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Title: Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons

Abstract

A free relativistic electron in an electromagnetic field is a pure case of a light-matter interaction. In the laboratory environment, this interaction can be realized by colliding laser pulses with electron beams produced from particle accelerators. The process of single photon absorption and reemission by the electron, so-called linear Thomson scattering, results in radiation that is Doppler shifted into the x-ray and {gamma}-ray regions. At elevated laser intensity, nonlinear effects should come into play when the transverse motion of the electrons induced by the laser beam is relativistic. In the present experiment, we achieved this condition and characterized the second harmonic of Thomson x-ray scattering using the counterpropagation of a 60 MeV electron beam and a subterawatt CO{sub 2} laser beam.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1];  [2];  [3];  [3];  [3]
  1. Brookhaven National Laboratory, Upton, New York 11973 (United States)
  2. (United States)
  3. (Japan)
Publication Date:
OSTI Identifier:
20777021
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevLett.96.054802; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ACCELERATORS; CARBON DIOXIDE LASERS; DOPPLER EFFECT; ELECTRODYNAMICS; ELECTROMAGNETIC FIELDS; ELECTRON BEAMS; ELECTRONS; GAMMA RADIATION; MATTER; MEV RANGE 10-100; NONLINEAR PROBLEMS; PHOTONS; PULSES; RELATIVISTIC RANGE; THOMSON SCATTERING; VISIBLE RADIATION; X RADIATION; X-RAY DIFFRACTION

Citation Formats

Babzien, Marcus, Ben-Zvi, Ilan, Kusche, Karl, Pavlishin, Igor V., Pogorelsky, Igor V., Siddons, David P., Yakimenko, Vitaly, Cline, David, Zhou Feng, Hirose, Tachishige, Kamiya, Yoshio, Kumita, Tetsuro, Omori, Tsunehiko, Urakawa, Junji, Yokoya, Kaoru, University of California at Los Angeles, Los Angeles, California 90095, Waseda University, Shinjuku-ku, Tokyo 169-8555, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, and High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801. Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons. United States: N. p., 2006. Web. doi:10.1103/PhysRevLett.96.054802.
Babzien, Marcus, Ben-Zvi, Ilan, Kusche, Karl, Pavlishin, Igor V., Pogorelsky, Igor V., Siddons, David P., Yakimenko, Vitaly, Cline, David, Zhou Feng, Hirose, Tachishige, Kamiya, Yoshio, Kumita, Tetsuro, Omori, Tsunehiko, Urakawa, Junji, Yokoya, Kaoru, University of California at Los Angeles, Los Angeles, California 90095, Waseda University, Shinjuku-ku, Tokyo 169-8555, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, & High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801. Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons. United States. doi:10.1103/PhysRevLett.96.054802.
Babzien, Marcus, Ben-Zvi, Ilan, Kusche, Karl, Pavlishin, Igor V., Pogorelsky, Igor V., Siddons, David P., Yakimenko, Vitaly, Cline, David, Zhou Feng, Hirose, Tachishige, Kamiya, Yoshio, Kumita, Tetsuro, Omori, Tsunehiko, Urakawa, Junji, Yokoya, Kaoru, University of California at Los Angeles, Los Angeles, California 90095, Waseda University, Shinjuku-ku, Tokyo 169-8555, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, and High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801. Fri . "Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons". United States. doi:10.1103/PhysRevLett.96.054802.
@article{osti_20777021,
title = {Observation of the Second Harmonic in Thomson Scattering from Relativistic Electrons},
author = {Babzien, Marcus and Ben-Zvi, Ilan and Kusche, Karl and Pavlishin, Igor V. and Pogorelsky, Igor V. and Siddons, David P. and Yakimenko, Vitaly and Cline, David and Zhou Feng and Hirose, Tachishige and Kamiya, Yoshio and Kumita, Tetsuro and Omori, Tsunehiko and Urakawa, Junji and Yokoya, Kaoru and University of California at Los Angeles, Los Angeles, California 90095 and Waseda University, Shinjuku-ku, Tokyo 169-8555 and Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 and High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801},
abstractNote = {A free relativistic electron in an electromagnetic field is a pure case of a light-matter interaction. In the laboratory environment, this interaction can be realized by colliding laser pulses with electron beams produced from particle accelerators. The process of single photon absorption and reemission by the electron, so-called linear Thomson scattering, results in radiation that is Doppler shifted into the x-ray and {gamma}-ray regions. At elevated laser intensity, nonlinear effects should come into play when the transverse motion of the electrons induced by the laser beam is relativistic. In the present experiment, we achieved this condition and characterized the second harmonic of Thomson x-ray scattering using the counterpropagation of a 60 MeV electron beam and a subterawatt CO{sub 2} laser beam.},
doi = {10.1103/PhysRevLett.96.054802},
journal = {Physical Review Letters},
number = 5,
volume = 96,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2006},
month = {Fri Feb 10 00:00:00 EST 2006}
}
  • We have observed longitudinal acceleration of free electrons by photon scattering in the low-energy Thomson regime. This is the first observation of the transition between the Thomson and Compton regimes of electron scattering due to higher-order photon interactions.
  • We observe relativistic modifications to the Thomson scattering spectrum in a traditionally classical regime: v{sub osc}/c = eE{sub 0}/cm{omega}{sub 0} << 1 and T{sub e} < 1 keV. The modifications result from scattering off electron-plasma fluctuations with relativistic phase velocities. Normalized phase velocities v/c between 0.03 and 0.12 have been achieved in a N{sub 2} gas-jet plasma by varying the plasma density from 3 x 10{sup 18} cm{sup -3} to 7 x 10{sup 19} cm{sup -3} and electron temperature between 85 eV and 700 eV. For these conditions, the complete temporally resolved Thomson scattering spectrum including the electron and ionmore » features has been measured. A fully relativistic treatment of the Thomson scattering form factor has been developed and shows excellent agreement with the experimental data.« less
  • We observe relativistic modifications to the Thomson scattering spectrum in a traditionally classical regime: v{sub osc}/c=eE{sub 0}/cm{omega}{sub 0}<<1 and T{sub e}<1 keV. The modifications result from scattering off electron-plasma fluctuations with relativistic phase velocities. Normalized phase velocities v/c between 0.03 and 0.12 have been achieved in a N{sub 2} gas-jet plasma by varying the plasma density from 3x10{sup 18} cm{sup -3} to 7x10{sup 19} cm{sup -3} and electron temperature between 85 and 700 eV. For these conditions, the complete temporally resolved Thomson scattering spectrum including the electron and ion features has been measured. A relativistic treatment of the Thomson scatteringmore » form factor shows excellent agreement with the experimental data.« less
  • A simple formula for reconstructing fully relativistic electron momentum distribution functions from incoherent Thomson scattering data is presented. Although the formula assumes the isotropy in momentum space, it may be useful for obtaining detailed information on the electron distribution function in fusion plasmas. {copyright} {ital 1997 American Institute of Physics.}
  • The optical second harmonic (SH) response from the n-Si(111) surface immersed in aqueous electrolyte solutions has been examined and is observed to be potential dependent. This potential dependence is observed for both the monohydrogen-terminated surface immersed in NH[sub 4]F as well as for surfaces which are photoanodically oxidized in H[sub 2]SO[sub 4]. The potential dependence from the latter is screened in part by the presence of the insulating overlayer. Furthermore, a minimum is observed in the potential-dependent response which is shifted well anodic of the flatband potential. The SH observations are attributed to field effects within the space charge regionmore » of the semiconductor which are manifested in the higher order bulk SH response. Photocurrent transient analysis is utilized as a means of determining the flatband potential of these surfaces immersed in electrolyte solution. Experiments performed in UHV are discussed and compared to that observed in solution. 71 refs., 9 figs., 1 tab.« less