High energy proton ejection from hydrocarbon molecules driven by highly efficient field ionization

Phys Rev Lett. 2011 Apr 22;106(16):163001. doi: 10.1103/PhysRevLett.106.163001. Epub 2011 Apr 20.

Abstract

We investigated the ejection of energetic protons from a series of polyatomic hydrocarbon molecules exposed to 790 nm 27 fs laser pulses. Using multiparticle coincidence imaging we were able to decompose the observed proton energy spectra into the contributions of individual fragmentation channels. It is shown that the molecules can completely fragment already at relatively low peak intensities of a few 10(14) W/cm(2), and that the protons are ejected in a concerted Coulomb explosion from unexpectedly high charge states. The observations are in agreement with enhanced ionization taking place at many C-H bonds in parallel.