Article
Optics
Huanyu Ma, Xincheng Wang, Linxuan Zhang, Zhihan Zou, Junyang Yuan, Yixuan Ma, Rujin Lv, Zhenjie Shen, Tianmin Yan, Matthias Weidemueller, Difa Ye, Yuhai Jiang
Summary: The photoionization process of rubidium atoms cooled in a magneto-optical trap was investigated experimentally and theoretically. The results showed that as the laser intensity increased, the momentum of the Rb+ ions from the 5P3/2 state approached zero, while the peaks from the 5S1/2 state remained unchanged. The ion-yield ratio between the 5S1/2 and 5P3/2 states also varied with laser intensity, indicating a transition from perturbative to strongly perturbative ionization for the 5P3/2 state.
Article
Multidisciplinary Sciences
Adam R. Patel, Apoorv Ranjan, Xingxing Wang, Mikhail N. Slipchenko, Mikhail N. Shneider, Alexey Shashurin
Summary: The paper presents a theoretical basis for the CMS diagnostic technique and validates its application in microplasmas through experiments. Findings suggest that in the Thomson free-electron regime, a detailed knowledge of plasma and collisional properties is unnecessary to extract the total number of electrons from the scattered signal.
SCIENTIFIC REPORTS
(2021)
Article
Optics
Danish Furekh Dar, Bjoern Minneker, Stephan Fritzsche
Summary: The ionization of atoms and molecules by strong laser fields has been extensively researched both theoretically and experimentally. The strong-field approximation (SFA) accurately predicts the behavior of ionization processes in intense laser fields by analytically solving the Schrodinger equation. This paper presents an extension of the SFA that incorporates the temporal structure of few-cycle pulses, resulting in improved predictions and enhanced control over above-threshold ionization.
Article
Multidisciplinary Sciences
M-F Lin, N. Singh, S. Liang, M. Mo, J. P. F. Nunes, K. Ledbetter, J. Yang, M. Kozina, S. Weathersby, X. Shen, A. A. Cordones, T. J. A. Wolf, C. D. Pemmaraju, M. Ihme, X. J. Wang
Summary: A study using ultrafast electron diffraction technique captured the short-lived radical-cation complex OH(H3O+) formed in the radiolysis of water, improving our fundamental understanding of elementary reaction dynamics in ionized liquid water.
Article
Physics, Multidisciplinary
Qing-Hua Ke, Yue-Ming Zhou, Yi-Jie Liao, Jin-Tai Liang, Yong Zhao, Jia Tan, Min Li, Pei-Xiang Lu
Summary: The study investigates the multiphoton ionization of hydrogen atom in two-color circularly polarized laser fields, revealing distinct structures and intensities of sideband peaks under specific conditions, which can be explained by the selection rules of photon-absorption channels.
FRONTIERS OF PHYSICS
(2021)
Article
Optics
Haiying Yuan, Yujun Yang, Fuming Guo, Jun Wang, Jigen Chen, Wei Feng, Zhiwen Cui
Summary: The interaction between ultrashort intense laser pulses and atoms can reveal the ultrafast dynamics of electrons through photoelectron emission spectra. By using the numerical solution of the time-dependent Schrodinger equation in momentum space, the photoelectron emission spectra of atoms irradiated by 400 nm intense lasers with different durations have been studied. The observed photoelectron peaks originate from the ionization of the excited state and their oscillations are due to the superposition with the sideband energy positions. The energy positions of the maximum intensity of the photoelectron emission spectra move towards higher energy end as the duration of the driving laser pulse extends.
Article
Optics
S. Popruzhenko, T. A. Lomonosova
Summary: The theory formulates a semiclassical analytic approach to describe the excitation of atomic Rydberg states by intense laser radiation in the multiphoton limit of ionization. By separating the electron motion in the laser field and Coulomb field of the nucleus, it allows for the calculation of classical cut-off positions in the distribution of excited atoms in principal and orbital quantum numbers, and the identification of the effects of quantum interference.
LASER PHYSICS LETTERS
(2021)
Article
Instruments & Instrumentation
Z. Shpilman, S. Silberstein, D. Rubin, Y. Ehrlich, Z. Oysher, Y. Ferber, I. Levy
Summary: The spectral x-ray streak camera (SXSC) is a new high-temporal-resolution spectral x-ray diagnostic system that allows researchers to differentiate between soft and hard x-ray regions, providing three spectral channels with a wide spectral range. The opto-mechanical design positions the filtered radiation at three different locations along the streak photo-cathode (PC) slit to provide time-dependent spectral channels with pico-second temporal resolution.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Physics, Multidisciplinary
D. P. Dong, B. H. Yang, D. B. Qian, W. C. Zhou, S. F. Zhang, X. Ma
Summary: In this study, a new approach was used to investigate the laser-intensity-dependent ionization and fragmentation yields of C60 molecules. It was found that the saturation intensities for C60 ionizations and the onset intensity for C60 fragmentation are much lower than previously reported, confirming the validity of over-the-barrier ionization using a conducting sphere model.
CHINESE PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Kaoruho Sakata, Masako Suzuki-Sakamaki, Kenta Amemiya
Summary: In this study, real-time observation of the evolving oxidation process of a Co thin film was achieved using fluorescence-yield wavelength-dispersive X-ray absorption spectroscopy, revealing the increase of oxide component from the surface to deeper regions as the reaction progresses. The oxidation progress in the depth direction was interpreted by the reaction with O-2 gas at the surface and the interlayer reaction by oxygen migration.
Article
Optics
P. Gonzalez de Alaiza Martinez, E. Smetanina, I Thiele, B. Chimier, G. Duchateau
Summary: In this paper, the electron dynamics in dielectric materials induced by two-color femtosecond laser pulses are studied, analyzing the influence of different parameters and finding an optimal pulse-to-pulse delay. The colors cooperate differently depending on the interaction process, enhancing significantly the energy deposition into the material with the given laser parameters.
Article
Physics, Multidisciplinary
D. Chetty, R. D. Glover, X. M. Tong, B. A. deHarak, H. Xu, N. Haram, K. Bartschat, A. J. Palmer, A. N. Luiten, P. S. Light, I. Litvinyuk, R. T. Sang
Summary: This joint experimental-theoretical study focuses on the carrier-envelope phase (CEP) of a few-cycle pulse and its effect on atomic excitation processes. The results confirm the theoretical predictions and suggest the use of tailored laser fields for coherent control of strong-field excitation. The study shows distinct CEP-dependent behavior for bound-state population at low and high intensities.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Dev R. Sadaula, Manuel A. Bautista, Javier A. Garcia, Timothy R. Kallman
Summary: Warm absorber spectra in active galactic nuclei show absorption features in X-ray and UV spectra, indicating outflowing gas that can affect the host galaxy. Models connecting observed absorption features with gas properties depend on assumptions about ionization and heating from the central black hole's continuum. Time-dependent models are shown to be important and differ from equilibrium models, suggesting that time variability should be considered in deriving properties of warm absorber outflows.
ASTROPHYSICAL JOURNAL
(2023)
Article
Optics
Peipei Ge, Yankun Dou, Meng Han, Yiqi Fang, Zhenning Guo, Chengyin Wu, Qihuang Gong, Yunquan Liu
Summary: In this study, we investigate the subcycle temporal property of multiphoton ionization of Ar atoms in a linearly polarized laser pulse at 400 nm using two-color phase-of-the-phase photoelectron spectroscopy. A weak 800-nm circularly polarized field is used to clock the intrinsic multiphoton ionization dynamics. The resulting phase-of-the-phase spectrum reveals a prominent angular-dependent feature. By analyzing the angular-dependent phase-of-the-phase, we are able to access the complex phase of the photoelectron wave packet of multiphoton ionization.
Article
Biochemistry & Molecular Biology
Je-Hoi Mun, Hirofumi Sakai, Dong-Eon Kim
Summary: The study discusses the calculation of time evolution operators for strongly ionizing medium using the TDUT method, focusing on its applicability in quasi-adiabatic regimes and non-Hermitian quantum systems. The method is verified for one-dimensional atom as a prototype, but it can be extended to three-dimensional atoms and molecules exposed to strong laser fields.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Larissa Egger, Michael Hollerer, Christian S. Kern, Hannes Herrmann, Philipp Hurdax, Anja Haags, Xiaosheng Yang, Alexander Gottwald, Mathias Richter, Serguei Soubatch, F. Stefan Tautz, Georg Koller, Peter Puschnig, Michael G. Ramsey, Martin Sterrer
Summary: This study investigates the self-metalation of porphyrin molecules on ultrathin MgO(001) films, revealing that charge transfer promotes the self-metalation process. By tuning the work function of the substrate, the charge and metalation state of porphyrin molecules on the surface can be controlled.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Wojciech Blachucki, Anna Wach, Joanna Czapla-Masztafiak, Mickael Delcey, Christopher Arrell, Rafal Fanselow, Pavle Juranic, Marcus Lundberg, Christopher Milne, Jacinto Sa, Jakub Szlachetko
Summary: This article introduces an innovative methodology called X-ray chronoscopy, which allows exploration of ultrafast processes in matter with attosecond precision using current XFEL sources. The method is based on measuring the change in an X-ray pulse temporal profile induced by interaction with a medium. This research is of great importance for observing and studying ultrafast dynamic processes.
APPLIED SCIENCES-BASEL
(2022)
Article
Astronomy & Astrophysics
Stefan Schippers, Sebastian Stock, Ticia Buhr, Alexander Perry-Sassmannshausen, Simon Reinwardt, Michael Martins, Alfred Mueller, Stephan Fritzsche
Summary: Experimental and theoretical investigations on multiple photoionization of Si+ and Si2+ ions and double photoionization of Si3+ ions were conducted. The results are valuable for distinguishing between the gaseous and solid components in the interstellar medium.
ASTROPHYSICAL JOURNAL
(2022)
Article
Chemistry, Physical
Marie S. Saettele, Andreas Windischbacher, Katharina Greulich, Larissa Egger, Anja Haags, Hans Kirschner, Ruslan Ovsyannikov, Erika Giangrisostomi, Alexander Gottwald, Mathias Richter, Serguei Soubatch, F. Stefan Tautz, Michael G. Ramsey, Peter Puschnig, Georg Koller, Holger F. Bettinger, Thomas Chasse, Heiko Peisert
Summary: Hexacene, an organic semiconductor material, shows superior electronic properties. The study reveals distinct differences in the structure and electronic properties of hexacene monolayers on Ag(110) and Cu(110) substrates.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Multidisciplinary Sciences
Anja Haags, Xiaosheng Yang, Larissa Egger, Dominik Brandstetter, Hans Kirschner, Francois C. Bocquet, Georg Koller, Alexander Gottwald, Mathias Richter, J. Michael Gottfried, Michael G. Ramsey, Peter Puschnig, Serguei Soubatch, F. Stefan Tautz
Summary: Tracing the modifications of molecules in surface chemical reactions is beneficial. sigma orbitals can be imaged in a broad energy range and photoemission orbital tomography is a unique tool for the detailed analysis of surface chemical reactions.
Article
Chemistry, Multidisciplinary
Philipp Hurdax, Christian S. Kern, Thomas Georg Bone, Anja Haags, Michael Hollerer, Larissa Egger, Xiaosheng Yang, Hans Kirschner, Alexander Gottwald, Mathias Richter, Francois C. Bocquet, Serguei Soubatch, Georg Koller, Frank Stefan Tautz, Martin Sterrer, Peter Puschnig, Michael G. Ramsey
Summary: This study demonstrates that a combined experimental and theoretical approach can directly observe large, geometry-induced modifications in the frontier orbitals of dye molecules adsorbed on an atomically thin dielectric layer. Experimental angle-resolved photoemission experiments and theoretical density functional calculations were used to determine the geometric and electronic structure of the adsorbed molecules and simulate the photoemission angular distribution patterns.
Article
Physics, Multidisciplinary
Alexander Gottwald, Michael Krumrey, Frank Scholze, Mathias Richter
Summary: The Physikalisch-Technische Bundesanstalt (PTB) is the national metrology institute of Germany and has been using synchrotron radiation (SR) for over 40 years. This article provides an overview of PTB's use of the BEssY II and MLS facilities for radiometry, as well as their upgrade plans and scientific challenges for the next decade.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Chemistry, Physical
S. Schippers, P. -M Hillenbrand, A. Perry-Sassmannshausen, T. Buhr, S. Fuchs, S. Reinwardt, F. Trinter, A. Mueller, M. Martins
Summary: The carbon 1s core-hole excitation of the molecular anion C-2(-) is studied experimentally at high resolution using the photon-ion merged-beams technique at a synchrotron light source. The photo-double-detachment cross section shows vibrational structures associated with core excitations of the C-2(-) ground and first excited levels. A detailed Franck-Condon analysis reveals molecular contraction upon core photoexcitation, resulting in rotational broadening of the observed spectral features. The spectroscopic parameters of the core-excited levels are determined in the present analysis.
Article
Optics
A. Mueller, A. Borovik, K. Holste, S. Klumpp, M. Martins, S. Schippers
Summary: Single and double ionization of berylliumlike C2+ by a single photon in the vicinity of the K-shell single-ionization threshold, in the energy range from 292 to 350 eV, is investigated. The experimental cross sections, with energy resolutions ranging from 160 meV to 11 meV, include contributions from the 1s(2)2s(2) S-1 ground level and the 1s(2)2s2p P-3 metastable levels. A comparison with a model based on previous R-matrix calculations shows very satisfying agreement.
Article
Physics, Multidisciplinary
S. Reiche, C. Bacellar, P. Bougiatioti, C. Cirelli, P. Dijkstal, P. Juranic, E. Ferrari, G. Knopp, A. Malyzhenkov, C. Milne, K. Nass, E. Prat, J. Vila-Comamala, C. David
Summary: Hard x-ray free-electron laser pulses, chirped in both photon energy and spatial position, were produced at the Aramis beamline at SwissFEL in Switzerland. These tailored pulses were used for absorption x-ray spectroscopy experiment and have potential applications in pulse compression and control of transverse coherence.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Chemistry, Physical
Julius Schwarz, Fridtjof Kielgast, Ivan Baev, Simon Reinwardt, Florian Trinter, Stephan Klumpp, Alexander Perry-Sassmannshausen, Ticia Buhr, Stefan Schippers, Alfred Mueller, Sadia Bari, Valerie Mondes, Roman Flesch, Eckart Ruehl, Michael Martins
Summary: The X-ray absorption of isolated H3O+ cations at the O 1s edge was studied, showing significant differences compared to neutral H2O and enabling the identification of individual molecules in charged small water clusters or liquid water using X-ray absorption spectroscopy.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Optics
S. Schippers, A. Hamann, A. Perry-Sassmannshausen, T. Buhr, A. Muller, M. Martins, S. Reinwardt, F. Trinter, S. Fritzsche
Summary: Experimental cross sections for m-fold photodetachment of oxygen anions were measured and showed clear signatures of direct double detachment. Theoretical calculations and large-scale cascade calculations were performed to study the subsequent de-excitation cascades.
Article
Physics, Multidisciplinary
Eduard Prat, Philipp Dijkstal, Eugenio Ferrari, Romain Ganter, Pavle Juranic, Alexander Malyzhenkov, Sven Reiche, Thomas Schietinger, Guanglei Wang, Andre Al Haddad, Sven Augustin, Christoph Bostedt, Gregor Knopp, Jonas Knurr, Ana Sofia Morillo-Candas, Zhibin Sun, Kirsten Schnorr
Summary: The Swiss Free-Electron Laser (FEL) Research Center has demonstrated the generation of widely tunable two-color x-ray FEL pulses, offering opportunities for studying ultrafast x-ray-induced energy transfer and relaxation processes in various scientific fields.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Chemistry, Physical
Charlotte Ruhmlieb, Maria Taplick, Matz Nissen, Ivan Baev, Christian Strelow, Sebastian Hentschel, Marcel Dohrmann, Michael Martins, Tobias Kipp, Alf Mews
Summary: A novel plasma-assisted approach is presented to deposit crystalline triazine-based graphitic carbon nitride directly onto solid substrates. The molecular structure of the precursor and its vaporization behavior are investigated using single-crystal diffraction, bond-energy calculations, and thermogravimetric analysis. In situ optical emission spectroscopy is used to study the fragmentation of the monomer in the plasma. The deposition product is accurately identified as pure triazine-based graphitic carbon nitride using powder X-ray diffraction and X-ray photoelectron spectroscopy, with a band gap of 2.1 eV determined by photoluminescence spectroscopy. The use of specific plasma conditions and a non-heated substrate prevents the co-deposition of the precursor. The morphology of the product is found to be sponge-like, which is beneficial for catalytic purposes. The photocatalytic behavior of the deposited polymer is investigated through water-splitting experiments.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Kaja Schubert, Meiyuan Guo, Kaan Atak, Simon Doerner, Christine Buelow, Bernd von Issendorff, Stephan Klumpp, J. Tobias Lau, Piter S. Miedema, Thomas Schlathoelter, Simone Techert, Martin Timm, Xin Wang, Vicente Zamudio-Bayer, Lucas Schwob, Sadia Bari
Summary: The study examined the electronic structure and deexcitation pathways of isolated cobalt protoporphyrin ions using near-edge X-ray absorption mass spectrometry and quantum-mechanical calculations. Results revealed that under resonant excitation, cobalt protoporphyrins form various charged fragments through competitive excitations to different molecular orbitals.
