Angular distributions of fragment ions arising from tetrahedral CH₃I and isomer identification using intense laser fields

Graham, P., Ledingham, K.W.D., Singhal, R.P., Hankin, S.M., McCanny, T., Fang, X., Taday, P.F., Langley, A.J. and Kosmidis, C. (2001) Angular distributions of fragment ions arising from tetrahedral CH₃I and isomer identification using intense laser fields. Laser and Particle Beams, 19(2), 187 -193. (doi: 10.1017/S0263034601192037)

Abstract

Utilizing an ultraintense (10(16) W cm(-2)) Is laser, the laser/matter interaction of the tetrahedral CH3I molecule is investigated. A mass spectrum and the angular distributions of fragment ions arising from Coulomb explosion of molecular ions, obtained with linearly polarized light, are presented. The distributions for In+ (n less than or equal to 7), CHm+ (m less than or equal to 3), Cp+ (p less than or equal to 4) and H+ ions are all anisotropic and maximal when the polarization lies along the spectrometer axis. The molecule hence seems to behave as a diatomic, with the fragment ions being ejected along the field direction. Also presented are mass spectra of the isomers 1- and 2-nitropropane, which are explosive species, taken for horizontal and vertical polarizations at both 375 and 750 nm. It is shown that femtosecond laser mass spectrometry (FLMS) can be used to distinguish between these two isomers through their differing dissociation patterns. Isomer identification is important for many different applications and FLMS may provide a means of achieving this for a wide range of molecules.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Singhal, Dr Ravi and Ledingham, Professor Kenneth
• Authors: Graham, P., Ledingham, K.W.D., Singhal, R.P., Hankin, S.M., McCanny, T., Fang, X., Taday, P.F., Langley, A.J., and Kosmidis, C.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Laser and Particle Beams
• ISSN: 0263-0346