Laser spectrosocopy of molecular ion beams
Laser spectrosocopy of molecular ion beams
A laser-ion beam spectrometer has been constructed to provide laser excitation of ion beams in both crossed and coaxial arrangements, and ion momentum analysis. This apparatus is used to study laser induced dissociations of molecular' ions and to observe electronic absorption spectra of ions by novel collisional detection methods.Laser photodissociation spectra of seven positive ions are presented. Vibrational structure in the photoproton momentum spectrum of H2 represents the highest momentum resolution possible using the present apparatus. In the coaxial beams geometry, excitation of rotational components of the A21T(--X2 E+ band system of CO + is detected by monitoring changes in thecol l isioncl attenuation of a fast CO + beam. As a result of the 'velocity bunching' effect in fast beams, the ions have a very narrow Doppler width for photon absorption, 160 MHz in this case. The coaxial geometry also allows the use of.the Doppler shift to bring ions into resonance with the laser. The high resolution is used to study the electronic absorption spectrum of 13 CO+' 13C nuclear hyperfine structure is observed. Analysis of this structure yields hyperfine parameters for the molecule inboth X and A states. A cell has been devised providing both Doppler tuning and low energy collision regions, to detect laser excitations in ion beams by low collision energy reactions. Electronic excitations of CO+ and H2O+ ion beams are detected by monitoringreactions of these ions with H2.
University of Southampton
Milverton, David Robert John
1978
Milverton, David Robert John
Milverton, David Robert John
(1978)
Laser spectrosocopy of molecular ion beams.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
A laser-ion beam spectrometer has been constructed to provide laser excitation of ion beams in both crossed and coaxial arrangements, and ion momentum analysis. This apparatus is used to study laser induced dissociations of molecular' ions and to observe electronic absorption spectra of ions by novel collisional detection methods.Laser photodissociation spectra of seven positive ions are presented. Vibrational structure in the photoproton momentum spectrum of H2 represents the highest momentum resolution possible using the present apparatus. In the coaxial beams geometry, excitation of rotational components of the A21T(--X2 E+ band system of CO + is detected by monitoring changes in thecol l isioncl attenuation of a fast CO + beam. As a result of the 'velocity bunching' effect in fast beams, the ions have a very narrow Doppler width for photon absorption, 160 MHz in this case. The coaxial geometry also allows the use of.the Doppler shift to bring ions into resonance with the laser. The high resolution is used to study the electronic absorption spectrum of 13 CO+' 13C nuclear hyperfine structure is observed. Analysis of this structure yields hyperfine parameters for the molecule inboth X and A states. A cell has been devised providing both Doppler tuning and low energy collision regions, to detect laser excitations in ion beams by low collision energy reactions. Electronic excitations of CO+ and H2O+ ion beams are detected by monitoringreactions of these ions with H2.
This record has no associated files available for download.
More information
Published date: 1978
Identifiers
Local EPrints ID: 458474
URI: http://eprints.soton.ac.uk/id/eprint/458474
PURE UUID: b67b1557-b2e5-41c8-bfc6-30a7b2e455e2
Catalogue record
Date deposited: 04 Jul 2022 16:49
Last modified: 04 Jul 2022 16:49
Export record
Contributors
Author:
David Robert John Milverton
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics