The scattering of electrons by lithium atoms

Resonance phenomena ine+-Li collisions

“…resonances have been predicted. The present results show that resonances in the positron-lithium system are probably caused by the long-range dipole r −2 potential which is the same as the electron-lithium case that has been indicated by Burke and Taylor [22]. Resonances are not influenced by the inclusion of positronium formation channels, even though resonance positions and widths may change.…”

“…Threshold effect has been a focus of discussion for many decades [19,20], since Wigner first predicted the presence of cusp structures. Experimental observation and theoretical calculation have demonstrated the existence of threshold cusps for a low-energy electron collision with a lithium target (Eyb and Hofmann [21] and Burke and Taylor [22]). It is interesting to note a broad hump appearing near 1.90 eV in the D wave in the present CCO calculation, and this is maybe the overlap of the 2p threshold cusp and a D-wave resonance.…”

Spin asymmetries in the low-energy electron impact excitation of 2S to 2P transitions in lithium atoms

“…The results of Burke and Taylor (1969a)-calculated from their published R matrices (Burke and Taylor 1969b)-are in agreement with the data up to an energy of 6 eV, but give an asymmetry of about 0.07 thereafter, which is consistently higher than our values. In the discussion of their two-state close-coupling model for lithium, Burke and Taylor (1969a) suggested that the dominance of singlet scattering near the 2p threshold is due to 'P and 'D resonances, with the 'D resonance having a broad structure ( = O S to 1 eV). From the steep change of the asymmetry within about 1 eV of threshold it is evident that the singlet and the triplet excitation cross sections have quite a different dependence on the excess energy ( E -E * ) .…”

“…Burke and Taylor (1969a) determined the differential cross sections for lithium using a two-state (2s, 2p) close-coupling approximation. The incident electron scattering functions were calculated according to the Kohn variational principle for each total orbital momentum L and total spin S using direct and exchange scattering potentials.…”

Interview with N. Bloembergen

“…Theoretical calculations (Burke and Taylor 1969, Moores and Norcross 1972, Bardsley and Nesbet 1973, Burke and Mitchell 1973 have predicted a threshold effect in the first inelastic threshold as well as sharp resonances slightly above the threshold of the ground state. Burke and Mitchell (1973) have reported a broad shape resonance above the first excitation threshold in the e--Cs elastic cross section.…”