Cluster dynamics transcending chemical dynamics toward nuclear fusion

Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 10¹⁵-10²⁰ W·cm ^-2). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C⁴⁺(D⁺)₄)_n and (D⁺I²²⁺)_n at I_M = 10¹⁸ W·cm^-2, that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D ₂)_n, (HT)_n, (CD₄)_n, (DI)_n, (CD₃I)_n, and (CH₃I) _n clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D₂)_n clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., ¹²C(P,γ) ¹³N driven by CE of (CH₃I)_n clusters, were explored.