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Komar D, Raspe K, Kazak L, Iwe N, Meiwes-Broer KH, Tiggesbäumker J. Transition from Surface to Volume Expansion in Argon Clusters Coulomb Explosion. PHYSICAL REVIEW LETTERS 2024; 133:073202. [PMID: 39213558 DOI: 10.1103/physrevlett.133.073202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 06/25/2024] [Indexed: 09/04/2024]
Abstract
The intensity-difference spectrum technique is applied to record charge-state resolved ion energy spectra from the Coulomb explosion of small Ar clusters under well-resolved laser intensity conditions. The far-reaching control of the experimental parameters permits us to identify a striking change in the expansion pattern of the nanoplasma beyond a given intensity. The simultaneous characterization of ion charge state and energy uncovers that a reduction of the laser intensity leads to a development of low energy cuts in the ion yields, not present at higher fluence. The complex interplay of outer ionization, recombination, ion screening, and the phenomenon of ionization saturation favors a surface-driven expansion at low plasma electron temperatures. With increasing laser intensity a transition into a volume-driven Coulomb explosion is observed.
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Last I, Jortner J. Microscopic and hydrodynamic impact energy transfer from nanoplasma electrons to ions in exploding clusters. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1478135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Isidore Last
- School of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Joshua Jortner
- School of Chemistry, Tel Aviv University, Tel Aviv, Israel
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3
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Electron–Ion Impact Energy Transfer in Nanoplasmas of Coulomb Exploding Clusters. ADVANCES IN QUANTUM CHEMISTRY 2017. [DOI: 10.1016/bs.aiq.2017.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Heidenreich A, Last I, Ron S, Jortner J. Conversion of laser energy to nuclear energy driven by Coulomb explosion of nanostructures. Mol Phys 2013. [DOI: 10.1080/00268976.2013.788746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Andreas Heidenreich
- Department of Chemistry, University of the Basque Country (UPV/EHU) , Donostia, Spain
- Donostia International Physics Center (DIPC) , Donostia, Spain
- IKERBASQUE, Basque Foundation for Science , Bilbao, Spain
| | - Isidore Last
- School of Chemistry, Tel Aviv University , Tel Aviv, Israel
| | - Shlomo Ron
- School of Chemistry, Tel Aviv University , Tel Aviv, Israel
| | - Joshua Jortner
- School of Chemistry, Tel Aviv University , Tel Aviv, Israel
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Grech M, Nuter R, Mikaberidze A, Di Cintio P, Gremillet L, Lefebvre E, Saalmann U, Rost JM, Skupin S. Coulomb explosion of uniformly charged spheroids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:056404. [PMID: 22181525 DOI: 10.1103/physreve.84.056404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Indexed: 05/31/2023]
Abstract
A simple, semianalytical model is proposed for nonrelativistic Coulomb explosion of a uniformly charged spheroid. This model allows us to derive the time-dependent particle energy distributions. Simple expressions are also given for the characteristic explosion time and maximum particle energies in the limits of extreme prolate and oblate spheroids as well as for the sphere. Results of particle simulations are found to be in remarkably good agreement with the model.
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Affiliation(s)
- M Grech
- Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany.
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Heidenreich A, Jortner J. Kinetic energy distribution of multiply charged ions in Coulomb explosion of Xe clusters. J Chem Phys 2011; 134:074315. [DOI: 10.1063/1.3521476] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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8
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Skopalová E, El-Taha YC, Zaïr A, Hohenberger M, Springate E, Tisch JWG, Smith RA, Marangos JP. Pulse-length dependence of the anisotropy of laser-driven cluster explosions: transition to the impulsive regime for pulses approaching the few-cycle limit. PHYSICAL REVIEW LETTERS 2010; 104:203401. [PMID: 20867025 DOI: 10.1103/physrevlett.104.203401] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Indexed: 05/29/2023]
Abstract
We have experimentally observed anisotropic ion emission from Xe and Ar clusters under intense ultrashort (∼30 fs) laser irradiation, with up to 1.8 times more energetic ions emitted in the direction perpendicular to the laser polarization than in the parallel direction. As the pulse length was varied in the range of 8-160 fs, we found this anisotropy to first grow and then diminish. Treating electrons inside the unexpanded cluster as a harmonic oscillator qualitatively demonstrates how intracluster electric field can result in an ion emission anisotropy of this kind. Our observations give direct access to the initial charging dynamics present in the first few cycles of an intense laser field interacting with any nanoscale dielectric.
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Affiliation(s)
- E Skopalová
- Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom.
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Lu H, Chen G, Ni G, Li R, Xu Z. Impact of Gas Backing Pressure and Geometry of Conical Nozzle on the Formation of Methane Clusters in Supersonic Jets. J Phys Chem A 2009; 114:2-9. [DOI: 10.1021/jp902094g] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Haiyang Lu
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Guanglong Chen
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Guoquan Ni
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Ruxin Li
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
| | - Zhizhan Xu
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China, and Key Laboratory for Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, the Chinese Academy of Sciences, Shanghai 201800, China
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Heidenreich A, Last I, Jortner J. Extreme dynamics and energetics of Coulomb explosion of Xe clusters. Phys Chem Chem Phys 2009; 11:111-24. [DOI: 10.1039/b819126n] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Soullard J, Santamaria R, Jellinek J. Pressure and size effects in endohedrally confined hydrogen clusters. J Chem Phys 2008; 128:064316. [DOI: 10.1063/1.2827487] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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12
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Heidenreich A, Last I, Jortner J. Simulations of Extreme Ionization and Electron Dynamics in Ultraintense Laser-Cluster Interactions. Isr J Chem 2007. [DOI: 10.1560/ijc.47.1.89] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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13
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Heidenreich A, Last I, Jortner J. Extreme multielectron ionization of elemental clusters in ultraintense laser fields. Isr J Chem 2007. [DOI: 10.1560/ijc.47.2.243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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14
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Vibrational excitation of simple molecular ions in resonant and under-resonant strong laser fields: Dissociation and ionization of ppe and pde; laser-enhanced nuclear fusion in ddμ and dtμ. Chem Phys 2007. [DOI: 10.1016/j.chemphys.2007.04.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Heidenreich A, Last I, Jortner J. Extreme ionization of Xe clusters driven by ultraintense laser fields. J Chem Phys 2007; 127:074305. [PMID: 17718611 DOI: 10.1063/1.2762217] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We applied theoretical models and molecular dynamics simulations to explore extreme multielectron ionization in Xe(n) clusters (n=2-2171, initial cluster radius R(0)=2.16-31.0 A) driven by ultraintense infrared Gaussian laser fields (peak intensity I(M)=10(15)-10(20) W cm(-2), temporal pulse length tau=10-100 fs, and frequency nu=0.35 fs(-1)). Cluster compound ionization was described by three processes of inner ionization, nanoplasma formation, and outer ionization. Inner ionization gives rise to high ionization levels (with the formation of [Xe(q+)](n) with q=2-36), which are amenable to experimental observation. The cluster size and laser intensity dependence of the inner ionization levels are induced by a superposition of barrier suppression ionization (BSI) and electron impact ionization (EII). The BSI was induced by a composite field involving the laser field and an inner field of the ions and electrons, which manifests ignition enhancement and screening retardation effects. EII was treated using experimental cross sections, with a proper account of sequential impact ionization. At the highest intensities (I(M)=10(18)-10(20) W cm(-2)) inner ionization is dominated by BSI. At lower intensities (I(M)=10(15)-10(16) W cm(-2)), where the nanoplasma is persistent, the EII contribution to the inner ionization yield is substantial. It increases with increasing the cluster size, exerts a marked effect on the increase of the [Xe(q+)](n) ionization level, is most pronounced in the cluster center, and manifests a marked increase with increasing the pulse length (i.e., becoming the dominant ionization channel (56%) for Xe(2171) at tau=100 fs). The EII yield and the ionization level enhancement decrease with increasing the laser intensity. The pulse length dependence of the EII yield at I(M)=10(15)-10(16) W cm(-2) establishes an ultraintense laser pulse length control mechanism of extreme ionization products.
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Symes DR, Hohenberger M, Henig A, Ditmire T. Anisotropic explosions of hydrogen clusters under intense femtosecond laser irradiation. PHYSICAL REVIEW LETTERS 2007; 98:123401. [PMID: 17501120 DOI: 10.1103/physrevlett.98.123401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2006] [Indexed: 05/15/2023]
Abstract
We report on measurements of ion energy distributions from hydrogen clusters irradiated by intense laser pulses of duration 40 and 250 fs. Contrary to the predictions of a simple Coulomb explosion model, we observe a pronounced spatial anisotropy of the ion energies from these explosions with the highest energy ions ejected along the laser polarization direction. The origin of the anisotropy is distinct from that previously seen in clusters of high Z atoms such as Ar and Xe. Furthermore, a measured increase in H+ ion energy when longer, lower intensity pulses are employed suggests that multiple-pass, vacuum heating of the cluster electrons is important in the deposition of energy by the laser.
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Affiliation(s)
- D R Symes
- The Texas Center for High Intensity Laser Science, Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA
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Last I, Jortner J. Tabletop nucleosynthesis driven by cluster Coulomb explosion. PHYSICAL REVIEW LETTERS 2006; 97:173401. [PMID: 17155473 DOI: 10.1103/physrevlett.97.173401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Indexed: 05/12/2023]
Abstract
Coulomb explosion of completely ionized (CH4)n, (NH3)n, and (H2O)n clusters will drive tabletop nuclear reactions of protons with 12C6+, 14N7+, and 16O8+ nuclei, extending the realm of nuclear reactions driven by ultraintense laser-heterocluster interaction. The realization for nucleosynthesis in exploding cluster beams requires complete electron stripping from the clusters (at laser intensities I(M) > or = 10(19) W cm(-2)), the utilization of nanodroplets of radius 300-700 A for vertical ionization, and the attainment of the highest energies for the nuclei (i.e., approximately 30 MeV for heavy nuclei and approximately 3 MeV for protons).
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Affiliation(s)
- Isidore Last
- School of Chemistry, Tel-Aviv University, 69978 Tel-Aviv, Israel
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Heidenreich A, Jortner J, Last I. Cluster dynamics transcending chemical dynamics toward nuclear fusion. Proc Natl Acad Sci U S A 2006; 103:10589-93. [PMID: 16740666 PMCID: PMC1502276 DOI: 10.1073/pnas.0508622103] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ultrafast cluster dynamics encompasses femtosecond nuclear dynamics, attosecond electron dynamics, and electron-nuclear dynamics in ultraintense laser fields (peak intensities 10(15)-10(20) W.cm(-2)). Extreme cluster multielectron ionization produces highly charged cluster ions, e.g., (C(4+)(D(+))(4))(n) and (D(+)I(22+))(n) at I(M) = 10(18) W.cm(-2), that undergo Coulomb explosion (CE) with the production of high-energy (5 keV to 1 MeV) ions, which can trigger nuclear reactions in an assembly of exploding clusters. The laser intensity and the cluster size dependence of the dynamics and energetics of CE of (D(2))(n), (HT)(n), (CD(4))(n), (DI)(n), (CD(3)I)(n), and (CH(3)I)(n) clusters were explored by electrostatic models and molecular dynamics simulations, quantifying energetic driving effects, and kinematic run-over effects. The optimization of table-top dd nuclear fusion driven by CE of deuterium containing heteroclusters is realized for light-heavy heteroclusters of the largest size, which allows for the prevalence of cluster vertical ionization at the highest intensity of the laser field. We demonstrate a 7-orders-of-magnitude enhancement of the yield of dd nuclear fusion driven by CE of light-heavy heteroclusters as compared with (D(2))(n) clusters of the same size. Prospective applications for the attainment of table-top nucleosynthesis reactions, e.g., (12)C(P,gamma)(13)N driven by CE of (CH(3)I)(n) clusters, were explored.
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Affiliation(s)
- Andreas Heidenreich
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Joshua Jortner
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
- *To whom correspondence should be addressed. E-mail:
| | - Isidore Last
- School of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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Jortner J. REFLECTIONS ON PHYSICAL CHEMISTRY: Science and Scientists. Annu Rev Phys Chem 2006; 57:1-35. [PMID: 16599803 DOI: 10.1146/annurev.physchem.56.092503.141246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
▪ Abstract This is the story of a young person who grew up in Tel-Aviv during the period of the establishment of the State of Israel and was inspired to become a physical chemist by the cultural environment, by the excellent high-school education, and by having been trained by some outstanding scientists at the Hebrew University of Jerusalem and, subsequently, by the intellectual environment and high-quality scientific endeavor at the University of Chicago. Since serving as the first chairman of the Chemistry Department of the newly formed Tel-Aviv University he has been immersed in research, in the training of young scientists, and in intensive and extensive international scientific collaboration. Together with the members of his “scientific family” he has explored the phenomena of energy acquisition, storage and disposal and structure-dynamics-function relations in large molecules, condensed phase, clusters and biomolecules, and is looking forward to many future adventures in physical chemistry. “What to leave out and what to put in? That's the problem.” Hugh Lofting, Doctor Dolittle's Zoo, 1925
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Affiliation(s)
- Joshua Jortner
- School of Chemistry, Raymond and Beverly Sackler Faculty of Sciences, Tel-Aviv University, Ramat Aviv, Tel-Aviv 69978, Israel.
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Levy† Y, Last I, Jortner J. Dynamics of fission and Coulomb explosion of multicharged large finite systems. Mol Phys 2006. [DOI: 10.1080/00268970500525630] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Livshits E, Baer R. Time-Dependent Density-Functional Studies of the D2 Coulomb Explosion. J Phys Chem A 2006; 110:8443-50. [PMID: 16821827 DOI: 10.1021/jp0600460] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Real-time first principle simulations are presented of the D(2) Coulomb explosion dynamics detonated by exposure to very intense few-cycle laser pulse. Three approximate functionals within the time-dependent density functional theory (TDDFT) functionals are examined for describing the electron dynamics, including time-dependent Hartree-Fock theory. Nuclei are treated classically with quantum corrections. The calculated results are sensitive to the underlying electronic structure theory, showing too narrow kinetic energy distribution peaked at too high kinetic energy when compared with recent experimental results (Phys. Rev. Lett. 2003, 91, 093002). Experiment also shows a low energy peak which is not seen in the present calculation. We conclude that while Ehrenfest-adiabatic-TDDFT can qualitatively account for the dynamics, it requires further development, probably beyond the adiabatic approximation, to be quantitative.
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Affiliation(s)
- Ester Livshits
- Department of Physical Chemistry and the Lise Meitner Minerva-Center for Quantum Chemistry, Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Jacobi S, Baer R. Variational grand-canonical electronic structure method for open systems. J Chem Phys 2005; 123:044112. [PMID: 16095351 DOI: 10.1063/1.1949202] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
An ab initio method is developed for variational grand-canonical molecular electronic structure of open systems based on the Gibbs-Peierls-Boguliobov inequality. We describe the theory and a practical method for performing the calculations within standard quantum chemistry codes using Gaussian basis sets. The computational effort scales similarly to the ground-state Hartree-Fock method. The quality of the approximation is studied on a hydrogen molecule by comparing to the exact Gibbs free energy, computed using full configuration-interaction calculations. We find the approximation quite accurate, with errors similar to those of the Hartree-Fock method for ground-state (zero-temperature) calculations. A further demonstration is given of the temperature effects on the bending potential curve for water. Some future directions and applications of the method are discussed. Several appendices give the mathematical and algorithmic details of the method.
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Affiliation(s)
- Shlomit Jacobi
- Department of Physical Chemistry and the Lise Meitner Center for Quantum Chemistry, the Hebrew University of Jerusalem, Jerusalem 91904 Israel
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Jortner J, Last I. Ultrafast nuclear dynamics and non-uniform Coulomb explosion of heteroclusters. Mol Phys 2005. [DOI: 10.1080/00268970500096046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- J. Jortner
- a School of Chemistry , Tel Aviv University , Ramat Aviv, -aviv , 69978 , Israel
| | - I. Last
- a School of Chemistry , Tel Aviv University , Ramat Aviv, -aviv , 69978 , Israel
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Niu D, Li H, Liang F, Wen L, Luo X, Wang B, Qu H. Coulomb explosion of ammonia clusters induced by intense nanosecond laser at 532 and 1064nm: Wavelength dependence of the multicharged nitrogen ions. J Chem Phys 2005; 122:151103. [PMID: 15945617 DOI: 10.1063/1.1894786] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Coulomb explosion of ammonia clusters induced by nanosecond laser field with intensity in the range of 10(10)-10(12) W cm(-2) and wavelength of 532 and 1064 nm has been studied. N2+ and N3+ ions are the main multicharged ions at 532 nm, while He-like N5+ ion is the domain multicharged ion at 1064 nm.
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Affiliation(s)
- Dongmei Niu
- Dalian Institute of Chemical Physics, Dalian 116023 and Anhui Institute of Optics and Fine Mechanics, Hefei 230031, Chinese Academy of Sciences, People's Republic of China
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Petrov GM, Davis J, Velikovich AL, Kepple PC, Dasgupta A, Clark RW, Borisov AB, Boyer K, Rhodes CK. Modeling of clusters in a strong 248-nm laser field by a three-dimensional relativistic molecular dynamic model. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:036411. [PMID: 15903592 DOI: 10.1103/physreve.71.036411] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Revised: 01/21/2005] [Indexed: 05/02/2023]
Abstract
A relativistic time-dependent three-dimensional particle simulation model has been developed to study the interaction of intense ultrashort KrF (248 nm) laser pulses with small Xe clusters. The trajectories of the electrons and ions are treated classically according to the relativistic equation of motion. The model has been applied to a different regime of ultrahigh intensities extending to 10(21) W/ cm(2). In particular, the behavior of the interaction with the clusters from intensities of approximately 10(15) W/cm(2) to intensities sufficient for a transition to the so-called "collective oscillation model" has been explored. At peak intensities below 10(20) W/cm(2), all electrons are removed from the cluster and form a plasma. It is found that the "collective oscillation model" commences at intensities in excess of 10(20) W/cm(2), the range that can be reached in stable relativistic channels. At these high intensities, the magnetic field has a profound effect on the shape and trajectory of the electron cloud. Specifically, the electrons are accelerated to relativistic velocities with energies exceeding 1 MeV in the direction of laser propagation and the magnetic field distorts the shape of the electron cloud to give the form of a pancake.
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Affiliation(s)
- G M Petrov
- Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375, USA
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Last I, Jortner J. Regular multicharged transient soft matter in Coulomb explosion of heteroclusters. Proc Natl Acad Sci U S A 2005; 102:1291-5. [PMID: 15665087 PMCID: PMC547852 DOI: 10.1073/pnas.0408636102] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nanointerfaces of mobile, thin spherical shells of light ions that expand on the femtosecond time scale, can be produced by Coulomb explosion of extremely ionized molecular heteroclusters consisting of light and heavy ions, e.g., (D+Iq+)n (q = 7-35), which are generated in ultraintense laser fields (intensity, I, = 10(16) to 10(20) W.cm(-2)). Modeling, together with molecular dynamics simulations, reveals the expansion of 2D monolayers with high energies and narrow energy distributions [e.g., Eav approximately 23 keV and DeltaE/Eav = 0.16 for D+ from (D+I25+)(2171)] arising from kinematic run-over effects. The expanding regular, monoionic, spherical nanointerfaces manifest the attainment of transient self-organization in complex systems driven by repulsive Coulomb interactions.
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Affiliation(s)
- Isidore Last
- School of Chemistry, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel
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Last I, Jortner J. Electron and nuclear dynamics of molecular clusters in ultraintense laser fields. IV. Coulomb explosion of molecular heteroclusters. J Chem Phys 2004; 121:8329-42. [PMID: 15511153 DOI: 10.1063/1.1802554] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this paper we present a theoretical and computational study of the temporal dynamics and energetics of Coulomb explosion of (CD4)(n) and (CH4)(n) (n=55-4213) molecular heteroclusters in ultraintense (I=10(16)-10(19) W cm(-2)) laser fields, addressing the manifestation of electron dynamics, together with nuclear energetic and kinematic effects on the heterocluster Coulomb instability. The manifestations of the coupling between electron and nuclear dynamics were explored by molecular dynamics simulations for these heteroclusters coupled to Gaussian laser fields (pulse width tau=25 fs), elucidating outer ionization dynamics, nanoplasma screening effects (being significant for I< or =10(17) W cm(-2)), and the attainment of cluster vertical ionization (CVI) (at I=10(17) W cm(-2) for cluster radius R(0)< or =31 A). Nuclear kinematic effects on heterocluster Coulomb explosion are governed by the kinematic parameter eta=q(C)m(A)/q(A)m(C) for (CA(4))(n) clusters (A=H,D), where q(j) and m(j) (j=A,C) are the ionic charges and masses. Nonuniform heterocluster Coulomb explosion (eta >1) manifests an overrun effect of the light ions relative to the heavy ions, exhibiting the expansion of two spatially separated subclusters, with the light ions forming the outer subcluster at the outer edge of the spatial distribution. Important features of the energetics of heterocluster Coulomb explosion originate from energetic triggering effects of the driving of the light ions by the heavy ions (C(4+) for I=10(17)-10(18) W cm(-2) and C(6+) for I=10(19) W cm(-2)), as well as for kinematic effects. Based on the CVI assumption, scaling laws for the cluster size (radius R(0)) dependence of the energetics of uniform Coulomb explosion of heteroclusters (eta=1) were derived, with the size dependence of the average (E(j,av)) and maximal (E(j,M)) ion energies being E(j,av)=aR(0) (2) and E(j,M)=(5a/3)R(0) (2), as well as for the ion energy distributions P(E(j)) proportional to E(j) (1/2); E(j)< or =E(j,M). These results for uniform Coulomb explosion serve as benchmark reference data for the assessment of the effects of nonuniform explosion, where the CVI scaling law for the energetics still holds, with deviations of the a coefficient, which increase with increasing eta. Kinematic effects (for eta>1) result in an isotope effect, predicting the enhancement (by 9%-11%) of E(H,av) for Coulomb explosion of (C(4+)H(4) (+))(eta) (eta=3) relative to E(D,av) for Coulomb explosion of (C(4+)D(4) (+))(eta) (eta=1.5), with the isotope effect being determined by the ratio of the kinematic parameters for the pair of Coulomb exploding clusters. Kinematic effects for nonuniform explosion also result in a narrow isotope dependent energy distribution (of width DeltaE) of the light ions (with DeltaE/E(H,av) approximately 0.3 and DeltaE/E(D,av) approximately 0.4), with the distribution peaking at the high energy edge, in marked contrast with the uniform explosion case. Features of laser-heterocluster interactions were inferred from the analyses of the intensity dependent boundary radii (R(0))(I) and the corresponding average D+ ion energies (E(D,av))(I), which provide a measure for optimization of the cluster size at intensity I for the neutron yield from dd nuclear fusion driven by Coulomb explosion (NFDCE) of these heteroclusters. We infer on the advantage of deuterium containing heteronuclear clusters, e.g., (CD4)(n) in comparison to homonuclear clusters, e.g., (D2)(n/2), for dd NFDCE, where the highly charged heavy ions (e.g., C4+ or C6+) serve as energetic and kinematic triggers driving the D+ ions to a high (10-200 keV) energy domain.
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Affiliation(s)
- Isidore Last
- School of Chemistry, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv, Israel
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