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McManus JW, Allum F, Featherstone J, Lam CS, Brouard M. Two-Dimensional Projected-Momentum Covariance Mapping for Coulomb Explosion Imaging. J Phys Chem A 2024; 128:3220-3229. [PMID: 38607425 PMCID: PMC11056990 DOI: 10.1021/acs.jpca.4c01084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/13/2024]
Abstract
We introduce projected-momentum covariance mapping, an extension of recoil-frame covariance mapping for 2D ion imaging studies. By considering the two-dimensional projection of the ion momenta as recorded by the detector, one opens the door to a complex suite of analysis tools adapted from three-dimensional momentum imaging studies. This includes the use of different frames of reference to unravel the dynamics of fragmentation and the application of fragment momentum constraints to isolate specific fragmentation channels. The technique is demonstrated on data from a two-dimensional ion imaging study of the Coulomb explosion of the cis and trans isomers of 1,2-dichloroethene, following strong-field ionization by an intense near-infrared femtosecond laser pulse. Classical simulations are used to guide the interpretation of projected-momentum covariance maps. The results offer a detailed insight into the distinct Coulomb explosion dynamics for this pair of isomers and lay the groundwork for future time-resolved studies of photoisomerization dynamics in this molecular system.
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Affiliation(s)
- Joseph W. McManus
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | | | - Josh Featherstone
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | - Chow-Shing Lam
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | - Mark Brouard
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
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Rajput J, Garg D, Cassimi A, Fléchard X, Rangama J, Safvan CP. Addressing three-body fragmentation of methane dication using "native frames": Evidence of internal excitation in fragments. J Chem Phys 2023; 159:184303. [PMID: 37955322 DOI: 10.1063/5.0171881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/23/2023] [Indexed: 11/14/2023] Open
Abstract
The three body fragmentation of methane dication has been studied using the technique of cold target recoil ion momentum spectroscopy. The process is initiated by impact of energetic Ar9+ ions on neutral methane and the data is subsequently collected in coincidence with Ar8+ projectile. By analysing the dissociation channels leading to (H + H+ + CH2+) and (H + H2+ + CH+) fragments, it is concluded that these fragments are formed in a sequential manner via formation of molecular intermediates CH3+ and CH2+ respectively. It is shown that these molecular intermediates carry a few eVs as their internal energies, part of which is released when they emit an H-atom with the open possibility that the final detected fragments may still be internally excited. This was accomplished by analysing the two-steps of the sequential process in their own native frames. For a molecular system having three-dimensional structure, our results prove to be an ideal example to highlight the importance of using native frames for correct interpretation of the obtained results. Our results indicate that the dissociation of methane dication can be a major source of production of H-atoms in addition to H+ fragments with the probability of the two being of similar order.
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Affiliation(s)
- Jyoti Rajput
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - Diksha Garg
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - X Fléchard
- Université de Caen Normandie, ENSICAEN, CNRS/IN2P3, LPC Caen UMR6534, F-14000 Caen, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - C P Safvan
- Inter-University Accelerator Centre, New Delhi 110067, India
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McManus JW, Walmsley T, Nagaya K, Harries JR, Kumagai Y, Iwayama H, Ashfold MNR, Britton M, Bucksbaum PH, Downes-Ward B, Driver T, Heathcote D, Hockett P, Howard AJ, Kukk E, Lee JWL, Liu Y, Milesevic D, Minns RS, Niozu A, Niskanen J, Orr-Ewing AJ, Owada S, Rolles D, Robertson PA, Rudenko A, Ueda K, Unwin J, Vallance C, Burt M, Brouard M, Forbes R, Allum F. Disentangling sequential and concerted fragmentations of molecular polycations with covariant native frame analysis. Phys Chem Chem Phys 2022; 24:22699-22709. [PMID: 36106844 DOI: 10.1039/d2cp03029b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present results from an experimental ion imaging study into the fragmentation dynamics of 1-iodopropane and 2-iodopropane following interaction with extreme ultraviolet intense femtosecond laser pulses with a photon energy of 95 eV. Using covariance imaging analysis, a range of observed fragmentation pathways of the resulting polycations can be isolated and interrogated in detail at relatively high ion count rates (∼12 ions shot-1). By incorporating the recently developed native frames analysis approach into the three-dimensional covariance imaging procedure, contributions from three-body concerted and sequential fragmentation mechanisms can be isolated. The angular distribution of the fragment ions is much more complex than in previously reported studies for triatomic polycations, and differs substantially between the two isomeric species. With support of simple simulations of the dissociation channels of interest, detailed physical insights into the fragmentation dynamics are obtained, including how the initial dissociation step in a sequential mechanism influences rovibrational dynamics in the metastable intermediate ion and how signatures of this nuclear motion manifest in the measured signals.
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Affiliation(s)
- Joseph W McManus
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Tiffany Walmsley
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Kiyonobu Nagaya
- Department of Physics, Kyoto University, Kyoto, 606-8502, Japan
| | | | - Yoshiaki Kumagai
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan
| | - Hiroshi Iwayama
- UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Mathew Britton
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Philip H Bucksbaum
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Briony Downes-Ward
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Taran Driver
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - David Heathcote
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Paul Hockett
- National Research Council of Canada, 100 Sussex Dr., Ottawa, ON K1A 0R6, Canada
| | - Andrew J Howard
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Edwin Kukk
- Department of Physics and Astronomy, University of Turku, Turku, FI-20014, Finland
| | - Jason W L Lee
- Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg, Germany
| | - Yusong Liu
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Dennis Milesevic
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Russell S Minns
- Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Akinobu Niozu
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Johannes Niskanen
- Department of Physics and Astronomy, University of Turku, Turku, FI-20014, Finland
| | - Andrew J Orr-Ewing
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Shigeki Owada
- RIKEN SPring-8 Center, Sayo, Hyogo, 679-5148, Japan.,Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Daniel Rolles
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, 66506, USA
| | - Patrick A Robertson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Artem Rudenko
- J. R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS, 66506, USA
| | - Kiyoshi Ueda
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, 980-8577, Japan
| | - James Unwin
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Claire Vallance
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Michael Burt
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Mark Brouard
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - Ruaridh Forbes
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
| | - Felix Allum
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK.,Stanford PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.,Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
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