BINP SB RAS, Novosibirsk
The first stage of Novosibirsk high power free electron laser (FEL) is in operation since 2003. Now the FEL provides average power up to 500 W in the wavelength range 120 - 240 micron. One orbit for 11-MeV energy with terahertz FEL lies in vertical plane. Other four orbits lie in the horizontal plane. The beam is directed to these orbits by switching on of two round magnets. In this case electrons pass four times through accelerating RF cavities, obtaining 40-MeV energy. Then, (at fourth orbit) the beam is used in FEL, and then is decelerated four times. At the second orbit (20 MeV) we have bypass with third FEL. When magnets of bypass are switched on, the beam passes through this FEL. The length of bypass is chosen to provide the delay, which necessary to have deceleration instead of acceleration at the third passage through accelerating cavities. Now two of four horizontal orbits are assembled and commissioned. The electron beam was accelerated twice and then decelerated down to low injection energy. Project average current 9 mA was achieved. First multi-orbit ERL operation was demonstrated successfully.
BINP SB RAS, Novosibirsk
The projected electron RF gun of Novosibirsk Microtron-Recuperator injector employs an industrial thermionic cathode grid assembly with 0.08 mm gap that usually used in metal-ceramic RF tubes. Three-dimensional (3D)computer simulations have been performed that use the mesh refinement capability of the both Microwave Studio and 2D SAM codes to examine the full region of the real cathode grid assembly in static fields in order to illustrate the beam quality that can result from such a gridded structure. These simulations have been found to reproduce the beam current behaviors versus of applied potentials that are observed experimentally. Based on it ASTRA RF beam simulations also predict a complicated time-dependent response to the waveform applied to the grid during the current turn-on, calculation of the dissipated power by electrons at the grid, and particle tracking downstream of the grid into RF gun cavity and farther on. These simulations may be representative in other sources, such as some L-band RF injectors for industrial applications.
BINP SB RAS, Novosibirsk
RRC, Moscow
The project of upgraded RF System of Siberia-2 Electron Storage Ring / SR Source, Moscow, Russia, is presented. The upgraded RF system will allow to increase the total accelerating voltage up to 1.8MV and ensure operation of the storage ring with new superconducting wiggler at beam currents up to 0.3A. RF system operates at 181MHz. It consists of 3 single bi-metal cavities, 2 power amplifiers based on GU-101A tetrodes with output power of 200kW, power transmission lines and control system. Parameters of the upgraded RF system are given, the design of its main elements is shown.