Electron collisional excitation of Ne III: (1s22s22p4 3P2,1,0,1D2,1S0) fine-structure transitions

Abstract

Effective collision strengths are evaluated from electron-impact excitation collision strengths of doubly ionized atomic neon (Ne III) calculated in the close-coupling approximation using the ab initio R-matrix method. The 56 fine-structure levels arising from the 28 LS target states; 2s22p4, 2s2p5, 2s22p33 ( = s,p,d) and 2s22p34s are retained in the present calculation. The effective collision strengths () for all forbidden transitions within the 1s22s22p4 3P2,1,0, 1D2, 1S0 ground configuration levels are obtained by averaging the electron collision strengths (), for a wide range of incident electron energies, over a Maxwellian distribution of velocities. Results are presented for electron temperatures in the range 1000-1 000 000 K, applicable to many laboratory and astrophysical plasmas. We believe that the results are the most accurate to date and so should be used in preference to previous values available in the literature.