Computer simulations

Introduction

Lately, a clear trend in the development and applications of line-broadening calculations is a significant increase in the computational results, in particular, using computer simulations [1].

Computer simulation is the discipline of designing an abstract model of an actual physical system, executing the model on a computer, and analyzing the execution output. The scale of models being simulated by computer simulations today far exceeds anything possible (or perhaps even imaginable) using traditional paper-and-pencil mathematical modeling.

Method

The calculations [2] are split into two largely independent computational pieces. The first one is the molecular-dynamics N-body simulation that models the motion of plasma particles. The fields produced at the radiators, as a result of the essentially chaotic motion of the plasma particles modeled, are stored as a function of time for a subsequent use in the second computational piece. The latter piece treats these "field histories'' as a time-dependent perturbating potential while solving the Schrödinger equation for a radiating atom.

The method is rather unique in its universality and in the broad scope of effects included, naturally accounting for all frequency regions of the plasma-particle fields and for the effects of the particle interactions, being applicable to line-shape calculations of isolated and overlapping spectral lines involving both dipole-allowed and dipole-forbidden radiative transitions under a simultaneous influence of externally-applied (constant or time-dependent) electric and magnetic fields in both weakly and strongly coupled plasmas.

 

Applications

The method has been used for benchmarking competing Stark-broadening theories [3], analyzing the influence of the correlations effects on the line shapes in plasmas [2,4], spectroscopic analysis of radiation-heated foams [5,6], state-of-the-art accurate atomic-data measurements [7], and 3D-mapping of fluctuating electric fields in pulsed plasmas [8].

References

1. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).
2. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).
3. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).
4. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).
5. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).
6. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).
7. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).
8. E. Stambulchik and Y. Maron
   A study of ion-dynamics and correlation effects for spectral line broadening in plasma: K-shell lines
   J. Quant. Spectr. Rad. Transfer 99, 730–749 (2006).

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