52 / 2020-01-18 16:35:54

Charge-state related effects for fast N2+ passing through Ag

Cluster ion beam (CIB); Stopping power; Charge states; Coulomb explosion

全体主题 > 激光和粒子束聚变

Interaction between energetic cluster ion beams(CIB) and matter has attracted much more attention due to their good qualities1,2. Compared with the traditional ion beams, molecular ion beams are very different. One of the characteristics is the interference effect aroused by the close spatial correlation among the ions, which is known as the vicinage effect. Vicinage effect can influence the whole interaction including the slowing down, charge evolution, Coulomb explosion and so on. Moreover, constructive interference is expected to give rise to an enhanced energy loss for each ion, when compared to the energy loss of an individual ion moving at the same speed, as long as the inter-ionic distances within the cluster are smaller than the characteristic length for the electronic excitation.
We studied the charge evolution processes and stopping power for N2+ cluster ion travelling through Ag target within the Brandt-Kitagawa charge state theoretical framework. The charge evolution, coulomb explosion, deflection of molecular axis and energy loss processes are investigated based on the dielectric-response theory. Especially, the influences of vicinage effects aroused by the molecular structure are discussed. The study results show that the charge state of the leading ion may have quite different mode from that of the trailing ion for nitrogen molecular ion due to the influences of the asymmetry wake potential aroused by the electronic exciting of the target electron. In generally speaking, the charge state is oscillating for trailing ion, while the leading ion doesn’t show the oscillation mode. By solving the equations of motion for the constituent ions, the effects of such ion-charge asymmetry on the Coulomb explosion and stopping power are discussed.