Beamshape effects in nonlinear Compton and Thomson scattering
Abstract
We discuss intensity effects in collisions between beams of optical photons from a highpower laser and relativistic electrons. Our main focus is on the modifications of the emission spectra due to realistic finitebeam geometries. By carefully analyzing the classical limit we precisely quantify the distinction between strongfield QED Compton scattering and classical Thomson scattering. A purely classical, but fully covariant, calculation of the bremsstrahlung emitted by an electron in a planewave laser field yields radiation into harmonics, as expected. This result is generalized to pulses of finite duration and explains the appearance of line broadening and harmonic substructure as an interference phenomenon. The ensuing numerical treatment confirms that strong focusing of the laser leads to a broad continuum while higher harmonics become visible only at moderate focusing, and hence lower intensity. We present a scaling law for the backscattered photon spectral density which facilitates averaging over electron beam phase space. Finally, we propose a set of realistic parameters such that the observation of intensityinduced spectral red shift, higher harmonics, and their substructure becomes feasible.
 Authors:

 School of Computing and Mathematics, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)
 Forschungszentrum Dresden Rossendorf, Post Office Box 51 01 19, D01314 Dresden (Germany)
 Publication Date:
 OSTI Identifier:
 21408195
 Resource Type:
 Journal Article
 Journal Name:
 Physical Review. A
 Additional Journal Information:
 Journal Volume: 81; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.81.022125; (c) 2010 The American Physical Society; Journal ID: ISSN 10502947
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BREMSSTRAHLUNG; COMPTON EFFECT; ELECTRON BEAMS; EMISSION SPECTRA; FOCUSING; GEOMETRY; HARMONICS; LASER RADIATION; LASERS; LINE BROADENING; NONLINEAR PROBLEMS; PHASE SPACE; QUANTUM ELECTRODYNAMICS; RED SHIFT; RELATIVISTIC RANGE; SCALING LAWS; SPECTRAL DENSITY; THOMSON SCATTERING; BASIC INTERACTIONS; BEAMS; ELASTIC SCATTERING; ELECTRODYNAMICS; ELECTROMAGNETIC INTERACTIONS; ELECTROMAGNETIC RADIATION; ENERGY RANGE; FIELD THEORIES; FUNCTIONS; INELASTIC SCATTERING; INTERACTIONS; LEPTON BEAMS; MATHEMATICAL SPACE; MATHEMATICS; OSCILLATIONS; PARTICLE BEAMS; QUANTUM FIELD THEORY; RADIATIONS; SCATTERING; SPACE; SPECTRA; SPECTRAL FUNCTIONS
Citation Formats
Heinzl, T, Seipt, D, and Kaempfer, B. Beamshape effects in nonlinear Compton and Thomson scattering. United States: N. p., 2010.
Web. doi:10.1103/PHYSREVA.81.022125.
Heinzl, T, Seipt, D, & Kaempfer, B. Beamshape effects in nonlinear Compton and Thomson scattering. United States. doi:10.1103/PHYSREVA.81.022125.
Heinzl, T, Seipt, D, and Kaempfer, B. Mon .
"Beamshape effects in nonlinear Compton and Thomson scattering". United States. doi:10.1103/PHYSREVA.81.022125.
@article{osti_21408195,
title = {Beamshape effects in nonlinear Compton and Thomson scattering},
author = {Heinzl, T and Seipt, D and Kaempfer, B},
abstractNote = {We discuss intensity effects in collisions between beams of optical photons from a highpower laser and relativistic electrons. Our main focus is on the modifications of the emission spectra due to realistic finitebeam geometries. By carefully analyzing the classical limit we precisely quantify the distinction between strongfield QED Compton scattering and classical Thomson scattering. A purely classical, but fully covariant, calculation of the bremsstrahlung emitted by an electron in a planewave laser field yields radiation into harmonics, as expected. This result is generalized to pulses of finite duration and explains the appearance of line broadening and harmonic substructure as an interference phenomenon. The ensuing numerical treatment confirms that strong focusing of the laser leads to a broad continuum while higher harmonics become visible only at moderate focusing, and hence lower intensity. We present a scaling law for the backscattered photon spectral density which facilitates averaging over electron beam phase space. Finally, we propose a set of realistic parameters such that the observation of intensityinduced spectral red shift, higher harmonics, and their substructure becomes feasible.},
doi = {10.1103/PHYSREVA.81.022125},
journal = {Physical Review. A},
issn = {10502947},
number = 2,
volume = 81,
place = {United States},
year = {2010},
month = {2}
}