Author: Murphy, J.B.
Paper Title Page
THP007 FEL Potential of eRHIC 2151
 
  • V. Litvinenko, I. Ben-Zvi, Y. Hao, C.C. Kao, D. Kayran, J.B. Murphy, V. Ptitsyn, T. Roser, D. Trbojevic, N. Tsoupas
    BNL, Upton, Long Island, New York, USA
 
  Brookhaven National Laboratory plans to build a 5-to-30 GeV energy-recovery linac (ERL) for its future electron-ion collider, eRHIC. In past few months, the Laboratory turned its attention to the potential of this unique machine for free electron lasers (FELS), which we initially assessed earlier*. In this paper, we present our current vision of a possible FEL farm, and of narrow-band FEL-oscillators driven by this accelerator.
* V.N. Litvinenko, I. Ben-Zvi, Proceedings of FEL'2004, http://jacow.org/f04/papers/WEBOS04/
 
 
THP107 Source of Microbunching at BNL NSLS Source Development Laboratory 2324
 
  • S. Seletskiy, Y. Hidaka, J.B. Murphy, B. Podobedov, H.J. Qian, Y. Shen, X.J. Wang, X. Yang
    BNL, Upton, Long Island, New York, USA
 
  We report experimental studies of the origins of electron beam microbunching instability at BNL Source Development Laboratory (SDL). We eliminated laser-induced microbunching by utilizing an ultra-short photocathode laser. The measurements of the resulting electron beam led us to conclude that, at SDL, microbunching arising from shot noise is not amplified to any significant level. Our results demonstrated that the only source of microbunching instability at SDL is the longitudinal modulation of the photocathode laser pulse. Our work shows that assuring a longitudinally smoothed photocathode laser pulse allows mitigating microbunching instability at a typical FEL injector with a moderate microbunching gain.  
 
THP148 Experimental Investigation of Superradiance in a Tapered Free-Electron Laser Amplifier 2396
 
  • Y. Hidaka, J.B. Murphy, B. Podobedov, S. Seletskiy, Y. Shen, X.J. Wang, X. Yang
    BNL, Upton, Long Island, New York, USA
 
  We report experimental studies of the effect of undulator tapering on superradiance in a single-pass high- gain free-electron laser (FEL) amplifier. The experiments were performed at the Source Development Laboratory (SDL) of National Synchrotron Light Source (NSLS). Efficiency was nearly tripled with tapering. Both the temporal and spectral properties of the superradiant FEL along the uniform and tapered undulator were experimentally characterized using frequency-resolved optical gating (FROG) images. Numerical studies predicted pulse broadening and spectral cleaning by undulator tapering Pulse broadening was experimentally verified. However, spectral cleanliness degraded with tapering.
* T. Watanabe et al, Phys. Rev. Lett. 98, 034802 (2007).
** X.J. Wang et al, Phys. Rev. Lett. 103, 154801 (2009).