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Blackbody-Radiation Correction To The Polarizability Of Helium, Mariusz Puchalski, Ulrich D. Jentschura, Peter J. Mohr
Blackbody-Radiation Correction To The Polarizability Of Helium, Mariusz Puchalski, Ulrich D. Jentschura, Peter J. Mohr
Physics Faculty Research & Creative Works
The correction to the polarizability of helium due to blackbody radiation is calculated near room temperature. A precise theoretical determination of the blackbody radiation correction to the polarizability of helium is essential for dielectric gas thermometry and for the determination of the Boltzmann constant. We find that the correction, for not too high temperature, is roughly proportional to a modified hyperpolarizability (two-color hyperpolarizability), which is different from the ordinary hyperpolarizability of helium. Our explicit calculations provide a definite numerical result for the effect and indicate that the effect of blackbody radiation can be excluded as a limiting factor for dielectric …
Triply Differential Single Ionization Of Argon: Charge Effects For Positron And Electron Impact, Sebastian Otranto, Ronald E. Olson, O. G. De Lucio, Robert D. Dubois
Triply Differential Single Ionization Of Argon: Charge Effects For Positron And Electron Impact, Sebastian Otranto, Ronald E. Olson, O. G. De Lucio, Robert D. Dubois
Physics Faculty Research & Creative Works
Triply differential single ionization of Ar by 200 eV positron and electron impact is measured and calculated. For an unequivocal test of kinematic differences, fully differential ejected electron angular distributions are measured using the same experimental apparatus and conditions for both positron and electron impact. The binary/recoil intensity ratios are shown to significantly differ for the two projectiles. These data are used to test theoretical calculations.
Light-Particle Single Ionization Of Argon: Influence Of The Projectile Charge Sign, Sebastian Otranto, Ronald E. Olson
Light-Particle Single Ionization Of Argon: Influence Of The Projectile Charge Sign, Sebastian Otranto, Ronald E. Olson
Physics Faculty Research & Creative Works
The ionization of the 3p orbital of argon by incident electrons and positrons is studied by means of the post version of the continuum distorted wave-eikonal initial-state model. Results are presented at both 200 and 500 eV impact energies for conditions amenable to present experiments. Differences in the fully differential cross sections (FDCSs) are analyzed and the influence of the projectile charge sign on the emission dynamics is discussed. The FDCSs are found to display the classic binary plus recoil peak structure at 500 eV, but transition to a more complicated four-lobed structure at the lower impact energy.
Accurate Retrieval Of Target Structures And Laser Parameters Of Few-Cycle Pulses From Photoelectron Momentum Spectra, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, J. Rauschenberger, M. F. Kling, C. D. Lin
Accurate Retrieval Of Target Structures And Laser Parameters Of Few-Cycle Pulses From Photoelectron Momentum Spectra, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, J. Rauschenberger, M. F. Kling, C. D. Lin
Physics Faculty Research & Creative Works
We illustrate a new method of analyzing three-dimensional momentum images of high-energy photoelectrons generated by intense phase-stabilized few-cycle laser pulses. Using photoelectron momentum spectra that were obtained by velocity-map imaging of above-threshold ionization of xenon and argon targets, we show that the absolute carrier-envelope phase, the laser peak intensity, and pulse duration can be accurately determined simultaneously (with an error of a few percent). We also show that the target structure, in the form of electron-target ion elastic differential cross sections, can be retrieved over a range of energies. The latter offers the promise of using laser-generated electron spectra for …
Quantitative Rescattering Theory For Nonsequential Double Ionization Of Atoms By Intense Laser Pulses, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, C. D. Lin
Quantitative Rescattering Theory For Nonsequential Double Ionization Of Atoms By Intense Laser Pulses, Samuel Micheau, Zhangjin Chen, Anh-Thu Le, C. D. Lin
Physics Faculty Research & Creative Works
Laser-induced electron recollisions are fundamental to many strong field phenomena in atoms and molecules. Using the recently developed quantitative rescattering theory, we demonstrate that the nonsequential double ionization (NSDI) of atoms by lasers can be obtained quantitatively in terms of inelastic collisions of the target ions with the free returning electrons where the latter are explicitly given by a spectrum-characterized wave packet. Using argon atoms as target, we calculated the NSDI yield including contributions from direct (e,2e) electron-impact ionization and electron-impact excitation accompanied by subsequent field ionization. We further investigate the dependence of total NSDI on the carrier-envelope phase of …
Triply Differential Ionization Of Ar By 500 Ev Positron And Electron Impact, O. G. De Lucio, Jared M. Gavin, Robert D. Dubois
Triply Differential Ionization Of Ar By 500 Ev Positron And Electron Impact, O. G. De Lucio, Jared M. Gavin, Robert D. Dubois
Physics Faculty Research & Creative Works
Coincidences between recoil ions-ejected electrons and recoil ions-scattered projectiles have been used to study the kinematics of electron and positron impact ionization. Triply Differential (TDCS) data for 500 eV positron and electron impact on Ar are presented here as function of scattering angle for a given range of energy losses. Binary and recoil interactions can be distinguished allowing us to determine the relative intensity between those interactions. Preliminary integration of the data indicate an enhancement of the binary region for positron interaction while for electron impact the intensity of the recoil and binary interactions is comparable.
Few-Photon Multiple Ionization Of Ne And Ar By Strong Free-Electron-Laser Pulses, Robert Moshammer, Yuhai Jiang, L. Foucar, Artem Rudenko, Th. Ergler, Claus Dieter Schroter, S. Ludemann, Karl Zrost, Daniel Fischer, J. Titze, Till Jahnke, Markus S. Schoffler, Th Weber, Reinhard Dorner, Theo J.M. Zouros, Alexander Dorn, T. Ferger, Kai Uwe Kuhnel, S. Dusterer, R. Treusch, Paul Radcliffe, Elke Plonjes, Joachim Hermann Ullrich
Few-Photon Multiple Ionization Of Ne And Ar By Strong Free-Electron-Laser Pulses, Robert Moshammer, Yuhai Jiang, L. Foucar, Artem Rudenko, Th. Ergler, Claus Dieter Schroter, S. Ludemann, Karl Zrost, Daniel Fischer, J. Titze, Till Jahnke, Markus S. Schoffler, Th Weber, Reinhard Dorner, Theo J.M. Zouros, Alexander Dorn, T. Ferger, Kai Uwe Kuhnel, S. Dusterer, R. Treusch, Paul Radcliffe, Elke Plonjes, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
Few-photon multiple ionization of Ne and Ar atoms by strong vacuum ultraviolet laser pulses from the free-electron laser at Hamburg was investigated differentially with the Heidelberg reaction microscope. The light-intensity dependence of Ne2+ production reveals the dominance of nonsequential two-photon double ionization at intensities of I< 6 x 1012W/cm2 and significant contributions of three-photon ionization as I increases. Ne2+ recoil-ion-momentum distributions suggest that two electrons absorbing "instantaneously" two photons are ejected most likely into opposite hemispheres with similar energies.
Differential Electron Emission For Single And Multiple Ionization Of Argon By 500 Ev Positrons, Jared M. Gavin, Robert D. Dubois, O. G. De Lucio
Differential Electron Emission For Single And Multiple Ionization Of Argon By 500 Ev Positrons, Jared M. Gavin, Robert D. Dubois, O. G. De Lucio
Physics Faculty Research & Creative Works
Triply differential electron emission cross sections are measured for single ionization of argon by 500 eV positrons. Data are presented for coincidences between projectiles scattered into angles of 3° and electrons with emission energies less than 10 eV that are observed between 45 and 135° along the beam direction. For interpretation, these are compared to cosine squared representations of the binary and recoil lobes which are convoluted over experimental parameters. Singly differential electron emission data for double and triple ionization by positrons are also presented.
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
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 …
Ionization Of Atoms With Spin Polarized Electrons, J. Lower, S. Bellm, R. Panajotovic, E. Weigold, A. Prideaux, Z. Stegen, Don H. Madison, Colm T. Whelan, B. Lohmann
Ionization Of Atoms With Spin Polarized Electrons, J. Lower, S. Bellm, R. Panajotovic, E. Weigold, A. Prideaux, Z. Stegen, Don H. Madison, Colm T. Whelan, B. Lohmann
Physics Faculty Research & Creative Works
The most detailed insight into the process of electron impact-induced ionization of atomic species is provided by measurements in which both kinematical and quantum mechanical variables are determined. Here we describe recent (e,2e) experimental and theoretical studies involving the ionization of xenon and argon by spin-polarized electrons in which the fine-structure levels of the ion are energetically resolved. Such investigations shed light on the mechanisms driving the ionization reaction and the role of exchange and relativistic processes.
Relativistic Electron Correlation, Quantum Electrodynamics, And The Lifetime Of The 1s²2s²2p²PO3/2 Level In Boronlike Argon, Alain Lapierre, Ulrich D. Jentschura, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Daniel A. Fischer, Antonio J. Gonzalez, Zoltan Harman, Walter Johnson, Christoph H. Keitel, Vladimir Sergeyevich Mironov, C. J. Osborne, Guenther Sikler, R. Soria Orts, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka
Relativistic Electron Correlation, Quantum Electrodynamics, And The Lifetime Of The 1s²2s²2p²PO3/2 Level In Boronlike Argon, Alain Lapierre, Ulrich D. Jentschura, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Daniel A. Fischer, Antonio J. Gonzalez, Zoltan Harman, Walter Johnson, Christoph H. Keitel, Vladimir Sergeyevich Mironov, C. J. Osborne, Guenther Sikler, R. Soria Orts, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka
Physics Faculty Research & Creative Works
The lifetime of the Ar13+ 1s22s22p2Po3/2 metastable level was determined at the Heidelberg Electron Beam Ion Trap to be 9.573(4)(5)ms(stat)(syst). The accuracy level of one per thousand makes this measurement sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM) and to relativistic electron-electron correlation effects like the frequency-dependent Breit interaction. Theoretical predictions, adjusted for the EAMM, cluster about a lifetime that is approximately 3σ shorter than our experimental result.
Separation Of Recollision Mechanisms In Nonsequential Strong Field Double Ionization Of Ar: The Role Of Excitation Tunneling, Bernold Feuerstein, Daniel Fischer, Alexander Dorn, Claus Dieter Schroter, J. Deipenwisch, Jose R. Crespo Lopez-Urrutia, C. Hohr, Paul B. Neumayer, Horst Rottke, Christoph Trump, M. Wittmann, Georg Korn, Wolfgang Sandner, Robert Moshammer, Joachim Hermann Ullrich
Separation Of Recollision Mechanisms In Nonsequential Strong Field Double Ionization Of Ar: The Role Of Excitation Tunneling, Bernold Feuerstein, Daniel Fischer, Alexander Dorn, Claus Dieter Schroter, J. Deipenwisch, Jose R. Crespo Lopez-Urrutia, C. Hohr, Paul B. Neumayer, Horst Rottke, Christoph Trump, M. Wittmann, Georg Korn, Wolfgang Sandner, Robert Moshammer, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
Vector momentum distributions of two electrons created in double ionization of Ar by 25 fs, 0.25PW/cm2 laser pulses at 795 nm have been measured using a “reaction microscope.” At this intensity, where nonsequential ionization dominates, distinct correlation patterns are observed in the two-electron momentum distributions. A kinematical analysis of these spectra within the classical “recollision model” revealed an (e,2e)-like process and excitation with subsequent tunneling of the second electron as two different ionization mechanisms. This allows a qualitative separation of the two mechanisms demonstrating that excitation-tunneling is the dominant contribution to the total double ionization yield.