Progress of the microwave coherent Smith-Purcell experiment at CESTA

At CEA/CESTA, we are performing a CSP experiment in the microwave regime (9 GHz) on the basis of our previously published simulations. A flat and thin cathode, driven by a 200 kV, 200 Omega pulsed generator, emits a sheet electron beam which propagates above a 2 cm period grating immersed in an axial magnetic field. Beam bunching is measured by a B-dot probe and microwave emission is monitored by two horns. The first (S-band) collects the evanescent wave which reflects at both ends of the grating and escapes downstream through a transparent vacuum window. The second horn (X band) is used to measure CSP emission. We provide an experimental validation of C. Brau and co-worker´s theory which had been supported by our 2D and 3D simulations.