J/A+AS/123/575 J/A+AS/123/575 IRON Project XXIII. Fe XXII excitation rate H L Zhang A K Pradhan Astron. Astrophys. Suppl. Ser. 123 575 1997 1997A&AS..123..575Z J/A+A/283/319 : IRON Project III. B-like ions J/A+AS/108/1 : IRON Project V. Collision strengths of O-like ions J/A+A/293/953 : IRON Project VI. Fe II collision strengths J/A+A/293/967 : IRON Project VII. Fe II radiative transitions J/A+AS/109/193 : IRON Project VIII. Electron excitation of Ti-like ions J/A+AS/119/509 : IRON Project XVII. Radiative transition in Fe III J/A+AS/119/523 : IRON Project XVIII. Electron impact for Fe III J/A+AS/120/361 : IRON Project XIX. Fe II radiative transitions J/A+AS/123/159 : IRON Project XXII. C and O radiative rates 1993A&A...279..298H : IRON Project I. Goal and methods 1994A&AS..107...29S : IRON Project IV. Electron excitation of F-like ions 1995A&AS..110..209P : IRON Project IX. Electron excitation of Cl-like ion 1995A&AS..111..347G : IRON Project X. Si- & S-like ions IR collision strengths 1996A&AS..115..151S : IRON Project XI. Ar VI, K VII and Ca VIII fine-structure 1995A&AS..114..367B : IRON Project XII. V-like ions electron excitation 1996A&AS..115..551B : IRON Project XIII. Ni II & Fe II electron excitation 1996A&A...309..677S : IRON Project XIV. Fe XIV fine-structure transition 1996A&AS..118..157K : IRON Project XV. Electron excitation of He II & Fe XXVI 1996A&AS..119..105B : IRON Project XVI. Fe V oscillator strengths 1997A&AS..122..167B : IRON Project XX. Fe I oscillator strengths 1997A&AS..122..177P : IRON Project XXI. Fe I fine-structure transition Atomic physics atomic data Sun: flares X-rays: general New collision strengths have been calculated for 990 transitions among 45 fine structure n=2 and n=3 levels of Fe XXII. The relativistic Breit-Pauli formulation of the R-matrix method was employed in the close coupling approximation, with radiation damping of autoionizing resonances included for the first time in the calculations of excitation rate coefficients. It is found that, at low temperatures, the relativistic effects considerably enhance rate coefficients for the intercombination transitions, and the radiation damping effect reduces those for a few transitions. It is also found that resonances due to coupling with the n=3 levels significantly enhance rate coefficients for the transitions to low-lying levels at intermediate and high temperatures, and for the transitions to the n=2 high-lying levels at all temperatures. It is expected that the new data, tabulated at a wide range of temperatures, would lead to a revision of the spectral diagnostics of Fe XXII in laboratory and astrophysical sources, in particular the X-ray spectra observed from solar flares and tokamaks.

Index Level index --- Conf Electronic configuration --- Term Electronic term --- J Total angular momentum --- E Theoretical energy Ry Patricia Bauer CDS 1996Nov12Honglin Zhang <zhang@payne.mps.ohio-state.edu> J_A+AS_123_575.xml