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Title: Experimental Characterization of Superradiance in a Single-Pass High-Gain Laser-Seeded Free-Electron Laser Amplifier

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930626
Report Number(s):
BNL-80967-2008-JA
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98
Country of Publication:
United States
Language:
English
Subject:
national synchrotron light source

Citation Formats

Watanabe,T., Wang, X., Murphy, J., Rose, J., Shen, Y., Tsang, T., Giannessi, L., Musumeci, P., and Reiche, S. Experimental Characterization of Superradiance in a Single-Pass High-Gain Laser-Seeded Free-Electron Laser Amplifier. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.98.034802.
Watanabe,T., Wang, X., Murphy, J., Rose, J., Shen, Y., Tsang, T., Giannessi, L., Musumeci, P., & Reiche, S. Experimental Characterization of Superradiance in a Single-Pass High-Gain Laser-Seeded Free-Electron Laser Amplifier. United States. doi:10.1103/PhysRevLett.98.034802.
Watanabe,T., Wang, X., Murphy, J., Rose, J., Shen, Y., Tsang, T., Giannessi, L., Musumeci, P., and Reiche, S. Mon . "Experimental Characterization of Superradiance in a Single-Pass High-Gain Laser-Seeded Free-Electron Laser Amplifier". United States. doi:10.1103/PhysRevLett.98.034802.
@article{osti_930626,
title = {Experimental Characterization of Superradiance in a Single-Pass High-Gain Laser-Seeded Free-Electron Laser Amplifier},
author = {Watanabe,T. and Wang, X. and Murphy, J. and Rose, J. and Shen, Y. and Tsang, T. and Giannessi, L. and Musumeci, P. and Reiche, S.},
abstractNote = {},
doi = {10.1103/PhysRevLett.98.034802},
journal = {Physical Review Letters},
number = ,
volume = 98,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • No abstract prepared.
  • In this Letter we report the first experimental characterization of superradiance in a single-pass high-gain free-electron laser (FEL) seeded by a 150 femtosecond (FWHM) Ti:sapphire laser. The nonlinear energy gain after an exponential gain regime was observed. We also measured the evolution of the longitudinal phase space in both the exponential and superradiant regimes. The output FEL pulse duration was measured to be as short as 81 fs, a roughly 50% reduction compared to the input seed laser. The temporal distribution of the FEL radiation as predicted by a numerical simulation was experimentally verified for the first time.
  • In this paper we describe the effects of slippage on the single-pass high-gain free-electron laser (FEL) amplifier. We use a one-dimensional computational code to show the existence of two new dynamical regimes characterized by a dimensionless parameter {ital K}, which is a measure of the slippage in one gain length. We define the long-pulse limit to be when {ital K}{much lt}1 or the electron pulse length {ital L}{sub {ital e}} is much greater than a properly defined cooperation length'' {ital L}{sub {ital c}} ({ital L}{sub {ital e}}{much gt}L{sub c}). In this case we find that only the leading region ofmore » the propagating radiation pulse exhibits the usual steady-state behavior, with peak power proportional to {ital n}{sub {ital e}}{sup 4/3} (where {ital n}{sub {ital e}} is the electron-beam density). The trailing (slippage) region exhibits a spiking behavior with peak intensities reaching many times the saturated intensity predicted by steady-state theory. We define the short-pulse regime to be when {ital K}{approx gt}1 ({ital L}{sub {ital e}}{approx lt}L{sub c}). In this regime the peak power emitted by the electrons does not scale as {ital n}{sub {ital e}}{sup 4/3}, as predicted by steady-state theory, but scales as {ital n}{sub {ital e}}{sup 2}, which is typical of superradiant behavior. Furthermore, energy is extracted from the electrons in a continuous way, with no steady-state synchrotron oscillatory-type behavior.« less
  • In this letter we examine the start-up of a high gain free electron laser in which a frequency-chirped coherent seed laser pulse interacts with a relativistic electron beam. A Green function formalism is used to evaluate the initial value problem. We have fully characterized the startup and evolution through the exponential growth regime. We obtain explicit expressions for the pulse duration, bandwidth and chirp of the amplified light and show that the FEL light remains fully longitudinally coherent.