High resolution Auger-electron and double-charge-transfer spectroscopi
es have been used to investigate the doubly ionized states in CF4. The
double-charge-transfer spectra show that both the lowest singlet and
triplet states in the CF4 dication have an energy of 38.0+/-0.4 eV. Au
ger-electron spectroscopy gives information concerning higher energy s
tates in the CF42+ ion. Peaks have been measured in the double ionizat
ion energy range 38-80 eV and have been assigned to the population of
dication states using theoretically calculated spectra. Recent data fr
om CF42+ fragmentation studies (Codling et al., J. Phys. B 24 (1991) 9
51) are discussed and correlated with the present work. The double-cha
rge-transfer and Auger-electron spectra have been analyzed in terms of
results obtained by two-particle Green's function calculations.