title: Velocity map imaging and theoretical study of the Coulomb explosion of CH3I under intense femtosecond IR pulses.
abstract: The Coulomb explosion of CH(3)I in an intense (10-100 TW cm(-2)), ultrashort (50 fs) and nonresonant (804 nm) laser field has been studied experimentally and justified theoretically. Ion images have been recorded using the velocity map imaging (VMI) technique for different singly and multiply charged ion fragments, CH(3)(p+) (p = 1) and I(q+) (q ≤ 3), arising from different Coulomb explosion channels. The fragment kinetic energy distributions obtained from the measured images for these ion fragments show significantly lower energies than those expected considering only Coulomb repulsion forces. The experimental results have been rationalized in terms of one-dimensional wave packet calculations on ab initio potential energy curves of the different multiply charged species. The calculations reveal the existence of a potential energy barrier due to a bound minimum in the potential energy curve of the CH(3)I(2+) species and a strong stabilization with respect to the pure Coulombic repulsion for the higher charged CH(3)I(n+) (n = 3, 4) species.
authors: Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors: María E
authors: ME
authors: Corrales
authors: Gregory
authors: G
authors: Gitzinger
authors: Jesús
authors: J
authors: González-Vázquez
authors: Vincent
authors: V
authors: Loriot
authors: Rebeca
authors: R
authors: de Nalda
authors: Luis
authors: L
authors: Bañares