This paper presents new refined results from the theoretical treatment of electron collision with the Fe-peak element Co3+. We have investigated the relevance of relativistic effects on the accurate representation of the target electron wave functions within the Breit-Pauli R-matrix approach. The calculated values for fine-structure levels are compared with the available experimental data in Atomic Structure Database of the National Institute for Standards and Technology. The agreement between the calculated and the experimental data is reasonably good, the energy difference average percentage of the low-lying levels usually agreeing to within 3.6% of each other. For completeness, we summarize herein the existing theoretical R-matrix treatments intended specifically to explore the role of including configuration interaction wave functions both in the target-state expansion, and in the ( )-electron quadratically integrable function expansion. To the best of our knowledge, the work reported herein describes for the first time a detailed calculation for this atomic system, and the results are relevant to the laboratory and astrophysical plasmas. 1. Introduction The present work aims to provide atomic data and electron collision data for the Fe-peak element Co IV and to supply with additional information the studies on astrophysical opacities. The electron collision data for Fe, Ni, and Co elements, and their ions are important in line identification in stellar objects or in tokamak plasmas, since the collisional rate of deexcitation for metastable levels may be lower than the decay rate by magnetic dipole or electric quadrupole transitions, which become observable. Due to a lack of precise abundance values these data are of importance in the analysis of many astronomical spectra. The needed atomic data can be obtained in various approximations that differ in their demands on resources by several orders of magnitude. Ranges of validity of expansions and applicability of perturbation treatments must be established in order to obtain reliable data with the most economical methods. The R-matrix approach has enabled vast amounts of accurate electron and photon collision data which have had wide applications.？？The recent volume by Burke [1] provides both a general review of the R-matrix method as applied to atomic and molecular collision processes and a very extensive bibliography. The R-matrix treatments [2–9] have provided results for electron collision with most of the ions of Fe, Ni and Co such as: Fe I, Fe II, Fe III, Fe IV, Fe V, Fe VI, Fe VII, Co V, Co
References
[1]
P. G. Burke, R-Matrix Theory of Atomic Collision, vol. 61 of Springer Series on Atomic, Optical and plasma Physics, Springer, New York, NY, USA, 2011.
[2]
K. A. Berrington and J. C. Pelan, “Atomic data from the IRON Project. XII. Electron excitation of forbidden transitions in V-like ions Mn III, Fe IV, Co V and Ni VI,” Astronomy and Astrophysics Supplement Series, vol. 114, pp. 367–371, 1995.
[3]
M. S. T. Watts and V. M. Burke, “Electron impact excitation of complex atoms and ions III: forbidden transitions in Ni2+,” Journal of Physics B, vol. 31, no. 1, article 145, 1998.
[4]
M. S. T. Watts, “Electron-impact excitation of complex atoms and ions: V. Forbidden transitions in Co+,” Journal of Physics B, vol. 31, no. 9, article 2065, 1998.
[5]
C. A. Ramsbottom, M. P. Scott, K. L. Bell et al., “Electron impact excitation of the iron peak element Fe II,” Journal of Physics B, vol. 35, no. 16, pp. 3451–3477, 2002.
[6]
C. A. Ramsbottom, C. J. Noble, V. M. Burke, M. P. Scott, and P. G. Burke, “Configuration interaction effects in low-energy electron collisions with Fe II,” Journal of Physics B, vol. 37, no. 18, pp. 3609–3631, 2004.
[7]
C. A. Ramsbottom, C. J. Noble, V. M. Burke, M. P. Scott, R. Kisielius, and P. G. Burke, “Electron impact excitation of Fe II: total LS effective collision strengths,” Journal of Physics B, vol. 38, no. 16, pp. 2999–3014, 2005.
[8]
S. N. Nahar, “Atomic data from the Iron Project LXII. Allowed and forbidden transitions in Fe XVIII in relativistic Breit-Pauli approximation,” Astronomy and Astrophysics, vol. 457, no. 2, pp. 721–728, 2006.
[9]
M. P. Scott, C. A. Ramsbottom, C. J. Noble, V. M. Burke, and P. G. Burke, “On the role of “two-particle-one-hole” resonances in electron collisions with Ni V,” Journal of Physics B, vol. 39, no. 2, article 387, 2006.
[10]
V. Stancalie, “Forbidden transitions in excitation by electron impact in Co3+: an R-matrix approach,” Physica Scripta, vol. 82, no. 2, Article ID 025301, 2011.
[11]
http://www.nist.gov.
[12]
J. Sugar and Ch. Corliss, “Atomic energy levels of the iron-period elements: potassium through nickel,” Journal of Physical and Chemical Reference Data, vol. 14, no. 2, article 664, 1985.
[13]
A. Hibbert, “CIV3—a general program to calculate configuration interaction wave functions and electric-dipole oscillator strengths,” Computer Physics Communications, vol. 9, no. 3, pp. 141–172, 1975.
[14]
K. A. Berrington, W. B. Eissner, and P. N. Norrington, “RMATX1: Belfast atomic R-matrix codes,” Computer PhysicsCommunications, vol. 41, p. 75, 1995.
[15]
V. M. Burke VM and C. J. Noble, “Farm—a flexible asymptotic R-matrix package,” Computer Physics Communications, vol. 85, no. 3, pp. 471–500, 1998.
[16]
D. W. Busby, P. G. Burke, V. M. Burke, C. J. Noble, N. S. Scott, and I. T. A. Spence, “HBrowse: a GRACE tool for browsing R-matrix H-files,” Computer Physics Communications, vol. 131, no. 3, pp. 202–224, 2000.
[17]
N. S. Scott and P. G. Burke, “Electron scattering by atoms and ions using the Breit-Pauli Hamiltonian: an R-matrix approach,” Journal of Physics B, vol. 13, no. 21, article 4299, 1980.
[18]
N. S. Scott and K. T. Taylor, “A general program to calculate atomic continuum processes incorporating model potentials and the Breit-Pauli Hamiltonian within the R-matrix method,” Computer Physics Communications, vol. 25, no. 4, pp. 347–387, 1982.
[19]
E. Clementi and C. Roetti, “Roothaan Hartree Fock atomic wavefunctions. Basis functions and their coefficients for ground and certain excited states of neutral and ionized atoms, ,” Atomic Data and Nuclear Data Tables, vol. 14, no. 3-4, pp. 177–478, 1974.
