-4    PrEj6    Probability of 2 electrons photoionisation (1)
  57- 61  I5     10-4    PrEj7    Probability of 2 electrons photoionisation (1)
  62- 66  I5     10-4    PrEj8    Probability of 2 electrons photoionisation (1)
  67- 71  I5     10-4    PrEj9    Probability of 2 electrons photoionisation (1)
  72- 76  I5     10-4    PrEj10   Probability of 2 electrons photoionisation (1)

Note (1): NOTE that the probabilities have been multiplied by 10000.



Byte-by-byte Description of file: table3

   Bytes Format  Units   Label    Explanations

   1-  3  I3     ---     Z        Atomic number
   4-  6  I3     ---     st       Ionisation stage of ion BEFORE ionisation
                                    (neutral=1 etc.)
   7-  9  I3     ---     s        Shell number of primary vacancy
                                    (1-7 correspond to K L1 L2 L3 M1 M2 M3)
  10- 12  I3     ---     Delta    Number of Auger electrons ejected before
                                    emission of the line; the line therefore
                                    occurs in the ion with ionisation stage
                                    st+Delta+1 (the factor 1 corresponds to the
                                    photo-electron)
  13- 15  I3     ---     il       Line identification number; labels according
                                    to table 1 of the paper. Note that il runs
                                    from 1 to 22.
  16- 23  F8.1   eV      E        Approximate line energy of the transition;
                                    note that often more accurate energies can
                                    be found in the literature.
  24- 30  F7.4   ---     omega    The fluorescence yield omega for this line
                                    (number of photons emitted
                                     per primary vacancy)

(End)                                    Francois Ochsenbein [CDS]   13-Apr-1993