J/ApJ/850/122 Electron-impact multiple-ionization cross sections (Hahn+, 2017)
Electron-impact multiple-ionization cross sections for atoms and ions of helium
through zinc.
Hahn M., Muller A., Savin D.W.
<Astrophys. J., 850, 122 (2017)>
=2017ApJ...850..122H 2017ApJ...850..122H
ADC_Keywords: Atomic physics; References
Keywords: atomic data ; atomic processes ; techniques: spectroscopic
Abstract:
We compiled a set of electron-impact multiple-ionization (EIMI) cross
section for astrophysically relevant ions. EIMIs can have a
significant effect on the ionization balance of non-equilibrium
plasmas. For example, it can be important if there is a rapid change
in the electron temperature or if there is a non-thermal electron
energy distribution, such as a kappa distribution. Cross section for
EIMI are needed in order to account for these processes in plasma
modeling and for spectroscopic interpretation. Here, we describe our
comparison of proposed semiempirical formulae to available
experimental EIMI cross-section data. Based on this comparison, we
interpolated and extrapolated fitting parameters to systems that have
not yet been measured. A tabulation of the fit parameters is provided
for 3466 EIMI cross sections and the associated Maxwellian plasma rate
coefficients. We also highlight some outstanding issues that remain to
be resolved.
Description:
Here, we produced a database of electron-impact multiple-ionization
(EIMI) cross sections for astrophysics. In order to generate this
database, we compared measurements of EIMI cross sections to
predictions using the proposed semiempirical formulae. Table 1 gives
the references for all of the experimental data sources that we
consulted.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . this file
table1.dat 135 175 Experimental EIMI data sources
table2.dat 68 3466 Fitting formulae for EIMI cross sections
table5.dat 151 3466 Fitting parameters for Maxwellian rate coefficients
refs.dat 249 48 References
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See also:
J/A+AS/97/443 : Fluorescence for Be to Zn (Kaastra+ 1993)
J/A+A/410/359 : Radiative and Auger decay for Fe II-Fe IX (Palmeri+, 2003)
J/A+A/414/377 : FeX-FeXVII fine-structure K-vacancy levels (Mendoza+, 2004)
J/ApJS/167/343 : Plasma Recombination rate coefficients (Bryans+, 2006)
J/A+A/466/771 : Ionization rate coefficients for elements H-Zn (Dere+, 2007)
J/ApJS/185/477 : N K-shell photoabsorption (Garcia+, 2009)
J/A+A/525/A59 : Atomic data for Al ions (Palmeri+, 2011)
J/ApJ/760/80 : Fe9+ and Fe10+ cross-section measurements (Hahn+, 2012)
J/A+A/543/A44 : Atomic data for iron peak & light odd-Z ions (Palmeri+, 2012)
J/ApJ/767/47 : Fe13+, Fe16+, Fe17+ cross-section measures (Hahn+, 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 I1 --- Order [2/7] Order
3- 4 A2 --- Seq Sequence
6- 12 A7 --- Ion Atom or Ion
14- 61 A48 --- Ref Reference (see refs.dat file)
63-135 A73 --- Comm Comment
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Z [2/30] nuclear charge
4- 5 I2 --- qi [0/28] initial charge state
7- 8 I2 --- qf [2/30] final charge state
10- 10 I1 --- Eq [1/7] equation
12- 21 F10.4 eV Ith [17.9/24254] ionization threshold
23- 30 F8.5 --- f [0/15] f fitting parameter
32- 40 F9.5 --- p0 [0/400.2] p0 fitting parameter
42- 47 F6.3 --- p1 [0/30] p1 fitting parameter
49- 53 F5.3 --- p2 [0/2] p2 fitting parameter
55- 61 F7.3 --- p3 [-19.7/1] p3 fitting parameter
63- 68 F6.3 --- p4 [0/11.7] p4 fitting parameter
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Z [2/30] nuclear charge
4- 5 I2 --- qi [0/28] initial charge state
7- 8 I2 --- qf [2/30] final charge state
10- 19 F10.4 eV Eth [17.9/24254] energy threshold
21- 32 F12.9 --- a0 [-0.1/32] a0 fitting parameter
34- 46 F13.9 --- a1 [0/426] a1 fitting parameter
48- 62 F15.9 --- a2 [-3090.3/1.8] a2 fitting parameter
64- 78 F15.9 --- a3 [-7.3/11869.4] a3 fitting parameter
80- 94 F15.8 --- a4 [-23017.3/13] a4 fitting parameter
96-110 F15.9 --- a5 [-11.1/22040.7] a5 fitting parameter
112-126 F15.9 --- a6 [-8285/619.4] a6 fitting parameter
128-140 F13.8 --- a7 [-483.7/0.4] a7 fitting parameter
142-151 F10.8 --- err [0/0.2] maximum relative error of fit
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 48 A48 --- Ref Reference code (Author and year)
50- 68 A19 --- BibCode ADS bibcode of the reference if any
70-249 A180 --- Comm Comment
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 28-Jun-2018