1
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Sun T, Zhao Q, Wan F, Salamin YI, Li JX. Generation of Ultrabrilliant Polarized Attosecond Electron Bunches via Dual-Wake Injection. PHYSICAL REVIEW LETTERS 2024; 132:045001. [PMID: 38335335 DOI: 10.1103/physrevlett.132.045001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 08/20/2023] [Accepted: 12/11/2023] [Indexed: 02/12/2024]
Abstract
Laser wakefield acceleration is paving the way for the next generation of electron accelerators, for their own sake and as radiation sources. A controllable dual-wake injection scheme is put forward here to generate an ultrashort triplet electron bunch with high brightness and high polarization, employing a radially polarized laser as a driver. We find that the dual wakes can be driven by both transverse and longitudinal components of the laser field in the quasiblowout regime, sustaining the laser-modulated wakefield which facilitates the subcycle and transversely split injection of the triplet bunch. Polarization of the triplet bunch can be highly preserved due to the laser-assisted collective spin precession and the noncanceled transverse spins. In our three-dimensional particle-in-cell simulations, the triplet electron bunch, with duration about 500 as, six-dimensional brightness exceeding 10^{14} A/m^{2}/0.1% and polarization over 80%, can be generated using a few-terawatt laser. Such an electron bunch could play an essential role in many applications, such as ultrafast imaging, nuclear structure and high-energy physics studies, and the operation of coherent radiation sources.
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Affiliation(s)
- Ting Sun
- Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qian Zhao
- Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Feng Wan
- Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yousef I Salamin
- Department of Physics, American University of Sharjah, Sharjah, POB 26666 Sharjah, United Arab Emirates
| | - Jian-Xing Li
- Ministry of Education Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Shaanxi Province Key Laboratory of Quantum Information and Quantum Optoelectronic Devices, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
- Department of Nuclear Physics, China Institute of Atomic Energy, P.O. Box 275(7), Beijing 102413, China
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2
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Xue K, Guo RT, Wan F, Shaisultanov R, Chen YY, Xu ZF, Ren XG, Hatsagortsyan KZ, Keitel CH, Li JX. Generation of arbitrarily polarized GeV lepton beams via nonlinear Breit-Wheeler process. FUNDAMENTAL RESEARCH 2021. [DOI: 10.1016/j.fmre.2021.11.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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3
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Spiliotis AK, Xygkis M, Tazes K, Katsoprinakis GE, Sofikitis D, Vasilakis G, Rakitzis TP. A nanosecond-resolved atomic hydrogen magnetometer. Phys Chem Chem Phys 2021; 23:21521-21531. [PMID: 34549209 DOI: 10.1039/d1cp03171f] [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 introduce a novel and sensitive ns-resolved atomic magnetometer, which is at least three orders of magnitude faster than conventional magnetometers. We use the magnetic field dependence of the hyperfine beating of high-density spin-polarized H atoms, produced from the rapid photodissociation of HCl gas with sub-ns laser pulses and measured with a pick-up coil, to demonstrate ns-resolved magnetometry, and project sensitivity of a few nT for a spin-projection-limited sensor with 10 nl measurement volume after 1 ns measurement time. The magnetometer will allow ultrafast continuous B-field measurements in many fields, including spin chemistry, spin physics, and plasma physics.
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Affiliation(s)
- Alexandros K Spiliotis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece. .,Department of Physics, University of Crete, Heraklion, Greece
| | - Michalis Xygkis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece. .,Department of Physics, University of Crete, Heraklion, Greece
| | - Konstantinos Tazes
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece. .,Department of Physics, University of Crete, Heraklion, Greece
| | - George E Katsoprinakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece. .,Department of Physics, University of Crete, Heraklion, Greece
| | - Dimitrios Sofikitis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece. .,Department of Physics, University of Crete, Heraklion, Greece
| | - Georgios Vasilakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece. .,Department of Physics, University of Crete, Heraklion, Greece
| | - T Peter Rakitzis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece. .,Department of Physics, University of Crete, Heraklion, Greece
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4
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Bünermann O, Kandratsenka A, Wodtke AM. Inelastic Scattering of H Atoms from Surfaces. J Phys Chem A 2021; 125:3059-3076. [PMID: 33779163 PMCID: PMC8154602 DOI: 10.1021/acs.jpca.1c00361] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/09/2021] [Indexed: 11/29/2022]
Abstract
We have developed an instrument that uses photolysis of hydrogen halides to produce nearly monoenergetic hydrogen atom beams and Rydberg atom tagging to obtain accurate angle-resolved time-of-flight distributions of atoms scattered from surfaces. The surfaces are prepared under strict ultrahigh vacuum conditions. Data from these experiments can provide excellent benchmarks for theory, from which it is possible to obtain an atomic scale understanding of the underlying dynamical processes governing H atom adsorption. In this way, the mechanism of adsorption on metals is revealed, showing a penetration-resurfacing mechanism that relies on electronic excitation of the metal by the H atom to succeed. Contrasting this, when H atoms collide at graphene surfaces, the dynamics of bond formation involving at least four carbon atoms govern adsorption. Future perspectives of H atom scattering from surfaces are also outlined.
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Affiliation(s)
- Oliver Bünermann
- Institute
for Physical Chemistry, Georg-August-University
of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany
- Department
of Dynamics at Surfaces, Max-Planck Institute
for Biophysical Chemistry, Am Faßberg 11, 37077 Göttingen, Germany
- International
Center for Advanced Studies of Energy Conversion, Georg-August University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany
| | - Alexander Kandratsenka
- Department
of Dynamics at Surfaces, Max-Planck Institute
for Biophysical Chemistry, Am Faßberg 11, 37077 Göttingen, Germany
| | - Alec M. Wodtke
- Institute
for Physical Chemistry, Georg-August-University
of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany
- Department
of Dynamics at Surfaces, Max-Planck Institute
for Biophysical Chemistry, Am Faßberg 11, 37077 Göttingen, Germany
- International
Center for Advanced Studies of Energy Conversion, Georg-August University of Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany
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5
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Spiliotis AK, Xygkis M, Koutrakis ME, Tazes K, Boulogiannis GK, Kannis CS, Katsoprinakis GE, Sofikitis D, Rakitzis TP. Ultrahigh-density spin-polarized hydrogen isotopes from the photodissociation of hydrogen halides: new applications for laser-ion acceleration, magnetometry, and polarized nuclear fusion. LIGHT, SCIENCE & APPLICATIONS 2021; 10:35. [PMID: 33579898 PMCID: PMC7881141 DOI: 10.1038/s41377-021-00476-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 01/08/2021] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
Recently, our group produced spin-polarized hydrogen (SPH) atoms at densities of at least 1019 cm-3 from the photodissociation of hydrogen halide molecules with circularly polarized UV light and measured them via magnetization-quantum beats with a pickup coil. These densities are approximately 7 orders of magnitude higher than those produced using conventional methods, opening up new fields of application, such as ultrafast magnetometry, the production of polarized MeV and GeV particle beams, such as electron beams with intensities approximately 104 higher than current sources, and the study of polarized nuclear fusion, for which the reaction cross sections of D-T and D-3He reactions are expected to increase by 50% for fully polarized nuclear spins. We review the production, detection, depolarization mechanisms, and potential applications of high-density SPH.
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Affiliation(s)
- Alexandros K Spiliotis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
| | - Michalis Xygkis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
| | - Michail E Koutrakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
| | - Konstantinos Tazes
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
| | - Gregoris K Boulogiannis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
| | - Chrysovalantis S Kannis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
| | - Georgios E Katsoprinakis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
| | - Dimitrios Sofikitis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece
- University of Crete, Department of Physics, Herakleio, Greece
- Department of Physics, Atomic and Molecular Physics Laboratory, University of Ioannina, University Campus, Ioannina, GR-45110, Greece
| | - T Peter Rakitzis
- Foundation for Research and Technology Hellas, Institute of Electronic Structure and Laser, N. Plastira 100, Heraklion, Crete, GR-71110, Greece.
- University of Crete, Department of Physics, Herakleio, Greece.
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6
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Allum F, Mason R, Burt M, Slater CS, Squires E, Winter B, Brouard M. Post extraction inversion slice imaging for 3D velocity map imaging experiments. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1842531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Felix Allum
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Robert Mason
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Michael Burt
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Craig S. Slater
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Eleanor Squires
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Benjamin Winter
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Mark Brouard
- The Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
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7
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Gong Z, Shou Y, Tang Y, Yan X. Energetic spin-polarized proton beams from two-stage coherent acceleration in laser-driven plasma. Phys Rev E 2020; 102:053212. [PMID: 33327078 DOI: 10.1103/physreve.102.053212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 10/27/2020] [Indexed: 11/07/2022]
Abstract
We propose a scheme to overcome the great challenge of polarization loss in spin-polarized ion acceleration. When a petawatt laser pulse penetrates through a compound plasma target consisting of a double layer slab and prepolarized hydrogen halide gas, a strong forward moving quasistatic longitudinal electric field is constructed by the self-generated laser-driven plasma. This field with a varying drift velocity efficiently boosts the prepolarized protons via a two-stage coherent acceleration process. Its merit is not only achieving a highly energetic beam but also eliminating the undesired polarization loss of the accelerated protons. We study the proton dynamics via Hamiltonian analyses, specifically deriving the threshold of triggering the two-stage coherent acceleration. To confirm the theoretical predictions, we perform three-dimensional PIC simulations, where unprecedented proton beams with energy approximating half GeV and polarization ratio ∼ 94% are obtained.
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Affiliation(s)
- Zheng Gong
- SKLNPT, KLHEDP, CAPT, and School of Physics, Peking University, Beijing 100871, China
| | - Yinren Shou
- SKLNPT, KLHEDP, CAPT, and School of Physics, Peking University, Beijing 100871, China
| | - Yuhui Tang
- SKLNPT, KLHEDP, CAPT, and School of Physics, Peking University, Beijing 100871, China
| | - Xueqing Yan
- SKLNPT, KLHEDP, CAPT, and School of Physics, Peking University, Beijing 100871, China.,CICEO, Shanxi University, Taiyuan, Shanxi 030006, China
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8
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Jin L, Wen M, Zhang X, Hützen A, Thomas J, Büscher M, Shen B. Spin-polarized proton beam generation from gas-jet targets by intense laser pulses. Phys Rev E 2020; 102:011201. [PMID: 32795078 DOI: 10.1103/physreve.102.011201] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/27/2020] [Indexed: 11/07/2022]
Abstract
A method of generating spin-polarized proton beams from a gas jet by using a multipetawatt laser is put forward. With currently available techniques of producing prepolarized monatomic gases from photodissociated hydrogen halide molecules and petawatt lasers, proton beams with energy ≳50 MeV and ≈80% polarization are proved to be obtained. Two-stage acceleration and spin dynamics of protons are investigated theoretically and by means of fully self-consistent three-dimensional particle-in-cell simulations. Our results predict the dependence of the beam polarization on the intensity of the driving laser pulse. Generation of bright energetic polarized proton beams would open a domain of polarization studies with laser driven accelerators and have potential application to enable effective detection in explorations of quantum chromodynamics.
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Affiliation(s)
- Luling Jin
- Department of Physics, Hubei University, Wuhan 430062, China
| | - Meng Wen
- Department of Physics, Hubei University, Wuhan 430062, China
| | - Xiaomei Zhang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Anna Hützen
- Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, Wilhelm-Johnen-Str. 1, 52425 Jülich, Germany.,Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Johannes Thomas
- Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Markus Büscher
- Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, Wilhelm-Johnen-Str. 1, 52425 Jülich, Germany.,Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Baifei Shen
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.,Department of Physics, Shanghai Normal University, Shanghai 200234, China
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9
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Wu Y, Ji L, Geng X, Yu Q, Wang N, Feng B, Guo Z, Wang W, Qin C, Yan X, Zhang L, Thomas J, Hützen A, Pukhov A, Büscher M, Shen B, Li R. Polarized electron acceleration in beam-driven plasma wakefield based on density down-ramp injection. Phys Rev E 2019; 100:043202. [PMID: 31770946 DOI: 10.1103/physreve.100.043202] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Indexed: 11/07/2022]
Abstract
We investigate the precession of electron spins during beam-driven plasma-wakefield acceleration based on density down-ramp injection by means of full three-dimensional (3D) particle-in-cell (PIC) simulations. A relativistic electron beam generated via, e.g., laser wakefield acceleration, serves as the driving source. It traverses the prepolarized gas target and accelerates polarized electrons via the excited wakefield. We derive the criteria for the driving beam parameters and the limitation on the injected beam flux to preserve a high degree of polarization for the accelerated electrons, which are confirmed by our 3D PIC simulations and single-particle modeling. The electron-beam driver is free of the prepulse issue associated with a laser driver, thus eliminating possible depolarization of the prepolarized gas due to ionization by the prepulse. These results provide guidance for future experiments towards generating a source of polarized electrons based on wakefield acceleration.
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Affiliation(s)
- Yitong Wu
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Liangliang Ji
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.,CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China
| | - Xuesong Geng
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Qin Yu
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Nengwen Wang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Bo Feng
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Zhao Guo
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Weiqing Wang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Chengyu Qin
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Xue Yan
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Lingang Zhang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Johannes Thomas
- Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Anna Hützen
- Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, Wilhelm-Johnen-Str. 1, 52425 Jülich, Germany.,Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Alexander Pukhov
- Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Markus Büscher
- Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich, Wilhelm-Johnen-Str. 1, 52425 Jülich, Germany.,Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Baifei Shen
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.,CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China.,Shanghai Normal University, Shanghai 200234, China
| | - Ruxin Li
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.,CAS Center for Excellence in Ultra-intense Laser Science, Shanghai 201800, China.,Shanghai Tech University, Shanghai 201210, China
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10
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Sofikitis D, Kannis CS, Boulogiannis GK, Katsoprinakis GE, Rakitzis TP. Photofragment spin-polarization measurements via magnetization quantum beats: dynamics of DI photodissociation. Phys Chem Chem Phys 2019; 21:14000-14004. [PMID: 30604785 DOI: 10.1039/c8cp07079b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the electron-spin polarization of D atoms from the photodissociation of DI, at 213 nm and 266 nm, by measuring the magnetization quantum beats of the D atoms with a pick-up coil. We determine that the polarization P is large at both wavelengths (|P|∼ 1), however it is positive at 213 nm, and negative at 266 nm. These results, in both cases, are of opposite sign to calculations, which assume adiabatic dissociation along the A1Π1 or a3Π1 states. We interpret these results as evidence that nonadiabatic coupling between these states needs to be included for the theoretical treatment of DI photodissociation.
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Affiliation(s)
- Dimitris Sofikitis
- Department of Physics, University of Crete, 71003 Heraklion-Crete, Greece and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece.
| | - Chrysovalantis S Kannis
- Department of Physics, University of Crete, 71003 Heraklion-Crete, Greece and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece.
| | - Gregoris K Boulogiannis
- Department of Physics, University of Crete, 71003 Heraklion-Crete, Greece and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece.
| | - Georgios E Katsoprinakis
- Department of Physics, University of Crete, 71003 Heraklion-Crete, Greece and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece.
| | - T Peter Rakitzis
- Department of Physics, University of Crete, 71003 Heraklion-Crete, Greece and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece.
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11
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Wen M, Tamburini M, Keitel CH. Polarized Laser-WakeField-Accelerated Kiloampere Electron Beams. PHYSICAL REVIEW LETTERS 2019; 122:214801. [PMID: 31283342 DOI: 10.1103/physrevlett.122.214801] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Indexed: 06/09/2023]
Abstract
High-flux polarized particle beams are of critical importance for the investigation of spin-dependent processes, such as in searches of physics beyond the standard model, as well as for scrutinizing the structure of solids and surfaces in material science. Here we demonstrate that kiloampere polarized electron beams can be produced via laser-wakefield acceleration from a gas target. A simple theoretical model for determining the electron beam polarization is presented and supported with self-consistent three-dimensional particle-in-cell simulations that incorporate the spin dynamics. By appropriately choosing the laser and gas parameters, we show that the depolarization of electrons induced by the laser-wakefield-acceleration process can be as low as 10%. Compared to currently available sources of polarized electron beams, the flux is increased by 4 orders of magnitude.
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Affiliation(s)
- Meng Wen
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Matteo Tamburini
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Christoph H Keitel
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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12
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Suits AG. Invited Review Article: Photofragment imaging. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:111101. [PMID: 30501356 DOI: 10.1063/1.5045325] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/25/2018] [Indexed: 06/09/2023]
Abstract
Photodissociation studies in molecular beams that employ position-sensitive particle detection to map product recoil velocities emerged thirty years ago and continue to evolve with new laser and detector technologies. These powerful methods allow application of tunable laser detection of single product quantum states, simultaneous measurement of velocity and angular momentum polarization, measurement of joint product state distributions for the detected and undetected products, coincident detection of multiple product channels, and application to radicals and ions as well as closed-shell molecules. These studies have permitted deep investigation of photochemical dynamics for a broad range of systems, revealed new reaction mechanisms, and addressed problems of practical importance in atmospheric, combustion, and interstellar chemistry. This review presents an historical overview, a detailed technical account of the range of methods employed, and selected experimental highlights illustrating the capabilities of the method.
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Affiliation(s)
- Arthur G Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
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13
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Bünermann O, Jiang H, Dorenkamp Y, Auerbach DJ, Wodtke AM. An ultrahigh vacuum apparatus for H atom scattering from surfaces. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:094101. [PMID: 30278702 DOI: 10.1063/1.5047674] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 08/28/2018] [Indexed: 06/08/2023]
Abstract
We present an apparatus to study inelastic H or D atom scattering from surfaces under ultra-high vacuum conditions. The apparatus provides high resolution information on scattering energy and angular distributions by combining a photolysis-based atom source with Rydberg atom tagging time-of-flight. Using hydrogen halides as precursors, H and D atom beams can be formed with energies from 500 meV up to 7 eV, with an energy spread of down to 2 meV and an intensity of up to 108 atoms per pulse. A six-axis manipulator holds the sample and allows variation of both polar and azimuthal incidence angles. Surface temperature can be varied from 45 K up to 1500 K. The apparatus' energy resolution ( E / Δ E ) can be as high as 1000 and its angular resolution can be adjusted between 0.3° and 3°.
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Affiliation(s)
- Oliver Bünermann
- Institute for Physical Chemistry, Georg-August University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany
| | - Hongyan Jiang
- Institute for Physical Chemistry, Georg-August University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany
| | - Yvonne Dorenkamp
- Institute for Physical Chemistry, Georg-August University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany
| | - Daniel J Auerbach
- Institute for Physical Chemistry, Georg-August University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany
| | - Alec M Wodtke
- Institute for Physical Chemistry, Georg-August University of Göttingen, Tammannstr. 6, 37077 Göttingen, Germany
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Sofikitis D, Kannis CS, Boulogiannis GK, Rakitzis TP. Ultrahigh-Density Spin-Polarized H and D Observed via Magnetization Quantum Beats. PHYSICAL REVIEW LETTERS 2018; 121:083001. [PMID: 30192591 DOI: 10.1103/physrevlett.121.083001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Indexed: 06/08/2023]
Abstract
We measure nuclear and electron spin-polarized H and D densities of at least 10^{19} cm^{-3} with ∼10 ns lifetimes, from the photodissociation of HBr and DI with circularly polarized UV light pulses. This density is ∼6 orders of magnitude higher than that produced by conventional continuous-production methods and, surprisingly, at least 100 times higher than expected densities for this photodissociation method. We observe the hyperfine quantum beating of the H and D magnetization with a pickup coil, i.e., the respective 0.7 and 3 ns periodic transfer of polarization from the electrons to the nuclei and back. The 10^{19} cm^{-3} spin-polarized H and D density is sufficient for laser-driven ion acceleration of spin-polarized electrons, protons, or deuterons, the preparation of nuclear-spin-polarized molecules, and the demonstration of spin-polarized D-T or D-^{3}He laser fusion, for which a reactivity enhancement of ∼50% is expected.
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Affiliation(s)
- Dimitris Sofikitis
- Institute of Electronic Structure and Lasers, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece
- Department of Physics, University of Crete, 70013 Heraklion-Crete, Greece
| | - Chrysovalantis S Kannis
- Institute of Electronic Structure and Lasers, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece
- Department of Physics, University of Crete, 70013 Heraklion-Crete, Greece
| | - Gregoris K Boulogiannis
- Institute of Electronic Structure and Lasers, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece
- Department of Physics, University of Crete, 70013 Heraklion-Crete, Greece
| | - T Peter Rakitzis
- Institute of Electronic Structure and Lasers, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece
- Department of Physics, University of Crete, 70013 Heraklion-Crete, Greece
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15
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Grygoryeva K, Rakovský J, Votava O, Fárník M. Imaging of rotational wave-function in photodissociation of rovibrationally excited HCl molecules. J Chem Phys 2018; 147:013901. [PMID: 28688430 DOI: 10.1063/1.4973680] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We demonstrate a visualization of quantum mechanical phenomena with the velocity map imaging (VMI) technique, combining vibrationally mediated photodissociation (VMP) of a simple diatomic HCl with the VMI of its H-photofragments. Free HCl molecules were excited by a pump infrared (IR) laser pulse to particular rotational J levels of the v = 2 vibrational state, and subsequently a probe ultraviolet laser photodissociated the molecule at a fixed wavelength of 243.07 nm where also the H-fragments were ionized. The molecule was aligned by the IR excitation with respect to the IR laser polarization, and this alignment was reflected in the angular distribution of the H-photofragments. In particular, the highest degree of molecular alignment was achieved for the J=1←0 transition, which exclusively led to the population of a single rotational state with M = 0. The obtained images were analyzed for further details of the VMP dynamics, and different J states were studied as well. Additionally, we investigated the dynamic evolution of the excited states by changing the pump-probe laser pulse delay; the corresponding images reflected dephasing due to a coupling between the molecular angular momentum and nuclear spin. Our measurements confirmed previous observation using the time-of-flight technique by Sofikitis et al. [J. Chem. Phys. 127, 144307 (2007)]. We observed a partial recovery of the originally excited state after 60 ns in agreement with the previous observation.
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Affiliation(s)
- K Grygoryeva
- J. Heyrovský Institute of Physical Chemistry v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 18223 Prague, Czech Republic
| | - J Rakovský
- J. Heyrovský Institute of Physical Chemistry v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 18223 Prague, Czech Republic
| | - O Votava
- J. Heyrovský Institute of Physical Chemistry v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 18223 Prague, Czech Republic
| | - M Fárník
- J. Heyrovský Institute of Physical Chemistry v.v.i., Academy of Sciences of the Czech Republic, Dolejškova 3, 18223 Prague, Czech Republic
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16
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Bai XL, Liang H, Zhou ZF, Hua ZF, Zhao DF, Chen Y. Photodissociation Dynamics of OCS at 217 nm. CHINESE J CHEM PHYS 2017. [DOI: 10.1063/1674-0068/30/cjcp1705092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Xi-lin Bai
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical physics, University of Science and Technology of China, Hefei 230026, China
| | - Hao Liang
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical physics, University of Science and Technology of China, Hefei 230026, China
| | - Zheng-fang Zhou
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical physics, University of Science and Technology of China, Hefei 230026, China
| | - Ze-feng Hua
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical physics, University of Science and Technology of China, Hefei 230026, China
| | - Dong-feng Zhao
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical physics, University of Science and Technology of China, Hefei 230026, China
| | - Yang Chen
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical physics, University of Science and Technology of China, Hefei 230026, China
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17
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Bai X, Liang H, Zhou Z, Hua Z, Jiang B, Zhao D, Chen Y. Photodissociation dynamics of OCS at ∼210 nm: The role of c(23A″) state. J Chem Phys 2017; 147:013930. [DOI: 10.1063/1.4982684] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Xilin Bai
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Hao Liang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Zhengfang Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Zefeng Hua
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Bin Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Dongfeng Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
| | - Yang Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
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Broderick BM, Suits AG, Vasyutinskii OS. Rydberg Detection of Spin-Polarized Hydrogen Atoms in Chemical Reactions. J CHIN CHEM SOC-TAIP 2017. [DOI: 10.1002/jccs.201700162] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Arthur G. Suits
- Department of Chemistry; University of Missouri; Columbia MO 65211 USA
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Hróðmarsson HR, Kartakoullis A, Zaouris D, Glodic P, Wang H, Samartzis PC, Kvaran Á. Excitation dynamics involving homogeneous multistate interactions: one and two color VMI and REMPI of HBr. Phys Chem Chem Phys 2017; 19:11354-11365. [PMID: 28421209 DOI: 10.1039/c7cp00345e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Velocity map imaging (VMI) data and mass resolved REMPI spectra are complementarily utilized to elucidate the involvement of homogeneous multistate interactions in excited state dynamics of HBr. The H1Σ+(v' = 0) and E1Σ+(v' = 1) Rydberg states and the V1Σ+(v'= m + 7) and V1Σ+(v'= m + 8) ion-pair states are explored as a function of rotational quantum number in the two-photon excitation region of 79 100-80 700 cm-1. H+ and Br+ images were recorded by one- as well as two-color excitation schemes. Kinetic energy release (KER) spectra and angular distributions were extracted from the data. Strong-to-medium interactions between the E(1) and V(m + 8)/V(m + 7) states on one hand and the H(0) and V(m + 7)/V(m + 8) states on the other hand were quantified from peak shifts and intensity analysis of REMPI spectra. The effects of those interactions on subsequent photoionization and photolytic pathways of HBr were evaluated in one-color VMI experiments of the H+ and two-color VMI experiments of the Br+ photoproducts.
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Kouzov A, Radi P. Line space theory of Resonant Four-Wave Mixing: New prospects for all-optical studies of photofragment states. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.02.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Broderick BM, Lee Y, Doyle MB, Chernyak VY, Vasyutinskii OS, Suits AG. Spin-polarized hydrogen Rydberg time-of-flight: experimental measurement of the velocity-dependent H atom spin-polarization. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:053103. [PMID: 24880349 DOI: 10.1063/1.4871995] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We have developed a new experimental method allowing direct detection of the velocity dependent spin-polarization of hydrogen atoms produced in photodissociation. The technique, which is a variation on the H atom Rydberg time-of-flight method, employs a double-resonance excitation scheme and experimental geometry that yields the two coherent orientation parameters as a function of recoil speed for scattering perpendicular to the laser propagation direction. The approach, apparatus, and optical layout we employ are described here in detail and demonstrated in application to HBr and DBr photolysis at 213 nm. We also discuss the theoretical foundation for the approach, as well as the resolution and sensitivity we achieve.
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Affiliation(s)
| | - Yumin Lee
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Michael B Doyle
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Vladimir Y Chernyak
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
| | - Oleg S Vasyutinskii
- Ioffe Institute, Russian Academy of Sciences, St. Petersburg 194021, Russia and St. Petersburg State Polytechnic University, St. Petersburg 195251, Russia
| | - Arthur G Suits
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
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23
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Hama T, Watanabe N. Surface Processes on Interstellar Amorphous Solid Water: Adsorption, Diffusion, Tunneling Reactions, and Nuclear-Spin Conversion. Chem Rev 2013; 113:8783-839. [DOI: 10.1021/cr4000978] [Citation(s) in RCA: 211] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tetsuya Hama
- Institute of Low Temperature
Science, Hokkaido University, N19W8 Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Naoki Watanabe
- Institute of Low Temperature
Science, Hokkaido University, N19W8 Kita-ku, Sapporo, Hokkaido 060-0819, Japan
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24
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Johnsen AJ, Alekseyev AB, Balint-Kurti GG, Brouard M, Brown A, Buenker RJ, Campbell EK, Kokh DB. A complete quantum mechanical study of chlorine photodissociation. J Chem Phys 2012; 136:164310. [PMID: 22559485 DOI: 10.1063/1.4704829] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A fully quantum mechanical dynamical calculation on the photodissociation of molecular chlorine is presented. The magnitudes and phases of all the relevant photofragment T-matrices have been calculated, making this study the computational equivalent of a "complete experiment," where all the possible parameters defining an experiment have been determined. The results are used to simulate cross-sections and angular momentum polarization information which may be compared with experimental data. The calculations rigorously confirm the currently accepted mechanism for the UV photodissociation of Cl(2), in which the majority of the products exit on the C(1)Π(1u) state, with non-adiabatic couplings to the A(3)Π(1u) and several other Ω = 1 states, and a small contribution from the B(3)Π state present at longer wavelengths.
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Affiliation(s)
- A J Johnsen
- The Department of Chemistry, University of Oxford, The Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
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25
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Lee JH, Sekhar A, Cavagnero S. 1H-Detected 13C photo-CIDNP as a sensitivity enhancement tool in solution NMR. J Am Chem Soc 2011; 133:8062-5. [PMID: 21548581 DOI: 10.1021/ja111613c] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
NMR is a powerful yet intrinsically insensitive technique. The applicability of NMR to chemical and biological systems would be substantially extended by new approaches going beyond current signal-to-noise capabilities. Here, we exploit the large enhancements arising from (13)C photochemically induced dynamic nuclear polarization ((13)C photo-CIDNP) in solution to improve biomolecular NMR sensitivity in the context of heteronuclear correlation spectroscopy. The (13)C-PRINT pulse sequence presented here involves an initial (13)C nuclear spin polarization via photo-CIDNP followed by conversion to anti-phase coherence and transfer to (1)H for detection. We observe substantial enhancements, up to ≫200-fold, relative to the dark (laser off) experiment. Resonances of both side-chain and backbone CH pairs are enhanced for the three aromatic residues Trp, His, and Tyr, the σ(32) peptide, and the drkN SH3 protein. The sensitivity of this experiment, defined as signal-to-noise per square root of unit time (S/N)(t), is unprecedented in the NMR polarization enhancement literature dealing with polypeptides in solution. Up to a 16-fold larger (S/N)(t) than for the (1)H-(13)C SE-HSQC reference sequence is achieved, for the σ(32) peptide. Data collection time is reduced up to 256-fold, highlighting the advantages of (1)H-detected (13)C photo-CIDNP in solution NMR.
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Affiliation(s)
- Jung Ho Lee
- Biophysics Graduate Program, University of Wisconsin, Madison, Wisconsin 53706, USA
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26
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Alexander AJ, Rakitzis TP. Effects of long-range potentials on polarization of chlorine atoms from photodissociation of ICl. Mol Phys 2011. [DOI: 10.1080/00268970500074985] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- A. J. Alexander
- a School of Chemistry , University of Edinburgh , Edinburgh , EH9 3JJ , UK
| | - T. Peter Rakitzis
- b Department of Physics , University of Crete , Heraklion-Crete , 71003 , Greece
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27
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Chang YP, Brouard M, Cireasa R, Perkins T, Seamons SA. Molecular photofragment orientation in the photodissociation of H2O2 at 193 nm and 248 nm. Phys Chem Chem Phys 2011; 13:8213-29. [DOI: 10.1039/c0cp02560g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Rakitzis TP. Photofragment angular momentum distributions in the molecular frame. III. Coherent effects in the photodissociation of polyatomic molecules with circularly polarized light. J Chem Phys 2010; 133:204301. [PMID: 21133438 DOI: 10.1063/1.3506578] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We extend the a(q) (k)(s) polarization parameter model [T. P. Rakitzis and A. J. Alexander, J. Chem. Phys. 132, 224310 (2010)] to describe the components of the product angular momentum polarization that arise from the one-photon photodissociation of asymmetric top molecules with circularly polarized photolysis light, and provide a general equation for fitting experimental signals. We show that the only polarization parameters that depend on the helicity of the circularly polarized photolysis light are the A(0) (k) and Re[A(1) (k)] (with odd k) and the Im[A(1) (k)] (with even k); in addition, for the unique recoil destination (URD) approximation [for which the photofragment recoil v arises from a unique parent molecule geometry], we show that these parameters arise only as a result the interference between at least two dissociative electronic states. Furthermore, we show that in the breakdown of the URD approximation (for which the photofragment recoil v arises from a distribution of parent molecule geometries), these parameters can also arise for dissociation via a single dissociative electronic state. In both cases, the A(0) (k) and Re[A(1) (k)] parameters (with odd k) are proportional to cosΔφ, and the Im[A(1) (k)] parameters (with even k) are proportional to sinΔφ, where Δφ is the phase shift (or average phase shift) between the interfering paths so that Δφ can be determined directly from the A(q) (k), or from ratios of these A(q) (k) parameters. Therefore, the determination of these A(q) (k) parameters with circularly polarized photolysis light allows the unambiguous measurement of coherent effects in polyatomic-molecule photodissociation.
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Affiliation(s)
- T Peter Rakitzis
- Department of Physics, University of Crete, and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, 71110 Heraklion-Crete, Greece.
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Bougas L, Sofikitis D, Everest MA, Alexander AJ, Rakitzis TP. (2+1) laser-induced fluorescence of spin-polarized hydrogen atoms. J Chem Phys 2010; 133:174308. [DOI: 10.1063/1.3503974] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Rakitzis TP, Alexander AJ. Photofragment angular momentum distributions in the molecular frame. II. Single state dissociation, multiple state interference, and nonaxial recoil in photodissociation of polyatomic molecules. J Chem Phys 2010; 132:224310. [PMID: 20550400 DOI: 10.1063/1.3429744] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present an a(q) (k)(s) polarization-parameter model to describe product angular momentum polarization from the one-photon photodissociation of polyatomic molecules in the molecular frame. We make the approximation that the final photofragment recoil direction is unique and described by the molecular frame polar coordinates (alpha,phi(i)), for which the axial recoil approximation is a special case (e.g., alpha=0). This approximation allows the separation of geometrical and dynamical factors, in particular, the expression of the experimental sensitivities to each of the a(q) (k)(s) in terms of the molecular frame polar angles (chi(i),phi(i)) of the transition dipole moment mu(i). This separation is applied to the linearly polarized photodissociation of polyatomic molecules (asymmetric, symmetric, and spherical top molecules are discussed) and to all dissociation mechanisms that satisfy our recoil approximation, including those with nonaxial recoil and multiple state interference, giving important insight into the geometrical properties of the photodissociation mechanism. For example, we demonstrate that the ratio of polarization parameters A(0) (k)(aniso)/A(0) (k)(iso)=beta (where beta is the spatial anisotropy parameter) is an indication that the dynamics can be explained by a single dissociative state. We also show that for asymmetric top photodissociation, the sensitivity to the a(1) (k)(s) parameters, which can arise either from single-surface or multiple-surface interference mechanisms, is nonzero only for components of the transition dipole moments within the v-d plane of the recoil frame.
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Affiliation(s)
- T Peter Rakitzis
- Department of Physics, University of Crete, Heraklion 71110, Crete, Greece.
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Rakitzis TP, Janssen MH. Photofragment angular momentum distributions from oriented and aligned polyatomic molecules: beyond the axial recoil limit. Mol Phys 2010. [DOI: 10.1080/00268970903580158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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33
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Chichinin AI, Gericke KH, Kauczok S, Maul C. Imaging chemical reactions – 3D velocity mapping. INT REV PHYS CHEM 2009. [DOI: 10.1080/01442350903235045] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Sofikitis D, Rubio-Lago L, Bougas L, Alexander AJ, Rakitzis TP. Laser detection of spin-polarized hydrogen from HCl and HBr photodissociation: comparison of H- and halogen-atom polarizations. J Chem Phys 2009; 129:144302. [PMID: 19045142 DOI: 10.1063/1.2989803] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Thermal HCl and HBr molecules were photodissociated using circularly polarized 193 nm light, and the speed-dependent spin polarization of the H-atom photofragments was measured using polarized fluorescence at 121.6 nm. Both polarization components, described by the a(0)(1)(perpendicular) and Re[a(1)(1)(parallel, perpendicular)] parameters which arise from incoherent and coherent dissociation mechanisms, are measured. The values of the a(0)(1)(perpendicular) parameter, for both HCl and HBr photodissociation, are within experimental error of the predictions of both ab initio calculations and of previous measurements of the polarization of the halide cofragments. The experimental and ab initio theoretical values of the Re[a(1)(1)(parallel, perpendicular)] parameter show some disagreement, suggesting that further theoretical investigations are required. Overall, good agreement occurs despite the fact that the current experiments photodissociate molecules at 295 K, whereas previous measurements were conducted at rotational temperatures of about 15 K.
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Affiliation(s)
- Dimitris Sofikitis
- Department of Physics, University of Crete, 71003 Heraklion-Crete, Greece
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Suits AG, Vasyutinskii OS. Imaging Atomic Orbital Polarization in Photodissociation. Chem Rev 2008; 108:3706-46. [DOI: 10.1021/cr040085c] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Arthur G. Suits
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, and Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Oleg S. Vasyutinskii
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, Michigan 48202, and Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
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Lee HM, Kolaski M, Kim KS. Photodissociation of Hydrated Hydrogen Iodide Clusters. Chemphyschem 2008; 9:567-71. [DOI: 10.1002/cphc.200700771] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Sofikitis D, Rubio-Lago L, Martin MR, Ankeny Brown DJ, Bartlett NCM, Alexander AJ, Zare RN, Rakitzis TP. Optical control of ground-state atomic orbital alignment: Cl(2P3/2) atoms from HCl(v=2,J=1) photodissociation. J Chem Phys 2008; 127:144307. [PMID: 17935395 DOI: 10.1063/1.2772272] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
H(35)Cl(v=0,J=0) molecules in a supersonic expansion were excited to the H(35)Cl(v=2,J=1,M=0) state with linearly polarized laser pulses at about 1.7 microm. These rotationally aligned J=1 molecules were then selectively photodissociated with a linearly polarized laser pulse at 220 nm after a time delay, and the velocity-dependent alignment of the (35)Cl((2)P(32)) photofragments was measured using 2+1 REMPI and time-of-flight mass spectrometry. The (35)Cl((2)P(32)) atoms are aligned by two mechanisms: (1) the time-dependent transfer of rotational polarization of the H(35)Cl(v=2,J=1,M=0) molecule to the (35)Cl((2)P(32)) nuclear spin [which is conserved during the photodissociation and thus contributes to the total (35)Cl((2)P(32)) photofragment atomic polarization] and (2) the alignment of the (35)Cl((2)P(32)) electronic polarization resulting from the photoexcitation and dissociation process. The total alignment of the (35)Cl((2)P(32)) photofragments from these two mechanisms was found to vary as a function of time delay between the excitation and the photolysis laser pulses, in agreement with theoretical predictions. We show that the alignment of the ground-state (35)Cl((2)P(32)) atoms, with respect to the photodissociation recoil direction, can be controlled optically. Potential applications include the study of alignment-dependent collision effects.
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Affiliation(s)
- Dimitris Sofikitis
- Institute of Electronic Structure and Laser, Foundation of Research and Technology-Hellas, 71110 Heraklion-Crete, Greece
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38
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Wang F, Lu IC, Yuan K, Cheng Y, Wu M, Parker DH, Yang X. Photodissociation dynamics of HI and DI at 157nm. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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39
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Lee SK, Silva R, Thamanna S, Vasyutinskii OS, Suits AG. S(D21) atomic orbital polarization in the photodissociation of OCS at 193nm: Construction of the complete density matrix. J Chem Phys 2006; 125:144318. [PMID: 17042601 DOI: 10.1063/1.2357948] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The absolute velocity-dependent alignment and orientation for S(1D2) atoms from the photodissociation of OCS at 193 nm were measured using the dc slice imaging method. Three main peaks ascribed to specific groups of high rotational levels of CO in the vibrational ground state were found, with rotationally resolved rings in a fourth slow region ascribed to weak signals associated with excited vibrational states of CO. The observed speed-dependent beta and polarization parameters support the interpretation that there are two main dissociation processes: a simultaneous two-surface (A' and A") excitation and the initial single-surface (A') excitation followed by the nonadiabatic crossing to ground state. At 193 nm photodissociation, the nonadiabatic dissociation process is strongly enhanced relative to longer wavelengths. The angle- and speed-dependent S(1D2) density matrix can be constructed including the higher order (K = 3,4) contributions for the circularly polarized dissociation light. This was explicitly done for selected energies and angles. It was found in one case that the density matrix is sensitively affected by the rank 4 terms, suggesting that the higher order contributions should not be overlooked for an accurate picture of the dissociation dynamics in this system.
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Affiliation(s)
- Suk Kyoung Lee
- Department of Chemistry, Wayne State Univeristy, Detroit, Michigan 48202, USA
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40
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Odde S, Mhin BJ, Lee KH, Lee HM, Tarakeshwar P, Kim KS. Hydration and Dissociation of Hydrogen Fluoric Acid (HF). J Phys Chem A 2006; 110:7918-24. [PMID: 16789781 DOI: 10.1021/jp060149i] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hydration and dissociation phenomena of HF(H(2)O)(n)() (n < or = 10) clusters have been studied by using both the density functional theory with the 6-311++G[sp] basis set and the Møller-Plesset second-order perturbation theory with the aug-cc-pVDZ+(2s2p/2s) basis set. The structures for n > or = 8 are first reported here. The dissociated form of the hydrogen-fluoric acid in HF(H(2)O)(n) clusters is found to be less stable at 0 K than the undissociated form until n = 10. HF may not be dissociated at 0 K solely by water molecules because the HF H bond is stronger than the OH H bond, against the expectation that the dissociated HF(H(2)O)(n) would be more stable than the undissociated one in the presence of a number of water molecules. The dissociation would be possible for only a fraction of a number of hydrated HF clusters by the Boltzmann distribution at finite temperatures. This is in sharp contrast to other hydrogen halide acids (HCl, HBr, HI) showing the dissociation phenomena at 0 K for n > or = 4. The IR spectra of dissociated and undissociated structures of HF(H(2)O)(n) are compared. The structures and binding energies of HF(H(2)O)(n) are found to be similar to those of (H(2)O)(n+1). It is interesting that HF(H(2)O)(n=5,6,10) are slightly less stable compared with other sizes of clusters, just like the fact that (H(2)O)(n=6,7,11) are slightly less stable. The present study would be useful for the experimental/spectroscopic investigation of not only the dissociation phenomena of HF but also the similarity of the HF-water clusters to the water clusters.
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Affiliation(s)
- Srinivas Odde
- Department of Chemistry, Pai Chai University, Daejeon, Korea
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41
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Smolin AG, Vasyutinskii OS, Balint-Kurti GG, Brown A. Photodissociation of HBr. 1. Electronic Structure, Photodissociation Dynamics, and Vector Correlation Coefficients. J Phys Chem A 2006; 110:5371-8. [PMID: 16623464 DOI: 10.1021/jp0562429] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio potential energy curves, transition dipole moments, and spin-orbit coupling matrix elements are computed for HBr. These are then used, within the framework of time-dependent quantum-mechanical wave-packet calculations, to study the photodissociation dynamics of the molecule. Total and partial integral cross sections, the branching fraction for the formation of excited-state bromine atoms Br(2P(1/2)), and the lowest order anisotropy parameters, beta, for both ground and excited-state bromine are calculated as a function of photolysis energy and compared to experimental and theoretical data determined previously. Higher order anisotropy parameters are computed for the first time for HBr and compared to recent experimental measurements. A new expression for the Re[a1(3) (parallel, perpendicular)] parameter describing coherent parallel and perpendicular production of ground-state bromine in terms of the dynamical functions is given. Although good agreement is obtained between the theoretical predictions and the experimental measurements, the discrepancies are analyzed to establish how improvements might be achieved. Insight is obtained into the nonadiabatic dynamics by comparing the results of diabatic and fully adiabatic calculations.
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Affiliation(s)
- Andrey G Smolin
- Ioffe Physico-Technical Institute Russian Academy of Sciences, 194021 St.-Petersburg, Russia.
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42
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Clark AP, Brouard M, Quadrini F, Vallance C. Atomic polarization in the photodissociation of diatomic molecules. Phys Chem Chem Phys 2006; 8:5591-610. [PMID: 17149481 DOI: 10.1039/b612590e] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The angular momentum polarization of atomic photofragments provides a detailed insight into the dynamics of the photodissociation process. In this article, the origins of electronic angular momentum polarization are introduced and experimental and theoretical methods for the measurement or calculation of atomic orientation and alignment parameters described. Many diatomic photodissociation systems are surveyed, in order to provide an overview both of the historical development of the field and of the most state-of-the-art contemporary studies.
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Affiliation(s)
- A P Clark
- The Department of Chemistry, University of Oxford, The Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford, UK
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43
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Ashfold MNR, Nahler NH, Orr-Ewing AJ, Vieuxmaire OPJ, Toomes RL, Kitsopoulos TN, Garcia IA, Chestakov DA, Wu SM, Parker DH. Imaging the dynamics of gas phase reactions. Phys Chem Chem Phys 2006; 8:26-53. [PMID: 16482242 DOI: 10.1039/b509304j] [Citation(s) in RCA: 240] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ion imaging methods are making ever greater impact on studies of gas phase molecular reaction dynamics. This article traces the evolution of the technique, highlights some of the more important breakthroughs with regards to improving image resolution and in image processing and analysis methods, and then proceeds to illustrate some of the many applications to which the technique is now being applied--most notably in studies of molecular photodissociation and of bimolecular reaction dynamics.
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44
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Abstract
Equations to enable determination of the helicity (angular momentum orientation) of photofragments resulting from single-photon dissociation of an isotropic sample of molecules are presented. The symmetry of the photofragment distribution is illustrated by three-dimensional vector plots of the expectation values of projections of the fragment total angular momentum. Equations describing circular polarization of light in the spherical tensor basis are presented. Methods for the optical measurement of angular momentum orientation are discussed, including determination of the helicity of circularly polarized light by a quarter-wave plate or single Fresnel rhomb.
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Affiliation(s)
- Andrew J Alexander
- School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, Scotland, UK.
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45
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Jodoin DN, Brown A. Photodissociation of HI and DI: Testing models for electronic structure via polarization of atomic photofragments. J Chem Phys 2005; 123:054301. [PMID: 16108633 DOI: 10.1063/1.1989327] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The photodissociation dynamics of HI and DI are examined using time-dependent wave-packet techniques. The orientation and alignment parameters aQ(K) (p) are determined as a function of photolysis energy for the resulting ground-state I(2P(3/2)) and excited-state I(2P(1/2)) atoms. The aQ(K) (p) parameters describe the coherent and incoherent contributions to the angular momentum distributions from the A 1pi(1), a 3pi(1), and t 3sigma(1) electronic states accessed by perpendicular excitation and the a 3pi(0+) state accessed by a parallel transition. The outcomes of the dynamics based on both shifted ab initio results and three empirical models for the potential-energy curves and transition dipole moments are compared and contrasted. It is demonstrated that experimental measurement of the aQ(K) (p) parameters for the excitation from the vibrational ground state (upsilon=0) would be able to distinguish between the available models for the HI potential-energy curves and transition dipole moments. The differences between the aQ(K) (p) parameters for the excitation from upsilon=0 stand in sharp contrast to the scalar properties, i.e., total cross section and I* branching fraction, which require experimental measurement of photodissociation from excited vibrational states (upsilon>0) to distinguish between the models.
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Affiliation(s)
- David N Jodoin
- Department of Chemistry, University of Alberta, Edmonton AB T6G 2G2, Canada
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46
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Rakitzis TP. Highly spin-polarized atoms and molecules from rotationally state-selected molecules. PHYSICAL REVIEW LETTERS 2005; 94:083005. [PMID: 15783890 DOI: 10.1103/physrevlett.94.083005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Indexed: 05/24/2023]
Abstract
It is shown that large nuclear polarizations in isolated molecules may be created via the hyperfine interaction following excitation to selected rotational states |JM>. Explicit time-dependent nuclear polarization expressions for pulsed rotational excitation are presented for the case of one nuclear spin I, and for the case of two nuclear spins I1 and I2 in the hierarchical coupling limit. Photodissociation of the polarized molecules allows the production of polarized atoms, on short time scales if pulsed, at densities close to the parent molecule density.
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Affiliation(s)
- T Peter Rakitzis
- Department of Physics, University of Crete, P.O. 2203, 71003 Heraklion-Crete, Greece
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47
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Brown A. Photodissociation of HI and DI: Polarization of atomic photofragments. J Chem Phys 2005; 122:84301. [PMID: 15836033 DOI: 10.1063/1.1850465] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The complete angular momentum distributions and vector correlation coefficients (orientation and alignment) of ground state I((2)P(32)) and excited state I((2)P(12)) atoms resulting from the photodissociation of HI have been computed as a function of photolysis energy. The orientation and alignment parameters a(Q) ((K))(p) that describe the coherent and incoherent contributions to the angular momentum distributions from the multiple electronic states accessed by parallel and perpendicular transitions are determined using a time-dependent wave packet treatment of the dissociation dynamics. The dynamics are based on potential energy curves and transition dipole moments that have been reported previously [R. J. LeRoy, G. T. Kraemer, and S. Manzhos, J. Chem. Phys. 117, 9353 (2002)] and used to successfully model the scalar (total cross section and branching fraction) and lowest order vector (anisotropy parameter beta) properties of the photodissociation. Predictions of the a(Q) ((K))(p), parameters for the isotopically substituted species DI are reported and contrasted to the analogous HI results. The resulting polarization for the corresponding H/D partners are also determined and demonstrate that both H and D atoms produced can be highly spin polarized. Comparison of these predictions for HI and DI with experimental measurement will provide the most stringent test of the current model for the electronic structure and the interpretation of the dissociation based on noncoupled excited state dynamics.
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Affiliation(s)
- Alex Brown
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.
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48
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Kyoung Lee S, Townsend D, Vasyutinskii OS, Suits AG. O(1D2) orbital orientation in the ultraviolet photodissociation of ozone. Phys Chem Chem Phys 2005; 7:1650-6. [DOI: 10.1039/b502371h] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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49
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Abstract
Spin-polarized hydrogen (SPH) atoms have traditionally been produced and detected using complex experimental methods with poor time resolution. Recently, SPH has been produced by pulsed-laser photodissociation of HCl using circularly polarized light. In combination with the proposed detection of SPH via polarized fluorescence, this approach should allow the production and spatially resolved detection of SPH with a higher sensitivity than that currently available, and with a time resolution in the nanosecond regime. This represents an improvement of several orders of magnitude over the existing methods.
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Affiliation(s)
- T Peter Rakitzis
- Department of Physics, University of Crete, Institute of Electronic Structure and Laser Foundation for Research and Technology-Hellas 711 10 Heraklion-Crete, Greece.
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50
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Smolin AG, Vasyutinskii OS, Wouters ER, Suits AG. Orbital alignment in N2O photodissociation. I. Determination of all even rank anisotropy parameters. J Chem Phys 2004; 121:6759-70. [PMID: 15473732 DOI: 10.1063/1.1785786] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a general method for determination of the photofragment K=4 state multipoles in an ion imaging experiment. These multipoles are important for determining the full density matrix for any photofragment with j(a)> or =2. They are expressed in terms of laboratory frame anisotropy parameters that have distinct physical origins and possess characteristic angular distributions. The explicit expression for the (2+1) resonant multiphoton ionization absorption signal for the case of arbitrarily polarized probe light is derived and a procedure for isolation of the rank-4 state multipoles from all others is shown. This treatment is applied to the case of O((1)D) produced in the 193 nm photodissociation of N2O. The results show nonzero values for all K=4 anisotropy parameters, indicating the complexity of the photodissociation dynamics in this system.
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Affiliation(s)
- Andrey G Smolin
- Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
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