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Density Functional Treatment of Photoionization of Sodium Clusters: Effects of Cluster Size and Exchange–Correlation Framework 钠团簇光电离的密度泛函处理:团簇大小和交换相关框架的影响
IF 1.8
Atoms Pub Date : 2023-08-18 DOI: 10.3390/atoms11080114
R. Shaik, H. R. Varma, H. Chakraborty
{"title":"Density Functional Treatment of Photoionization of Sodium Clusters: Effects of Cluster Size and Exchange–Correlation Framework","authors":"R. Shaik, H. R. Varma, H. Chakraborty","doi":"10.3390/atoms11080114","DOIUrl":"https://doi.org/10.3390/atoms11080114","url":null,"abstract":"The ground state and photoionization properties of Nax (x = 20, 40, and 92) clusters are investigated using a method based on density functional theory (DFT) in a spherical jellium frame. Two different exchange–correlation treatments with the Gunnarsson–Lundqvist parametrization are used: (i) the electron self-interaction correction (SIC) scheme and (ii) the van Leeuwen–Baerends (LB94) scheme based on the gradient of the electron density. The shapes of the mean-field potentials and bound state properties, obtained in the two schemes, qualitatively agree, but differ in the details. The effect of the schemes on the photoionization dynamics, calculated in linear response time-dependent DFT is compared, in which the broader features are found to be universal. The general similarity of the results in SIC and LB94 demonstrates the reliability of DFT treatments. The study further elucidates the evolution of the ground state and ionization description as a function of the cluster size.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43129027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Calculation of Energy and Angular Distributions of Electrons Produced in Intermediate-Energy p + H2 Collisions 中能p+H2碰撞中电子能量和角分布的计算
IF 1.8
Atoms Pub Date : 2023-08-14 DOI: 10.3390/atoms11080112
C. Plowman, Kade H. Spicer, A. Kadyrov
{"title":"Calculation of Energy and Angular Distributions of Electrons Produced in Intermediate-Energy p + H2 Collisions","authors":"C. Plowman, Kade H. Spicer, A. Kadyrov","doi":"10.3390/atoms11080112","DOIUrl":"https://doi.org/10.3390/atoms11080112","url":null,"abstract":"We extend the two-centre wave-packet convergent close-coupling approach to doubly differential ionisation in proton collisions with H2 to intermediate projectile energies. The results for the doubly differential cross section at projectile energies from 48 to 200 keV are presented as a function of the energy and angle of emitted electrons. We consider a wide range of emission angles from 10 to 160∘, and compare our results to experimental data, where available. Excellent agreement between the presented results and the experimental data was found, especially for emission angles less than 130∘. For very large backward emission angles our calculations tended to slightly overestimate the experimental data when energetic electrons are ejected and the doubly differential cross section is very small. This discrepancy may be due to the large uncertainties in the experimental data in this region and the model target description. Overall, the present results show significant improvement upon currently available theoretical results and provide a consistently accurate description of this process across a wide range of incident energies.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47690058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Dynamic Response of a Light-Modulated Magnetometer to Time-Dependent Fields 光调制磁强计对时间相关场的动态响应
IF 1.8
Atoms Pub Date : 2023-08-11 DOI: 10.3390/atoms11080111
G. Bevilacqua, V. Biancalana, Y. Dancheva
{"title":"Dynamic Response of a Light-Modulated Magnetometer to Time-Dependent Fields","authors":"G. Bevilacqua, V. Biancalana, Y. Dancheva","doi":"10.3390/atoms11080111","DOIUrl":"https://doi.org/10.3390/atoms11080111","url":null,"abstract":"The dynamic response of a Bell-and-Bloom magnetometer to a parallel (to the bias field) time-dependent field is studied by means of a model that goes beyond the commonly assumed quasi-static regime. The findings unveil features that are related to the parametric nature of the considered system. It is shown that for low-amplitude time-dependent fields, different operating conditions are possible and that, besides the commonly reported low-pass filter behavior, a band-pass response emerges. Moreover, we show that a larger amplitude of the time-dependent field makes the parametric nature of the system appear more clearly in the output signal. A harmonic analysis of the latter is numerically performed to highlight and characterize these emerging features.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46201665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Bose Polaron in a One-Dimensional Lattice with Power-Law Hopping 幂律跳变一维晶格中的玻色极化子
IF 1.8
Atoms Pub Date : 2023-08-06 DOI: 10.3390/atoms11080110
G. A. Domínguez-Castro
{"title":"Bose Polaron in a One-Dimensional Lattice with Power-Law Hopping","authors":"G. A. Domínguez-Castro","doi":"10.3390/atoms11080110","DOIUrl":"https://doi.org/10.3390/atoms11080110","url":null,"abstract":"Polarons, quasiparticles resulting from the interaction between an impurity and the collective excitations of a medium, play a fundamental role in physics, mainly because they represent an essential building block for understanding more complex many-body phenomena. In this manuscript, we study the spectral properties of a single impurity mixed with identical bosons in a one-dimensional lattice with power-law hopping. In particular, based on the so-called T-matrix approximation, we show the existence of well-defined quasiparticle branches for several tunneling ranges and for both repulsive and attractive impurity-boson interactions. Furthermore, we demonstrate the persistence of the attractive polaron branch when the impurity-boson bound state is absorbed into the two-body continuum and that the attractive polaron becomes more robust as the range of the hopping increases. The results discussed here are relevant for the understanding of the equilibrium properties of quantum systems with power-law interactions.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47482277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Setup for the Ionic Lifetime Measurement of the 229mTh3+ Nuclear Clock Isomer 229mTh3+核时钟异构体离子寿命测量装置
IF 1.8
Atoms Pub Date : 2023-07-24 DOI: 10.3390/atoms11070108
Kevin Scharl, Shiqian Ding, Georg Holthoff, M. I. Hussain, S. Kraemer, Lilli Löbell, Daniel Moritz, Tamila Rozibakieva, B. Seiferle, Florian Zacherl, P. Thirolf
{"title":"Setup for the Ionic Lifetime Measurement of the 229mTh3+ Nuclear Clock Isomer","authors":"Kevin Scharl, Shiqian Ding, Georg Holthoff, M. I. Hussain, S. Kraemer, Lilli Löbell, Daniel Moritz, Tamila Rozibakieva, B. Seiferle, Florian Zacherl, P. Thirolf","doi":"10.3390/atoms11070108","DOIUrl":"https://doi.org/10.3390/atoms11070108","url":null,"abstract":"For the realization of an optical nuclear clock, the first isomeric excited state of thorium-229 (229mTh) is currently the only candidate due to its exceptionally low-lying excitation energy (8.338±0.024 eV). Such a nuclear clock holds promise not only to be a very precise metrological device but also to extend the knowledge of fundamental physics studies, such as dark matter research or variations in fundamental constants. Considerable progress was achieved in recent years in characterizing 229mTh from its first direct identification in 2016 to the only recent observation of the long-sought-after radiative decay channel. So far, nuclear resonance as the crucial parameter of a nuclear frequency standard has not yet been determined with laser-spectroscopic precision. To determine another yet unknown basic property of the thorium isomer and to further specify the linewidth of its ground-state transition, a measurement of the ionic lifetime of the isomer is in preparation. Theory and experimental investigations predict the lifetime to be 103–104 s. To precisely target this property using hyperfine structure spectroscopy, an experimental setup is currently being commissioned at LMU Munich. It is based on a cryogenic Paul trap providing long-enough storage times for 229mTh ions, that will be sympathetically cooled with 88Sr+. This article presents a concept for an ionic lifetime measurement and discusses the laser-optical part of a setup specifically developed for this purpose.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42865839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Exponentially Correlated Hylleraas–Configuration Interaction Studies of Atomic Systems. III. Upper and Lower Bounds to He-Sequence Oscillator Strengths for the Resonance 1S→1P Transition 原子系统的指数相关海勒原子组态相互作用研究。III、 谐振1S的He序列振子强度的上下界→1P过渡
IF 1.8
Atoms Pub Date : 2023-07-22 DOI: 10.3390/atoms11070107
J. Sims, B. Padhy, María Belén Ruiz Ruiz
{"title":"Exponentially Correlated Hylleraas–Configuration Interaction Studies of Atomic Systems. III. Upper and Lower Bounds to He-Sequence Oscillator Strengths for the Resonance 1S→1P Transition","authors":"J. Sims, B. Padhy, María Belén Ruiz Ruiz","doi":"10.3390/atoms11070107","DOIUrl":"https://doi.org/10.3390/atoms11070107","url":null,"abstract":"The exponentially correlated Hylleraas–configuration interaction method (E-Hy-CI) is a generalization of the Hylleraas–configuration interaction method (Hy-CI) in which the single rij of an Hy-CI wave function is generalized to a form of the generic type rijνije−ωijrij. This work continues the exploration, begun in the first two papers in this series (on the helium atom and on ground and excited S states of Li II), of whether wave functions containing both linear and exponential rij factors converge more rapidly than either one alone. In the present study, we examined not only 1s2 1S states but 1s2p 1P states for the He I, Li II, Be III, C V and O VII members of the He isoelectronic sequence as well. All 1P energies except He I are better than previous results. The wave functions obtained were used to calculate oscillator strengths, including upper and lower bounds, for the He-sequence lowest (resonance) 1S→1P transition. Interpolation techniques were used to make a graphical study of the oscillator strength behavior along the isoelectronic sequence. Comparisons were made with previous experimental and theoretical results. The results of this study are oscillator strengths for the 1s2 1S→ 1s2p1P He isoelectronic sequence with rigorous non-relativistic quantum mechanical upper and lower bounds of (0.001–0.003)% and probable precision ≤ 0.0000003, and were obtained by extending the previously developed E-Hy-CI formalism to include the calculation of transition moments (oscillator strengths).","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45323309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Towards Understanding Incomplete Fusion Reactions at Low Beam Energies: Modified Sum Rule Model 理解低束流能量下的不完全聚变反应:修正和规则模型
IF 1.8
Atoms Pub Date : 2023-07-21 DOI: 10.3390/atoms11070106
Bhushan Bhujang, Pragya Das
{"title":"Towards Understanding Incomplete Fusion Reactions at Low Beam Energies: Modified Sum Rule Model","authors":"Bhushan Bhujang, Pragya Das","doi":"10.3390/atoms11070106","DOIUrl":"https://doi.org/10.3390/atoms11070106","url":null,"abstract":"We investigated the enhanced production of nuclei formed via incomplete fusion (ICF) reactions near and above the Coulomb barrier energies (5–8 MeV/A). The cross-sections of the evaporation residues formed in the reactions—11B+124Sn, 10B+124Sn and 11B+122Sn—were measured using off-line gamma-ray spectrometry. The sum rule model (SRM) by Wilczyński et al. predicted the cross-section values too low compared to our experimental results. In earlier studies, the same model has been very successful in explaining ICF reactions at high beam energies (>10 MeV/A). We, therefore, modified the SRM, specifically incorporating the energy dependence in the definition of critical angular momentum ℓcr. The resulting modified SRM gave an improved theoretical estimate for the reactions we studied.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45801354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On Invariant Vectors in the Presence of Electric and Magnetic Fields 电场和磁场存在下的不变向量
IF 1.8
Atoms Pub Date : 2023-07-20 DOI: 10.3390/atoms11070105
J. Pain
{"title":"On Invariant Vectors in the Presence of Electric and Magnetic Fields","authors":"J. Pain","doi":"10.3390/atoms11070105","DOIUrl":"https://doi.org/10.3390/atoms11070105","url":null,"abstract":"In this non-exhaustive review, we discuss the importance of invariant vectors in atomic physics, such as the Laplace–Runge–Lenz vector, the Redmond vector in the presence of an electric field, the Landau–Avron–Sivardièrevector when the system is subject to a magnetic field, and the supergeneralized Runge–Lenz vector for the two-center problem. The application to the Stark and Zeeman effects are outlined. The existence of constants of motion in the charge-dyon system is also briefly mentioned.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45951208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Role of Simple Spatial Gradient in Reinforcing the Accuracy of Temperature Determination of HED Plasma via Spectral Line-Area Ratios 简单空间梯度在提高谱线面积比法测定HED等离子体温度精度中的作用
IF 1.8
Atoms Pub Date : 2023-07-12 DOI: 10.3390/atoms11070104
G. Riggs, M. Koepke, T. Lane, T. Steinberger, P. Kozlowski, I. Golovkin
{"title":"Role of Simple Spatial Gradient in Reinforcing the Accuracy of Temperature Determination of HED Plasma via Spectral Line-Area Ratios","authors":"G. Riggs, M. Koepke, T. Lane, T. Steinberger, P. Kozlowski, I. Golovkin","doi":"10.3390/atoms11070104","DOIUrl":"https://doi.org/10.3390/atoms11070104","url":null,"abstract":"We report on the simulation of temperature gradients in tamped NaFMgO target-foil plasma, heated and backlit by z-pinch dynamic hohlraum radiation. Our approach compares the spectroscopic output of a collisional-radiative model (prismspect) with soft X-ray absorption spectra collected on Sandia National Laboratories’ (SNL) Z Pulsed Power Facility. The pattern of minimum χ2 is seen to agree with an efficient, three-parameter model. Results show that a negligible gradient in electron temperature Te is consistent with experimental data, justifying the assumptions of previous work. The predicted sensitivity of line spectra to the gradient-aligned profile of Te is documented for each spectral feature, so that the line-area ratio between a pair of spectral features may be assessed as a proxy for the existence and quantification of such gradients.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45991203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Role of Gas Pressure in Quasi-Phase Matching in High Harmonics Driven by Two-Color Laser Field 气压在双色激光场驱动的高次谐波准相位匹配中的作用
IF 1.8
Atoms Pub Date : 2023-07-07 DOI: 10.3390/atoms11070103
S. Stremoukhov
{"title":"Role of Gas Pressure in Quasi-Phase Matching in High Harmonics Driven by Two-Color Laser Field","authors":"S. Stremoukhov","doi":"10.3390/atoms11070103","DOIUrl":"https://doi.org/10.3390/atoms11070103","url":null,"abstract":"The results of a study on the effect of pressure in a medium consisting of a set of gas jets separated by vacuum gaps, interacting with two-color laser fields formed by the fundamental and the second harmonics of a laser, are presented herein. It has been demonstrated that a decrease in pressure leads to a shift in the region of harmonics where quasi-phase matching (QPM) occurs towards shorter wavelength radiation, accompanied by an increase in the efficiency of amplification of these harmonics. A feature of this process is the identical power-law character of the shift in the region and the increase in the efficiency of harmonic QPM amplification. Additionally, the study presents the results of the effect of inaccurately setting the width of the gas jets on the shape of the spectrum of harmonic QPM amplification.","PeriodicalId":8629,"journal":{"name":"Atoms","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49053323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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