Simulations and preliminary experimental results of a coherent Smith-Purcell experimentin the microwave domain

Summary form only given as follows. The generation of coherent Smith-Purcell (SP) radiation at terahertz frequencies is under investigation in several laboratories. We have previously reported PIC code simulations in good agreement with two different kinds of SP experiments. In the MIT experiment, the electron beam is highly energetic (15 MeV) and is already bunched at a given frequency (17 GHz) whereas in the Dartmouth College experiment a low energy (50 keV) continuous beam becomes bunched (at a sub SP frequency) by its interaction with an evanescent grating mode. At CEA/CESTA, a SP experiment in the microwave regime (8 GHz) has been designed on the basis of our previously published 2D simulations. We present here the corresponding 3D simulations, the set-up of the experiment and our preliminary results. Since the physics involved does not depend on the frequency, we hope to make an experimental validation of C. Brau and co-worker's theory as well as a justification of our 2D and 3D simulation results.