发布求助
文献互助 智能选刊 最新文献

Australian Journal of Physics最新文献

筛选
英文 中文
Calculating trajectories for atoms in near-resonant lightfields 计算近共振光场中原子的轨迹
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH99014
R. Scholten, T. O’Kane, Tracy R. Mackin, T. Hunt, P. Farrell
{"title":"Calculating trajectories for atoms in near-resonant lightfields","authors":"R. Scholten, T. O’Kane, Tracy R. Mackin, T. Hunt, P. Farrell","doi":"10.1071/PH99014","DOIUrl":"https://doi.org/10.1071/PH99014","url":null,"abstract":"We review several methods for calculating the time development of the internal state and the external motion of atoms in near-resonant light fields, with emphasis on studying the focussing of atomic beams into microscopic and potentially nanoscopic patterns. Three different approaches are considered: two-level semiclassical, multi-level semiclassical, and the Monte Carlo wavefunction method. The two-level semiclassical technique of McClelland and Scheinfein (1991) and McClelland (1995) is extended to three dimensions, and used to calculate the trajectories of atoms and the imaging properties of a simple lens formed from a near-resonant travelling TEM01 mode laser. The model is then extended to multi-level atoms, where we calculate the density matrix for the internal state of a sample of thermal atoms in a standing wave, and show how cooling processes can be simulated. Finally, we use the Monte Carlo wavefunction method to calculate the internal state of the atom, and compare the results and required computation time to those of the multi-level semiclassical technique.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123340434","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: 5
Coherence and correlation in electron scattering from the alkalis 碱基电子散射的相干性和相关性
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH98081
P. Teubner, V. Karaganov, K. Stockman
{"title":"Coherence and correlation in electron scattering from the alkalis","authors":"P. Teubner, V. Karaganov, K. Stockman","doi":"10.1071/PH98081","DOIUrl":"https://doi.org/10.1071/PH98081","url":null,"abstract":"A series of superelastic electron scattering experiments from lithium and from potassium is described in which the total polarisation parameter P+ is measured. We report significant departures from the coherence condition P+ = 1 for both targets. The structure observed in the parameter P+ can be interpreted by a qualitative wave mechanical model that had been introduced by our research group to explain similar structure in superelastic electron scattering experiments from sodium.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129985969","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
Paul trap promotion of electrons in atomic collisions 保罗阱在原子碰撞中促进电子
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH98082
G. Oppen, M. Tschersich, R. Drozdowski, M. Busch
{"title":"Paul trap promotion of electrons in atomic collisions","authors":"G. Oppen, M. Tschersich, R. Drozdowski, M. Busch","doi":"10.1071/PH98082","DOIUrl":"https://doi.org/10.1071/PH98082","url":null,"abstract":"Electron promotion on rotating potential saddles is proposed as an important and efficient excitation mechanism taking place in atomic collisions at intermediate energies. Measurements on the excitation of atoms by positively charged particles, in particular, excitation of He I states in p–He collisions provides experimental evidence for this ‘Paul trap’ promotion in two-centre Coulomb potentials.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114911568","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: 8
Angular distribution of hydrogen fragment ions in H + -H 2 collisions H + - h2碰撞中氢碎片离子的角分布
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH99021
B. Siegmann, R. Hippler
{"title":"Angular distribution of hydrogen fragment ions in H + -H 2 collisions","authors":"B. Siegmann, R. Hippler","doi":"10.1071/PH99021","DOIUrl":"https://doi.org/10.1071/PH99021","url":null,"abstract":"The angular distribution of H+ fragment ions produced in 5–25 keV H+–H2 collisions was investigated in coincidence with Lyman-α photons. The observed photons arise from electron capture to the projectile H(2p) state and/or from the fragmentation of the H2 molecule via 2sσg, 2pσu or 2pΠ u states of the excited H+2* ion. An analysis of the measured angular distributions has been performed to distinguish the separate degenerate channels available to an emitted Lyman-α photon. The results show similarities to the data of Lindsay et al. (1987) who measured the non-coincident angular distribution of H+ fragment ions within the same energy range.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128270445","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
Correlations in electron-atom collisions involving polarised electrons and photons 涉及极化电子和光子的电子-原子碰撞的相关性
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH98087
G. Hanne
{"title":"Correlations in electron-atom collisions involving polarised electrons and photons","authors":"G. Hanne","doi":"10.1071/PH98087","DOIUrl":"https://doi.org/10.1071/PH98087","url":null,"abstract":"More sophisticated experimental methods to study inelastic electron–atom collisions include polarisation-correlation measurements such as electron–photon (e, eγ) and electron–electron (e, 2e) coincidence studies or stepwise electron–photon (eγ, γ) correlations. Electron correlations and spin effects can be explored on the most fundamental level in such experiments. In this paper recent (e, eγ) studies with Hg and Xe, (eγ, γ) studies with Ne and (e, 2e) studies with Xe using polarised electrons and/or polarised photons are reviewed.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116922545","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
Transfer of angular momentum in electron collisions with alkali atoms 电子与碱原子碰撞时角动量的转移
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH98097
B. Hall, M. Shurgalin, A. Murray, W. Macgillivray, M. Standage
{"title":"Transfer of angular momentum in electron collisions with alkali atoms","authors":"B. Hall, M. Shurgalin, A. Murray, W. Macgillivray, M. Standage","doi":"10.1071/PH98097","DOIUrl":"https://doi.org/10.1071/PH98097","url":null,"abstract":"Measurements of the transfer of angular momentum to rubidium and sodium atoms in collisions with electrons are reported. For excitation of the rubidium 52S1/2–52 P3/2 transition, it is found that existing first order distorted wave Born approximation calculations show poor agreement with the data and that a model which includes the relativistic interaction between the electrons and the atoms in the potential is needed. For the de-excitation of the sodium 42S1/2 –32 P3/2 transition, a long standing proposal relating to the sign of the transferred angular momentum is not supported except at small scattering angles. A convergent close coupling calculation displays excellent agreement with the measured data.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"247 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123027389","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: 4
The dynamics of two-electron atoms 双电子原子的动力学
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH98114
J. Briggs
{"title":"The dynamics of two-electron atoms","authors":"J. Briggs","doi":"10.1071/PH98114","DOIUrl":"https://doi.org/10.1071/PH98114","url":null,"abstract":"Since the first attempts to calculate the helium ground state in the early days of Bohr–Sommerfeld quantisation, two-electron atoms have posed a series of challenges to theoretical physics. Despite the seemingly simple problem of three charged particles with known interactions it took more than half a century after quantum mechanics was established to describe spectra of two-electron atoms satisfactorily. The evolution of the understanding of correlated two-electron dynamics and its importance for doubly excited resonance states is described in this overview.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"226 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127684551","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: 4
Electron recapture near thresholds 接近阈值的电子重获
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH98090
D. Waterhouse, J. F. Williams
{"title":"Electron recapture near thresholds","authors":"D. Waterhouse, J. F. Williams","doi":"10.1071/PH98090","DOIUrl":"https://doi.org/10.1071/PH98090","url":null,"abstract":"Electron recapture following photon or electron-impact ionisation near thresholds attracts considerable interest. A comparison is made of the information gained from studies utilising different methods of observation including ion yields, (e, 2e) coincidence, and photo-electron spectroscopy, to increase understanding of the electron recapture process.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130273777","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
Cold target helum recoil ion momentum imaging: understanding correlated electron motion in the double ionisation process 冷靶氦反冲离子动量成像:理解双电离过程中的相关电子运动
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH99020
H. Schmidt-Böcking, V. Mergel, R. Dörner, H. Bräuning, M. Achler, L. Spielberger, O. Jagutzki, T. Weber, Kh. Khayyat, J. Ulrich, C. Cocke, M. Prior, Y. Azuma, Y. Awaya, T. Kambara
{"title":"Cold target helum recoil ion momentum imaging: understanding correlated electron motion in the double ionisation process","authors":"H. Schmidt-Böcking, V. Mergel, R. Dörner, H. Bräuning, M. Achler, L. Spielberger, O. Jagutzki, T. Weber, Kh. Khayyat, J. Ulrich, C. Cocke, M. Prior, Y. Azuma, Y. Awaya, T. Kambara","doi":"10.1071/PH99020","DOIUrl":"https://doi.org/10.1071/PH99020","url":null,"abstract":"Novel imaging techniques enable a highly efficient detection of ions and electrons from ionising multi-fragmentation processes of atoms and molecules induced by photons and charged particles. From position and time-of-flight measurements the vector momenta of these fragments are determined. These devices combine 4Π solid angle with high resolution in momentum space. They deliver multi-dimensional images of the multi-particle break-up processes. These fully differential cross sections unveil the physical processes dominating the reaction. We discuss double ionisation of He induced by photons and fast protons, which is one of the most fundamental two-electron systems. New results are presented. In a speculative manner the future perspectives with respect to the investigation of dynamical electron– electron correlation are discussed.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"664 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133322415","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
Excitation of heavy metal clusters by strong fs laser pulses 强激光脉冲对重金属团簇的激发
Australian Journal of Physics Pub Date : 1999-06-01 DOI: 10.1071/PH99046
S. Teuber, T. Döppner, M. Schumacher, J. Tiggesbäumker, K. H. Meiswes-Broer
{"title":"Excitation of heavy metal clusters by strong fs laser pulses","authors":"S. Teuber, T. Döppner, M. Schumacher, J. Tiggesbäumker, K. H. Meiswes-Broer","doi":"10.1071/PH99046","DOIUrl":"https://doi.org/10.1071/PH99046","url":null,"abstract":"The excitation of neutral platinum and lead clusters by intense femtosecond laser pulses is studied by time-of-flight spectroscopy. Clusters are completely destroyed when interacting in the high intensity region of the laser focus. Moreover, highly charged atomic ions with up to 20 charges are detected under special pulse conditions. The atomic ion distribution shows a pronounced dependence on the chosen pulse width, suggesting that multi-plasmon excitations are responsible for the high charge states measured. The Coulomb explosion of a metal sphere is simulated under tunneling ionisation conditions. The calculated optical response of such a cluster within the framework of the random phase approximation agrees well with the experimental observations.","PeriodicalId":170873,"journal":{"name":"Australian Journal of Physics","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134207865","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
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信