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Full-Text Articles in Physical Sciences and Mathematics

All-Optical Atom Trap As A Target For Motrims-Like Collision Experiments, S. Sharma, B. P. Acharya, Daniel Fischer, For Full List Of Authors, See Publisher's Website. Apr 2018

All-Optical Atom Trap As A Target For Motrims-Like Collision Experiments, S. Sharma, B. P. Acharya, Daniel Fischer, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Momentum-resolved scattering experiments with laser-cooled atomic targets have been performed since almost two decades with magneto-optical trap recoil ion momentum spectroscopy (MOTRIMS) setups. Compared to experiments with gas-jet targets, MOTRIMS features significantly lower target temperatures allowing for an excellent recoil ion momentum resolution. However, the coincident and momentum-resolved detection of electrons was long rendered impossible due to incompatible magnetic field requirements. Here we report on an experimental approach which is based on an all-optical 6Liatom trap that--in contrast to magneto-optical traps--does not require magnetic field gradients in the trapping region. Atom temperatures of about 2 mK and number densities ...


The Role Of Multiple Electron Capture In The X-Ray Emission Process Following Charge Exchange Collisions With Neutral Targets, Sebastian Otranto, N. D. Cariatore, Ronald E. Olson Jan 2015

The Role Of Multiple Electron Capture In The X-Ray Emission Process Following Charge Exchange Collisions With Neutral Targets, Sebastian Otranto, N. D. Cariatore, Ronald E. Olson

Physics Faculty Research & Creative Works

In this work we theoretically study photonic spectra that follow charge exchange processes between highly charged ions and neutral argon and CO targets. The range of collision energies studied is 5 eV/amu-10 keV/amu, covering typical EBIT-traps and Solar Wind energies. Our studies are based on multiple electrons schemes within the classical trajectory Monte Carlo method. Electrons are sorted with the sequential binding energies for the target under consideration. The role played by the multiple electron capture process for the different collision systems under consideration is explicitly analyzed and its contribution separated as arising from double radiative decay and ...


X-Ray Emission Produced In Charge-Exchange Collisions Between Highly Charged Ions And Argon: Role Of The Multiple Electron Capture, Sebastian Otranto, N. D. Cariatore, Ronald E. Olson Dec 2014

X-Ray Emission Produced In Charge-Exchange Collisions Between Highly Charged Ions And Argon: Role Of The Multiple Electron Capture, Sebastian Otranto, N. D. Cariatore, Ronald E. Olson

Physics Faculty Research & Creative Works

In this work we use the classical trajectory Monte Carlo method within an eight-electron scheme to theoretically study photonic spectra that follow charge-exchange processes between highly charged ions of charge states 10+, 17+, 18+, and 36+ with neutral argon. The energy range considered is 18 eV/amu to 4 keV/amu, covering typical electron beam ion traps and solar wind energies. The role played by multiple electron capture processes for the different collision systems under consideration is explicitly analyzed and its contribution separated as arising from radiative decay and autoionizing multiple capture. For the present collision systems we find that ...


Laser-Induced Electron Diffraction For Probing Rare Gas Atoms, Junliang Xu, Cosmin I. Blaga, Anthony D. Dichiara, Emily Sistrunk, Kaikai Zhang, Zhangjin Chen, Anh-Thu Le, Toru Morishita, C. D. Lin, Pierre Agostini, Louis F. Dimauro Dec 2012

Laser-Induced Electron Diffraction For Probing Rare Gas Atoms, Junliang Xu, Cosmin I. Blaga, Anthony D. Dichiara, Emily Sistrunk, Kaikai Zhang, Zhangjin Chen, Anh-Thu Le, Toru Morishita, C. D. Lin, Pierre Agostini, Louis F. Dimauro

Physics Faculty Research & Creative Works

Recently, using midinfrared laser-induced electron diffraction (LIED), snapshots of a vibrating diatomic molecule on a femtosecond time scale have been captured [C.I. Blaga et al., Nature (London) 483, 194 (2012)]. In this Letter, a comprehensive treatment for the atomic LIED response is reported, a critical step in generalizing this imaging method. Electron-ion differential cross sections (DCSs) of rare gas atoms are extracted from measured angular-resolved, high-energy electron momentum distributions generated by intense midinfrared lasers. Following strong-field ionization, the high-energy electrons result from elastic rescattering of a field-driven wave packet with the parent ion. For recollision energies [greater or equal ...


Ion-Lithium Collision Dynamics Studied With A Laser-Cooled In-Ring Target, Daniel Fischer, Dominik Globig, Johannes Goullon, Manfred Grieser, Renate Hubele, Vitor L B D De Jesus, Aditya H. Kelkar, Aaron C. Laforge, H. Lindenblatt, Deepankar S. Misra, B. Najjari, Katharina R. Schneider, Michael Schulz, Martin Sell, Xincheng Wang Sep 2012

Ion-Lithium Collision Dynamics Studied With A Laser-Cooled In-Ring Target, Daniel Fischer, Dominik Globig, Johannes Goullon, Manfred Grieser, Renate Hubele, Vitor L B D De Jesus, Aditya H. Kelkar, Aaron C. Laforge, H. Lindenblatt, Deepankar S. Misra, B. Najjari, Katharina R. Schneider, Michael Schulz, Martin Sell, Xincheng Wang

Physics Faculty Research & Creative Works

We present a novel experimental tool allowing for kinematically complete studies of break-up processes of laser-cooled atoms. This apparatus, the 'MOTReMi,' is a combination of a magneto-optical trap (MOT) and a reaction microscope (ReMi). Operated in an ion-storage ring, the new setup enables us to study the dynamics in swift ion-atom collisions on an unprecedented level of precision and detail. In the inaugural experiment on collisions with 1.5MeV/amu O8 +-Li the pure ionization of the valence electron as well as the ionization-excitation of the lithium target was investigated.


Strong-Field Nonsequential Double Ionization Of Ar And Ne, Zhangjin Chen, Yaqiu Liang, Don H. Madison, Chiidong Lin Aug 2011

Strong-Field Nonsequential Double Ionization Of Ar And Ne, Zhangjin Chen, Yaqiu Liang, Don H. Madison, Chiidong Lin

Physics Faculty Research & Creative Works

We investigate the nonsequential double ionization (NSDI) of Ar and Ne based on quantitative rescattering theory (QRS). According to QRS theory, each elementary NSDI process can be calculated by multiplying the returning electron wave packet with appropriate differential electron-ion scattering cross sections. We include (e, 2e) and electron-impact excitation cross sections of Ar+ to obtain the correlated electron momentum spectra for the NSDI of Ar by few-cycle pulses to check the dependence of NSDI on the carrier-envelope phase. The results are compared to the ion momentum spectra from the recent experiment of Johnson [Phys. Rev. APLRAAN1050-294710.1103/ PhysRevA.83.013412 ...


Fundamental Constants And Tests Of Theory In Rydberg States Of Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr, Joseph Tan, Benedikt J. Wundt Apr 2008

Fundamental Constants And Tests Of Theory In Rydberg States Of Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr, Joseph Tan, Benedikt J. Wundt

Physics Faculty Research & Creative Works

A comparison of precision frequency measurements to quantum electrodynamics (QED) predictions for Rydberg states of hydrogenlike ions can yield information on values of fundamental constants and test theory. With the results of a calculation of a key QED contribution reported here, the uncertainty in the theory of the energy levels is reduced to a level where such a comparison can yield an improved value of the Rydberg constant.


Exploring Relativistic Many-Body Recoil Effects In Highly Charged Ions, R. Soria Orts, Zoltan Harman, Jose R. Crespo Lopez-Urrutia, Anton N. Artemyev, Hjalmar Bruhns, Antonio J. Gonzalez, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Vladimir Sergeyevich Mironov, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka Sep 2006

Exploring Relativistic Many-Body Recoil Effects In Highly Charged Ions, R. Soria Orts, Zoltan Harman, Jose R. Crespo Lopez-Urrutia, Anton N. Artemyev, Hjalmar Bruhns, Antonio J. Gonzalez, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Vladimir Sergeyevich Mironov, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka

Physics Faculty Research & Creative Works

The relativistic recoil effect has been the object of experimental investigations using highly charged ions at the Heidelberg electron beam ion trap. Its scaling with the nuclear charge Z boosts its contribution to a measurable level in the magnetic-dipole (M1) transitions of B- and Be-like Ar ions. The isotope shifts of 36Ar versus 40Ar have been detected with sub-ppm accuracy, and the recoil effect contribution was extracted from the 1s22s22p 2P1/2-2P3/2 transition in Ar13+ and the 1s22s2p 3P1-3P2 transition ...


Mutual Ionization In 200-Kev H⁻+ He Collisions, T. Ferger, Daniel Fischer, Michael Schulz, R. Moshammer, A. B. Voitkiv, B. Najjari, J. Ullrich Dec 2005

Mutual Ionization In 200-Kev H⁻+ He Collisions, T. Ferger, Daniel Fischer, Michael Schulz, R. Moshammer, A. B. Voitkiv, B. Najjari, J. Ullrich

Physics Faculty Research & Creative Works

We studied mutual ionization in 200-keV H-+He collisions in a kinematically complete experiment by measuring the fully momentum-analyzed recoil ions and both active electrons in coincidence. Comparison of the data to our calculations, based on various theoretical models, show that mutual ionization proceeds predominantly through the interaction between both electrons. The post-collision interaction between the outgoing ejected electrons as well as higher order processes involving the interaction between the core of both collision partners are also important.


Autoionization Of He Atoms By Partially Stripped Ion Impact, Sebastian Otranto, Ronald E. Olson Aug 2005

Autoionization Of He Atoms By Partially Stripped Ion Impact, Sebastian Otranto, Ronald E. Olson

Physics Faculty Research & Creative Works

A study of the autoionization process induced by partially stripped ion impact is performed. Electron spectra in momentum space are predicted within a classical model for partially stripped ions. The results are compared with those obtained for pure Coulomb-like projectiles. A quantum-mechanical extension of the Barrachina-Macek model is proposed for partially stripped projectiles. Structure on the electron angular distribution arising in quantum and classical treatments is identified and compared. The presence of rainbow scattering interference is observed in the binary ring profile of the outgoing autoionized electrons for positive-ion impact.


Complete Two-Loop Correction To The Bound-Electron Factor, Krzysztof Pachucki, Andrzej Czarnecki, Ulrich D. Jentschura, Vladimir A. Yerokhin Aug 2005

Complete Two-Loop Correction To The Bound-Electron Factor, Krzysztof Pachucki, Andrzej Czarnecki, Ulrich D. Jentschura, Vladimir A. Yerokhin

Physics Faculty Research & Creative Works

Within a systematic approach based on dimensionally regularized nonrelativistic quantum electrodynamics, we derive a complete result for the two-loop correction to order ( α/ π )2 ( Zα )4 for the g factor of an electron bound in an nS state of a hydrogenlike ion. The results obtained significantly improve the accuracy of the theoretical predictions for the hydrogenlike carbon and oxygen ions and influence the value of the electron mass inferred from g-factor measurements. D


Electron Loss From 1.4-Mev / U U4,6,10+ Ions Colliding With Ne, N₂, And Ar Targets, Robert D. Dubois, Antonio C. Santos, Th. Stohlker, F. Bosch, A. Brauning-Demian, A. Gumberidze, S. Hagmann, C. Kozhuharov, R. Mann, A. Orsic Muthig, U. Spillman, S. Tachenov, W. Bart, L. Dahl, B. Franzke, J. Glatz, L. Groning, S. Richter, D. Wilms, K. Ullmann, O. Jagutzki Sep 2004

Electron Loss From 1.4-Mev / U U4,6,10+ Ions Colliding With Ne, N₂, And Ar Targets, Robert D. Dubois, Antonio C. Santos, Th. Stohlker, F. Bosch, A. Brauning-Demian, A. Gumberidze, S. Hagmann, C. Kozhuharov, R. Mann, A. Orsic Muthig, U. Spillman, S. Tachenov, W. Bart, L. Dahl, B. Franzke, J. Glatz, L. Groning, S. Richter, D. Wilms, K. Ullmann, O. Jagutzki

Physics Faculty Research & Creative Works

Absolute, total, single- and multiple-electron-loss cross sections are measured for 1.4-MeV / u U4,6,10+ ions colliding with neon and argon atoms and nitrogen molecules. It is found that the cross sections all have the same dependence on the number of electrons lost and that multiplying the cross sections by the initial number of electrons in the 6s, 6p, and 5f shells yields good agreement between the different projectiles. By combining the present data with previous measurements made at the same velocity, it is shown that the scaled cross sections slowly decrease in magnitude for ...


Doubly Differential Electron-Emission Spectra In Single And Multiple Ionization Of Noble-Gas Atoms By Fast Highly-Charged-Ion Impact, Tom Kirchner, Laszlo Gulyas, Robert Moshammer, Michael Schulz, Joachim Hermann Ullrich Apr 2002

Doubly Differential Electron-Emission Spectra In Single And Multiple Ionization Of Noble-Gas Atoms By Fast Highly-Charged-Ion Impact, Tom Kirchner, Laszlo Gulyas, Robert Moshammer, Michael Schulz, Joachim Hermann Ullrich

Physics Faculty Research & Creative Works

Low-energy electron emission spectra are studied in collisions of 3.6 MeV/amu Au53+ ions with neon and argon atoms for well-defined degrees of target ionization. We calculate doubly differential cross sections as functions of the recoil-ion charge state in the continuum-distorted-wave with eikonal initial-state approximation using a binomial analysis of the total and differential ionization probabilities, and compare them with the present and with previously published experimental data. Very good agreement is found for the single-ionization spectra and for double ionization of neon, while some discrepancies are observed in the spectra for double and triple ionization of argon.


Electron Self-Energy For The K And L Shells At Low Nuclear Charge, Ulrich D. Jentschura, Peter J. Mohr, Gerhard Soff Apr 2001

Electron Self-Energy For The K And L Shells At Low Nuclear Charge, Ulrich D. Jentschura, Peter J. Mohr, Gerhard Soff

Physics Faculty Research & Creative Works

A nonperturbative numerical evaluation of the one-photon electron self-energy for the K- and L-shell states of hydrogenlike ions with nuclear charge numbers Z =1 to 5 is described. Our calculation for the 1S1/2 state has a numerical uncertainty of 0.8 Hz in atomic hydrogen, and for the L-shell states (2S1/2 , 2P1/2 , and 2P3/2) the numerical uncertainty is 1.0 Hz. The method of evaluation for the ground state and for the excited states is described in detail. The numerical results are compared to results based on known terms in the expansion ...


Short-Pulse Laser-Induced Stabilization Of Autoionizing States, Heider N. Ereifej, J. Greg Story Sep 2000

Short-Pulse Laser-Induced Stabilization Of Autoionizing States, Heider N. Ereifej, J. Greg Story

Physics Faculty Research & Creative Works

Atoms in doubly excited states above the first ionization limit can decay via autoionization in which an electron is emitted leaving an ion, or by photoemission which leaves the atom in a singly excited state. In this paper, it is demonstrated that interaction between the atoms and a laser pulse that is short compared to the autoionization lifetime can lead to large enhancement of the photoemission process by stimulating the atoms to emit a photon. Since the resultant singly excited atoms do not autoionize, this process can be viewed as an enhancement of the stabilization of the doubly excited atoms ...