Frequency-locked terahertz Smith-Purcell radiation

We present experimental measurements of coherent frequency-locked Terahertz Smith-Purcell radiation generation by a train of 15 MeV, femtosecond-scale electron bunches passing over a metal grating. This scheme leads to an increase in intensity by the number of grating periods, the number of electron bunches and the number of electrons in each bunch. This powerful SPR THz radiation can be detected with a high signal to noise ratio by a heterodyne receiver.