Ejection of triatomic molecular ion H₃⁺ from methyl chloride in an intense femtosecond laser field

Ejection of H3+ and ³⁵Cl⁺ from CH₃Cl molecule is investigated and the Coulomb explosion channels are confirmed by their kinetic energy release and angular distributions. The fragment anisotropy of H3+ ejection can be attributed to the dynamic alignment of CH ₃³⁵Cl²⁺ induced by femtosecond laser field, the non-zero H3+ ejection angle with respect to the a-axis of CH₃ ³⁵Cl²⁺ and the remarkable overall rotation of the precursor species [CCl⁺.H3+]. Lifetimes and geometries of precursor species [CCl⁺.H3+] at different laser intensities are investigated. Competition between Coulomb explosion channels with H3+ and ³⁵Cl ⁺ ejection is also discussed.