Measurements of the mean lifetime and kinetic-energy release of metastable ${\mathrm{CO}}^{2+}$

We present a method that allows state-selective measurement of the lifetime of metastable doubly charged molecular ions. The method is based on the simultaneous measurement of kinetic-energy release upon dissociation and lifetime and relies on three-dimensional fragment imaging. The experimental determination of the energy and lifetime of a vibrational state provides a stringent test for the theory. Using this method, we have measured the lifetime of two vibrational states of ${}^{12}{\mathrm{C}}^{16}{\mathrm{O}}^{2+}.$ Explicitly, $\tau =670\mathrm{}\pm 50\hspace{0.5em}\mathrm{ns}$ and $\tau =26\mathrm{}\pm 5\hspace{0.5em}\mathrm{ns}$ were measured for the states with $E_k=5.713\mathrm{}\hspace{0.5em}\mathrm{eV}$ and $E_k=5.841\mathrm{}\hspace{0.5em}\mathrm{eV},$ respectively. The measured mean lifetimes and kinetic-energy releases are consistent with previous measurements, and the results indicate that further theoretical work is required.