Article
Chemistry, Physical
Mingyu Zhu, Yuxiang Liu, Chunli Wei, Hongcheng Ni, Qi Wei
Summary: Atomic stabilization is influenced by the ponderomotive (PM) force, which can induce tunneling and over-barrier ionization. This study highlights the importance of considering the influence of the PM force when treating atomic stabilization, as it may outweigh multiphoton ionization under moderate laser intensities.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Optics
Wei-Chao Jiang, Mu-Xue Wang, Liang-You Peng, Joachim Burgdorfer
Summary: We investigate the features of stabilization in the angle-resolved spectra of photoelectrons when ground-state atomic hydrogen is exposed to an intense (around 10(18) W/cm(2)) linearly polarized ultrashort XUV pulse. In this scenario, atomic stabilization is attributed to the temporal destructive interference between wave packets released by the intense field at different time instants. By comparing numerical solutions of the time-dependent Schrodinger equation with a semi-analytical model, we are able to identify observed oscillations in momentum distribution and suppression of photoemission into the laser polarization direction as direct consequences of stabilization. The impact of nondipole corrections on angular distribution is also explored.
Article
Optics
Lei Geng, Hao Liang, K. Krajewska, Liang-You Peng, Qihuang Gong
Summary: Ionization of atoms and molecules in laser fields can create various interference structures in the photoelectron spectrum, with superintense extreme ultraviolet laser pulses leading to a novel petal-like interference structure in the electron momentum distribution. This structure is shown to be caused by Fresnel diffraction of the electronic wave packet by the nucleus, demonstrated through numerical solutions of the time-dependent Schrodinger equation. The physical picture of laser-induced electron Fresnel diffraction is established and reinforced by both quantum and semiclassical models.
News Item
Physics, Multidisciplinary
Paraskevas Tzallas
Summary: Strongly laser-driven quantum correlated many-body systems result in the production of light that exhibits exotic quantum features, with the quantumness of the many-body system being imprinted on the emitted light.
Article
Optics
M. Zitnik, A. Mihelic, K. Bucar, S. Krusic, R. Squibb, R. Feifel, I. Ismail, P. Lablanquie, J. Palaudoux, O. Plekan, M. Di Fraia, M. Coreno, M. Manfredda, A. Simoncig, P. Rebernik Ribi, F. Sottocorona, E. Allaria, K. C. Prince, C. Callegari, F. Penent
Summary: By varying the relative phase of extreme ultraviolet light pulses, the population of the 2s(2) state in helium can be controlled. The interference of two-photon excitation paths results in maximum yield when the relative phase of the two harmonics matches the phase difference of complex atomic amplitudes governing the two paths. These findings enable the measurement of phase differences in two-photon ionization paths and the performance of interferometry in the extreme ultraviolet range.
Article
Optics
Li Guo, Yi Jia, Mingqing Liu, Xinyan Jia, Shilin Hu, Ronghua Lu, ShenSheng Han, Jing Chen
Summary: Using a Wigner distribution-like function based on the strong field approximation theory, we obtained the time-energy distributions and ionization time distributions of electrons ionized by XUV pulses alone or in the presence of IR pulses. The interference of low-energy structures plays a key role in shaping the ionization time distribution, with the electron emission direction, carrier-envelope phase, and counter-rotating term all affecting the distribution. Furthermore, the presence of the IR field not only alters the electron's final kinetic energy but also changes its emission time, with less impact seen on electrons from atoms with higher ionization energy.
Article
Chemistry, Physical
Giovanni Bressan, Jasper J. van Thor
Summary: This study presents an analytical expression to describe the orientational part of molecular response, which is evaluated for different conditions. Results obtained in the strong-field conditions suggest that careful analysis of two-dimensional spectroscopic experimental data should include laser pulse intensity considerations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Yuzhong Yao, Jie Zhang, Wei Kong
Summary: The study investigated the effect of fluorene and 1,3,5-trichlorobenzene embedded in atomic argon clusters on the generation of multiply charged atomic ions. It was found that enclosing the cluster with layers of Ar can significantly increase the charge state of MCAIs, while an excess of aromatic molecules is detrimental to the production of Ar+ and MCAIs. Exponential fittings revealed a systematic change in the yield of MCAIs with increasing concentrations of 3ClB in Ar clusters.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
N. Medvedev, H. Noei, S. Toleikis, B. Ziaja
Summary: The study found that nonthermal disintegration is the main damage mechanism for a free-standing graphene layer, with charge-induced disintegration prevailing only at high absorbed doses. It was also discovered that femtosecond optical pulses in the soft UV regime can probe the progressing damage.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Mechanics
Z. Wang, C. Zhang, H. Xia, Q. Xie, W. Deng
Summary: The presence of intense radial electric fields on a small wetted disk foil leads to the formation of numerous cone-jets and electrosprays, offering a simple and convenient method for creating quasi-monodisperse droplets at high throughput. This study quantitatively investigates the flow characteristics of an axisymmetric thin liquid film subjected to a radial electric field. Experimental measurements of the film thickness and velocity field provide insights into the multiplexed electrohydrodynamic tip streaming from a thin disk.
Article
Optics
Takashi Hiroi, Yuya Morimoto, Reika Kanya, Kaoru Yamanouchi
Summary: The study observed a laser-assisted (e, 2e) process of Ar in an ultrashort near-infrared intense laser field, with a shoulder structure in the sum of kinetic energies indicating the existence of the process. The determined triply differential cross section was approximately twice as large as theoretical estimates, suggesting evidence of the formation of light-dressed states of Ar.
Article
Optics
Zhiyong Qin, Zibo Xu, Changhai Yu, Jiansheng Liu, Jintan Cai, Zhijun Zhang, Shiyi Zhou, Xuhui Jiao, Zhongtao Xiang
Summary: This work demonstrates a feasible approach to enhance extreme-ultraviolet harmonics by increasing the intensity of the driving laser while keeping the laser energy constant. The quantitative analysis and phase matching reveal that the enhancement in harmonics can be attributed to the amplification of the induced atomic dipole moment amplitude and the favorable transient phase matching in the overdriven regime.
Article
Physics, Multidisciplinary
Franz E. Haniel, Hartmut Schroeder, Subhendu Kahaly, Arjun Nayak, Mathieu Dumergue, Sudipta Mondal, Filus Zoltan, Roland Flender, Mate Kurucz, Ludovit Haizer, Balint Kiss, Dimitris Charalambidis, Matthias F. Kling, Paraskevas Tzallas, Boris Bergues
Summary: The experimental study investigates the double ionization of xenon and krypton under intense four-cycle pulses, revealing significant saturation of double ionization at intensities close to 1.2 x 10(14) W cm(-2). The yield ratio of doubly to singly charged xenon is about 75%, while for krypton it is 25%. Additionally, the Perelomov-Popov-Terentyev theory underestimates the observed double ionization yield in the deeply saturated regime of the experiment.
NEW JOURNAL OF PHYSICS
(2021)
Article
Optics
Meng Zhao, YanLan Wang, Wei Quan, XuanYang Lai, HongPing Liu, JianDuo Lu, XiaoJun Liu
Summary: In this work, the high-lying Rydberg state excitation of noble gas atoms in an intense near-infrared laser field was investigated experimentally and theoretically. Coincident detection of photoelectrons and photoions with well-chosen arrival times allowed for extraction of a principal quantum number distribution related to the strength of the constant electric field. The extracted PQND was in qualitative agreement with a semiclassical model calculation, providing a method to study ultrafast high-lying Rydberg state excitation.
Article
Multidisciplinary Sciences
Ganjaboy S. Boltaev, Mazhar Iqbal, Naveed A. Abbasi, Vyacheslav V. Kim, Rashid A. Ganeev, Ali S. Alnaser
Summary: The study utilized an orthogonally-polarized two-color laser field to generate strong even and odd high order harmonics from gas targets, investigating the dynamics of harmonics from oxygen and nitrogen gases. The relative efficiency of harmonics was analyzed as a function of the thickness of the second harmonic generation crystal, achieving defocusing-assisted phase matching conditions in nitrogen gas.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Environmental
Tjalling Jager, Ida Beathe Overjordet, Raymond Nepstad, Bjorn Henrik Hansen
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2017)
Article
Environmental Sciences
Raymond Nepstad, Emlyn Davies, Dag Altin, Trond Nordtug, Bjorn Henrik Hansen
JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH-PART A-CURRENT ISSUES
(2017)
Article
Engineering, Environmental
Ida Beathe Overjordet, Raymond Nepstad, Bjorn Henrik Hansen, Tjalling Jager, Julia Farkas, Dag Altin, Ute Bronner, Trond Nordtug
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2018)
Article
Environmental Sciences
JoLynn Carroll, Frode Vikebo, Daniel Howell, Ole Jacob Broch, Raymond Nepstad, Starrlight Augustine, Geir Morten Skeie, Radovan Bast, Jonas Juselius
MARINE POLLUTION BULLETIN
(2018)
Article
Ecology
Tjalling Jager, Raymond Nepstad, Bjorn Henrik Hansen, Julia Farkas
ECOLOGICAL MODELLING
(2018)
Article
Environmental Sciences
Tor Nordam, C. J. Beegle-Krause, Jorgen Skancke, Raymond Nepstad, Mark Reed
MARINE POLLUTION BULLETIN
(2019)
Article
Environmental Sciences
Bjorn Henrik Hansen, Lisbet Sorensen, Trond R. Storseth, Raymond Nepstad, Dag Altin, Daniel Krause, Sonnich Meier, Trond Nordtug
MARINE ENVIRONMENTAL RESEARCH
(2019)
Article
Environmental Sciences
Tor Nordam, Raymond Nepstad, Emma Litzler, Johannes Rohrs
MARINE POLLUTION BULLETIN
(2019)
Article
Ecology
Raymond Nepstad, Maria Liste, Morten O. Alver, Tor Nordam, Emlyn Davies, Tormod Glette
REGIONAL STUDIES IN MARINE SCIENCE
(2020)
Article
Environmental Sciences
Ole Jacob Broch, Raymond Nepstad, Ingrid Ellingsen, Radovan Bast, Geir Morten Skeie, JoLynn Carroll
MARINE ENVIRONMENTAL RESEARCH
(2020)
Article
Environmental Sciences
Raymond Nepstad, Bjorn Henrik Hansen, Jorgen Skancke
Summary: Offshore oil and gas platforms discharge produced water containing PAHs into the ocean, impacting the early life stages of Atlantic Cod in the North Sea. A numerical model was used to study the fate and uptake of PAHs, showing significant differences between predicted internal concentrations and discharge concentrations of PAHs over multiple years of simulation.
MARINE ENVIRONMENTAL RESEARCH
(2021)
Review
Environmental Sciences
Eva Ramirez-Llodra, Hilde Cecilie Trannum, Guri S. Andersen, Nicole J. Baeten, Steven J. Brooks, Carlos Escudero-Onate, Hege Gundersen, Rolf Arne Kleiv, Olga Ibragimova, Aivo Lepland, Raymond Nepstad, Roar Sandoy, Morten Thorne Schaanning, Tracy Shimmield, Evgeniy Yakushev, Laura Ferrando-Climent, Per Helge Hogaas
Summary: A multidisciplinary programme in Norway has studied the environmental impacts of submarine tailing disposal (STD), providing new knowledge for global assessments and mitigation. Through detailed seafloor mapping, modelling, and toxicity tests, they have developed tools for monitoring and assessing the behavior of tailing particles and chemicals. Results suggest that full community recovery and normalization of metal leakage rates from sulfidic tailings may take several decades.
MARINE POLLUTION BULLETIN
(2022)
Article
Environmental Sciences
Raymond Nepstad, Tor Nordam, Ingrid H. Ellingsen, Lionel Eisenhauer, Emma Litzler, Konstantinos Kotzakoulakis
Summary: This study investigates the effects of model resolution and seasons on the dispersion of produced water during offshore petroleum production. By comparing different models, it finds significant differences in tracer distribution and concentrations between resolutions and seasons.
MARINE POLLUTION BULLETIN
(2022)
Article
Environmental Sciences
JoLynn Carroll, Havard G. Froysa, Frode Vikebo, Ole Jacob Broch, Daniel Howell, Raymond Nepstad, Starrlight Augustine, Geir Morten Skeie, Mathias Bockwoldt
Summary: This study simulates the survival of early life stages of NEA cod and haddock under the combined influence of natural processes and pollutants, and investigates the impact on adult fish populations in the event of a major oil spill. The research shows how dynamic ocean processes control the magnitude of population losses due to an oil spill, with the largest impacts occurring during the initial rise in marine productivity and spawning season. The reproductive health of adult fish populations remained unaffected in all scenarios.
MARINE POLLUTION BULLETIN
(2022)
Article
Environmental Sciences
Ole J. Broch, Ragnhild L. Daae, Ingrid H. Ellingsen, Raymond Nepstad, Eldar A. Bendiksen, Jenny L. Reed, Gunnar Senneset
FRONTIERS IN MARINE SCIENCE
(2017)