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Dynamique de photofragmentation de petits agrégats d'Argon et de molécules biologiques : nouvel outil par piégeage et corrélation vectorielle.

Abstract : The present work concerns the building up of a complex set-up the aim of which being the investigation of the photofragmentation of ionised clusters and biological molecules.
This new tool is based on the association of several techniques. Two ion sources are available: clusters produced in a supersonic beam are ionised by 70 eV electrons while ions of biological interest are produced in an “Electrospray”. Rovibrational cooling is achieved in a “Zajfman” electrostatic ion trap. Lifetime of ions can also be measured using the trap. Two types of lasers are used to excite the ionised species: The femtosecond laser available at the “ELYSE” facilities and a nanosecond laser. Both lasers have a repetition rate of 1 kHz. The neutral andionised fragments are detected in coincidence using a sophisticated detection system allowing time and localisation of the various fragments to be determined. With such a tool, I was able to investigate in details the fragmentation dynamics of ionised clusters and bio-molecules.
The first experiments deal with the measurement of the lifetime of the Ar2+ dimer II(1/2)u metastable state. The relative population of this state was also determined. The Ar2+ and Ar3+ photofragmentation was then studied and electronic transitions responsible for their dissociation identified. The detailed analysis of our data allowed to distinguish the various fragmentation mechanisms. Finally, a preliminary investigation of the protonated tryptamin fragmentation is presented.
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https://tel.archives-ouvertes.fr/tel-00106744
Contributor : Mireille Geurts <>
Submitted on : Monday, October 16, 2006 - 11:09:18 AM
Last modification on : Thursday, January 11, 2018 - 6:19:24 AM
Document(s) archivé(s) le : Tuesday, April 6, 2010 - 6:08:41 PM

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  • HAL Id : tel-00106744, version 1

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Valéria Lepère. Dynamique de photofragmentation de petits agrégats d'Argon et de molécules biologiques : nouvel outil par piégeage et corrélation vectorielle.. Biophysique [physics.bio-ph]. Université Paris Sud - Paris XI, 2006. Français. ⟨tel-00106744⟩

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