Generation of powerful subnanosecond microwave pulses by intense electron bunches moving in a periodic backward wave structure in the superradiative regime.
Experimental results of the observation of coherent stimulated radiation from subnanosecond electron bunches moving through a periodic waveguide and interacting with a backward propagating wave are presented. The subnanosecond microwave pulses in Ka and W bands were generated with repetition frequencies of up to 25 Hz. The mechanism of microwave pulse generation was associated with self-bunching, and the mutual influence of different parts of the electron pulse due to slippage of the wave with respect to the electrons; this can be interpreted as superradiance. The illumination of a panel of neon bulbs resulted in a finely structured pattern corresponding to the excitation of the TM01 mode. Observation of rf breakdown of ambient air, as well as direct measurements by hot-carrier germanium detectors, leads to an estimate of the absolute peak power as high as 60 MW for the 300-ps pulses at 38 GHz. These results are compared with numerical simulations. The initial observation of 75-GHz, 10-15-MW radiation pulses with a duration of less than 150 ps is also reported.
Ginzburg
N S
NS
Institute of Applied Physics, RAS, 603600 Nizhny Novgorod, Russia.
Novozhilova
N Y
NY
Zotova
I V
IV
Sergeev
A S
AS
Peskov
N Y
NY
Phelps
A D
AD
Wiggins
S M
SM
Cross
A W
AW
Ronald
K
K
He
W
W
Shpak
V G
VG
Yalandin
M I
MI
Shunailov
S A
SA
Ulmaskulov
M R
MR
Tarakanov
V P
VP