Integral cross sections for electron scattering by ground-state Ba atoms

Abstract

We have used the convergent close-coupling method and a unitarized firstorder many-body theory to calculate integral cross sections for elastic scattering and momentum transfer, for excitation of the 5d 2 1 S,

Radiative Losses of Solar Coronal Plasmas

“…For example, for electron-impact excitation, our calculations have been compared with other calculations and experimental measurements for a variety of atoms and ions, including Mg, Ba, Xe, Ne, and Ar (Clark et al 1989(Clark et al , 1991b(Clark et al , 1992Khakoo et al 1996;Zetner et al 1997;Baerveldt et al 1998;Johnson et al 1998;Fursa et al 1999Fursa et al , 2002Zetner et al 2001;Meneses et al 2002). For electron-impact ionization, recent calculations using the Los Alamos codes have been shown to be in good agreement with the experiment for inner shell ionization of heavy atoms (Colgan et al 2006b) and for many of the ions of Si and Ar (Colgan et al 2008).…”

Electron impact coherence parameters for superelastic transitions terminating on the (…6s6p1P1) level of the barium atom

“…Theoretical results for this blended feature were obtained by calculating the PDCS (equations ( 5)) for the individual transitions, summing the PDCS and generating the EICP using these summed values in equations (7). Alternatively, one can show that the Stokes parameters for a two-component blended transition can be expressed in terms of the parameters for the individual transitions according to P ( ) i = P (1) i cos 2 ξ + P (2) i sin 2 ξ (10a) where P i (for i = (1, 2, 3) indicates the Stokes parameter, and…”

“…In the heavier alkaline earth atoms the complexity of target wavefunctions is increased by the importance of two electron excitations and by the breakdown of the non-relativistic approximation. In addition to the measurement and calculation of differential cross sections (DCS) and integral cross sections (ICS) [2,3] there is continuing interest in the fine details of excitation (or de-excitation) processes available through studies of collisional alignment and orientation.…”

“…The work presented here focuses on electron collision processes involving the barium atom, extending our earlier investigations of this system. The CCC formalism has been particularly successful in calculating DCS and ICS for electron impact excitation out of the ground and excited states of this atom [2,3]. The CCC theory has also been applied to calculate P state alignment and orientation produced in electron impact induced transitions of the type X → P where 'P' stands for the ( .…”

Differential cross sections for electron impact excitation out of the (…6s6p1P1) state of barium

“…There has been considerable progress in the theoretical description of electron scattering from rather complex atomic targets. The barium atom has been a focus of recent theoretical work because of a fairly extensive set of available experimental data and because of interest in this atom as a possible candidate for efficient (discharge) lighting [1,2]. The convergent close coupling (CCC) method has been particularly successful in describing electron impact processes involving excited state barium atoms [2].…”