Eur. Phys. J. D (2017) 71: 148
https://doi.org/10.1140/epjd/e2017-80027-8

Regular Article

Dissociative ionization and Coulomb explosion of CH₃I in intense femto second laser fields^*

¹ Institute of Atomic and Molecular Physics, Jilin University, Qianjin Avenue 2699, Changchun 130012, P.R. China
² Institute for Molecules and Materials, Radboud Universiteit Nijmegen, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
³ HIMS, Faculty of Science, Mathematics and Informatics, University of Amsterdam, Science Park 904, 1090 GD Amsterdam, The Netherlands
⁴ Dept. of Physics and Astronomy, LaseRLaB, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081HV Amsterdam, The Netherlands
⁵ CEA-Saclay, IRAMIS/LIDYL, Bât. 462, 91191 Gif-sur-Yvette Cedex, France

^a e-mail: stolte@chem.vu.nl

Received: 13 January 2017
Published online: 13 June 2017

Abstract

The interaction of CH₃I molecules with 100 fs 800 nm linearly polarized laser fields has been investigated at the intensity region from 2.6 × 10¹⁴ to 5.8 × 10¹⁴ W/cm² by means of a velocity map imaging method. The kinetic energy distribution of the various atomic fragment ions I^q+ (q = 1–3) has been measured and reproduced by a fit of multiple Gaussian functions. Several dissociative ionization and Coulomb explosion channels were identified for I^q+ (q = 1–3). As expected for a geometric alignment dominated interaction process the anisotropic angular recoil distributions of the atomic ion fragments are peaked in the laser polarization direction. The kinetic energy release (KER) of I^q+ (q = 1–3) depending upon the laser intensity has been investigated. The relative weight of the various contributions from the identified dissociative ionization (DI) and Coulomb explosion (CE) channels is found to depend strongly on the laser intensity.