Space- and time-resolved spectroscopy of laser-produced plasmas: Study of density-sensitive x-ray transitions in helium-like and neon-like ions
The determination of level populations and detailed population mechanisms in dense plasmas has become an increasingly important problem in atomic physics. In the present work, the density variation of line intensities and level populations in aluminum K-shell and molybdenum and silver L-shell emission spectra have been measured from high-powered, laser-produced plasmas. For each case, the density dependence of the observed line emission is due to the effect of high frequency electron-ion collisions on metastable levels. The density dependent line intensities vary greatly in laser-produced plasmas and can be used to extract detailed information concerning the population kinetics and level populations of the ions. In aluminum, the electron density dependence of various helium-like line intensity ratios were measured. Standard collisional radiative equilibrium models fail to account for the observed density dependence measured for the He{sub {alpha}}/IC ratio. Instead, a quasi-steady state atomic model based on a purely recombining plasma is shown to accurately predict the measured density dependence. This same recombining plasma calculation successfully models the density dependence of the high-n He{sub {gamma}}/He{sub {beta}} and He{sub {delta}}/He{sub {beta}} helium-like resonance line intensity ratios. The density dependence of metastable levels of neon-like ions is also measured. Detailed neon-like theoretical atomic model calculations are shown to correctly predict the observed density sensitivity of the electric quadrupole to dipole-allowed resonance line x/3A ratio. The measured density dependence of the 3A/3G resonance line ratio does not agree with theory.
- Research Organization:
- California Univ., Davis, CA (USA)
- OSTI ID:
- 6047169
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dissociation Energy and Dissociative Recombination of Ne{sub 2}{sup +} and HeNe{sup +} Ions
X-ray observations of ${{\rm{K}}_{\beta }}$ emission from medium Z He-like ions in C-Mod tokamak plasmas
Related Subjects
ALUMINIUM IONS
EMISSION SPECTRA
MOLYBDENUM IONS
SILVER IONS
ATOMIC PHYSICS
DENSITY
ELECTRON DENSITY
ELECTRON-ION COLLISIONS
ELECTRONIC STRUCTURE
ENERGY-LEVEL TRANSITIONS
IONS
LASER-PRODUCED PLASMA
METASTABLE STATES
RECOMBINATION
X RADIATION
CHARGED PARTICLES
COLLISIONS
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ENERGY LEVELS
EXCITED STATES
ION COLLISIONS
IONIZING RADIATIONS
PHYSICAL PROPERTIES
PHYSICS
PLASMA
RADIATIONS
SPECTRA
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory