J/A+AS/136/395      IRON Project XXXVII. Fe VI collision strengths (Chen+ 1999)
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Atomic data from the Iron Project. XXXVII. Electron impact excitation collision
strengths and rate coefficients for Fe VI
       Chen G.X., Pradhan A.K.
      <Astron. Astrophys. Suppl. Ser. 136, 395 (1999)>
      =1999A&AS..136..395C      (SIMBAD/NED BibCode)
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ADC_Keywords: Atomic physics

Keywords: electron collision rates - fine structure transitions -
          hot stellar sources: white dwarfs - H II regions: planetary nebulae

Abstract:
    Collision strengths and Maxwellian-averaged rate coefficients have
    been calculated for 3,160 non-vanishing transitions among 80 fine
    structure levels, dominated by configurations 3d3, 3d24s, and
    3d24p in Fe VI. Collision strengths are calculated using the
    R-matrix method with a 34-term close-coupling target expansion and for
    electron energies up to 10 Rydbergs. Detailed comparisons of rate
    coefficients are presented with the relativistic Breit-Pauli
    calculations using a 19-level expansion corresponding to the first
    8 LS terms dominated by the ground configuration 3d3. For the
    low-lying transitions of practical interest there is excellent
    agreement, better than 10%, among three sets of rate coefficients
    calculated using 34 term and 8-term non-relativistic calculations and
    the 19-level Breit-Pauli calculation, indicating that (i) the
    relativistic effects are not too significant, and (ii) the numerical
    uncertainties associated with the resolution of the extensive
    resonances in the collision strengths are small. Rate coefficients are
    tabulated in a range of temperatures, 104-106K, where Fe VI is
    normally abundant in radiatively photoionized or collisionally ionized
    plasmas sources. The present rates for Fe VI are expected to find
    applications in UV spectral diagnostics of hot stellar sources and
    planetary nebulae.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
level4            35       80   Levels for table4
table4            80     8798   Maxwellian-averaged collision strengths
                             Upsilon(i,j) for the 3160 transitions between
                             the 140 levels at T=10000-1000000K in Fe VI
prog.f            74       36   Fortran code to read the data file table4


Structure of file table4:
--------------------------------------------------------------------------------
    Records    Format          Explanations
--------------------------------------------------------------------------------
    1-   4  20A4               Title
         5  3I5                Nuclear charge number Z (26), number of electrons
                                per ion N (21) and the number of levels (80)
    6-  85  2I4,1X,F8.6,(A8)   Level index, twice total angular momentum
                                2J, and the energy (configuration and term)
        86  2I8                Number of transitions NTR (3160=80*79/2) and
                                number of temperatures NTEMP (21)
   87- 481  7x,8(3x,i2,i3,1x)  Transition keys ((i,j),i=1,j-1),j=2,ntr)),
                                with i and j being the initial and the
                                final levels.
       482  F8.0               Temperature T = 2000 K
  483- 877  8(1PE9.2)          Upsilons for the corresponding transitions
                                specified in Record 87 - 481.
  878-8797  F8/8((1PE9.2,1X)   Repeating the above for 20 more temperatures:
                                 10000,  20000,   30000,  40000,  50000,  60000,
                                 70000,  80000,   90000, 100000, 150000, 200000,
                                250000, 300000,  400000, 500000, 600000, 700000,
                                800000, 900000, 1000000

See also:
    J/A+AS/103/273 : IRON Project II      IR collision strengths of C-like ions
    J/A+A/283/319  : IRON Project III     B-like ions
    J/A+AS/108/1   : IRON Project V       Collision strengths of O-like ions
    J/A+A/293/953  : IRON Project VI      Fe II collision strengths
    J/A+A/293/967  : IRON Project VII     Fe II radiative transitions
    J/A+AS/109/193 : IRON Project VIII    Electron excitation of Ti-like ions
    J/A+AS/119/509 : IRON Project XVII    Radiative transition in Fe III
    J/A+AS/119/523 : IRON Project XVIII   Electron impact for Fe III
    J/A+AS/120/361 : IRON Project XIX     Fe II radiative transitions
    J/A+AS/123/159 : IRON Project XXII    C and O radiative rates
    J/A+AS/123/575 : IRON Project XXIII   Fe XXII excitation rate coefficients
    J/A+AS/131/499 : IRON Project XXIX    Boron isoelectronic sequence
    J/A+AS/131/153 : IRON Project XXXI    Fe XII electron excitation
    J/A+AS/126/373 : IRON Project XXVII   Fe IV collision strengths
    J/A+AS/135/347 : IRON Project XXXV    Fe XXIV & Fe XXV oscillator strengths
    J/A+AS/137/165 : IRON Project XXXVIII Fe XV electron excitation
    J/A+AS/143/483 : IRON Project XLII    Fe XXI electron impact excitation
    J/A+AS/144/141 : IRON Project XLIII   Fe V transition probabilities
    J/A+AS/147/111 : IRON Project XLIV    Fe VI trans. prob. & line ratio
    J/A+AS/147/253 : IRON Project XLV     Ar XIII, Fe XXI trans. probabilities
    J/A+A/365/268  : IRON Project XLVII   Ni III electron impact excitation
    J/A+A/372/1078 : IRON Project XLIX    Fe XX electron impact excitation
    J/A+A/372/1083 : IRON Project L       Fe XIX electron impact excitation
    J/A+A/394/753  : IRON Project LI      Fe IX electron impact excitation
    J/A+A/408/789  : IRON Project LIII    Fe XVII transition probabilities
    J/A+A/413/779  : IRON Project LIV     Fe XX transition probabilities
    J/A+A/420/763  : IRON Project LV      Ni II electron impact excitation
    J/A+A/437/345  : IRON Project LIX     Fe IV transition probabiliti
    J/A+A/448/779  : IRON Project LXI     Fe IV radiative transitions
    J/A+A/457/721  : IRON Project LXII    Fe XVIII allowed and forbidden trans.
    J/A+A/466/763  : IRON Project LXIII   Fe19+ electron impact excitation


Byte-by-byte Description of file:  level4

   Bytes Format Units   Label     Explanations

   1-  2  I2    ---     Index     Level index
   5-  6  I2    ---     2J        Twice total angular momentum
  10- 17  F8.6  Ry      E         Experimental energy
  23- 35  A13   ---     Term      configuration and electronic term


History:
  * 02-Apr-1999: first version
  * 17-Jun-1999: table4 was updated (new version supplied by the author)
  * 18-Jul-1999: table4 newly updated (a newer version supplied by the author)

Acknowledgements: Guo-xin Chen 


References:
  1993A&A...279..298H : IRON Project I      Goal and methods
  1994A&AS..107...29S : IRON Project IV     Electron excitation of F-like ions
  1995A&AS..110..209P : IRON Project IX     Electron excitation of Cl-like ion
  1995A&AS..111..347G : IRON Project X      Si- & S-like ions IR coll. strengths
  1996A&AS..115..151S : IRON Project XI     Ar VI, K VII & CaVIII fine-structure
  1995A&AS..114..367B : IRON Project XII    V-like ions electron excitation 
  1996A&AS..115..551B : IRON Project XIII   Ni II & Fe II electron excitation
  1996A&A...309..677S : IRON Project XIV    Fe XIV fine-structure transition 
  1996A&AS..118..157K : IRON Project XV     He II & Fe XXVI Electron excitation 
  1996A&AS..119..105B : IRON Project XVI    Fe V oscillator strengths
  1997A&AS..122..167B : IRON Project XX     Fe I oscillator strengths
  1997A&AS..122..177P : IRON Project XXI    Fe I fine-structure transition
  1997A&AS..126..105B : IRON Project XXIV   Fe XXIV electron excitation
  1998A&AS..127..545B : IRON Project XXV    Fe XII electron excitation
  1997A&AS..126..365B : IRON Project XXVI   Fe IV oscillator strengths
  1998A&AS..129..161B : IRON Project XXVIII F-like ions fine-structure trans.
  1999A&AS..134..369S : IRON Project XXX    P III, S IV & Cl V collision data
  1998A&AS..133..245G : IRON Project XXXII  Ar III effective collision strength
  1999A&AS..135..159M : IRON Project XXXIII Carbon radiative rates 
  1999A&AS..136..385E : IRON Project XXXIV  Fe XVI electron impact excitation
  1999A&AS..137..175C : IRON Project XXXVI  Fe XXIII electron excitation
  1999A&AS..137..529B : IRON Project XXXIX  Ni II oscillator strengths 
  2000A&AS..141..285S : IRON Project XL     Fe XIV electron excitation
  2000A&AS..142..313B : IRON Project XLI    Fe VII electron excitation
  2001A&A...365..258P : IRON Project XLVI   Fe X electron excitation
  2003A&A...401.1177C : IRON Project LII    Ni24 electron excitation
  2005A&A...436.1123M : IRON Project LVII   Ni IV radiative transition rates
  2005A&A...433..717S : IRON Project LVIII  Fe XII electron impact excitation
  2006A&A...446..361W : IRON Project LX     Fe17+ electron impact excitation
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(End)                                         Patricia Bauer [CDS]   17-Jun-1999