2,960 research outputs found

    Hyperfine Quenching of the 4s4p3P04s4p ^{3}P_{0} Level in Zn-like Ions

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    In this paper, we used the multiconfiguration Dirac-Fock method to compute with high precision the influence of the hyperfine interaction on the [Ar]3d104s4p3P0[Ar]3d^{10} 4s4p ^3P_0 level lifetime in Zn-like ions for stable and some quasi-stable isotopes of nonzero nuclear spin between Z=30 and Z=92. The influence of this interaction on the [Ar]3d104s4p3P1[Ar]3d104s4p3P0[Ar]3d^{10} 4s4p ^3P_1 - [Ar]3d^{10} 4s4p ^3P_0 separation energy is also calculated for the same ions

    New expression for the K-shell ionization

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    A new expression for the total K-shell ionization cross section by electron impact based on the relativistic extension of the binary encounter Bethe (RBEB) model, valid from ionization threshold up to relativistic energies, is proposed. The new MRBEB expression is used to calculate the K-shell ionization cross sections by electron impact for the selenium atom. Comparison with all, to our knowledge, available experimental data shows good agreement

    Analysis of X-ray spectra emitted from laser-produced plasmas of uranium

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    In this paper, we used the multiconfiguration Dirac-Fock method to generate theoretical X-ray spectra for Co-, Ni-, Cu-, Zn-, Ga-, Ge-, As-, Se-, Br-, Kr-, and Rb-like uranium ions. Using the distribution of these ions in a laser-produced plasma, for different plasma temperatures, we generate theoretical spectra, which are compared to experimental data

    Convergent processes in numerical analysis

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    Thesis (M.A.)--Boston UniversityIn this paper, several numerical methods, instructive for the calculation of the approximate solutions of differential equations, are exhibited to be convergent. In the first two methods (Picard's Method and the Cauchy-Euler method), the theoretical importance of numerical solutions is demonstrated by establishing existence and uniqueness theorems for the linear differential equation of the first order dy/dx = f(x,y) subject to the following conditions: The equation is considered in some region of xy space containing a point (xo,yo) and in addition to being continuous, f(x,y) is assumed to satisfy a Lipschitz condition with respect to y, i.e. |f(x,y1)-f(x,y2)| < k|y1 - y2| where k is called the Lipschitz constant [TRUNCATED

    K X-Ray Energies and Transition Probabilities for He-, Li- and Be-like Praseodymium ions

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    Theoretical transition energies and probabilities for He-, Li- and Be-like Praseodymium ions are calculated in the framework of the multi-configuration Dirac-Fock method (MCDF), including QED corrections. These calculated values are compared to recent experimental data obtained in the Livermore SuperEBIT electron beam ion trap facility
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