"Enhanced Multiphoton Effects in Laser-Assisted Electron-Atom Collisions" by Alexander Flegel (The University of Nebraska-Lincoln)

Date: 
Tuesday, March 19, 2013 - 2:00pm to 3:30pm
Series: 
Plasma Seminars

Plasma Physics / Electrical Engineering Seminar
Tuesday, March 19 @ 2:00PM
Physics & Astronomy Building (PAB) Room 4-330

"Enhanced Multiphoton Effects in Laser-Assisted Electron-Atom Collisions"

Alexander Flegel (The University of Nebraska-Lincoln)

Abstract:

Laser-assisted electron-atom collisions are among the most fundamental processes in laser field interactions with matter. They involve the interaction of an initially free (i.e., continuum) electron with an atomic target in the presence of a laser field. In this seminar I will discuss laser-assisted electron scattering (LAES) on an atomic target accompanied by the exchange of a number of laser photons, thus increasing or decreasing the electron's kinetic energy. Among the most spectacular non-linear phenomena in laser-atom physics are the broad, plateau-like structures in the spectra of strong field processes, i.e., the dependence of the outcome of a strong field process on the number of photons exchanged. These features are well known in multiphoton laser-induced processes such as high harmonic generation and above threshold ionization. I will discuss predicted results for plateau structures in laser-assisted electron-atom collisions. I will address the physical origins of this phenomena, the dependence on the parameters of driving laser field, and manifestations of field-free electron-atom dynamics in LAES spectra. Based on an analysis of theoretical and experimental LAES results obtained to date, I also summarize the experimental criteria that must be met in order to observe the new LAES predictions I will discuss.