Vibrational excitation of simple molecular ions in resonant and under-resonant strong laser fields: Dissociation and ionization of ppe and pde; laser-enhanced nuclear fusion in ddμ and dtμ

The dynamics of vibrational excitation of ppe, pde, ddμ and dtμ in very intense laser fields (I0 ∼ 1014 W/cm2 for ppe and pde, and I0 ∼ 1020 and 1022 W/cm2 for ddμ and dtμ) is studied by the numerical solution of the time-dependent Schrödinger equations with the explicit treatment of the nuclear motion and the electron or muon motion beyond the Born-Oppenheimer approximation. The laser frequencies used were chosen (i) on resonance with the corresponding ∣v = 0〉 → ∣v = 1〉 transitions: ω = ω10, and (ii) two times smaller: ω = ω10/2. It has been found that the strong-field vibrational excitation with the latter, under-resonant frequencies (ω = ω10/2), is much more efficient than that with the resonant ones. In particular, on the timescale of 120 femtoseconds (fs) the dissociation yield of pde is about 25% at ω = ω10/2, but only about 3.8% at ω = ω10. It has been also shown that, similarly to an electron in ppe and pde, a muon in ddμ and dtμ also follows the fast oscillations of the resonant X-ray laser fields, despite its very large mass and extremely high laser frequencies, ω ≈ 10 a.u. The X-ray enhancement of the nuclear fusion in ddμ and dtμ is studied on the attosecond (as) timescale. It is found, in particular, that the energy released from the dt fusion in dtμ can by 8.02 GeV exceed the energy required to produce a usable μ− and the energy of the 300 as X-ray laser pulse used to enhance the fusion.