Author: Feldman, D.W.
Paper Title Page
TUPPC094 Experimental Observations of Large-amplitude Solitary Waves in Electron Beams 1377
  • Y. Mo, B.L. Beaudoin, D.W. Feldman, I. Haber, R.A. Kishek, P.G. O'Shea
    UMD, College Park, Maryland, USA
  • J.C.T. Thangaraj
    Fermilab, Batavia, USA
  Funding: Work funded by the US Dept. of Energy Offices of Fusion Energy Sciences and High Energy Physics and Fusion Energy Sciences, and by the Dept. of Defense Office of Naval Research.
The longitudinal dynamics of space charge dominated beams plays an important role in particle accelerators and other applications such as heavy ion fusion and free electron lasers (FELs). All beams are space-charge dominated near the source. Furthermore, the longitudinal profile is not necessarily an ideal mathematical function. By means of experiments on the University of Maryland Electron Ring (UMER), we studied how a perturbation to the line charge density could affect the beam propagation. By varying the initial amplitude of the perturbation, we access nonlinear space charge physics. When starting with large-amplitude perturbations, we have observed, for the first time in charged particle beams, solitary waves for which the nonlinear steepening exactly balances the wave dispersion, leading to persistent waves that preserves their shape over a long distance. This paper presents the results of the soliton experiments, including systematic studies of the dependence of the soliton propagation on beam current, perturbation level and width. The data is compared with theory and simulation.