Title :
On the feedback in the Smith-Purcell experiment
Author :
Skrynnik, B.K. ; Korneenkov, V.K. ; Demchenko, M.Yu.
Author_Institution :
A. Usikov Inst. of Radiophys. & Electron., Acad. of Sci., Kharkov, Ukraine
Abstract :
Refers to the well understood mm-wave region with a standard accelerating voltage 3-5 kV. The positive feedback is held not on the zeroth but minus first space harmonic of the grating surface wave, i.e. the modulated electron beam is self-excited in BWT mode at λ≈ 11 mm. The high time harmonics of the modulated electron beam are radiated under certain conditions nearly orthogonal to it as fast (volume) waves. Just an experimental verification of the near-millimeter radiation of the fast (volume) waves not from externally modulated but self-excited surface eigenwave mode electron beam is proof that the coherent radiation of light on fast (volume) waves is due to the nonrecognized Smith-Purcell beam automodulation by infrared surface eigenwaves of the planar reflecting grating
Keywords :
backward wave tubes; diffraction gratings; eigenvalues and eigenfunctions; electron beams; free electron lasers; harmonics; laser feedback; millimetre wave lasers; 11 mm; 3 to 5 kV; Smith-Purcell experiment; accelerating voltage; grating surface wave; infrared surface eigenwaves; mm-wave region; modulated electron beam; planar reflecting grating; positive feedback; self-excited BWT mode; space harmonic; surface eigenwave mode electron beam; time harmonics; Electromagnetic radiation; Electron beams; Electron optics; Gratings; Humans; Optical feedback; Optical modulation; Optical surface waves; Surface treatment; Surface waves;
Conference_Titel :
Physics and Engineering of Millimeter and Sub-Millimeter Waves, 2001. The Fourth International Kharkov Symposium on
Conference_Location :
Kharkov
Print_ISBN :
0-7803-6473-2
DOI :
10.1109/MSMW.2001.947228
