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Bogot A, Lioubashevski O, Heber O, Zajfman D, Strasser D. Simultaneous electrostatic trapping of merged cation & anion beams. Phys Chem Chem Phys 2023; 25:25701-25710. [PMID: 37721452 DOI: 10.1039/d3cp03633b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Simultaneous trapping of merged cation and anion beams in the hybrid electrostatic ion beam trap (HEIBT) opens new opportunities for the study of the interactions of isolated atomic molecular or cluster ions with oppositely charged ionic species. Application of the trapped merged beams requires a detailed understanding of the trapping dynamics and the effect of the Coulombic attractive and repulsive forces between the ions on their motion in the trap. The simultaneous trapping regime is explored experimentally for SF6- anion and SF5+ cation beams and compared to realistic ion trajectory simulations. The respective stability of the simultaneously trapped cation and anion beams is experimentally tracked by nondestructive and mass sensitive image charge monitoring. An approximate analytical potential model is presented for modeling the dynamics of trapped ions, providing insight into the role of ion-ion interactions, and suggesting a simplified mirror design.
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Affiliation(s)
- Alon Bogot
- The Hebrew University of Jerusalem, Institute of Chemistry, Jerusalem 91904, Israel.
| | - Oleg Lioubashevski
- The Hebrew University of Jerusalem, Institute of Chemistry, Jerusalem 91904, Israel.
| | - Oded Heber
- Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot 7610001, Israel
| | - Daniel Zajfman
- Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot 7610001, Israel
| | - Daniel Strasser
- The Hebrew University of Jerusalem, Institute of Chemistry, Jerusalem 91904, Israel.
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2
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Jain N, Kálosi Á, Nuesslein F, Paul D, Wilhelm P, Ard SG, Grieser M, von Hahn R, Heaven MC, Miliordos E, Maffucci D, Shuman NS, Viggiano AA, Wolf A, Novotný O. Near-thermo-neutral electron recombination of titanium oxide ions. J Chem Phys 2023; 158:144305. [PMID: 37061488 DOI: 10.1063/5.0146365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023] Open
Abstract
While the dissociative recombination (DR) of ground-state molecular ions with low-energy free electrons is generally known to be exothermic, it has been predicted to be endothermic for a class of transition-metal oxide ions. To understand this unusual case, the electron recombination of titanium oxide ions (TiO+) with electrons has been experimentally investigated using the Cryogenic Storage Ring. In its low radiation field, the TiO+ ions relax internally to low rotational excitation (≲100 K). Under controlled collision energies down to ∼2 meV within the merged electron and ion beam configuration, fragment imaging has been applied to determine the kinetic energy released to Ti and O neutral reaction products. Detailed analysis of the fragment imaging data considering the reactant and product excitation channels reveals an endothermicity for the TiO+ dissociative electron recombination of (+4 ± 10) meV. This result improves the accuracy of the energy balance by a factor of 7 compared to that found indirectly from hitherto known molecular properties. Conversely, the present endothermicity yields improved dissociation energy values for D0(TiO) = (6.824 ± 0.010) eV and D0(TiO+) = (6.832 ± 0.010) eV. All thermochemistry values were compared to new coupled-cluster calculations and found to be in good agreement. Moreover, absolute rate coefficients for the electron recombination of rotationally relaxed ions have been measured, yielding an upper limit of 1 × 10-7 cm3 s-1 for typical conditions of cold astrophysical media. Strong variation of the DR rate with the TiO+ internal excitation is predicted. Furthermore, potential energy curves for TiO+ and TiO have been calculated using a multi-reference configuration interaction method to constrain quantum-dynamical paths driving the observed TiO+ electron recombination.
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Affiliation(s)
- Naman Jain
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Ábel Kálosi
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Felix Nuesslein
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Daniel Paul
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Patrick Wilhelm
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Shaun G Ard
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, USA
| | - Manfred Grieser
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Robert von Hahn
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Michael C Heaven
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
| | - Evangelos Miliordos
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA
| | - Dominique Maffucci
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, USA
| | - Nicholas S Shuman
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, USA
| | - Albert A Viggiano
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, USA
| | - Andreas Wolf
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
| | - Oldřich Novotný
- Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany
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3
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Hansen VL. Global tectonic evolution of Venus, from exogenic to endogenic over time, and implications for early Earth processes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 377:20180412. [PMID: 30275161 DOI: 10.1098/rsta.2018.0412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/04/2018] [Indexed: 05/23/2023]
Abstract
Venus provides a rich arena in which to stretch one's tectonic imagination with respect to non-plate tectonic processes of heat transfer on an Earth-like planet. Venus is similar to Earth in density, size, inferred composition and heat budget. However, Venus' lack of plate tectonics and terrestrial surficial processes results in the preservation of a unique surface geologic record of non-plate tectonomagmatic processes. In this paper, I explore three global tectonic domains that represent changes in global conditions and tectonic regimes through time, divided respectively into temporal eras. Impactors played a prominent role in the ancient era, characterized by thin global lithosphere. The Artemis superstructure era highlights sublithospheric flow processes related to a uniquely large super plume. The fracture zone complex era, marked by broad zones of tectonomagmatic activity, witnessed coupled spreading and underthrusting, since arrested. These three tectonic regimes provide possible analogue models for terrestrial Archaean craton formation, continent formation without plate tectonics, and mechanisms underlying the emergence of plate tectonics. A bolide impact model for craton formation addresses the apparent paradox of both undepleted mantle and growth of Archaean crust, and recycling of significant Archaean crust to the mantle.This article is part of a discussion meeting issue 'Earth dynamics and the development of plate tectonics'.
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Affiliation(s)
- Vicki L Hansen
- Department of Earth and Environmental Sciences, University of Minnesota Duluth, 1114 Kirby Drive, Duluth, MN 55812, USA
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Melnikov VV, Yurchenko SN, Tennyson J, Jensen P. Radiative cooling of H 3O + and its deuterated isotopologues. Phys Chem Chem Phys 2016; 18:26268-26274. [PMID: 27711706 PMCID: PMC5315019 DOI: 10.1039/c6cp04661d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 08/28/2016] [Indexed: 11/21/2022]
Abstract
In conjunction with ab initio potential energy and dipole moment surfaces for the electronic ground state, we have made a theoretical study of the radiative lifetimes for the hydronium ion H3O+ and its deuterated isotopologues. We compute the ro-vibrational energy levels and their associated wavefunctions together with Einstein coefficients for electric dipole transitions. A detailed analysis of the stability of the ro-vibrational states has been carried out and the longest-living states of the hydronium ions have been identified. We report estimated radiative lifetimes and cooling functions for temperatures <200 K. A number of long-living meta-stable states are identified, capable of population trapping.
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Affiliation(s)
- Vladlen V Melnikov
- Siberian Institute of Physics & Technology, Tomsk State University, Tomsk, 634050, Russia
| | - Sergei N Yurchenko
- Department of Physics & Astronomy, University College London, London WC1E 6BT, UK.
| | - Jonathan Tennyson
- Department of Physics & Astronomy, University College London, London WC1E 6BT, UK.
| | - Per Jensen
- Physikalische und Theoretische Chemie, Fakultät für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, 42097 Wuppertal, Germany
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van Dishoeck EF. Astrochemistry of dust, ice and gas: introduction and overview. Faraday Discuss 2014; 168:9-47. [DOI: 10.1039/c4fd00140k] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A brief introduction and overview of the astrochemistry of dust, ice and gas and their interplay is presented. The importance of basic chemical physics studies of critical reactions is illustrated through a number of recent examples. Such studies have also triggered new insight into chemistry, illustrating how astronomy and chemistry can enhance each other. Much of the chemistry in star- and planet-forming regions is now thought to be driven by gas–grain chemistry rather than pure gas-phase chemistry, and a critical discussion of the state of such models is given. Recent developments in studies of diffuse clouds and PDRs, cold dense clouds, hot cores, protoplanetary disks and exoplanetary atmospheres are summarized, both for simple and more complex molecules, with links to papers presented in this volume. In spite of many lingering uncertainties, the future of astrochemistry is bright: new observational facilities promise major advances in our understanding of the journey of gas, ice and dust from clouds to planets.
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Affiliation(s)
- Ewine F. van Dishoeck
- Leiden Observatory
- Leiden University
- 2300 RA Leiden, the Netherlands
- Max-Planck-Institute für Extraterrestrische Physik
- Garching, Germany
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6
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Geppert WD, Larsson M. Experimental Investigations into Astrophysically Relevant Ionic Reactions. Chem Rev 2013; 113:8872-905. [DOI: 10.1021/cr400258m] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wolf D. Geppert
- Department
of Physics, AlbaNova
University Center, Stockholm University, Roslagstullsbacken 21, Stockholm SE-10691, Sweden
| | - Mats Larsson
- Department
of Physics, AlbaNova
University Center, Stockholm University, Roslagstullsbacken 21, Stockholm SE-10691, Sweden
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Thomas RD, Kashperka I, Vigren E, Geppert WD, Hamberg M, Larsson M, af Ugglas M, Zhaunerchyk V. Dissociative recombination of CH4(+). J Phys Chem A 2013; 117:9999-10005. [PMID: 23651407 DOI: 10.1021/jp400353x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CH4(+) is an important molecular ion in the astrochemistry of diffuse clouds, dense clouds, cometary comae, and planetary ionospheres. However, the rate of one of the common destruction mechanisms for molecular ions in these regions, dissociative recombination (DR), is somewhat uncertain. Here, we present absolute measurements for the DR of CH4(+) made using the heavy ion storage ring CRYRING in Stockholm, Sweden. From our collision-energy dependent cross-sections, we infer a thermal rate constant of k(Te) = 1.71(±0.02) × 10(–6)(Te/300)(−0.66(±0.02)) cm3 s(–1) over the region of electron temperatures 10 ≤ Te ≤ 1000 K. At low collision energies, we have measured the branching fractions of the DR products to be CH4 (0.00 ± 0.00); CH3 + H (0.18 ± 0.03); CH2 + 2H (0.51 ± 0.03); CH2 + H2 (0.06 ± 0.01); CH + H2 + H (0.23 ± 0.01); and CH + 2H2 (0.02 ± 0.01), indicating that two or more C–H bonds are broken in 80% of all collisions.
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Affiliation(s)
- Richard D Thomas
- Department of Physics, Stockholm University , Albanova University Center, SE-106 91 Stockholm, Sweden
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Mann JE, Xie Z, Savee JD, Bowman JM, Continetti RE. Vibrational excitation and product branching ratios in dissociation of the isotopologs of H3O: experiment and theory. J Phys Chem A 2013; 117:7256-66. [PMID: 23668439 DOI: 10.1021/jp4010949] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dissociation dynamics of the Rydberg radical H3O and the deuterated isotopologs have been studied by dissociative charge exchange of H3O(+) with Cs. Center-of-mass kinetic energy release distributions were measured with a fast-beam translational spectrometer and compared with direct dynamics quasiclassical trajectory calculations with initial conditions from an ab initio potential energy surface for H3O(+). The experimental branching fractions for dissociation of each isotopolog were obtained and compared with the calculated branching fractions. The dominant dissociation channel for all species is elimination of an H/D atom, and the water product was formed with a significant vibrational inversion in stretching vibrations that varies with the mass of the leaving atom in the dissociation. Branching fractions for the mixed isotopologs show that H atom elimination is favored over D atom elimination. Given the importance of H3O(+) in plasmas, astrochemistry, and in condensed phases, the striking energy partitioning found in this neutralization process is notable.
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Affiliation(s)
- Jennifer E Mann
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, USA
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