Study of low-temperature uranium plasmas not within local thermodynamical equilibrium
A Compant La Fontaine; A Compant La Fontaine; CENS, Gif-sur-Yvette, France
Журнал:
Journal of Physics B: Atomic and Molecular Physics
Дата:
1987-12-28
Аннотация:
A collisional-radiative model constituted by statistical equilibrium equations has been built up, the considered atomic levels of U I and U II being coupled by the elementary processes; while the electronic temperature T<sub>e</sub> and density n<sub>e</sub> are fixed with T<sub>e</sub><or=5 eV and n<sub>e</sub>>or=10<sup>10</sup> cm<sup>-3</sup>. It is assumed that the plasma is stationary, optically thin and that the electrons are Maxwellian. Absolute oscillator strengths of U I and U II transitions are derived using the published radiative lifetimes and branching ratio values obtained mainly by the laser induced fluorescence (LIF) method. It is found that the previously published U II gf values are underestimated by a mean factor of 2.8. The results derived by the model against T<sub>e</sub> and n<sub>e</sub> are the relative populations of the U I and U II fundamental and metastable levels, the relative densities of the atomic and ionic species U I, U II and U III, the excitation temperatures of U I and U II and the radiative power loss.
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