Author: Vinokurov, N.
Paper Title Page
WEOC03 The Novosibirsk Terahertz FEL Facility - Current Status and Future Prospects 361
 
  • O.A. Shevchenko, V.S. Arbuzov, K.N. Chernov, E.N. Dementyev, B.A. Dovzhenko, Ya.V. Getmanov, E.I. Gorniker, B.A. Knyazev, E.I. Kolobanov, A.A. Kondakov, V.R. Kozak, E.V. Kozyrev, V.V. Kubarev, G.N. Kulipanov, E.A. Kuper, I.V. Kuptsov, G.Y. Kurkin, L.E. Medvedev, L.A. Mironenko, V.K. Ovchar, B.Z. Persov, A.M. Pilan, V.M. Popik, V.V. Repkov, T.V. Salikova, M.A. Scheglov, I.K. Sedlyarov, G.V. Serdobintsev, S.S. Serednyakov, A.N. Skrinsky, S.V. Tararyshkin, V.G. Tcheskidov, N. Vinokurov, M.G. Vlasenko, P. Vobly, V. Volkov
    BINP SB RAS, Novosibirsk, Russia
 
  The Novosibirsk terahertz FEL facility is based on the normal conducting CW energy recovery linac (ERL) with rather complicated lattice. This is the only multiorbit ERL in the world. It can operate in three different modes providing electron beam for three different FELs. The first FEL works for users since 2003. This FEL radiation is used by several groups of scientists which include biologists, chemists and physicists. Its maximum average and peak powers are 500 W and 1MW and wavelength can be tuned from 110 up to 240 microns. The high peak and average powers are used in experiments on material ablation and biological objects modification. The second FEL is installed on the second orbit. The first lasing of this FEL was achieved in 2009. Its radiation has almost the same average and peak powers and is delivered to the same user stations as the first FEL one, but its tunability range lies between 35 and 80 microns. The third FEL will be installed on the fourth orbit. In this paper we report the latest results obtained from the operating FELs as well as our progress with the commissioning of the two remaining ERL orbits. We also discuss possible options for the future upgrade.  
slides icon Slides WEOC03 [5.364 MB]  
 
THOB03 The Generator of High-power Short Terahertz Pulses 535
 
  • N. Vinokurov
    BINP SB RAS, Novosibirsk, Russia
  • Y.U. Jeong
    KAERI, Daejon, Republic of Korea
 
  The multi-foil cone radiator to generate high field short terahertz pulses with the short electron bunches is described. A round flat foil plates with successively decreasing radius are stacked, comprising a truncated cone with axis z. The gaps between foils are equal and filled by some dielectric (it may be vacuum). A short relativistic electron bunch propagates along the z axis from left to right. At high enough particle energy the energy losses and multiple scattering does not change the bunch shape significantly. Then, passing through each gap between foils, the bunch radiates some energy into the gap. After that the radiation pulses propagates radially. For the TEM-like waves with longitudinal (along the z axis) electric and azimuthal magnetic field there is no dispersion in these radial lines, therefore the radiation pulses conserve their shapes (time dependence). At the cone outer surface we have synchronous circular radiators. Their radiation fields forms the conical wave. The cone angle may be optimized, moreover, the nonlinear dependence of the foil plates radii on their longitudinal coordinate z may be used for the wave front shape control.  
slides icon Slides THOB03 [1.624 MB]  
 
WEOC02
Status of the KAERI Table-Top THz Free-Electron Laser Development  
 
  • Y.U. Jeong, S. Bae, B.H. Cha, B.A. Gudkov, K.H. Jang, K.N. Kim, K. Lee, S.V. Miginsky, J. Mun, S. H. Park, N. Vinokurov
    KAERI, Daejon, Republic of Korea
  • S. Park
    Kyungpook National University, Daegu, Republic of Korea
 
  Funding: This work was supported by the World Class Institute (WCI) Program of the NRF funded by the MEST (NRF Grant Number: WCI 2011-001).
Korea Atomic Energy Research Institute is under development of a table-top terahertz (THz) free electron laser (FEL) driven by a conventional microtron accelerator. The THz FEL is composed of a compact variable-period helical undulator and a cylindrical-waveguide resonator with a mesh outcoupling mirror to achieve a small scale. The target wavelength and average power of the system are 400-600 um and 1 W. The energy and peak current of the microtron is designed to be 6.5 MeV and 1 A. We fabricated a compact microtron accelerator including a thermionic RF gun, a magnetron and a modulator having a maximum repetition rate of 200 Hz. We fabricated a variable-period helical undulator having tunable periods of 23-26 mm while keeping the on-axis field strength of 1 T, and total length of 700-800 mm. A compact beamline with two 45-degree bending magnets and 6 permanent-magnet quadrupoles has been designed to transport optimal electron beams to the variable-period helical undulator. A cylindrical-waveguide resonator having a mesh outcoupling mirror and a full mirror with the function of beam dump will decrease the size of the FEL. The size of the FEL is expected to be 2.3 m x 1.6 m.
 
slides icon Slides WEOC02 [6.856 MB]