In 2005, we hypothesized that if ions are expelled from the surface of the droplet at an early stage after droplet production, these ions may undergo more collisions and could end up with higher internal energies . The same conclusions are reached independently on ionic liquid electrospray emitters, used in the pure ionic regime (pure ion evaporation) for aerospace propulsion applications. By combining molecular modeling with retarding potential analysis of emitted ionic liquid clusters, Schroeder et al. deduced that ionic liquid dimers were evaporated with an internal temperature between 590 and 690 K, and trimers with a temperature between 990 and 1090 K .