EFFECTIVE COLLISION STRENGTHS AMONG FINE-STRUCTURE LEVELS OF CA-XV - ERRATUM

An error has been found in the calculation of Aggarwal, Berrington, & Keenan, made in 1990, due to a mistake in the term coupling coefficients used to transform the collision strengths to intermediate coupling. The 190 fine-structure transitions among the 1s2(2)s2(2)p2, 1s2(2)s2p3 and 1s2(2)p4 configurations of Ca xv are therefore corrected and retabulated. Major differences between the R-matrix calculation of Aggarwal et al. and the distorted wave method of Dere et al. have now been resolved though minor differences still remain. The effective collision strengths obtained after averaging the collision strengths over a Maxwellian distribution of electron velocities are also presented in the temperature range below 10(7) K. About half of the transitions, reported earlier, need significant corrections. The differences between the R-matrix and distorted wave effective collision strengths can be up to one order of magnitude in some transitions, e.g., 2s2(2)p2P-3(2) --> 2s2p3D-3(1)0, and these differences are largely attributed to resonances.