Selective photodissociation of trapped ions after ion cloud manipulation with an impulsive quadrupolar electric field
- Purdue Univ., West Lafayette, IN (United States)
- Los Alamos National Lab., NM (United States)
Trapped ions of different masses can be separated in space within a quadrupole ion trap, making it possible to perform efficient mass-selective photodissociation on a mixture of ions. This method is described here. Under the given operating conditions, this method improves the photodissociation efficiency from 9% to 35%. The photodissociation efficiency steadily decreases with longer delay times as the oscillating ions undergo increasing numbers of collisions with the helium buffer gas and lose coherence. Since the secular frequencies of trapped ions are mass-dependent at a fixed rf amplitude, ions of different mass-to-charge ratios will cross the z-axis at different times. Mass-selective photodissociation is illustrated for a mixture of benzoyl-h{sub 5} and -d{sub 5} cations by appropriately adjusting the delay time between the dc pulse and the laser pulse. Simulations using the program ITSIM were used to design this experiment, and the data which describe the ion motion are provided. 27 refs., 5 figs.
- OSTI ID:
- 226692
- Journal Information:
- Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 13 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
- Country of Publication:
- United States
- Language:
- English
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