VERY SLOW SPONTANEOUS DISSOCIATION OF CO2+ OBSERVED BY MEANS OF A HEAVY-ION STORAGE-RING

Long lived (0.8 ms, 6 ms, and > 3.8 s) states in CO2+ have been observed for the first time by monitoring beams of 75-300 keV ions in the ion storage ring ASTRID. It is the first experimental evidence that a doubly charged molecule can be stable on a time scale of seconds. The results are theoretically interpreted by means of a multichannel Schrodinger analysis based on ab initio computations of potential energy curves and off-diagonal spin-orbit couplings. This analysis indicates that 3PI(nu=0) accounts for the long lived component. The two decay components in the ms range probably derive from higher excited states in CO2+.