J/A+A/634/A117 Screening potential and continuum lowering (Zeng+, 2020)
Screening potential and continuum lowering in a dense plasma under
solar-interior conditions.
Zeng J., Li Y., Gao C., Yuan J.
<Astron. Astrophys. 634, A117 (2020)>
=2020A&A...634A.117Z 2020A&A...634A.117Z (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Sun
Keywords: atomic data - atomic processes - Sun: interior - stars: interior -
dense plasma
Abstract:
An accurate description of the screening potential induced by a hot,
dense plasma is a fundamental problem in atomic physics and plasma
physics, and it plays a pivotal role in the investigation of
microscopic atomic processes and the determination of macroscopic
physical properties, such as opacities and equations of state as well
as nuclear fusion cross sections. Recent experimental studies show
that currently available analytical models of plasma screening have
difficulty in accurately describing the ionization-potential
depression, which is directly determined by the screening potential.
Here, we propose a consistent approach to determine the screening
potential in dense plasmas under solar-interior conditions from the
free-electron micro-space distribution. It is assumed that the
screening potential for an ion embedded in a dense plasma is
predominately determined by the free electrons in the plasma. The
free-electron density is obtained by solving the
ionization-equilibrium equation for an average-atom model to obtain
the average degree of ionization of the plasma. The proposed model was
validated by comparing the theoretically predicted
ionization-potential depression of a solid-density Si plasma with
recent experiments. Our approach was applied to investigate the
screening potential and ionization-potential depression of Si plasmas
under solar-interior conditions over a temperature range of 150-500eV
and an electron-density range of 5.88x1022-3.25x1024cm-3. It
can be easily incorporated into atomic-structure codes and used to
investigate basic atomic processes, such as photoionization,
electron-ion collisional excitation and ionization, and Auger decay,
in a dense plasma.
Description:
The ionization potential depressions for solar plasmas are given from
0.7523R☉ to 0.3529R☉. In order to determine the ionization
potential depressions, the plasma screening potentials are given as
well.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 63 10 Comparison of ionization potential depressions
for solid-density Si plasmas
fig2.dat 127 321 Screening potential in Si plasmas
fig3.dat 106 10 Ionization-potential depressions of Si plasmas
fig4.dat 162 11 Comparison of our theoretical ionization-potential
depression with the analytical models
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Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Stage Ionization stage
6- 11 F6.2 eV IPD ? Results using the present model
17- 25 F9.5 eV Expt ? The experimental results
30- 37 F8.4 eV EK ? Ecker & Kroll model
43- 50 F8.4 eV IS Ion-sphere model
56- 63 F8.4 eV SP Stewart & Pyatt model
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Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
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1- 10 E10.3 au r Radial Coordinate
13- 19 F7.4 au P156 Screening potential at 156.90eV, 5.88E22cm-3
22- 28 F7.4 au P189 ? Screening potential at 189.00eV, 8.00E22cm-3
31- 37 F7.4 au P205 ? Screening potential at 205.12eV, 9.89E22cm-3
40- 46 F7.4 au P227 ? Screening potential at 227.53eV, 1.36E23cm-3
49- 55 F7.4 au P244 ? Screening potential at 244.94eV, 1.70E23cm-3
58- 64 F7.4 au P275 ? Screening potential at 275.80eV, 2.76E23cm-3
67- 73 F7.4 au P304 ? Screening potential at 304.23eV, 4.06E23cm-3
76- 82 F7.4 au P334 ? Screening potential at 334.40eV, 6.12E23cm-3
85- 91 F7.4 au P373 ? Screening potential at 373.18eV, 9.79E23cm-3
94-100 F7.4 au P407 ? Screening potential at 407.65eV, 1.43E24cm-3
103-109 F7.4 au P438 ? Screening potential at 438.70eV, 1.96E24cm-3
112-118 F7.4 au P468 ? Screening potential at 468.84eV, 2.57E24cm-3
121-127 F7.4 au P496 ? Screening potential at 496.42eV, 3.25E24cm-3
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Byte-by-byte Description of file: fig3.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Stage Ionization stage
5- 10 F6.2 eV IPD156 Ionization-potential depression
at 156.90eV, 5.88E22cm-3
13- 18 F6.2 eV IPD189 Ionization-potential depression
at 189.00eV, 8.00E22cm-3
21- 26 F6.2 eV IPD205 Ionization-potential depression
at 205.10eV, 9.89E22cm-3
29- 34 F6.2 eV IPD227 Ionization-potential depression
at 227.50eV, 1.36E23cm-3
37- 42 F6.2 eV IPD244 Ionization-potential depression
at 244.9eV, 1.70E23cm-3
45- 50 F6.2 eV IPD275 Ionization-potential depression
at 275.80eV, 2.76E23cm-3
53- 58 F6.2 eV IPD304 ? Ionization-potential depression
at 304.20eV, 4.06E23cm-3
61- 66 F6.2 eV IPD334 ? Ionization-potential depression
at 334.40eV, 6.12E23cm-3
69- 74 F6.2 eV IPD373 ? Ionization-potential depression
at 373.18eV, 9.79E23cm-3
77- 82 F6.2 eV IPD407 ? Ionization-potential depression
at 407.65eV, 1.43E24cm-3
85- 90 F6.2 eV IPD438 ? Ionization-potential depression
at 438.70eV, 1.96E24cm-3
93- 98 F6.2 eV IPD468 ? Ionization-potential depression
at 468.84eV, 2.57E24cm-3
101-106 F6.2 eV IPD496 ? Ionization-potential depression
at 496.42eV, 3.25E24cm-3
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Byte-by-byte Description of file: fig4.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Stage Ionization stage
5- 10 F6.2 eV IPD156 Ionization-potential depression of this work
at 156.90eV, 5.88E22cm-3
13- 18 F6.2 eV DH156 Debye & Huckel model
21- 26 F6.2 eV SP156 Stewart & Pyatt model
29- 34 F6.2 eV IS156 Ion-sphere model
37- 42 F6.2 eV EK156 Ecker & Kroll model
45- 50 F6.2 eV IPD227 Ionization-potential depression of this work
at 227.50eV, 1.36E23cm-3
53- 58 F6.2 eV DH227 Debye & Huckel model
61- 66 F6.2 eV SP227 Stewart & Pyatt model
69- 74 F6.2 eV IS227 Ion-sphere model
77- 82 F6.2 eV EK227 Ecker & Kroll model
85- 90 F6.2 eV IPD407 Ionization-potential depression of this work
at 407.65eV, 1.43E24cm-3
93- 98 F6.2 eV DH407 Debye & Huckel model
101-106 F6.2 eV SP407 Stewart & Pyatt model
109-114 F6.2 eV IS407 Ion-sphere model
117-122 F6.2 eV EK407 Ecker & Kroll model
125-130 F6.2 eV IPD496 Ionization-potential depression of this work
at 496.42eV, 3.25E24cm-3
133-138 F6.2 eV DH496 Debye & Huckel model
141-146 F6.2 eV SP496 Stewart & Pyatt model
149-154 F6.2 eV IS496 Ion-sphere model
157-162 F6.2 eV EK496 Ecker & Kroll model
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Acknowledgements:
Jiaolong Zeng, jiaolongzeng(at)hotmail.com
(End) Patricia Vannier [CDS] 20-Jan-2020