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Full-Text Articles in Physics

Real-Time Optical Holography Using A Spatial Light Modulator, Ting-Chung Poon, Bradley Duncan, Ming Hsien Wu, K. Shinoda, Y. Suzuki Nov 2015

Real-Time Optical Holography Using A Spatial Light Modulator, Ting-Chung Poon, Bradley Duncan, Ming Hsien Wu, K. Shinoda, Y. Suzuki

Bradley D. Duncan

Paper proposes a real-time technique for recording and reconstructing optical holograms. Holographic recording is accomplished by scanning an object with two superposed light beams of different temporal frequencies. For reconstruction, the scanned information is transferred to an electron beam addressed spatial light modulator for coherent processing and optically read out to reconstruct an image of the scanned object.


Measurement Of Charging And Discharging Of High Resistivity Materials Spacecraft Materials By Electron Beams, Ryan Hoffmann, Joshua L. Hodges, Jesse Hayes, Jr Dennison Jan 2009

Measurement Of Charging And Discharging Of High Resistivity Materials Spacecraft Materials By Electron Beams, Ryan Hoffmann, Joshua L. Hodges, Jesse Hayes, Jr Dennison

Conference Proceedings

New instrumentation has been developed for in situ measurements of the electron beam- induced surface voltage of high resistivity spacecraft materials in an existing ultra-high vacuum electron emission analysis chamber. Design details, calibration and characterization measurements of the system are presented, showing sensitivity to a range of surface voltages from12000 V, with resolution surface, using a paddle attached to a vacuum compatible stepper motor mounted within a hemispherical grid retarding field analyzer. These electrodes formed one end of a floating charge transfer probe that enabled measurements to be made by a standard electrostatic field probe external to the vacuum chamber. …


Zeeman Splitting And G Factor Of The 1s²2s²2p ²P3/2 And ²P1/2 Levels In Ar¹³⁺, R. Soria Orts, Jose R. Crespo Lopez-Urrutia, Hjalmar Bruhns, Antonio J. Gonzalez, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka Nov 2007

Zeeman Splitting And G Factor Of The 1s²2s²2p ²P3/2 And ²P1/2 Levels In Ar¹³⁺, R. Soria Orts, Jose R. Crespo Lopez-Urrutia, Hjalmar Bruhns, Antonio J. Gonzalez, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, Alain Lapierre, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka

Physics Faculty Research & Creative Works

The Zeeman line components of the magnetic-dipole (M1) 1s2 2s2 2 P1/2 -2P3/2 transition in boronlike Ar13+ were experimentally resolved by high-precision emission spectroscopy using the Heidelberg electron beam ion trap. We determined the gyromagnetic (g) factors of the ground and first-excited levels to be g1/2 =0.663(7) and g3/2 =1.333(2), respectively. This corresponds to a measurement of the g factor of a relativistic electron in a bound non- S state of a multielectron ion with a 1.5 parts-per-thousand accuracy. The results are compared to theoretical calculations by means of the configuration …


Photon Angular Distribution And Nuclear-State Alignment In Nuclear Excitation By Electron Capture, Adriana Palffy, Zoltan Harman, Andrey S. Surzhykov, Ulrich D. Jentschura Jan 2007

Photon Angular Distribution And Nuclear-State Alignment In Nuclear Excitation By Electron Capture, Adriana Palffy, Zoltan Harman, Andrey S. Surzhykov, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

The alignment of nuclear states resonantly formed in nuclear excitation by electron capture (NEEC) is studied by means of a density matrix technique. The vibrational excitations of the nucleus are described by a collective model and the electrons are treated in a relativistic framework. Formulas for the angular distribution of photons emitted in the nuclear relaxation are derived. We present numerical results for alignment parameters and photon angular distributions for a number of heavy elements in the case of E2 nuclear transitions. Our results are intended to help future experimental attempts to discern NEEC from radiative recombination, which is the …


Evaluation Of Laser-Assisted Bremsstrahlung With Dirac-Volkov Propagators, Erik Lotstedt, Ulrich D. Jentschura, Christoph H. Keitel Jan 2007

Evaluation Of Laser-Assisted Bremsstrahlung With Dirac-Volkov Propagators, Erik Lotstedt, Ulrich D. Jentschura, Christoph H. Keitel

Physics Faculty Research & Creative Works

We study spontaneous bremsstrahlung emission in a highly intense laser field. In this regime the interaction with the laser field has to be treated nonperturbatively by using the relativistic formalism including Dirac-Volkov propagators, while the interaction with the Coulomb field and the bremsstrahlung radiation can be treated in first-order perturbation theory. For the intermediate electron state a fully laser-dressed propagator is used, including radiative corrections to avoid singularities on the mass shell. We find that the use of the Dirac-Volkov propagator is crucial to obtain correct numerical results. The cross section of the process is evaluated for laser intensities of …


Differential Electron Emission For Single And Multiple Ionization Of Argon By 500 Ev Positrons, Jared M. Gavin, Robert D. Dubois, O. G. De Lucio Dec 2006

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 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 …


Benchmarking High-Field Few-Electron Correlation And Qed Contributions In Hg⁷⁵⁺ To Hg⁷⁸⁺ Ions. I. Experiment, Antonio J. Gonzalez, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Alain Lapierre, Vladimir Sergeyevich Mironov, R. Soria Orts, Hiroyuki Tawara, Michael Trinczek, Joachim Hermann Ullrich, Anton N. Artemyev, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, James H. Scofield, I. I. Tupitsyn May 2006

Benchmarking High-Field Few-Electron Correlation And Qed Contributions In Hg⁷⁵⁺ To Hg⁷⁸⁺ Ions. I. Experiment, Antonio J. Gonzalez, Jose R. Crespo Lopez-Urrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Alain Lapierre, Vladimir Sergeyevich Mironov, R. Soria Orts, Hiroyuki Tawara, Michael Trinczek, Joachim Hermann Ullrich, Anton N. Artemyev, Zoltan Harman, Ulrich D. Jentschura, Christoph H. Keitel, James H. Scofield, I. I. Tupitsyn

Physics Faculty Research & Creative Works

The photorecombination of highly charged few-electron mercury ions Hg75+ to Hg78+ has been explored with the Heidelberg electron beam ion trap. By monitoring the emitted x rays (65-76 keV) and scanning the electron beam energy (45-54 keV) over the KLL dielectronic recombination (DR) region, the energies of state-selected DR resonances were determined to within ±4 eV (relative) and ±14 eV (absolute). At this level of experimental accuracy, it becomes possible to make a detailed comparison to various theoretical approaches and methods, all of which include quantum electrodynamic (QED) effects and finite nuclear size contributions (for a 1s electron, …