A MILLIMETER WAVELENGTH RADIATION SOURCE USING A DUAL GRATING RESONATOR

A novel means of producing coherent radiation by passing an electron t hrough a dual-grating resonator is presented. The observed radiation i s in accordance with the Smith-Purcell dispersion relation for a singl e grating. Feedback is provided by a second grating. Experiments carri ed out at beam energies from 30-55 KeV produced radiation at wavelengt hs from 6 to 0.75 mm. Power measurement were used to clarify the grati ng-beam interaction. Indications are that operation could be easily ex tended to shorter wavelengths to provide an inexpensive and compact ra diation source in the far-infrared.