scholarly journals Numerical simulation of emission spectra from ion beam-heated aluminum plasmas

1992 ◽  
Vol 10 (2) ◽  
pp. 349-363 ◽  
Author(s):  
J. J. MacFarlane ◽  
P. Wang
Keyword(s):  
Cross Sections ◽  
Impact Ionization ◽  
Ion Beam ◽  
Emission Spectra ◽  
Particle Beam ◽  
Rate Equations ◽  
Hartree Fock ◽  
Non Local ◽  
Temperature Diagnostic ◽  
Ionization Cross Sections

Non-local thermodynamic equilibrium radiative transfer calculations have been performed to predict emission spectra from plasma heated by intense proton beams. Multilevel, steady-state atomic rate equations were solved self-consistently with the radiation field to determine excitation and ionization populations. Ion beam effects were, included in the rate equations. Proton-impact ionization cross sections were calculated using a plane wave Born approximation model with Hartree-Fock wave functions for the electrons. We examined the dependence of emission spectra on the temperature and thickness of the plasma. In addition, Kα satellite line spectra were computed to assess its potential as a temperature diagnostic. Calculated Kα spectral results are compared with recent Particle Beam Fusion Accelerator II experimental data.

scholarly journals Plasma diagnostics using Kα satellite emission spectroscopy in light ion beam fusion experiments

1995 ◽  
Vol 13 (2) ◽  
pp. 231-241 ◽  
Author(s):  
J.J. MacFarlane ◽  
P. Wang ◽  
J.E. Bailey ◽  
T.A. Mehlhorn ◽  
R.J. Dukart
Keyword(s):  
Emission Spectroscopy ◽  
Impact Ionization ◽  
Ion Beam ◽  
Emission Spectra ◽  
Particle Beam ◽  
High Energy ◽  
Atomic Level ◽  
High Energy Density ◽  
Equilibrium Equations ◽  
X Ray

Kα satellite spectroscopy can be a valuable technique for diagnosing conditions in high energy density plasmas. Kα emission lines are produced in intense light ion beam plasma interaction experiments as 2p electrons fill partially open Is shells created by the ion beam. In this paper, we present results from collisional-radiative equilibrium (CRE) calculations which show how Kα emission spectroscopy can be used to determine target plasma conditions in intense lithium beam experiments on Particle Beam Fusion Accelerator-II (PBFAII) at Sandia National Laboratories. In these experiments, 8–10 MeV lithium beams with intensities of 1–2 TW/cm2 irradiate planar multilayer targets containing a thin Al tracer. Kα emission spectra are measured using an X-ray crystal spectrometer with a resolution of λ/∆λ = 1200. The spectra are analyzed using a CRE model in which multilevel (NL ∼ 103) statistical equilibrium equations are solved self-consistently with the radiation field and beam properties to determine atomic level populations. Atomic level-dependent fluorescence yields and ion-impact ionization cross sections are used in computing the emission spectra. We present results showing the sensitivity of the Kα emission spectrum to temperature and density of the Al tracer. We also discuss the dependence of measured spectra on the X-ray crystal spectral resolution, and how additional diagnostic information could be obtained using multiple tracers of similar atomic number.

A comparison of theory and experiment for photo-ionization cross-sections I. Neon and the elements from boron to neon

1951 ◽  
Vol 208 (1094) ◽  
pp. 408-418 ◽  
Keyword(s):  
Cross Sections ◽  
General Trend ◽  
Wave Functions ◽  
Ionization Cross ◽  
Hartree Fock ◽  
Quantal Theory ◽  
Ionization Cross Sections ◽  
Photo Ionization ◽  
Near Future ◽  
Dipole Length

The quantal theory of the continuous photo-electric absorption of radiation is briefly summarized, pàrticular attention being given to the alternative formulae available and to the accuracy to be expected in practical calculations. Detailed calculations are described for the photo-ionization cross-section of neon, a system for which it is understood that experimental data should be available in the near future. The calculation is made using Hartree-Fock wave functions and the two formulae of the dipole length and the dipole velocity. The corresponding cross-sections are found to be 5.8 and 4.4 x 10- 18 cm 2 . at the spectral head and to rise slowly with increasing frequency until a broad maximum is reached for an energy of the ejected electron of about 11 eV. A comparison is made with previous calculations on the elements from boron to neon ; the general trend of the results is discussed and improved estimates for boron and fluorine are given (10 x 10 -18 cm 2 . for boron and 4.3 x 10- 18 cm 2 . for fluorine at the spectral head).

Electron‐impact ionization cross sections of the SiF3 free radical

1988 ◽  
Vol 89 (7) ◽  
pp. 4035-4041 ◽  
Author(s):  
Todd R. Hayes ◽  
Randy J. Shul ◽  
Frank A. Baiocchi ◽  
Robert C. Wetzel ◽  
Robert S. Freund
Keyword(s):  
Free Radical ◽  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Electron Impact Ionization ◽  
Ionization Cross ◽  
Ionization Cross Sections

scholarly journals The Electron Impact Ionization Cross Sections of Methanol, Ethanol and 1-Propanol

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 60 ◽  
Author(s):  
Yogesh Kumar ◽  
Manoj Kumar ◽  
Sachin Kumar ◽  
Rajeev Kumar
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Experimental Results ◽  
Oscillator Strengths ◽  
Ionization Cross ◽  
Total Ionization ◽  
Plane Wave Born Approximation ◽  
Ionization Cross Sections ◽  
Good Agreement

In the present investigation, the plane-wave Born approximation was employed to calculate the total ionization cross sections by electron impact of methanol, ethanol and 1-propanol from the threshold of ionization to 10 MeV. This method requires continuum generalized oscillator strengths (CGOSs). The two different semi-phenomenological expressions of CGOS, given by Mayol and Salvat and Weizsacker and Williams, along with approximated form of the continuum optical oscillator strength (COOS) by Khare et al. were used. Furthermore, the average of the above two CGOSs was also used. The calculated ionization cross sections were compared to the available previous theoretical results and experimental data. Out of three CGOSs, the present results with the average CGOS were found in good agreement with the available experimental results for all the considered molecules. Collision parameters CRP were also calculated from 0.1 to 100 MeV and the calculations were found to be in excellent agreement with the experimental results of Reike and Prepejchal.

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