Mass spectrum of coronene following collisions with 11.25 keV He⁺. The highest peaks correspond to the single and double ionizations of coronene without fragmentation on the experimental time scale of ∼10 μs. The left and right zoom-ins respectively show the intensity distributions for the losses of different numbers, n, of H atoms from the coronene dications and cations. The loss of an even number of H atoms is more favorable than the loss of an odd number of H atoms. Other peaks are due to the fragmentation of the carbon skeleton in one or several steps. See Chen et al. (2015) for details.