Sedykh, S.N.
(Sergey Sedykh)

MOPOS47 Simulating FEM Amplifiers: Features in Various Regimes
Artem Elzhov, Alim Kaminsky, Elkuno Perelstein, Sergey Sedykh, Anatoly Sergeev (JINR, Dubna, Moscow Region)

The results of previous experiments with free electron maser amplifiers in high-gain Compton and Raman regimes are analyzed by numerical simulation. Compact quasi-one-dimensional models in a helical trajectory approximation were employed. A tare on the stationary trajectories due to radiation was inserted. Reasonable agreement between simulation and experimental results get in the regimes with reversed guide magnetic field. A handy means for determination of the basic amplification parameters for possible future experiment is available.

MOPOS49 Improving Selectivity of 1D Bragg Resonator Using Coupling of Propagating and Trapped Waves
Naum Samuilovich Ginzburg, Andrey Malkin, Nikolay Peskov, Alexander Sergeevich Sergeev (IAP RAS, Nizhny Novgorod), Artem Elzhov, Alim Kaminsky, Sergey Sedykh, Anatoly Sergeev (JINR, Dubna, Moscow Region)

A novel 1D Bragg resonator based on coupling propagated and locked (quasi cut-off) modes should be tested in a JINR- IAP FEM-oscillator to improve selectivity over the transverse mode index. In this scheme the electron beam interacts with only propagating wave, and the latter is coupled with a quasi cut-off mode. This coupling can be realized by either helical or azimuthally-symmetric corrugation. The quasi cut-off mode provides the feedback in the system leading to the absolute instability and the self-excitation of the whole system while efficiency in the steady-state regime of generation is almost completely determined by the propagating mode, synchronous to the beam. Analytical consideration and numerical simulation show that the efficiency of such an FEM can be rather high. The main advantage of this scheme is provision of higher selectivity over the transverse mode index than traditional scheme of Bragg FEL that encourage increasing operating frequency for fixed transverse size of the interaction space.

THPOS37 Status of 30 GHz Facility for Experimental Investigation of the Copper Cavity Lifetime (Clic Collider Project)
Alim Kaminsky, Artem Elzhov, Eugene Gorbachev, Vitaly Kosukhin, Elkuno Perelstein, Nikolay Pilyar, Tatiana Rukoyatkina, Sergey Sedykh, Anatoly Sergeev, Alexey Sidorov, Vladimir Tarasov (JINR, Dubna, Moscow Region), Naum Samuilovich Ginzburg, Sergey Kuzikov, Nikolay Peskov, Mikhail Petelin, Alexander Sergeevich Sergeev, Nikolay Zaitsev (IAP RAS, Nizhny Novgorod)

Facility for experimental investigation of a copper cavity lifetime under multiple action of 30 GHz power pulses is now created by the collaboration of CLIC team (CERN) [1], FEM groups of JINR (Dubna) and IAP RAS (Nizhny Novgorod). Design of the test cavity, estimation of the operating parameters of the FEM oscillator and the RF power transmission line was already reported at FEL’03 [2]. Last year was devoted to the achievement of the design parameters of all the elements of the facility. We have developed the equipment and the procedure of RF transmission line adjustment, improved the stability of the linac power supplies, created the new system of data acquisition. Start of the full-scale experiments is planned to the end of 2004.