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Title: A cylindrical quadrupole ion trap in combination with an electrospray ion source for gas-phase luminescence and absorption spectroscopy

Abstract

A relatively simple setup for collection and detection of light emitted from isolated photo-excited molecular ions has been constructed. It benefits from a high collection efficiency of photons, which is accomplished by using a cylindrical ion trap where one end-cap electrode is a mesh grid combined with an aspheric condenser lens. The geometry permits nearly 10% of the emitted light to be collected and, after transmission losses, approximately 5% to be delivered to the entrance of a grating spectrometer equipped with a detector array. The high collection efficiency enables the use of pulsed tunable lasers with low repetition rates (e.g., 20 Hz) instead of continuous wave (cw) lasers or very high repetition rate (e.g., MHz) lasers that are typically used as light sources for gas-phase fluorescence experiments on molecular ions. A hole has been drilled in the cylinder electrode so that a light pulse can interact with the ion cloud in the center of the trap. Simulations indicate that these modifications to the trap do not significantly affect the storage capability and the overall shape of the ion cloud. The overlap between the ion cloud and the laser light is basically 100%, and experimentally >50% of negatively charged chromophore ionsmore » are routinely photodepleted. The performance of the setup is illustrated based on fluorescence spectra of several laser dyes, and the quality of these spectra is comparable to those reported by other groups. Finally, by replacing the optical system with a channeltron detector, we demonstrate that the setup can also be used for gas-phase action spectroscopy where either depletion or fragmentation is monitored to provide an indirect measurement on the absorption spectrum of the ion.« less

Authors:
; ; ; ;  [1]
  1. Department of Physics and Astronomy, Aarhus University, Aarhus (Denmark)
Publication Date:
OSTI Identifier:
22598015
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION; ABSORPTION SPECTRA; ABSORPTION SPECTROSCOPY; COMPRESSORS; CYLINDRICAL CONFIGURATION; DRILLS; FLUORESCENCE; FLUORESCENCE SPECTROSCOPY; HEAT EXCHANGERS; ION SOURCES; LASERS; LIGHT SOURCES; MOLECULAR IONS; OPTICAL SYSTEMS; PHOTONS; SPECTROMETERS; TRAPS

Citation Formats

Stockett, Mark H., E-mail: stockett@phys.au.dk, Houmøller, Jørgen, Støchkel, Kristian, Svendsen, Annette, and Brøndsted Nielsen, Steen. A cylindrical quadrupole ion trap in combination with an electrospray ion source for gas-phase luminescence and absorption spectroscopy. United States: N. p., 2016. Web. doi:10.1063/1.4948316.
Stockett, Mark H., E-mail: stockett@phys.au.dk, Houmøller, Jørgen, Støchkel, Kristian, Svendsen, Annette, & Brøndsted Nielsen, Steen. A cylindrical quadrupole ion trap in combination with an electrospray ion source for gas-phase luminescence and absorption spectroscopy. United States. doi:10.1063/1.4948316.
Stockett, Mark H., E-mail: stockett@phys.au.dk, Houmøller, Jørgen, Støchkel, Kristian, Svendsen, Annette, and Brøndsted Nielsen, Steen. Sun . "A cylindrical quadrupole ion trap in combination with an electrospray ion source for gas-phase luminescence and absorption spectroscopy". United States. doi:10.1063/1.4948316.
@article{osti_22598015,
title = {A cylindrical quadrupole ion trap in combination with an electrospray ion source for gas-phase luminescence and absorption spectroscopy},
author = {Stockett, Mark H., E-mail: stockett@phys.au.dk and Houmøller, Jørgen and Støchkel, Kristian and Svendsen, Annette and Brøndsted Nielsen, Steen},
abstractNote = {A relatively simple setup for collection and detection of light emitted from isolated photo-excited molecular ions has been constructed. It benefits from a high collection efficiency of photons, which is accomplished by using a cylindrical ion trap where one end-cap electrode is a mesh grid combined with an aspheric condenser lens. The geometry permits nearly 10% of the emitted light to be collected and, after transmission losses, approximately 5% to be delivered to the entrance of a grating spectrometer equipped with a detector array. The high collection efficiency enables the use of pulsed tunable lasers with low repetition rates (e.g., 20 Hz) instead of continuous wave (cw) lasers or very high repetition rate (e.g., MHz) lasers that are typically used as light sources for gas-phase fluorescence experiments on molecular ions. A hole has been drilled in the cylinder electrode so that a light pulse can interact with the ion cloud in the center of the trap. Simulations indicate that these modifications to the trap do not significantly affect the storage capability and the overall shape of the ion cloud. The overlap between the ion cloud and the laser light is basically 100%, and experimentally >50% of negatively charged chromophore ions are routinely photodepleted. The performance of the setup is illustrated based on fluorescence spectra of several laser dyes, and the quality of these spectra is comparable to those reported by other groups. Finally, by replacing the optical system with a channeltron detector, we demonstrate that the setup can also be used for gas-phase action spectroscopy where either depletion or fragmentation is monitored to provide an indirect measurement on the absorption spectrum of the ion.},
doi = {10.1063/1.4948316},
journal = {Review of Scientific Instruments},
number = 5,
volume = 87,
place = {United States},
year = {Sun May 15 00:00:00 EDT 2016},
month = {Sun May 15 00:00:00 EDT 2016}
}