Open AccessElectron impact excitation of the ground‐state 3 P fine‐structure levels in atomic oxygen
Author(s) -
K L Bell,
K A Berrington,
M. R. J. Thomas
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01364.x
Subject(s) - physics , ground state , atomic physics , excitation , atomic oxygen , oxygen , electron , electron ionization , ionization , nuclear physics , ion , quantum mechanics
Fine‐structure collision strengths are calculated for transitions between the ground‐state levels of atomic oxygen. The R ‐matrix method is used in which the (2p 4 ) 3 P, 1 D and 1 S terms are included as well as three pseudo‐states chosen to represent the dipole polarizability of the 3 P ground state. Very sophisticated configuration–interaction wavefunctions are used for the target states and a recoupling transformation to pair coupling is applied to the inner‐region Hamiltonian matrix, with the 3 P fine‐structure energy levels being adjusted to match the observed splitting prior to diagonalization. Effective collision strengths are obtained by integrating over a Maxwellian distribution and the rate coefficient of the cooling of electron gas is determined. The cooling rates are significantly lower than those currently available, in confirmation of the result deduced from measurements of the Earth's ionosphere electron gas.