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Full-Text Articles in Physics
Illuminating The Kapitza-Dirac Effect With Electron Matter Optics [Colloquium], Herman Batelaan
Illuminating The Kapitza-Dirac Effect With Electron Matter Optics [Colloquium], Herman Batelaan
Department of Physics and Astronomy: Faculty Publications
The observation of the Kapitza-Dirac effect raises conceptual, theoretical, and experimental questions. The Kapitza-Dirac effect is often described as diffraction of free electrons from a standing wave of light or stimulated Compton scattering. However, for the two-color Kapitza-Dirac effect these two interpretations appear to lead to paradoxical conclusions. The discussion of this paradox deepens our understanding of both of these versions of the Kapitza-Dirac effect.
Laser-Induced Ultrafast Electron Emission From A Field Emission Tip, Brett E. Barwick, C. Corder, James Strohaber, Nathan A. Chandler-Smith, Cornelis J. Uiterwaal, Herman Batelaan
Laser-Induced Ultrafast Electron Emission From A Field Emission Tip, Brett E. Barwick, C. Corder, James Strohaber, Nathan A. Chandler-Smith, Cornelis J. Uiterwaal, Herman Batelaan
Department of Physics and Astronomy: Faculty Publications
We show that a field emission tip electron source that is triggered with a femtosecond laser pulse can generate electron pulses shorter than the laser pulse duration (100&#; fs). The emission process is sensitive to a power law of the laser intensity, which supports an emission mechanism based on multiphoton absorption followed by over-the-barrier emission. Observed continuous transitions between power laws of different orders are indicative of field emission processes. We show that the source can also be operated so that thermionic emission processes become significant. Understanding these different emission processes is relevant for the production of sub-cycle electron pulses.
Low-Energy Electron Collisions With Ch3Br: The Dependence Of Elastic Scattering, Vibrational Excitation, And Dissociative Attachment On The Initial Vibrational Energy, M. Braun, Ilya I. Fabrikant, M-W. Ruf, H. Hotop
Low-Energy Electron Collisions With Ch3Br: The Dependence Of Elastic Scattering, Vibrational Excitation, And Dissociative Attachment On The Initial Vibrational Energy, M. Braun, Ilya I. Fabrikant, M-W. Ruf, H. Hotop
Department of Physics and Astronomy: Faculty Publications
Using the laser photoelectron attachment (LPA) method at an energy width of 1–2 meV, the Br- yield due to dissociative electron attachment to the molecule CH3Br has been measured over the energy range 1–180 meV at a gas temperature of 600 K. The data clearly exhibit the vibrational Feshbach resonance predicted by Wilde et al. (2000 J. Phys. B: At. Mol. Opt. Phys. 33 5479) and associated with the v3 = 4 vibrational level of the C–Br stretch mode in the neutral molecule. We also report the dependence of the rate coefficient for Rydberg electron attachment …
A Macroscopic Test Of The Aharonov-Bohm Effect, Adam Caprez, Brett E. Barwick, Herman Batelaan
A Macroscopic Test Of The Aharonov-Bohm Effect, Adam Caprez, Brett E. Barwick, Herman Batelaan
Department of Physics and Astronomy: Faculty Publications
The Aharonov-Bohm (AB) effect is a purely quantum mechanical effect. The original (classified as Type-I) AB-phase shift exists in experimental conditions where the electromagnetic fields and forces are zero. It is the absence of forces that makes the ABeffect entirely quantum mechanical. Although the AB-phase shift has been demonstrated unambiguously, the absence of forces in Type-I AB-effects has never been shown. Here, we report the observation of the absence of time delays associated with forces of the magnitude needed to explain the AB-phase shift for a macroscopic system.
Comment On “Wave-Breaking Limits For Relativistic Electrostatic Waves In A One-Dimensional Warm Plasma” [Phys. Plasmas 13, 123102 (2006)], Carl B. Schroeder, Eric Esarey, Bradley Allan Shadwick
Comment On “Wave-Breaking Limits For Relativistic Electrostatic Waves In A One-Dimensional Warm Plasma” [Phys. Plasmas 13, 123102 (2006)], Carl B. Schroeder, Eric Esarey, Bradley Allan Shadwick
Department of Physics and Astronomy: Faculty Publications
In this Comment, several incorrect and misleading claims made by Trines and Norreys (TN) in Ref. 1 are addressed.
Acoustic Analog To Quantum Mechanical Level Splitting, Shawn A. Hilbert, Herman Batelaan
Acoustic Analog To Quantum Mechanical Level Splitting, Shawn A. Hilbert, Herman Batelaan
Department of Physics and Astronomy: Faculty Publications
A simple physical system is discussed that mirrors the quantum mechanical infinite square well with a central delta well potential. The physical realization consists of a continuous sound wave traveling in a pair of tubes separated by an adjustable diaphragm. The equivalence between the quantum system and the acoustic system is explored. The analytic solution to the quantum system exhibits level splitting as does the acoustic system.