Pub Date : 2023-08-30DOI: 10.1088/1361-6455/acf53e
Rong-Zhu Zhang, Jin Hu, Gaoren Wang, Bina Fu, Yong‐Chang Han
Photoassociation (PA) of 85Rb atoms from the ground X1Σg+ state to the excited A1Σg+ and b3Πu states by two-color laser pulses at 100 μK×kB is investigated by using quantum wavepacket method. Two pulses with detunings δ 1 and δ 2 varying from −1.0 to 1. cm−1 are taken into account. The specific case δ1=−δ2 is generalized to the condition of arbitrary combination of δ 1 and δ 2 for both the Gaussian-pulse field and the slowly-turned-on and rapidly-turned-off (STRT) field. It is found that the introduce of the detunings in the two pluses can enhance the asymmetry of the time profile and broaden the linewidth of the laser field. The two factors can further enhance the PA probability for both resonant and nonresonant regions. Compared to the Gaussian field, the STRT field which is even more asymmetric in time profile and more broaden in linewidth can significantly enhance the PA probability, with the nonresonant transition dominating the PA process. It can be expected that once the two detunings are both positive, which is a relatively loose restriction for coherent control, a considerable PA probability can be obtained in a two-color STRT field.
{"title":"Steering photoassociation of cold 85Rb atoms by two-color slowly-turned-on and rapidly-turned-off laser pulses","authors":"Rong-Zhu Zhang, Jin Hu, Gaoren Wang, Bina Fu, Yong‐Chang Han","doi":"10.1088/1361-6455/acf53e","DOIUrl":"https://doi.org/10.1088/1361-6455/acf53e","url":null,"abstract":"Photoassociation (PA) of 85Rb atoms from the ground X1Σg+ state to the excited A1Σg+ and b3Πu states by two-color laser pulses at 100 μK×kB is investigated by using quantum wavepacket method. Two pulses with detunings δ 1 and δ 2 varying from −1.0 to 1. cm−1 are taken into account. The specific case δ1=−δ2 is generalized to the condition of arbitrary combination of δ 1 and δ 2 for both the Gaussian-pulse field and the slowly-turned-on and rapidly-turned-off (STRT) field. It is found that the introduce of the detunings in the two pluses can enhance the asymmetry of the time profile and broaden the linewidth of the laser field. The two factors can further enhance the PA probability for both resonant and nonresonant regions. Compared to the Gaussian field, the STRT field which is even more asymmetric in time profile and more broaden in linewidth can significantly enhance the PA probability, with the nonresonant transition dominating the PA process. It can be expected that once the two detunings are both positive, which is a relatively loose restriction for coherent control, a considerable PA probability can be obtained in a two-color STRT field.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49278825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-28DOI: 10.1088/1361-6455/acf483
Jing Sun, G. Guo, B. Zhou, Yugang Ma
We propose a new method, termed generator coordinate method (GCM)-correlated pair wave function (CPWF), for studying one-dimensional bosons confined in harmonic potentials with contact repulsive interactions. Our approach involves using the effective CPWF as a basis, combined with the GCM to handle complex many-particle correlations accurately. We demonstrate the reliability of our GCM-CPWF wave functions by comparing ground energy and one-body density with those obtained by other numerical methods. Moreover, we present the energy spectrum up to six particles and the occupation number on the harmonic oscillator state. Utilizing these GCM-CPWF wave functions, we explore the properties of the ground and excited states of the many-particle system. Our GCM-CPWF framework is highly flexible and can be generalized to investigate more complex many-particle systems.
{"title":"Generator coordinate method for 1D contacting bosons in harmonic trap","authors":"Jing Sun, G. Guo, B. Zhou, Yugang Ma","doi":"10.1088/1361-6455/acf483","DOIUrl":"https://doi.org/10.1088/1361-6455/acf483","url":null,"abstract":"We propose a new method, termed generator coordinate method (GCM)-correlated pair wave function (CPWF), for studying one-dimensional bosons confined in harmonic potentials with contact repulsive interactions. Our approach involves using the effective CPWF as a basis, combined with the GCM to handle complex many-particle correlations accurately. We demonstrate the reliability of our GCM-CPWF wave functions by comparing ground energy and one-body density with those obtained by other numerical methods. Moreover, we present the energy spectrum up to six particles and the occupation number on the harmonic oscillator state. Utilizing these GCM-CPWF wave functions, we explore the properties of the ground and excited states of the many-particle system. Our GCM-CPWF framework is highly flexible and can be generalized to investigate more complex many-particle systems.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43455368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-28DOI: 10.1088/1361-6455/acf484
H. S. Chương, T. M. Duc
Pair coherent states (PCSs) as a kind of two-mode non-Gaussian and nonclassical states were introduced and studied. Some nonclassical characteristics of them such as two-mode sum-squeezing, two-mode antibunching, and entanglement have been well investigated. In this paper, we focus on studying the superposition of photon addition and subtraction to the PCSs called superposition of photon-added and photon-subtracted pair coherent states (SPAPSPCSs). Our main purpose is to show that the non-Gaussian feature and all the above-mentioned nonclassical properties of the SPAPSPCSs can be enhanced compared with the photon-added-and-subtracted two modes pair coherent states (PAASTMPCSs) and the original PCSs. In general, we demonstrate that the SPAPSPCSs have more enhanced non-Gaussian character and nonclassical properties than the PCSs and the PAASTMPCSs by examining the negativity of the Wigner function. Specifically, we indicate that both the SPAPSPCSs and the PAASTMPCSs can exist in two-mode sum-squeezing while the original PCSs (without photon-addition and photon-subtraction) cannot, and the degree of squeezing is stronger in the SPAPSPCSs than in the PAASTMPCSs. The obtained results also indicate that the superposition of photon addition and subtraction of the SPAPSPCSs plays a vital role in enhancing the two-mode antibunching property and the entanglement degree compared with the PCSs and the PAASTMPCSs.
{"title":"Enhancement of non-Gaussianity and nonclassicality of pair coherent states by superposition of photon addition and subtraction","authors":"H. S. Chương, T. M. Duc","doi":"10.1088/1361-6455/acf484","DOIUrl":"https://doi.org/10.1088/1361-6455/acf484","url":null,"abstract":"Pair coherent states (PCSs) as a kind of two-mode non-Gaussian and nonclassical states were introduced and studied. Some nonclassical characteristics of them such as two-mode sum-squeezing, two-mode antibunching, and entanglement have been well investigated. In this paper, we focus on studying the superposition of photon addition and subtraction to the PCSs called superposition of photon-added and photon-subtracted pair coherent states (SPAPSPCSs). Our main purpose is to show that the non-Gaussian feature and all the above-mentioned nonclassical properties of the SPAPSPCSs can be enhanced compared with the photon-added-and-subtracted two modes pair coherent states (PAASTMPCSs) and the original PCSs. In general, we demonstrate that the SPAPSPCSs have more enhanced non-Gaussian character and nonclassical properties than the PCSs and the PAASTMPCSs by examining the negativity of the Wigner function. Specifically, we indicate that both the SPAPSPCSs and the PAASTMPCSs can exist in two-mode sum-squeezing while the original PCSs (without photon-addition and photon-subtraction) cannot, and the degree of squeezing is stronger in the SPAPSPCSs than in the PAASTMPCSs. The obtained results also indicate that the superposition of photon addition and subtraction of the SPAPSPCSs plays a vital role in enhancing the two-mode antibunching property and the entanglement degree compared with the PCSs and the PAASTMPCSs.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46813488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-25DOI: 10.1088/1361-6455/acf428
David M Jacobs, M. Horbatsch
Atomic hydrogen energy levels calculated to high precision are required to assist experimental researchers working on spectroscopy in the pursuit of testing quantum electrodynamics (QEDs) and probing for physics beyond the Standard Model. There are two important parts to the problem of computing these levels: an accurate evaluation of contributions from QED and using an accurate value for the proton charge radius as an input. Recent progress on QED corrections to the fine structure, as well as increasing evidence that a proton charge radius in the range of 0.84 fm is favored over the previously adopted larger value in the 0.88 fm range, has advanced the field, yet several state-of-the-art measurements remain in contradiction with this smaller value. Motivated by on-going and future work in this area, we present here a simple parameterization for the energy levels of hydrogen at the level of hyperfine structure using the so-called relativistic Ritz approach. The fitting of a finite sample of QED-generated levels at low to intermediate principal quantum number, n, gives a generally applicable formula for all values of n for each distinct angular momentum channel, given in this work up to orbital angular momentum number ℓ=30 . We also provide a simple linear parameterization for the shift in hydrogen energy levels as a function of the proton radius, providing a useful cross check for extant and future measured energy intervals.
{"title":"Fitting for the energy levels of hydrogen","authors":"David M Jacobs, M. Horbatsch","doi":"10.1088/1361-6455/acf428","DOIUrl":"https://doi.org/10.1088/1361-6455/acf428","url":null,"abstract":"Atomic hydrogen energy levels calculated to high precision are required to assist experimental researchers working on spectroscopy in the pursuit of testing quantum electrodynamics (QEDs) and probing for physics beyond the Standard Model. There are two important parts to the problem of computing these levels: an accurate evaluation of contributions from QED and using an accurate value for the proton charge radius as an input. Recent progress on QED corrections to the fine structure, as well as increasing evidence that a proton charge radius in the range of 0.84 fm is favored over the previously adopted larger value in the 0.88 fm range, has advanced the field, yet several state-of-the-art measurements remain in contradiction with this smaller value. Motivated by on-going and future work in this area, we present here a simple parameterization for the energy levels of hydrogen at the level of hyperfine structure using the so-called relativistic Ritz approach. The fitting of a finite sample of QED-generated levels at low to intermediate principal quantum number, n, gives a generally applicable formula for all values of n for each distinct angular momentum channel, given in this work up to orbital angular momentum number ℓ=30 . We also provide a simple linear parameterization for the shift in hydrogen energy levels as a function of the proton radius, providing a useful cross check for extant and future measured energy intervals.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45586101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-25DOI: 10.1088/1361-6455/acf429
V. D. da Mata, M. M. Fujimoto, M. Homem
A systematic investigation was carried out on the elastic scattering of low- to intermediate-energy electrons ( E0 = 0.1–1000 eV eV) by acetonitrile (CH3CN). We calculated differential (DCS), integral (ICS), momentum-transfer (MTCS), and total absorption cross sections from 0.1 to 1000 eV energy range using an absorption-effects-implemented ePolyScat-E3 suite of codes, which applies the Schwinger variational method combined with the Padé-approximants technique. Also, the screen-corrected independent atom model was used to compute DCSs, ICSs, and MTCSs from 10–1000 eV impact energies. Present results are compared to other theoretical and experimental data when available. In general, our DCS and MTCS results show a good agreement with available data, however, the ICSs and the resonance features exhibit fair accordance. Our results show two shape-resonance structures: one at about 3.4 eV and a second at about 7 eV. They are labeled as π∗ and σ∗ , and comprise the 2E and 2A1 scattering channels, respectively.
对乙腈（CH3CN）对中低能量电子（E0=0.1–1000 eV eV）的弹性散射进行了系统的研究。我们使用吸收效应实现的ePolyScat-E3代码套件计算了0.1至1000eV能量范围内的微分（DCS）、积分（ICS）、动量传递（MTCS）和总吸收截面，该代码应用了Schwinger变分法和Padé-近似技术。此外，屏幕校正的独立原子模型用于计算10–1000 eV碰撞能量的DCSs、ICSs和MTCSs。将目前的结果与其他可用的理论和实验数据进行比较。总的来说，我们的DCS和MTCS结果与现有数据显示出良好的一致性，然而，ICSs和共振特征表现出相当的一致性。我们的结果显示了两种形状共振结构：一种在大约3.4eV处，另一种在约7eV处。它们被标记为π*和σ*，分别包括2E和2A1散射通道。
{"title":"Collisions of low- to intermediate-energy electrons with acetonitrile","authors":"V. D. da Mata, M. M. Fujimoto, M. Homem","doi":"10.1088/1361-6455/acf429","DOIUrl":"https://doi.org/10.1088/1361-6455/acf429","url":null,"abstract":"A systematic investigation was carried out on the elastic scattering of low- to intermediate-energy electrons ( E0 = 0.1–1000 eV eV) by acetonitrile (CH3CN). We calculated differential (DCS), integral (ICS), momentum-transfer (MTCS), and total absorption cross sections from 0.1 to 1000 eV energy range using an absorption-effects-implemented ePolyScat-E3 suite of codes, which applies the Schwinger variational method combined with the Padé-approximants technique. Also, the screen-corrected independent atom model was used to compute DCSs, ICSs, and MTCSs from 10–1000 eV impact energies. Present results are compared to other theoretical and experimental data when available. In general, our DCS and MTCS results show a good agreement with available data, however, the ICSs and the resonance features exhibit fair accordance. Our results show two shape-resonance structures: one at about 3.4 eV and a second at about 7 eV. They are labeled as π∗ and σ∗ , and comprise the 2E and 2A1 scattering channels, respectively.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48339927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-24DOI: 10.1088/1361-6455/acf3be
P. Hagelstein
A moving nucleus experiences a Lorentz contraction and spin rearrangement due to relativity. A nucleus that oscillates in a molecule or solid due to vibrations will undergo minor relativistic modifications which are a result of the vibrations, indicative of a relativistic phonon-nuclear interaction. The derivation of the lowest-order interaction from the many-particle Dirac model is reviewed. The Dirac model with a realistic potential model is not covariant, which is a source of concern. The lowest-order phonon-nuclear interaction obtained from a covariant two-body Bethe–Salpeter model is found to be similar to the interaction obtained from the Dirac model, supporting the notion that the interaction is not an artifact. Matrix elements of the lowest-order interaction are expressed in terms of one-body operators, which facilitates evaluation and allows for quantitative estimates of the magnitude.
{"title":"Lowest-order relativistic interaction between lattice vibrations and internal degrees of freedom of a nucleus","authors":"P. Hagelstein","doi":"10.1088/1361-6455/acf3be","DOIUrl":"https://doi.org/10.1088/1361-6455/acf3be","url":null,"abstract":"A moving nucleus experiences a Lorentz contraction and spin rearrangement due to relativity. A nucleus that oscillates in a molecule or solid due to vibrations will undergo minor relativistic modifications which are a result of the vibrations, indicative of a relativistic phonon-nuclear interaction. The derivation of the lowest-order interaction from the many-particle Dirac model is reviewed. The Dirac model with a realistic potential model is not covariant, which is a source of concern. The lowest-order phonon-nuclear interaction obtained from a covariant two-body Bethe–Salpeter model is found to be similar to the interaction obtained from the Dirac model, supporting the notion that the interaction is not an artifact. Matrix elements of the lowest-order interaction are expressed in terms of one-body operators, which facilitates evaluation and allows for quantitative estimates of the magnitude.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47889770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-24DOI: 10.1088/1361-6455/acf3c1
Suman Garain, Suman B Mondal, K. Mal, S. Roy, A. Bandyopadhyay
We present a theoretical study on optical bistability (OB), optical multistability (OM) and tunable all-optical switching in a four-level cascade type atomic system. The density matrix formalism is used to find out the response of the probe laser field. We explore OB and OM under unidirectional optical ring cavity configuration. A comparison between the effects of electromagnetically induced transparency and electromagnetically induced absorption windows on OB is presented. The threshold of OB and the hysteresis width can be tuned effectively by adjusting the applied coherent fields. A transition from OB to OM and vice-versa can be easily achieved by tuning the field parameters and the atomic cooperation parameter. Dynamic control of the probe laser propagating through the medium has been investigated. We also demonstrate conversion of a continuous wave input probe field into output switched pulse. The ON/OFF time of the switched probe pulse can also be controlled by tuning the field parameters.
{"title":"Controlling optical bistability, multistability and all-optical switching through multi-photon excitation process","authors":"Suman Garain, Suman B Mondal, K. Mal, S. Roy, A. Bandyopadhyay","doi":"10.1088/1361-6455/acf3c1","DOIUrl":"https://doi.org/10.1088/1361-6455/acf3c1","url":null,"abstract":"We present a theoretical study on optical bistability (OB), optical multistability (OM) and tunable all-optical switching in a four-level cascade type atomic system. The density matrix formalism is used to find out the response of the probe laser field. We explore OB and OM under unidirectional optical ring cavity configuration. A comparison between the effects of electromagnetically induced transparency and electromagnetically induced absorption windows on OB is presented. The threshold of OB and the hysteresis width can be tuned effectively by adjusting the applied coherent fields. A transition from OB to OM and vice-versa can be easily achieved by tuning the field parameters and the atomic cooperation parameter. Dynamic control of the probe laser propagating through the medium has been investigated. We also demonstrate conversion of a continuous wave input probe field into output switched pulse. The ON/OFF time of the switched probe pulse can also be controlled by tuning the field parameters.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48199265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-24DOI: 10.1088/1361-6455/acf3bd
Leo Sala, J. Rakovský, Agnes Zerolová, J. Kočišek
DNA origami nanostructures provide precisely addressable substrates for in singulo experiments as well as for applications in nanotechnology. We report on experiments evaluating the stability of DNA origami upon irradiation with light at different wavelengths and buffer solutions. DNA is irradiated with nanosecond pulsed lasers and the damage is evaluated using UV–Vis spectroscopy and atomic force microscopy imaging. We show that the wavelength dependence of the damage follows the UV absorption spectrum of DNA. Electronic excitation of DNA is primarily responsible for DNA origami damage at present wavelengths. We also demonstrate UV–Vis absorption of tris reaction products, influencing the UV–Vis absorption evaluation in experiments studying DNA damage.
{"title":"Light-induced damage to DNA origami nanostructures in the 193 nm–310 nm range","authors":"Leo Sala, J. Rakovský, Agnes Zerolová, J. Kočišek","doi":"10.1088/1361-6455/acf3bd","DOIUrl":"https://doi.org/10.1088/1361-6455/acf3bd","url":null,"abstract":"DNA origami nanostructures provide precisely addressable substrates for in singulo experiments as well as for applications in nanotechnology. We report on experiments evaluating the stability of DNA origami upon irradiation with light at different wavelengths and buffer solutions. DNA is irradiated with nanosecond pulsed lasers and the damage is evaluated using UV–Vis spectroscopy and atomic force microscopy imaging. We show that the wavelength dependence of the damage follows the UV absorption spectrum of DNA. Electronic excitation of DNA is primarily responsible for DNA origami damage at present wavelengths. We also demonstrate UV–Vis absorption of tris reaction products, influencing the UV–Vis absorption evaluation in experiments studying DNA damage.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47574353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-24DOI: 10.1088/1361-6455/acf3c0
Tamanna Zaman, D. Lambert, N. D. Cariatore, P. Stancil, D. Schultz
Multiple theoretical methods are used to calculate the elastic scattering cross section for collisions of alpha particles with atomic hydrogen in the center-of-mass energy range of 10−4–108 eV. At the lowest energies where elastic scattering greatly dominates other reaction channels, a single-channel quasi-molecular-orbital approach is used. With the opening of inelastic channels at higher energies the multi-channel atomic-orbital, close-coupling method is applied, and at the highest energies considered perturbation theory (the Born approximation) is used. The results are compared with other data available in the literature and from preliminary multi-channel molecular-orbital, close-coupling calculations in order to assess the accuracy of the results and to create a recommended set of data spanning the entire energy range. The data is made available for use in astrophysical modeling and other plasma science applications online.
{"title":"Multi-method treatment of elastic scattering of alpha particles from atomic hydrogen over a wide impact energy range","authors":"Tamanna Zaman, D. Lambert, N. D. Cariatore, P. Stancil, D. Schultz","doi":"10.1088/1361-6455/acf3c0","DOIUrl":"https://doi.org/10.1088/1361-6455/acf3c0","url":null,"abstract":"Multiple theoretical methods are used to calculate the elastic scattering cross section for collisions of alpha particles with atomic hydrogen in the center-of-mass energy range of 10−4–108 eV. At the lowest energies where elastic scattering greatly dominates other reaction channels, a single-channel quasi-molecular-orbital approach is used. With the opening of inelastic channels at higher energies the multi-channel atomic-orbital, close-coupling method is applied, and at the highest energies considered perturbation theory (the Born approximation) is used. The results are compared with other data available in the literature and from preliminary multi-channel molecular-orbital, close-coupling calculations in order to assess the accuracy of the results and to create a recommended set of data spanning the entire energy range. The data is made available for use in astrophysical modeling and other plasma science applications online.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45139861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-23DOI: 10.1088/1361-6455/acf354
N. Kimura, Genichi Kiyama, Daiki Ito, N. Nakamura
We demonstrate a versatile method for injecting metallic elements into an electron-beam ion trap using a metal vapor source. This method is based on the evaporation of a metal target by continuous electron-beam impact. We present visible emission spectra of highly charged tungsten ions prepared by the present injection scheme. By comparison with the conventional injection method using a high-vapor-pressure W(CO)6 compound, several advantages of the present method, i.e. suppressing charge exchange reactions in the trap region and quick recovery of the vacuum condition after stopping the injection, are found. The present injection method also facilitates the measurement of emission spectra of highly charged niobium ions, which have never previously been observed using electron-beam ion traps.
{"title":"Injection of metallic elements into an electron-beam ion trap using an electron impact metal vapor source","authors":"N. Kimura, Genichi Kiyama, Daiki Ito, N. Nakamura","doi":"10.1088/1361-6455/acf354","DOIUrl":"https://doi.org/10.1088/1361-6455/acf354","url":null,"abstract":"We demonstrate a versatile method for injecting metallic elements into an electron-beam ion trap using a metal vapor source. This method is based on the evaporation of a metal target by continuous electron-beam impact. We present visible emission spectra of highly charged tungsten ions prepared by the present injection scheme. By comparison with the conventional injection method using a high-vapor-pressure W(CO)6 compound, several advantages of the present method, i.e. suppressing charge exchange reactions in the trap region and quick recovery of the vacuum condition after stopping the injection, are found. The present injection method also facilitates the measurement of emission spectra of highly charged niobium ions, which have never previously been observed using electron-beam ion traps.","PeriodicalId":16826,"journal":{"name":"Journal of Physics B: Atomic, Molecular and Optical Physics","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47304560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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