High-charge Coulomb explosions of clusters in ultra-dense deuterium D(−1)

► Laser ionization of small clusters D3 and D4 of ultra-dense deuterium give maximum-charge Coulomb explosions. ► The kinetic energy release (KER) in a D4 cluster gives 945 eV to each D+ ion. ► By cooling the clusters on a solid surface, it is possible to decrease the rotational energy of the clusters, which gives a shorter bond distance. ► The rotational energy of a small cluster of ultra-dense deuterium is large even at small J numbers due to the bond distance of 2.3 pm.