EXPERIMENTAL COUPLING OF 35 GHZ RF-CAVITIES WITH AN INTENSE BUNCHED ELECTRON BEAM

We present the first utilization of a FEL-bunched electron beam in the framework of Two Beam Accelerator (TBA) studies. A 2.2 MeV, 800 A electron beam, produced by the induction accelerator LELIA, is bunched at 35 GHz by the FEL interaction. Then it is extracted from the wiggler by a suitable adiabatic exit. A solenoid is used to produce a narrow beam waist downstream at the position of a 35 GHz resonating cavity. First, we test the so-called "idler " cavity, a closed RF-structure which can be slightly detuned from the resonant frequency in order to enhance bunching. In a second step, open cavities will be tested in order to study the production of high frequency RF-power by an intense bunched beam.