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WEOC02 |
Status of the KAERI Table-Top THz Free-Electron Laser Development |
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- 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
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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.
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Slides WEOC02 [6.856 MB]
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| THOB03 |
The Generator of High-power Short Terahertz Pulses |
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- N. Vinokurov
BINP SB RAS, Novosibirsk, Russia
- Y.U. Jeong
KAERI, Daejon, Republic of Korea
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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.
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Slides THOB03 [1.624 MB]
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