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1990

Anthony F. Starace Publications

Articles 1 - 5 of 5

Full-Text Articles in Physics

Laser-Induced Detachment Processes In An Electric Field, Bo Gao, Anthony F. Starace Nov 1990

Laser-Induced Detachment Processes In An Electric Field, Bo Gao, Anthony F. Starace

Anthony F. Starace Publications

An analytic momentum-space wave function for an electron in both laser and static uniform electric fields is presented. It is used to obtain analytic multiphoton detachment cross sections in a static, uniform electric field which include effects of static-field-induced electron-photon interactions. These general results are not restricted to weak laser intensities or to weak static-field strengths and depend only on (a) the electric dipole approximation and (b) the approximation that final-state electron-atom interactions are ignored. Four specific predictions of our general formulas for the most interesting case of linearly polarized light polarized along the static-field direction are presented for weakly ...


Doubly Differential Detachment Cross Sections For Fast H-–Rare-Gas Collisions, Chih-Ray Liu, Anthony F. Starace Sep 1990

Doubly Differential Detachment Cross Sections For Fast H-–Rare-Gas Collisions, Chih-Ray Liu, Anthony F. Starace

Anthony F. Starace Publications

Detailed theoretical analyses are presented of the projectile-energy dependence as well as the target dependence of the electron-detachment collision processes, H-+T→H(n=2)+T*+e-. These analyses are illustrated by calculations of both projectile-frame and laboratory-frame doubly differential cross sections (DDCS’s) for 0.5-, 1.0-, and 1.5-MeV H- collisions with He targets and for 0.5-MeV H- collisions with Ne, Ar, Kr, and Xe targets; in addition, we present laboratory frame DDCS’s for 0.1-MeV H- collisions with Xe targets. Comparisons with available experimental data are given.


Two-Photon Ionization Of The Ar Atom And Detachment Of The F- Ionv, Cheng Pan, Bo Gao, Anthony F. Starace Jun 1990

Two-Photon Ionization Of The Ar Atom And Detachment Of The F- Ionv, Cheng Pan, Bo Gao, Anthony F. Starace

Anthony F. Starace Publications

Theoretical calculations of the two-photon ionization cross section of argon and of the two-photon detachment cross section of the negative fluorine ion are presented for the energy region from threshold to the single-photon ionization or detachment threshold. Detailed analyses are presented of the effects of various kinds of electron correlations, whose contributions to the two-photon transition amplitudes are evaluated using variationally stable procedures to sum implicitly over intermediate states. These variationally stable procedures enable us to give much more reliable predictions in the region of the first few intermediate-state resonances in argon than were provided by previous calculations of one ...


Variational Methods For High-Order Multiphoton Processes, Bo Gao, Cheng Pan, Chih-Ray Liu, Anthony F. Starace Apr 1990

Variational Methods For High-Order Multiphoton Processes, Bo Gao, Cheng Pan, Chih-Ray Liu, Anthony F. Starace

Anthony F. Starace Publications

Methods for applying the variationally stable procedure for N th-order perturbative transition matrix elements of Gao and Starace [Phys. Rev. Lett. 61, 404 (1988); Phys. Rev. A 39, 4550 (1989)] to multiphoton processes involving systems other than atomic H are presented. Three specific cases are discussed: one-electron ions or atoms in which the electron-ion interaction is described by a central potential; two-electron ions or atoms in which the electronic states are described by the adiabatic hyperspherical representation; and closed-shell ions or atoms in which the electronic states are described by the multiconfiguration Hartree-Fock representation. Applications are made to the dynamic ...


Near-100% Production Of The Excited Be+ 1s22p Ion From Decay Of Be 1s2S22p, C. Denise Caldwell, Mark G. Flemming, Manfred O. Krause, Peter Van Der Meulen, Cheng Pan, Anthony F. Starace Jan 1990

Near-100% Production Of The Excited Be+ 1s22p Ion From Decay Of Be 1s2S22p, C. Denise Caldwell, Mark G. Flemming, Manfred O. Krause, Peter Van Der Meulen, Cheng Pan, Anthony F. Starace

Anthony F. Starace Publications

In examining the decay of photon-produced Be 1s2s2np(1P), n=2,3, we discovered that the vastly predominant decay mode is to the final excited ionic states Be+ 1s2np, rather than the ground state. For n=2, the 2p ion accounts for 95% of the total production, with Be+ 1s23p the other main contributor. For n=3, 3p is predominant, again with a very small fraction of 2s. The result for n=2 occurs as a consequence of the similarity between the 2s and 2p ...