Nuclear Fusion Driven by Coulomb Explosion of Methane Clusters†

Multielectron ionization and Coulomb explosion of methane clusters (CA4)n, A ) H, D, and T, in very intense (I ) 1018-1019 W cm-2) laser fields were studied using classical dynamics simulations. The products of Coulomb explosion involve light A+ ions (p, d, and t nuclei) with energies up to 20 keV, C4+ ions at I ) 1018 W cm-2, and C6+ ions (carbon nuclei) with energies up to 110 keV at I ) 1019 W cm-2. Important advantages of nuclear fusion driven by Coulomb explosion of methane (CA4)n and (CA4)n heteronuclear clusters pertain to energetic effects, with the heavy multielectron ions driving the light H+, D+, or T+ ions (d or t nuclei) to considerably higher energies than for homonuclear deuterium clusters of the same size, and to kinematic effects, which result in a sharp high-energy maximum in the light-ion spectrum for the (CA4)n and(C6 A4)n clusters. We studied the energetics of Coulomb explosion in conjunction with isotope effects on the product A+ and Ck+ ions energies and established the cluster size dependence of dd and dt fusion reaction yields from an assembly of Coulomb-exploding clusters. The C6+ nuclei produced by Coulomb explosion of (CD4)n (n ) 5425) clusters are characterized by an average energy of Eav ) 65.2 keV and a maximum energy of EM ) 112 keV. A search was undertaken for the 12C6+ + 1H+ fusion reaction of astrophysical interest.