Time-Resolved Dynamics on the Giant Plasmon Resonance of C₆₀

We will present the time-resolved ionization and fragmentation dynamics of C₆₀ using intense, ultrashort radiation from the FLASH free-electron laser tuned above, on, and below the giant plasmon resonance around 20 eV. The ion dynamics were probed using a one-color XUV pump-probe technique in combination with a reaction microscope. We performed a systematic study of the time-dependent kinetic energies of the atomic and molecular ionic fragments as a function of photon energy and pulse intensity. Comparison with simulations for C⁺ and C₂⁺ reveal that their measured kinetic energy distributions are characteristic of neutral fragments, i.e., C and C₂. This suggests that our experiment provides information on the dynamics of neutral light fragments which typically remain unobserved.