Relativistic Radiative Transitions

摘要: We have calculated the oscillator strength for electric dipole transitions with retardation between $1s$ state and higher discrete states a single Dirac electron in Coulomb field. Numerical values atomic number 82 show that retarded relativistic each shell is about 0.8 of nonrelativistic value. give numerical relative intensity different $K$ x-ray lines lead, neglecting screening: $\frac{K{\ensuremath{\alpha}}_{1}}{K{\ensuremath{\alpha}}_{2}}$ doublet ratio 1.93 as compared to NR value 2.0. introduce an average "oscillator density" states, extrapolate series limit find photoelectric cross section at threshold. Our lead 740 barns 23% larger than given by Hulme et al. also calculate summed strength, using cutoff arbitrary high energy convergence. The results are insensitive used: 10 Mev, we 0.85, increase 0.01 factor two energy. less nonrelativistically Thomas, Reiche, Kuhn; or relativistically Gell-Mann, Goldberger, Thirring.