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Full-Text Articles in Physics
Photodetachment In Combined Static And Dynamic Electric Fields, Chitra Rangan, A.R.P. Rau
Photodetachment In Combined Static And Dynamic Electric Fields, Chitra Rangan, A.R.P. Rau
Physics Publications
Through an exact solution of the time-dependent Schrödinger equation for an electron in a static electric field plus the time-dependent electric field of the detaching radiation, the photodetachment cross section of H - is calculated. Careful attention is paid to ensuring proper limiting behavior as the frequency of the time-dependent field goes to zero. We do not find observable effects of a cross term between the two fields on the detachment cross section. Our results point to possible gauge dependence and other difficulties of S-matrix formulations of multiphoton detachment and ionization.
Dynamics Of Diamagnetic Zeeman States Ionized By Half-Cycle Pulses, Chitra Rangan, K.J. Schafer, A.R.P. Rau
Dynamics Of Diamagnetic Zeeman States Ionized By Half-Cycle Pulses, Chitra Rangan, K.J. Schafer, A.R.P. Rau
Physics Publications
We study the dynamical evolution of diamagnetic Zeeman states in hydrogen and sodium atoms ionized by half-cycle pulses. The eigenstates of the combined Coulombdiamagnetic potential are determined by solving the Schrödinger equation using a grid-based pseudopotential method. We study states with principal quantum number n between 15-20 in the l-mixing regime at a magnetic field of 6 T. Diamagnetic states that are initially localized parallel and perpendicular to the magnetic field are subjected to the electric field of a half-cycle pulse (HCP) and their time evolution is monitored. We calculate the total ionized fraction, and also the spectrum of the …
Lithium Isotope Shifts As A Measure Of Nuclear Size, Z. C. Yan, Gordon W. F. Drake
Lithium Isotope Shifts As A Measure Of Nuclear Size, Z. C. Yan, Gordon W. F. Drake
Physics Publications
The isotope shifts for 2 2PJ-2 2S and 3 2S-2 2S transition energies in lithium are calculated variationally in Hylleraas coordinates, including nonrelativistic, relativistic, and QED terms up to O(μ/M), O(μ/M)2, O(α2 μ/M), and O(α3 μ/M) atomic units, and the lowest-order finite nuclear size correction. With high-precision isotope shift measurements, our results can potentially yield a precise determination of the nuclear charge radius for different isotopes of lithium, and especially for the exotic 11Li "halo" isotope. For the case of 7Li-6Li, using the nuclear charge radii from nuclear scattering data, our calculated isotope shifts for the 2 2P1/2-2 2S, 2 …
High Accuracy For Atomic Calculations Involving Logarithmic Sums, S. P. Goldman, Gordon W. F. Drake
High Accuracy For Atomic Calculations Involving Logarithmic Sums, S. P. Goldman, Gordon W. F. Drake
Physics Publications
A method for the calculation of logarithmic sums that yields very high accuracy even for small basis-set dimensions is introduced. The best values achieved are accurate to 23 significant figures without extrapolation. The sums are performed directly on variational intermediate sets. The method automatically rejects any basis functions that could introduce linear dependence, therefore guaranteeing high numerical stability for a wide range of nonlinear parameters. Accurate values for the ordinary and a higher-order version of the Bethe logarithm are presented for a range of energy states and angular momenta. Given that the intermediate basis functions are increasingly confined to extremely …