EUV line ratios from MgVII and SiIX

Abstract

Following the work of Burgess et al. (1991), the EUV line ratios from MgVII and SiIX ions have been computed using most appropriate atomic data. The density dependent line ratio R1 = ε (2s2p31D°-2s22p21D)/ ε(2s2p33S°-2s22p23P2) and R2 = ε (2s2p31p°-2s2- -2p21D)/ε(2s2p33S°-2s22p23P2) for MgVII and SiIX are compared with the earlier results of Mason and Bhatia (1978) and Keenan et al. (1986). Electron densities derived using observed R1 and R2 ratios from skylab NRL EUV spectra of solar flares and active regions are tabulated along with the values obtained by Keenan et al. (1986). © 1993 Kluwer Academic Publishers.