scholarly journals Non-LTE atomic modeling for laser-produced plasmas

1993 ◽  
Vol 11 (1) ◽  
pp. 119-126 ◽  
Author(s):  
H. Takabe ◽  
T. Nishikawa ◽  
S. Nakamura
Keyword(s):  
Statistical Method ◽  
Electronic State ◽  
Radiation Hydrodynamics ◽  
Model Based ◽  
Atom Model ◽  
Average Population ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Bound Electrons ◽  
Average Atom Model

Atomic modeling of high-Z partially ionized plasma is essential for simulating radiation hydrodynamics of laser-produced plasma. A collisional-radiative model based upon an average atom model is used to calculate plasma opacity and emissivity. Because line radiations are most dominant in such plasma, the detail configuration accounting (DCA) for electronic state is required. We propose a statistical method to carry out the DCA with the use of the average population of bound electrons. Further modeling of line group made of the same transition from ions in different change states is discussed by considering the detail structure (hierarchy) of the line group.

scholarly journals Calculations of radiation opacity for high Z elements

1990 ◽  
Vol 8 (1-2) ◽  
pp. 265-279 ◽  
Author(s):  
Tomasz Błeński ◽  
Jacques Ligou
Keyword(s):  
Cross Sections ◽  
Temperature Dependent ◽  
Absorption Bands ◽  
Thomas Fermi ◽  
Model Based ◽  
Atom Model ◽  
Independent Particle ◽  
Average Atom Model

We present some results of our opacity calculations for lead and gold at temperatures and densities relevant to ICF conditions. We use an average atom model based on the temperature dependent Thomas-Fermi shell approach. The absorption bands (broadening of lines) are accounted for with a simple T.F. fluctuation formula. The independent particle bound-bound, bound-free, and free-free photon cross-sections are taken without further approximations.

scholarly journals Line profile modeling for non-LTE partially ionized plasmas based on average atom model with l–splitting

1993 ◽  
Vol 11 (1) ◽  
pp. 81-87 ◽  
Author(s):  
T. Nishikawa ◽  
H. Takabe ◽  
K. Mima
Keyword(s):  
Electronic State ◽  
Radiation Transport ◽  
Bound State ◽  
Electron Energy Level ◽  
Atom Model ◽  
Partially Ionized Plasmas ◽  
Partially Ionized ◽  
Charge States ◽  
The Difference ◽  
Average Atom Model

We have developed a new opacity modeling of partially ionized high-Z plasma to solve radiation transport in fluid codes. The average atom model is used to describe the electronic state of the plasma. The electronic state of the plasma is determined by solving the collisional radiative equilibrium model. We have taken into account the electron energy level splitting owing to the difference in the azimuthal quantum number. To model the line groups made of the same electronic transitions from ions indifferent charge states, we used a statistical method and calculated the distribution of the charge states from the averaged electron population in each bound state. By using the new opacity model, we can well reproduce the X-ray spectra from the plasmas. It is found that the Δn = 0 transition can explain the peaked spectra near hv = 300 eV and l–splitted emission of the n = 5–4 transition can explain the flat spectra in the region of hv = 400–800 eV seen in the experiments.

scholarly journals Time-dependent collisional radiative model of ionizing and recombining plasmas

1990 ◽  
Vol 8 (4) ◽  
pp. 697-708
Author(s):  
H. Minoo ◽  
M. Cukier ◽  
J. Haidar
Keyword(s):  
Charge State ◽  
Atomic Physics ◽  
Computing Time ◽  
Time Dependent ◽  
Model Based ◽  
Spacetime Point ◽  
Collisional Radiative Model ◽  
Radiative Model ◽  
Transient Plasma

A time-dependent collisional radiative model, based on a five-charge state at any spacetime point in the plasma, is elaborated in order to follow the basic atomic physics processes in a plasma undergoing ionization and recombination. This model can either be used independently or be included in a magnetohydrodynamics code of a transient plasma. In the latter case, the efficiency of the model makes it particularly useful in saving computing time of hydrodynamic codes developed in connection with ion-driven fusion.

Dielectronic Recombination in the Average-Atom Model

1988 ◽  
Vol 102 ◽  
pp. 215
Author(s):  
R.M. More ◽  
G.B. Zimmerman ◽  
Z. Zinamon
Keyword(s):  
Detailed Balance ◽  
Systematic Errors ◽  
Dielectronic Recombination ◽  
Rate Equations ◽  
Strong Correlations ◽  
Dense Plasmas ◽  
Atom Model ◽  
New Feature ◽  
Average Atom Model ◽  
Attachment Process

Autoionization and dielectronic attachment are usually omitted from rate equations for the non–LTE average–atom model, causing systematic errors in predicted ionization states and electronic populations for atoms in hot dense plasmas produced by laser irradiation of solid targets. We formulate a method by which dielectronic recombination can be included in average–atom calculations without conflict with the principle of detailed balance. The essential new feature in this extended average atom model is a treatment of strong correlations of electron populations induced by the dielectronic attachment process.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

DIELECTRONIC RECOMBINATION IN THE AVERAGE-ATOM MODEL

1988 ◽  
Vol 49 (C1) ◽  
pp. C1-215-C1-215
Author(s):  
R. M. MORE ◽  
G. B. ZIMMERMAN ◽  
Z. ZINAMON
Keyword(s):  
Dielectronic Recombination ◽  
Atom Model ◽  
Average Atom Model
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