Author: Park, S.
Paper Title Page
Spatiotemporal Optimization of UV-Pump Pulses for the Ultrafast Electron Diffraction  
  • I.H. Baek, B. Han, K.H. Jang, Y.U. Jeong, H.W. Kim, K. Lee, S. H. Park, S. Park, N. Vinokurov
    KAERI, Daejon, Republic of Korea
  Ultraviolet (UV) light has been devoted to escape electrons from common metals due to their work function energies. Nowadays the pulsed electron beam has triggered numerous fundamental studies and technological applications. Electron beam-based pump/probe spectroscopy requires a low timing jitter between pump- and probe-beams for the precise observation and analysis. Herein, we performed the systematic characterization of electron bunches depending on UV pulse conditions using the electro-optic streaking of electron pulses for the ultrafast electron diffraction (UED) experiment. The temporal stabilization between UV-pump and electron-probe beams within a 100 femtoseconds jitter is in progress by compensating a relative phase shift of RF master oscillator and Ti:sapphire laser oscillator. We are under optimization of the spatial distribution and size of the UV light for getting electron bunches with low emittance and energy spread.  
THP010 Analysis of Beam Stability in the KAERI Ultrashort Pulse Accelerator 697
  • H.W. Kim, S. Bae, B.A. Gudkov, K.H. Jang, Y.U. Jeong, Y. Kim, K. Lee, S.V. Miginsky, J. Mun, S. H. Park, S. Park, N. Vinokurov
    KAERI, Daejon, Republic of Korea
  • K.H. Jang, Y.U. Jeong, H.W. Kim, K. Lee, S.V. Miginsky, S. H. Park, N. Vinokurov
    UST, Daejeon City, Republic of Korea
  • S.V. Miginsky, N. Vinokurov
    BINP SB RAS, Novosibirsk, Russia
  An RF-photogun-based linear accelerator for the Korea Atomic Energy Research Institute (KAERI) ultrashort pulse facility is under construction. It has a symmetry structure with four different beamlines. The UED beamlines will generate ultrashort electron pulses with over 106 electrons per pulse for the single-shot measurements on femtoseconds dynamics of atomic or molecular structures. Electron bunches with an energy of ~3 MeV from the RF photogun can be compressed up to less than 50 fs by achromatic and isochronous bends. The intrinsic r.m.s. timing jitter of the pulses through the bends is estimated to be less than 30 fs with the r.m.s. energy fluctuation of 0.1%. In the THz pump and X-ray probe beamline, two successive laser pulses with a time interval of ~10 ns are used to generate two electron bunches having bunch charges more than 100 pC. Two electron bunches are accelerated by a linac up to ~25 MeV and separated into individual beamlines by a fast kicker. We will present on estimated timing jitter and effects of magnet errors to the beam dynamics in the accelerator by considering beam dilution effects.