1
|
Ngai A, Dulitz K, Hartweg S, Franz JC, Mudrich M, Stienkemeier F. Method of kinetic energy reconstruction from time-of-flight mass spectra. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2024; 95:033305. [PMID: 38517257 DOI: 10.1063/5.0201425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 03/05/2024] [Indexed: 03/23/2024]
Abstract
We present a method for the reconstruction of ion kinetic energy distributions from ion time-of-flight mass spectra through ion trajectory simulations. In particular, this method is applicable to complicated spectrometer geometries with largely anisotropic ion collection efficiencies. A calibration procedure using a single ion mass peak allows the accurate determination of parameters related to the spectrometer calibration, experimental alignment, and instrument response function, which improves the agreement between simulations and experiment. The calibrated simulation is used to generate a set of basis functions for the time-of-flight spectra, which are then used to transform from time-of-flight to kinetic-energy spectra. We demonstrate this reconstruction method on a recent pump-probe experiment by Asmussen et al. [Asmussen et al., Phys. Chem. Chem. Phys., 23, 15138, (2021)] on helium nanodroplets and retrieve time-resolved kinetic-energy-release spectra for the ions from ion time-of-flight spectra.
Collapse
Affiliation(s)
- A Ngai
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - K Dulitz
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, 6020 Innsbruck, Austria
| | - S Hartweg
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| | - J C Franz
- Institut für Physik, Universität Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - M Mudrich
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - F Stienkemeier
- Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
| |
Collapse
|
2
|
Ben Ltaief L, Sishodia K, Mandal S, De S, Krishnan SR, Medina C, Pal N, Richter R, Fennel T, Mudrich M. Efficient Indirect Interatomic Coulombic Decay Induced by Photoelectron Impact Excitation in Large Pure Helium Nanodroplets. PHYSICAL REVIEW LETTERS 2023; 131:023001. [PMID: 37505945 DOI: 10.1103/physrevlett.131.023001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 06/05/2023] [Indexed: 07/30/2023]
Abstract
Ionization of matter by energetic radiation generally causes complex secondary reactions that are hard to decipher. Using large helium nanodroplets irradiated by extreme ultraviolet (XUV) photons, we show that the full chain of processes ensuing primary photoionization can be tracked in detail by means of high-resolution electron spectroscopy. We find that elastic and inelastic scattering of photoelectrons efficiently induces interatomic Coulombic decay (ICD) in the droplets. This type of indirect ICD even becomes the dominant process of electron emission in nearly the entire XUV range in large droplets with radius ≳40 nm. Indirect ICD processes induced by electron scattering likely play an important role in other condensed-phase systems exposed to ionizing radiation as well, including biological matter.
Collapse
Affiliation(s)
- L Ben Ltaief
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - K Sishodia
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - S Mandal
- Indian Institute of Science Education and Research, Pune 411008, India
| | - S De
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - S R Krishnan
- Quantum Center of Excellence for Diamond and Emergent Materials and Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - C Medina
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - N Pal
- Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy
| | - R Richter
- Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste, Italy
| | - T Fennel
- Institute for Physics, University of Rostock, 18051 Rostock, Germany
| | - M Mudrich
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| |
Collapse
|
3
|
von Haeften K, Laarmann T, Wabnitz H, Möller T. Relaxation dynamics of 3He and 4He clusters and droplets studied using near infrared and visible fluorescence excitation spectroscopy. Phys Chem Chem Phys 2023; 25:1863-1880. [PMID: 36541224 DOI: 10.1039/d2cp04594j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The relaxation dynamics of electronically excited 3He and 4He clusters and droplets is investigated using time-correlated near-infrared and visible (NIR/VIS) fluorescence excitation spectroscopy. A rich data set spanning a wide range of cluster and droplet sizes is produced. The spectral features broadly follow the vacuum ultraviolet excitation (VUV) spectra. However, when the NIR/VIS spectra are normalised to the VUV fluorescence, regions with distinctly different cluster size and isotope dependence are identified, enabling deeper insight into the relaxation mechanism. Particle density, location of atomic-like states and their principal quantum number, n, are found to play an important role in the relaxation. For states with n = 3 and higher, only energy within the surface region is transferred to excited atoms which are subsequently ejected from the surface and fluoresce in vacuum. For states with n = 2, energy from the entire region within clusters and droplets is transferred to the surface, leading to the ejection of excited atoms and excimers. Here, the energy is transferred by excitation hopping, which competes with radiative and non-radiative decay, making ejection and NIR/VIS fluorescence inefficient in increasingly larger droplets.
Collapse
|
4
|
Bastian B, Asmussen JD, Ben Ltaief L, Czasch A, Jones NC, Hoffmann SV, Pedersen HB, Mudrich M. A new endstation for extreme-ultraviolet spectroscopy of free clusters and nanodroplets. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:075110. [PMID: 35922303 DOI: 10.1063/5.0094430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
In this work, we present a new endstation for the AMOLine of the ASTRID2 synchrotron at Aarhus University, which combines a cluster and nanodroplet beam source with a velocity map imaging and time-of-flight spectrometer for coincidence imaging spectroscopy. Extreme-ultraviolet spectroscopy of free nanoparticles is a powerful tool for studying the photophysics and photochemistry of resonantly excited or ionized nanometer-sized condensed-phase systems. Here, we demonstrate this capability by performing photoelectron-photoion coincidence experiments with pure and doped superfluid helium nanodroplets. Different doping options and beam sources provide a versatile platform to generate various van der Waals clusters as well as He nanodroplets. We present a detailed characterization of the new setup and show examples of its use for measuring high-resolution yield spectra of charged particles, time-of-flight ion mass spectra, anion-cation coincidence spectra, multi-coincidence electron spectra, and angular distributions. A particular focus of the research with this new endstation is on intermolecular charge and energy-transfer processes in heterogeneous nanosystems induced by valence-shell excitation and ionization.
Collapse
Affiliation(s)
- Björn Bastian
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Jakob D Asmussen
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Ltaief Ben Ltaief
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Achim Czasch
- Institut für Kernphysik, Goethe Universität, Max-von-Laue-Strasse 1, 60438 Frankfurt, Germany
| | - Nykola C Jones
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Søren V Hoffmann
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Henrik B Pedersen
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Marcel Mudrich
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| |
Collapse
|
5
|
Asmussen JD, Michiels R, Bangert U, Sisourat N, Binz M, Bruder L, Danailov M, Di Fraia M, Feifel R, Giannessi L, Plekan O, Prince KC, Squibb RJ, Uhl D, Wituschek A, Zangrando M, Callegari C, Stienkemeier F, Mudrich M. Time-Resolved Ultrafast Interatomic Coulombic Decay in Superexcited Sodium-Doped Helium Nanodroplets. J Phys Chem Lett 2022; 13:4470-4478. [PMID: 35561339 DOI: 10.1021/acs.jpclett.2c00645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The autoionization dynamics of superexcited superfluid He nanodroplets doped with Na atoms is studied by extreme-ultraviolet (XUV) time-resolved electron spectroscopy. Following excitation into the higher-lying droplet absorption band, the droplet relaxes into the lowest metastable atomic 1s2s 1,3S states from which interatomic Coulombic decay (ICD) takes place either between two excited He atoms or between an excited He atom and a Na atom attached to the droplet surface. Four main ICD channels are identified, and their decay times are determined by varying the delay between the XUV pulse and a UV pulse that ionizes the initial excited state and thereby quenches ICD. The decay times for the different channels all fall in the range of ∼1 ps, indicating that the ICD dynamics are mainly determined by the droplet environment. A periodic modulation of the transient ICD signals is tentatively attributed to the oscillation of the bubble forming around the localized He excitation.
Collapse
Affiliation(s)
- Jakob D Asmussen
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - Rupert Michiels
- Institute of Physics, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Ulrich Bangert
- Institute of Physics, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Nicolas Sisourat
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique Matière et Rayonnement, 75005 Paris, France
| | - Marcel Binz
- Institute of Physics, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Lukas Bruder
- Institute of Physics, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | | | | | - Raimund Feifel
- Department of Physics, University of Gothenburg, 41133 Gothenburg, Sweden
| | - Luca Giannessi
- Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza TS, Italy
| | - Oksana Plekan
- Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza TS, Italy
| | - Kevin C Prince
- Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza TS, Italy
| | - Richard J Squibb
- Department of Physics, University of Gothenburg, 41133 Gothenburg, Sweden
| | - Daniel Uhl
- Institute of Physics, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Andreas Wituschek
- Institute of Physics, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Marco Zangrando
- Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza TS, Italy
| | - Carlo Callegari
- Elettra-Sincrotrone Trieste S.C.p.A., 34149 Basovizza TS, Italy
| | - Frank Stienkemeier
- Institute of Physics, University of Freiburg, 79104 Freiburg im Breisgau, Germany
| | - Marcel Mudrich
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| |
Collapse
|
6
|
Michiels R, Abu-Samha M, Madsen LB, Binz M, Bangert U, Bruder L, Duim R, Wituschek A, LaForge AC, Squibb RJ, Feifel R, Callegari C, Di Fraia M, Danailov M, Manfredda M, Plekan O, Prince KC, Rebernik P, Zangrando M, Stienkemeier F, Mudrich M. Enhancement of Above Threshold Ionization in Resonantly Excited Helium Nanodroplets. PHYSICAL REVIEW LETTERS 2021; 127:093201. [PMID: 34506185 DOI: 10.1103/physrevlett.127.093201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 06/05/2021] [Accepted: 07/15/2021] [Indexed: 06/13/2023]
Abstract
Clusters and nanodroplets hold the promise of enhancing high-order nonlinear optical effects due to their high local density. However, only moderate enhancement has been demonstrated to date. Here, we report the observation of energetic electrons generated by above-threshold ionization (ATI) of helium (He) nanodroplets which are resonantly excited by ultrashort extreme ultraviolet (XUV) free-electron laser pulses and subsequently ionized by near-infrared (NIR) or near-ultraviolet (UV) pulses. The electron emission due to high-order ATI is enhanced by several orders of magnitude compared with He atoms. The crucial dependence of the ATI intensities with the number of excitations in the droplets suggests a local collective enhancement effect.
Collapse
Affiliation(s)
- R Michiels
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - M Abu-Samha
- College of Engineering and Technology, American University of the Middle East, Egaila, Kuwait
| | - L B Madsen
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - M Binz
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - U Bangert
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - L Bruder
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - R Duim
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - A Wituschek
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - A C LaForge
- Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
| | - R J Squibb
- Department of Physics, University of Gothenburg, 41296 Gothenburg, Sweden
| | - R Feifel
- Department of Physics, University of Gothenburg, 41296 Gothenburg, Sweden
| | - C Callegari
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
| | - M Di Fraia
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
| | - M Danailov
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
| | - M Manfredda
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
| | - O Plekan
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
| | - K C Prince
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
| | - P Rebernik
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
| | - M Zangrando
- Elettra-Sincrotrone Trieste S.C.p.A, 34149 Basovizza, Trieste, Italy
- IOM-CNR, 34149 Trieste, Italy
| | - F Stienkemeier
- Institute of Physics, University of Freiburg, 79104 Freiburg, Germany
| | - M Mudrich
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| |
Collapse
|