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Description and performance of an electron-ion coincidence TOF spectrometer used at the Brazilian synchrotron facility LNLS

Burmeister, F.; Coutinho, L. H.; Marinho, R. R. T.; Homem, M. G. P.; de Morais, M. A. A.; Mocellin, A.; Bjorneholm, O.; Ristinmaa Sörensen, Stacey LU ; Fonseca, P. T. and Lindgren, Andreas LU , et al. (2010) In Journal of Electron Spectroscopy and Related Phenomena 180(1-3). p.6-13
Abstract
This paper reports the characteristics and performance of a Time-of-Flight Mass Spectrometer (TOF-MS) for coincidence measurements between electrons and ions that has been developed jointly in Sweden and Brazil. The spectrometer, used for studies of inner-shell photoexcitation of molecules in the gas-phase, has been optimized by implementing ion and electron lenses to allow the use of relatively small diameter detectors. Simulations were performed to understand the lens performance and they show that ions (electrons) could be collected without angular discrimination with a maximum kinetic energy up to ten (two) times higher than without the lens actions. A rotary vacuum chamber allows the spectrometer axis to be positioned at different... (More)
This paper reports the characteristics and performance of a Time-of-Flight Mass Spectrometer (TOF-MS) for coincidence measurements between electrons and ions that has been developed jointly in Sweden and Brazil. The spectrometer, used for studies of inner-shell photoexcitation of molecules in the gas-phase, has been optimized by implementing ion and electron lenses to allow the use of relatively small diameter detectors. Simulations were performed to understand the lens performance and they show that ions (electrons) could be collected without angular discrimination with a maximum kinetic energy up to ten (two) times higher than without the lens actions. A rotary vacuum chamber allows the spectrometer axis to be positioned at different angles relative to the polarization vector of the excitation beam. An important characteristic of the apparatus is that the acquisition setup allows a multi-hit capability with 1 ns resolution. Hereby, Photoelectron-Photoion-Photoion Coincidence (PEPIPICO) measurements can be performed on molecules containing two or more atoms of equal mass. A method to obtain experimental detection efficiencies of a single ion and one of one, two or three electrons has been developed. A systematic study of the interaction region has been performed to determine the shape of the photon and gas beams. Measurements on molecular nitrogen demonstrate the spectrometer's ability to resolve fragments with the same charge to mass ratio arriving within only a few ns. Simulations and experimental results of fragmentation of two singly charged cation nitrogen atoms agree, confirming that the spectrometer performance is well understood. (C) 2010 Elsevier B.V. All rights reserved. (Less)
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subject
keywords
Synchrotron, Time-of-Flight, Multicoincidence, Instrumentation
in
Journal of Electron Spectroscopy and Related Phenomena
volume
180
issue
1-3
pages
6 - 13
publisher
Elsevier
external identifiers
  • wos:000279612800002
  • scopus:77954215200
ISSN
0368-2048
DOI
10.1016/j.elspec.2010.02.007
language
English
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yes
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69bd145c-994f-42a3-877b-6959d9a459bd (old id 1657877)
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2010-08-31 12:55:56
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2018-05-29 11:26:27
@article{69bd145c-994f-42a3-877b-6959d9a459bd,
  abstract     = {This paper reports the characteristics and performance of a Time-of-Flight Mass Spectrometer (TOF-MS) for coincidence measurements between electrons and ions that has been developed jointly in Sweden and Brazil. The spectrometer, used for studies of inner-shell photoexcitation of molecules in the gas-phase, has been optimized by implementing ion and electron lenses to allow the use of relatively small diameter detectors. Simulations were performed to understand the lens performance and they show that ions (electrons) could be collected without angular discrimination with a maximum kinetic energy up to ten (two) times higher than without the lens actions. A rotary vacuum chamber allows the spectrometer axis to be positioned at different angles relative to the polarization vector of the excitation beam. An important characteristic of the apparatus is that the acquisition setup allows a multi-hit capability with 1 ns resolution. Hereby, Photoelectron-Photoion-Photoion Coincidence (PEPIPICO) measurements can be performed on molecules containing two or more atoms of equal mass. A method to obtain experimental detection efficiencies of a single ion and one of one, two or three electrons has been developed. A systematic study of the interaction region has been performed to determine the shape of the photon and gas beams. Measurements on molecular nitrogen demonstrate the spectrometer's ability to resolve fragments with the same charge to mass ratio arriving within only a few ns. Simulations and experimental results of fragmentation of two singly charged cation nitrogen atoms agree, confirming that the spectrometer performance is well understood. (C) 2010 Elsevier B.V. All rights reserved.},
  author       = {Burmeister, F. and Coutinho, L. H. and Marinho, R. R. T. and Homem, M. G. P. and de Morais, M. A. A. and Mocellin, A. and Bjorneholm, O. and Ristinmaa Sörensen, Stacey and Fonseca, P. T. and Lindgren, Andreas and Naves de Brito, A.},
  issn         = {0368-2048},
  keyword      = {Synchrotron,Time-of-Flight,Multicoincidence,Instrumentation},
  language     = {eng},
  number       = {1-3},
  pages        = {6--13},
  publisher    = {Elsevier},
  series       = {Journal of Electron Spectroscopy and Related Phenomena},
  title        = {Description and performance of an electron-ion coincidence TOF spectrometer used at the Brazilian synchrotron facility LNLS},
  url          = {http://dx.doi.org/10.1016/j.elspec.2010.02.007},
  volume       = {180},
  year         = {2010},
}