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Motion of charged particles in bright squeezed vacuum

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Light(Science & Applications) 2024年第2期13卷 347-353页

作者： Matan Even Tzur Oren Cohen Solid State Institute and Physics Department Technion-Israel Institute of TechnologyHaifa3200003Israel

The motion of laser-driven electrons quivers with an average energy termed pondermotive energy.We explore electron dynamics driven by bright squeezed vacuum(BSV),finding that BSV induces width oscillations,akin to electron quivering in laser light,with an equivalent ponderomotive energy.We identify closed and open trajectories of the electronic width that are associated with high harmonic generation and above-threshold ionization,respectively,similarly to trajectories of the electron position when its motion is driven by coherent light.In the case of bound electrons,the width oscillations may lead to ionization with noisy sub-cycle structure.Our results are foundational for strong-field and free-electron quantum optics,as they shed light on ionization,high harmonic generation,and nonlinear Compton scattering in BSV.

关键词： structure vacuum ionization

ionization cross sections for electron scattering from metastable rare-gas atoms （Ne~＊ and Ar~＊）

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Chinese Physics B 2013年第7期22卷 159-162页

作者：张永志周雅君 Center for Theoretical Atomic and Molecular Physics Academy of Fundamental and Interdisciplinary SciencesHarbin Institute of Technology Academy of Physical Science and Technology Heilongjiang University

The optical-model approach has been used to investigate the electron-impact ionization of metastable rare-gas atoms. A complex equivalent-local polarization potential is obtained to describe the ionization continuum channels. We have calculated the cross sections for collisional ionization of the metastable atoms Ne＊ and Ar＊ by electrons in the energy range from threshold to 200 eV. The present results are in agreement with the available experimental measurements and other theoretical calculations.

关键词： electron scattering metastable rare-gas atom ionization

High-throughput analysis of anthocyanins in horticultural crops using probe electrospray ionization tandem mass spectrometry (PESI/MS/MS)

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Horticulture Research 2023年第4期10卷 249-258页

作者： Misaki Ishibashi Kei Zaitsu Ikue Yoshikawa Shungo Otagaki Shogo Matsumoto Akira Oikawa Katsuhiro Shiratake Graduate School of Bioagricultural Sciences Nagoya UniversityChikusaNagoyaAichi 464-8601Japan Graduate School of Agriculture Kyoto UniversitySakyoKyoto 606-8502Japan Faculty of Biology-Oriented Science and Technology Kindai UniversityNishimitaniKinokawaWakayama 649-6493Japan Faculty of Agriculture Meijo UniversityTenpakuNagoyaAichi 468-8502Japan

Plant secondary metabolites exhibit various horticultural traits.Simple and rapid analysis methods for evaluating these metabolites are in demand in breeding and consumer markets dealing with horticultural crops.We applied probe electrospray ionization(PESI)to evaluate secondary metabolite levels in horticultural crops.PESI does not require pre-treatment and separation of samples,which makes it suitable for high-throughput analysis.In this study,we targeted anthocyanins,one of the primary pigments in horticultural crops.Eighty-one anthocyanins were detected in approximately 3 minutes in the selected reaction-monitoring mode.Tandem mass spectrometry(MS/MS)could adequately distinguish between the fragments of anthocyanins and flavonols.Probe sampling,an intuitive method of sticking a probe directly to the sample,could detect anthocyanins qualitatively on a micro-area scale,such as achenes and receptacles in strawberry fruit.Our results suggest that PESI/MS/MS can be a powerful tool to characterize the profile of anthocyanins and compare their content among cultivars.

关键词： MS/MS ionization dealing

ionization behavior and dynamics of picosecond laser filamentation in sapphire

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Opto-Electronic Advances 2019年第8期2卷 9-15页

作者： Amina Lingfei Ji Tianyang Yan Rui Ma Institute of Laser Engineering Beijing University of TechnologyBeijing 100124China Key Laboratory of Trans-scale Laser Manufacturing Technology Ministry of EducationBeijing 100124China.

Currently,laser-induced structural modifications in optical materials have been an active field of research.In this paper,we reported structural modifications in the bulk of sapphire due to picosecond(ps)laser filamentation and analyzed the ionization dynamics of the filamentation.Numerical simulations uncovered that the high-intensity ps laser pulses generate plasma through multi-photon and avalanche ionizations that leads to the creation of two distinct types of structural changes in the material.The experimental bulk modifications consist of a void like structures surrounded by cracks which are followed by a submicrometer filamentary track.By increasing laser energy,the length of the damage and filamentary track appeared to increase.In addition,the transverse diameter of the damage zone increased due to the electron plasma produced by avalanche ionizations,but no increase in the filamentary zone diameter was observed with increasing laser energy.

关键词： structural modifications sapphire picosecond laser filamentation ionization dynamics

ionization properties in the collision of Rydberg Cs atoms with CCl_4 molecules

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Science China Mathematics 1998年第7期41卷 779-784页

作者：龚顺生刘炳模王嘉珉顾思洪戴作跃李白文 Wuhan Institute of Physics & Mathematics Chinese Academy of Sciences Wuhan China

The experimental study of ionization in the collision of Rydberg Cs atoms with CCl 4 molecules is conducted using the crossed atomic and molecular beam apparatus. It is found that the relative collision rate constants are not consistent with the prediction of the essentially free electron model in the range of n =30-50. The possible reason for this discrepancy is discussed.

关键词： ionization Rydberg atoms.

ionization Channels of the Molecular Ion H^(+)_(2) in Intense Laser Field

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Chinese Physics Letters 2013年第11期30卷 71-75页

作者：苗向阳施昊霆 College of Physics and Information Engineering Shanxi Normal UniversityLinfen 041004

ionization channels of the molecular ion H^(+)_(2) for various initial vibrational states in intense laser field(80 fs,800 nm,I=6.8×10^(13) W/cm^(2))are theoretically investigated by numerically solving the time-dependent Schrödinger equation.The results confirm that the channels largely depend on the selection of initial vibrational states by analyzing the variations of peak locations in the nuclear initial kinetic-energy-release spectra.Furthermore,the selection of the ionization channels is sensitive to the wavelength of the laser pulse.In addition,time-dependent competition between direct multi-photon ionization and charge-resonance-enhanced ionization are is discussed.

关键词： spectra ionization ionization

ionization and Fragmentation of Butanone Clusters Irradiated by Photons at 355 and 118 nm

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Chemical Research in Chinese Universities 2011年第3期27卷 508-511页

作者： SUN Chang-kai HU Zhan YANG Xue JIN Ming-xing HU Wen-cheng DING Da-jun Institute of Atomic and Molecular Physics Jilin University Changchun 130012 P. R. China

Time-of-flight（TOF） mass spectra of molecular butanone clusters were measured under the irradiation of photons at 355 and 118 nm. Butanone molecular parent ion and several series of butanone cluster fragments such as （CH3COC2H5）nH＋, （CH3COC2H5）nC2H5＋, （CH3COC2H5）nCH3CO＋ and （CH3COC2H5）nC2H5CO＋ were observed. Odd-even variation pattern in the intensity of （CH3COC2H5）nCH3CO＋ is obvious from n=4 to 8. A connection is es-tablished between the fragment clusters （CH3COC2H5）nCH3CO＋ and the neutral clusters （CH3COC2H5）n＋1 based on the consideration of butanone cluster dissociation mainly by losing a radical C2H5？. The stability variation of the neutral clusters calculated via the HF-B3LYP method based on DFT is in agreement with the observed phenomena experimentally, indicating （CH3COC2H5）n＋1（n＋1=5,7） with a ring structure are with higher stability over the adjacent even-number clusters.

关键词： Cluster ionization Fragment Butanone

Nonlinear ionization dynamics of hot dense plasma observed in a laser-plasma amplifier

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Light(Science & Applications) 2020年第1期9卷 196-203页

作者： F.Tuitje P.Martinez Gil T.Helk J.Gautier F.Tissandier J.-P.Goddet A.Guggenmos U.Kleineberg S.Sebban E.Oliva C.Spielmann M.Zurch Institute for Optics and Quantum Electronics Abbe Center of PhotonicsUniversity of JenaJenaGermany Helmholtz Institute Jena JenaGermany Departamento de Ingenieria Energetica and Instituto de Fusion Nuclear“Guillermo Velarde” ETSI IndustrialesUniversidad Politecnica de MadridMadridSpain Laboratoire d’Optique Appliquee ENSTA ParisEcole PolytechniqueCNRSInstitut Polytechnique de ParisPalaiseauFrance Department for Physics Ludwig-Maximilian-University MunichGarchingGermany Ultra Fast Innovations GmbH GarchingGermany Fritz Haber Institute of the Max Planck Society BerlinGermany Department of Chemistry University of California at BerkeleyBerkeleyCAUSA Materials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCAUSA

Understanding the behaviour of matter under conditions of extreme temperature,pressure,density and electromagnetic fields has profound effects on our understanding of cosmologic objects and the formation of the universe.Lacking direct access to such objects,our interpretation of observed data mainly relies on theoretical models.However,such models,which need to encompass nuclear physics,atomic physics and plasma physics over a huge dynamic range in the dimensions of energy and time,can only provide reliable information if we can benchmark them to experiments under well-defined laboratory conditions.Due to the plethora of effects occurring in this kind of highly excited matter,characterizing isolated dynamics or obtaining direct insight remains challenging.High-density plasmas are turbulent and opaque for radiation below the plasma frequency and allow only near-surface insight into ionization processes with visible wavelengths.Here,the output of a high-harmonic seeded laser-plasma amplifier using eightfold ionized krypton as the gain medium operating at a 32.8 nm wavelength is ptychographically imaged.A complexvalued wavefront is observed in the extreme ultraviolet(XUV)beam with high resolution.Ab initio spatio-temporal Maxwell–Bloch simulations show excellent agreement with the experimental observations,revealing overionization of krypton in the plasma channel due to nonlinear laser-plasma interactions,successfully validating this four-dimensional multiscale model.This constitutes the first experimental observation of the laser ion abundance reshaping a laserplasma amplifier.The presented approach shows the possibility of directly modelling light-plasma interactions in extreme conditions,such as those present during the early times of the universe,with direct experimental verification.

关键词： extreme ionization dynamics

ionization Equilibrium and NLTE Effects on Compact Circumstellar HII Regions

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Science China Mathematics 1994年第7期37卷 850-861页

作者：蒋栋荣侯金良傅承启 Shanghai Observatory Academia Sinica Shanghai 200030 PRC

This paper presents the results of an extensive set of calculations about ionization equilibrium and NLTE effects on compact circumstellar HII regions embedded in clouds. In the mode! of a spherically symmetric and isothermal wind with a steady mass loss, pure hydrogen composition as well as Sobolev approximation, our research indicates that compact HII regions are far away from LTE state. The collisional ionization and photoionization from excited levels have great effects on the size of an HII region, the distribution of departure coefficients and the flux ratio of observed spectral lines. They can be used to explain the infrared line excess and the line deficit problems of YSOs. We conclude that it is unreasonable to infer the spectral type, mass loss rate and foreground extinction of the central star from optically thin line recombination theory.

关键词： compact HII region NLTE ionization equilibrium line excess and line deficit.