| Paper | Title | Page |
|---|---|---|
| TUPC65 | Observation of Coherent Smith-Purcell Radiation Using an Initially Continuous Flat Beam | 386 |
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A few years ago, a new theory for producing coherent Smith-Purcell (SP) radiation from an initially continuous electron beam was proposed. It was two-dimensional (2-D), and it has been supported by 2-D particle-in-code simulations. We report here the results of an experiment using an intense continuous flat beam that confirms the theory. A maximum voltage of 200 kV was supplied by a single-shot pulsed-power source. The beam was typically 10 cm wide and a few mm thick, with a peak current of 200 A. The laminar grating had twenty 2-cm periods, and radiation was observed at the predicted fundamental grating mode frequency near 4 GHz. The second and third harmonics were also observed at the angles predicted by the SP formula. Direct evidence for beam bunching was obtained using both a current monitor and a pick-up loop placed at the end of a groove. In general, good agreement between this experiment and theory is found. |