The flowing afterglow technique has been applied to the dissociative recombination CO2++e(-)-->CO*+O, in order to determine the radiative cascade contribution from high-energy triplet states of CO, (a(') (3)Sigma(+)), (d (3)Delta(i)), and (e (3)Sigma(-)), to the total yield of the long-lived (a (3)Pi) state. The yields of the a('), d, e states were found to be approximately 18%, 20%, and 0.3%, respectively, of the total CO(a) yield, which leads us to conclude that (38+/-8)% of the total CO(a) yield is due to radiative cascading, rather than direct formation. When combined with our previously reported total CO(a) yield of 0.29+/-0.10, the absolute yields of the triplet states become f(a('))=0.053+/-0.024, f(d)=0.057+/-0.022, and f(e)similar to9x10(-4). (C) 2003 American Institute of Physics.