Low kinetic energy release in the strong-field dissociation of H$_{3}^{+}$*

The triatomic hydrogen molecular ion is a fundamentally important system for the understanding of the laser-driven dynamics of polyatomic molecules. Recently, Alexander \textit{et al}. [J. Phys. B, \textbf{42}, 141004, (2009)] reported the laser-induced dissociation of D$_{3}^{+}$ as a function of the time the D$_{3}^{+}$ was stored in an electrostatic ion trap, using 30 fs, 800 nm pulses. They ascribed the detected low kinetic energy release neutral fragments to the D$_{2}^{+}$+D dissociation channel even though the neutral fragments D and D$_{2}$ could not be clearly distinguished in their measurement. Using coincidence 3D momentum imaging we clearly separate and distinguish between all fragments and measure kinetic energy release down to 0 eV. Our results suggest that the low kinetic energy release is associated with the H$^{+}$+H$_{2}$ dissociation channel of H$_{3}^{+}$.