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Wells E, Rallis C, Zohrabi M, Siemering R, Jochim B, Andrews P, Ablikim U, Gaire B, De S, Carnes K, Bergues B, de Vivie-Riedle R, Kling M, Ben-Itzhak I. Adaptive strong-field control of chemical dynamics guided by three-dimensional momentum imaging. Nat Commun 2013; 4:2895. [DOI: 10.1038/ncomms3895] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 11/07/2013] [Indexed: 11/09/2022] Open
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Kling NG, Betsch KJ, Zohrabi M, Zeng S, Anis F, Ablikim U, Jochim B, Wang Z, Kübel M, Kling MF, Carnes KD, Esry BD, Ben-Itzhak I. Carrier-envelope phase control over pathway interference in strong-field dissociation of H2+. PHYSICAL REVIEW LETTERS 2013; 111:163004. [PMID: 24182264 DOI: 10.1103/physrevlett.111.163004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Indexed: 06/02/2023]
Abstract
The dissociation of an H2+ molecular-ion beam by linearly polarized, carrier-envelope-phase-tagged 5 fs pulses at 4×10(14) W/cm2 with a central wavelength of 730 nm was studied using a coincidence 3D momentum imaging technique. Carrier-envelope-phase-dependent asymmetries in the emission direction of H+ fragments relative to the laser polarization were observed. These asymmetries are caused by interference of odd and even photon number pathways, where net zero-photon and one-photon interference predominantly contributes at H+ + H kinetic energy releases of 0.2-0.45 eV, and net two-photon and one-photon interference contributes at 1.65-1.9 eV. These measurements of the benchmark H2+ molecule offer the distinct advantage that they can be quantitatively compared with ab initio theory to confirm our understanding of strong-field coherent control via the carrier-envelope phase.
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Laurent G, Cao W, Ben-Itzhak I, Cocke CL. Attosecond pulse characterization. OPTICS EXPRESS 2013; 21:16914-16927. [PMID: 23938540 DOI: 10.1364/oe.21.016914] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this work we propose a novel procedure for the characterization of attosecond pulses. The method relies on the conversion of the attosecond pulse into electron wave-packets through photoionization of atoms in the presence of a weak IR field. It allows for the unique determination of the spectral phase making up the pulses by accurately taking into account the atomic physics of the photoionization process. The phases are evaluated by optimizing the fit of a perturbation theory calculation to the experimental result. The method has been called iPROOF (improved Phase Retrieval by Omega Oscillation Filtering) as it bears a similarity to the PROOF technique [Chini et al. Opt. Express 18, 13006 (2010)]. The procedure has been demonstrated for the characterization of an attosecond pulse train composed of odd and even harmonics. We observe a large phase shift between consecutive odd and even harmonics. The resulting attosecond pulse train has a complex structure not resembling a single attosecond pulse once per IR period, which is the case for zero phase. Finally, the retrieval procedure can be applied to the characterization of single attosecond pulses as well.
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Laurent G, Cao W, Li H, Wang Z, Ben-Itzhak I, Cocke CL. Attosecond control of orbital parity mix interferences and the relative phase of even and odd harmonics in an attosecond pulse train. PHYSICAL REVIEW LETTERS 2012; 109:083001. [PMID: 23002742 DOI: 10.1103/physrevlett.109.083001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Indexed: 06/01/2023]
Abstract
We experimentally demonstrate that atomic orbital parity mix interferences can be temporally controlled on an attosecond time scale. Electron wave packets are formed by ionizing argon gas with a comb of odd and even high-order harmonics, in the presence of a weak infrared field. Consequently, a mix of energy-degenerate even and odd parity states is fed in the continuum by one- and two-photon transitions. These interfere, leading to an asymmetric electron emission along the polarization vector. The direction of the emission can be controlled by varying the time delay between the comb and infrared field pulses. We show that such asymmetric emission provides information on the relative phase of consecutive odd and even order harmonics in the attosecond pulse train.
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Zhu G, Schuricke M, Steinmann J, Albrecht J, Ullrich J, Ben-Itzhak I, Zouros TJM, Colgan J, Pindzola MS, Dorn A. Controlling two-electron threshold dynamics in double photoionization of lithium by initial-state preparation. PHYSICAL REVIEW LETTERS 2009; 103:103008. [PMID: 19792307 DOI: 10.1103/physrevlett.103.103008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Indexed: 05/28/2023]
Abstract
Double photoionization (DPI) and ionization-excitation (IE) of Li(2s) and Li(2p), state-prepared and aligned in a magneto-optical trap, were explored in a reaction microscope at the free-electron laser in Hamburg (FLASH). From 6 to 12 eV above threshold (homega = 85, 91 eV), total as well as differential DPI cross sections were observed to critically depend on the initial state and, in particular, on the alignment of the 2p orbital with respect to the VUV-light polarization, whereas no effect is seen for IE. The alignment sensitivity is traced back to dynamical electron correlation at threshold.
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McKenna J, Anis F, Gaire B, Johnson NG, Zohrabi M, Carnes KD, Esry BD, Ben-Itzhak I. Suppressed dissociation of H(2)(+) vibrational states by reduced dipole coupling. PHYSICAL REVIEW LETTERS 2009; 103:103006. [PMID: 19792305 DOI: 10.1103/physrevlett.103.103006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Indexed: 05/28/2023]
Abstract
The suppression of H(2)(+) strong-field dissociation has intrigued experimentalists and theorists since the early days of laser-molecular science. We unravel a vibrational suppression effect due to weak dipole-matrix element coupling strengths of certain vibrational states, dependent on the laser frequency-a form of Cooper minima. This effect is demonstrated by our full-dimensional calculations on H(2)(+) dissociation and persists for a broad range of laser conditions including both weak and strong-field dissociation. Using a crossed-beams coincidence, three-dimensional momentum-imaging technique, the vibrational suppression effect is clearly observed for H(2)(+) and HD(+) at 790 and 395 nm, in good agreement with our theory.
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McKenna J, Sayler AM, Gaire B, Johnson NG, Carnes KD, Esry BD, Ben-Itzhak I. Benchmark measurements of H(3)(+) nonlinear dynamics in intense ultrashort laser pulses. PHYSICAL REVIEW LETTERS 2009; 103:103004. [PMID: 19792303 DOI: 10.1103/physrevlett.103.103004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Indexed: 05/28/2023]
Abstract
The H(3)(+) ion is the simplest polyatomic molecule and is destined to play a central role in understanding such molecules in intense ultrashort laser pulses. We present the first measurements of the intense field dissociation and ionization of D(3)(+) using coincidence three-dimensional momentum imaging. Our results show features that are a consequence of this molecule's unique equilateral triangular geometry, providing a fundamentally new system for theoretical development.
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McKenna J, Sayler AM, Anis F, Gaire B, Johnson NG, Parke E, Hua JJ, Mashiko H, Nakamura CM, Moon E, Chang Z, Carnes KD, Esry BD, Ben-Itzhak I. Enhancing high-order above-threshold dissociation of H2+ beams with few-cycle laser pulses. PHYSICAL REVIEW LETTERS 2008; 100:133001. [PMID: 18517942 DOI: 10.1103/physrevlett.100.133001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Indexed: 05/26/2023]
Abstract
High-order (three-photon or more) above-threshold dissociation (ATD) of H(2)(+) has generally not been observed using 800 nm light. We demonstrate a strong enhancement of its probability using intense 7 fs laser pulses interacting with beams of H(2)(+), HD(+), and D(2)(+) ions. The mechanism invokes a dynamic control of the dissociation pathway. These measurements are supported by theory that additionally reveals, for the first time, an unexpectedly large contribution to ATD from highly excited electronic states.
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Gaire B, Sayler AM, Wang PQ, Johnson NG, Leonard M, Parke E, Carnes KD, Ben-Itzhak I. Determining the absolute efficiency of a delay line microchannel-plate detector using molecular dissociation. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2007; 78:024503. [PMID: 17578132 DOI: 10.1063/1.2671497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We present a method to measure the absolute detection efficiency of a delay-line microchannel-plate detector using the breakup of diatomic molecular ions. This method provides the absolute total detection efficiency, as well as the individual efficiency for each signal of the detector. The method is based on the fact that molecular breakup always yields two hits on the detector, but due to finite detection efficiency some of these events are recorded as single particles while others are detected in pairs. We demonstrate the method by evaluating the detection efficiency for both timing and position signals of a delay-line detector using laser-induced dissociation of molecular ions. In addition, the detection efficiency as a function of position has been determined by dividing the detector into sectors.
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Esry BD, Sayler AM, Wang PQ, Carnes KD, Ben-Itzhak I. Above threshold Coulomb explosion of molecules in intense laser pulses. PHYSICAL REVIEW LETTERS 2006; 97:013003. [PMID: 16907372 DOI: 10.1103/physrevlett.97.013003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Indexed: 05/11/2023]
Abstract
We have measured and explained a new mechanism of molecular ionization near the appearance intensity that produces a sequence of peaks in the nuclear kinetic energy spectrum separated by the photon energy. Our interpretation is based on an internally consistent model for the nuclear motion during an intense laser pulse. Within this model, the same concepts and language can be used for both dissociation and ionization, leading to a more unified understanding of the dynamics.
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Ben-Itzhak I, Wang PQ, Xia JF, Sayler AM, Smith MA, Carnes KD, Esry BD. Dissociation and ionization of H+2 by ultrashort intense laser pulses probed by coincidence 3D momentum imaging. PHYSICAL REVIEW LETTERS 2005; 95:073002. [PMID: 16196777 DOI: 10.1103/physrevlett.95.073002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2005] [Indexed: 05/04/2023]
Abstract
Laser-induced dissociation and ionization of H(+)(2) were simultaneously measured using coincidence 3D momentum imaging, allowing direct separation of the two processes, even where the fragment kinetic energy is the same for both processes. The results for 45 and 135 fs 790 nm pulses with an intensity of approximately 2.5 x 10(14) W/cm(2) differ from each other much more than one would expect from previous measurements with longer pulses. Ionization was negligible for the longer pulse and was strongly aligned along the laser polarization for the shorter pulse, but showed no structure in its kinetic energy distribution. In addition, the ionization to dissociation ratio was found to be much smaller than theoretically predicted for H(+)(2).
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Wang P, Sayler AM, Carnes KD, Esry BD, Ben-Itzhak I. Disentangling the volume effect through intensity-difference spectra: application to laser-induced dissociation of H2+. OPTICS LETTERS 2005; 30:664-666. [PMID: 15792010 DOI: 10.1364/ol.30.000664] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
An intensity-difference spectrum method is developed to disentangle the intensity volume effect inherent in focused laser beam interaction with gas-phase matter. This method is applicable to a Gaussian beam of constant axial intensity, which keeps the exact contribution from a predetermined intensity range and eliminates the contributions from lower intensities. We apply this method to the angularly resolved kinetic energy release spectrum of laser-induced dissociation of H2+. The difference spectrum at higher intensities is found to be dominated by the bond-softening process, and the distribution shifts to lower energy and becomes narrower with increasing intensity.
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Roudnev V, Esry BD, Ben-Itzhak I. Controlling HD+ and H+2 dissociation with the carrier-envelope phase difference of an intense ultrashort laser pulse. PHYSICAL REVIEW LETTERS 2004; 93:163601. [PMID: 15524988 DOI: 10.1103/physrevlett.93.163601] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Indexed: 05/24/2023]
Abstract
Carrier-envelope phase difference effects in the dissociation of the HD+ molecular ion in the field of an intense, linearly polarized, ultrashort laser pulse are studied in the framework of the time-dependent Schrödinger equation. We consider a reduced-dimensionality model in which the nuclei are free to vibrate along the field polarization and the electrons move in two dimensions. The laser has a central wavelength of 790 nm and a pulse length of 10 fs with intensities in the range 6x10(14) to 9x10(14) W/cm(2). We find that the angular distribution of dissociation to p+D and H+d can be controlled by varying the phase difference, generating differences between the dissociation channels of more than a factor of 2. Moreover, the asymmetry is nearly as large for H+2 dissociation.
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Diner A, Toker Y, Strasser D, Heber O, Ben-Itzhak I, Witte PD, Wolf A, Schwalm D, Rappaport ML, Bhushan KG, Zajfman D. Size-dependent electron-impact detachment of internally cold Cn- and Aln- clusters. PHYSICAL REVIEW LETTERS 2004; 93:063402. [PMID: 15323629 DOI: 10.1103/physrevlett.93.063402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2004] [Indexed: 05/24/2023]
Abstract
The cross sections for electron detachment of internally cold Cn- and Aln- clusters were measured using an electrostatic ion beam trap fitted with an internal electron target. The measured electron-impact detachment cross sections for the Cn- (n = 1-9) clusters exhibit even-odd oscillations reflecting the binding energy trend, namely, higher cross sections for weaker binding. Surprisingly, however, these cross sections increase on the average with cluster size, n, in spite of the increase in electron binding. In contrast, the Aln- (n = 2-5) clusters follow the known scaling laws for electron detachment. We suggest that the size-dependent polarizability of these clusters is responsible for the observed behavior.
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Wells E, Ben-Itzhak I, Jones RR. Ionization of atoms by the spatial gradient of the pondermotive potential in a focused laser beam. PHYSICAL REVIEW LETTERS 2004; 93:023001. [PMID: 15323908 DOI: 10.1103/physrevlett.93.023001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2002] [Indexed: 05/24/2023]
Abstract
Ionization of atoms by the spatial gradient of the pondermotive potential in a focused laser beam is investigated. Rydberg ions, formed during the interaction of noble gas atoms with an intense laser pulse, are used to probe the gradient field. Rydberg ion species with higher ionization potentials are produced at locations where the gradient field is largest. The measured Rydberg ion yields differ dramatically from estimates that ignore gradient-field ionization, but are in good agreement with predictions that include the effect.
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Flechard X, Nguyen H, Wells E, Ben-Itzhak I, DePaola BD. Kinematically complete charge exchange experiment in the Cs(+)+Rb collision system using a MOT target. PHYSICAL REVIEW LETTERS 2001; 87:123203. [PMID: 11580508 DOI: 10.1103/physrevlett.87.123203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2001] [Indexed: 05/23/2023]
Abstract
Charge exchange is examined with unprecedented precision using the newly developed magneto-optical trap-target recoil ion momentum spectroscopy (MOTRIMS) technique. Initial and final state selective, charge exchange cross sections are obtained for 6 keV Cs+ colliding with rubidium in 5s and 5p states. For each charge transfer channel, cross sections differential in scattering angle are measured. These data are used to overturn previous long-standing conjecture as to the origin of oscillations seen in total charge exchange cross section measurements, and compare well with an enhanced Demkov model calculation.
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Wells E, Carnes KD, Esry BD, Ben-Itzhak I. Charge transfer and elastic scattering in very slow H(+)+D(1s) half collisions. PHYSICAL REVIEW LETTERS 2001; 86:4803-4806. [PMID: 11384352 DOI: 10.1103/physrevlett.86.4803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2001] [Indexed: 05/23/2023]
Abstract
Charge transfer and elastic scattering probabilities were measured for half collisions between very slow protons and atomic deuterium. Collision energies down to a few meV, lower by more than an order of magnitude and with better energy resolution than previous measurements, were studied using the dissociation of the HD+ electronic ground state. The collision energy is determined a posteriori from the measured momentum vector of the dissociating charged fragments. The experimental results are in good agreement with our coupled channel calculations.
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Ben-Itzhak I, Wells E, Carnes KD, Krishnamurthi V, Weaver OL, Esry BD. Symmetry breakdown in ground state dissociation of HD+. PHYSICAL REVIEW LETTERS 2000; 85:58-61. [PMID: 10991158 DOI: 10.1103/physrevlett.85.58] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/1999] [Indexed: 05/23/2023]
Abstract
Experimental studies of the dissociation of the electronic ground state of HD+ following ionization of HD by fast proton impact indicate that the H++D(1s) dissociation channel is more likely than the H(1s)+D+ dissociation channel by about 7%. This isotopic symmetry breakdown is due to the finite nuclear mass correction to the Born-Oppenheimer approximation which makes the 1ssigma state 3.7 meV lower than the 2psigma state at the dissociation limit. The measured fractions of the two dissociation channels are in agreement with coupled-channels calculations of 1ssigma to 2psigma transitions.
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Haber O, Ben-Itzhak I, Gertner I, Mann A, Rosner B. Formation of He20and He22+molecules by charge exchange collisions of He2+ions in the sub-MeV region. ACTA ACUST UNITED AC 1999. [DOI: 10.1088/0022-3700/18/7/007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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45
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Ben-Itzhak I, Bouhnik JP, Chen Z, Gertner I, Heinemann C, Koch W, Lin CD, Rosner B. Erratum: Isotopic effect of the mean lifetimes of the NeAr2+ doubly charged rare-gas dimer. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:981-982. [PMID: 9920646 DOI: 10.1103/physreva.54.981.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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46
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Ben-Itzhak I, Bouhnik JP, Esry BD, Gertner I, Heber O, Rosner B. Mean lifetime measurements of HeH2+(2p sigma ) isotopes. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:474-479. [PMID: 9913500 DOI: 10.1103/physreva.54.474] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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47
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Heber O, Sampoll G, Bandong BB, Maurer RJ, Watson RL, Ben-Itzhak I, Sanders JM, Shinpaugh JL, Richard P. Multiple-electron ionization, capture, and loss by 19-MeV Fq+ (q=2-9) in collisions with Ne and Ar. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1995; 52:4578-4585. [PMID: 9912796 DOI: 10.1103/physreva.52.4578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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48
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Ben-Itzhak I, Bouhnik JP, Chen Z, Gertner I, Heinemann C, Koch W, Lin CD, Rosner B. Isotopic effect of the mean lifetimes of the NeAr2+ doubly charged rare-gas dimer. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1995; 52:R3401-R3404. [PMID: 9912760 DOI: 10.1103/physreva.52.r3401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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49
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Ben-Itzhak I, Chen Z, Lin CD. Scaling of mean lifetimes of metastable molecular states with angular-momentum and vibrational quantum numbers. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1995; 51:2619-2622. [PMID: 9911881 DOI: 10.1103/physreva.51.2619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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50
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Ben-Itzhak I, Ginther SG, Krishnamurthi V, Carnes KD. Kinetic-energy release in CO dissociation caused by fast F4+ impact. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1995; 51:391-399. [PMID: 9911596 DOI: 10.1103/physreva.51.391] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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