Title :
Analysis of a rectangular grating Cerenkov maser
Author :
Joe, J. ; Scharer, John E. ; Booske, John H. ; McVey, B.D. ; Basten, M.
Author_Institution :
Dept. of Electr. & Comput. Eng., Wisconsin Univ., Madison, WI, USA
Abstract :
Summary form only given. Electron sheet beam propagation over a rectangular deep groove grating in a rectangular waveguide is considered. The lowest-order mode in the grating rectangular waveguide is the hybrid TE/sub x10/ mode. A complex dispersion relation for the hybrid modes an electron sheet beam interaction has been derived and analyzed. A finite axial energy spread in the beam is included in the dispersion relation. The growth rates for TE/sub x10/ and TE/sub x11/ hybrid modes are obtained. It is found that the growth rate of the TE/sub x11/ mode can be suppressed by allowing a small axial energy spread to the beam and a small increase in the beam-grading separation distance. With a 20 kV, 0.25 A, 3% axial spread electron beam and a 1 mm beam to grating separation distance, the growth rate of the TE/sub x10/ mode is 1 dB/cm. The absolute and convective nature of the interaction has been analyzed utilizing Briggs´ criteria. It is found that the instability is always convective in the forward mode regime.
Keywords :
masers; 0.25 A; 20 kV; Briggs´ criteria; TE/sub x11/ hybrid modes; beam-grading separation distance; convective instability; dispersion relation; electron sheet beam propagation; finite axial energy; forward mode regime; hybrid TE/sub x10/ mode; hybrid modes; lowest-order mode; rectangular deep groove grating; rectangular grating Cerenkov maser; rectangular waveguide; Charge carrier processes; Dispersion; Electron beams; Frequency; Gratings; Laboratories; Masers; Optical reflection; Piecewise linear techniques; Rectangular waveguides;
Conference_Titel :
Plasma Science, 1993. IEEE Conference Record - Abstracts., 1993 IEEE International Conference on
Conference_Location :
Vancouver, BC, Canada
Print_ISBN :
0-7803-1360-7
DOI :
10.1109/PLASMA.1993.593499
