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Physics of Plasmas 03/2012; 19(3):033508. · 2.15 Impact Factor
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ABSTRACT: The excitation of a low-frequency surface wave can provide coherent high-frequency Smith–Purcell radiation due to the frequency multiplication effect. The use of an open cavity allows an additional power increase due to the induced nature of the radiation. A radiation source based on these effects is experimentally demonstrated at a frequency of about 190 GHz.
Applied Physics Letters 02/2011; 98(6):061503-061503-3. · 3.84 Impact Factor
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ABSTRACT: The capabilities of two types of terahertz sources based on stimulated Smith-Purcell radiation of electrons in open cavities are discussed. A series of developed pulsed orotrons provides coherent radiation with an output power of 1-0.1 W in the frequency range of 90-410 GHz, with high frequency stability and broad-band electromechanical frequency tuning. A promising alternative source with smaller currents than that in orotrons is a frequency multiplier based on excitation of a surface wave of a periodic structure and Smith-Purcell radiation of arising electron bunches inside the orotron cavity. In contrast to a number of works where only an open grating is used, exploiting a cavity enables a stimulated radiation process with a much higher power. The developed theory demonstrates the possibility of single-mode generation in such multipliers with wide electron beams.
IEEE Transactions on Plasma Science 07/2010; · 1.17 Impact Factor
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ABSTRACT: A linear and non-linear theory of the orotron with an electron beam inclined with respect to the surface of a periodic structure
is presented. The beam inclination provides the possibility of the effective interaction of all particles of thick electron
beam with slow evanescent harmonic of the cavity mode. On the basis of obtained analytical expression for the orotron starting
current, the possibility to increase the device frequency up to 600GHz is discussed. According to numerical simulations,
the inclination of the beam allows increasing significantly both the electron efficiency and the output power of the device.
The project of low-voltage orotron with the operating frequency of 100GHz and output power of 10W is proposed.
International Journal of Infrared and Millimeter Waves 10/2008; 29(11):997-1003. · 0.58 Impact Factor
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Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves and Workshop on Terahertz Technologies, 2007. MSMW '07. The Sixth International Kharkov Symposium on; 07/2007
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ABSTRACT: In this paper, the low-voltage pulse orotron generators of the short millimeter and long submillimeter waves with power level up to 1 W have been developed. Some methods of frequency and power enhancement are proposed.
Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves and Workshop on Terahertz Technologies, 2007. MSMW '07. The Sixth International Kharkov Symposium on; 07/2007
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ABSTRACT: Output field patterns of a 110-GHz, 10-kW gyrotron with a pulsed magnetic field and a 140-GHz, 0.5-W millisecond-pulse orotron have been imaged using visible continuum emitted by a slab of the Cs-Xe DC discharge.
Infrared Millimeter Waves and 14th International Conference on Teraherz Electronics, 2006. IRMMW-THz 2006. Joint 31st International Conference on; 10/2006
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ABSTRACT: Summary form only given. Electron vacuum sources of coherent terahertz radiation are being now intensively developed at the Institute of Applied Physics (IAP). These devices are intended for wide-spread utilizing in many research and technical applications including spectroscopy, diagnostics of different media, communications, material processing etc. In this presentation, two types of promising THz electron oscillators, namely orotrons and gyrotrons, will be discussed. The orotrons have been realized at the IAP in collaboration with the Institute of Metrology for Time and Space and Institute of Spectroscopy. The operation of the orotron (or diffraction radiation generator) is based on the stimulated Smith-Purcell radiation of a rectilinear electron beam in a selective open cavity which has a periodic structure on one of its mirrors. At the moment, a series of the low-voltage (0.5-5 kV) orotrons developed generate in the frequency range of 0.1-0.4 THz with output power of 1.0-0.1 W and typical electrical-mechanical frequency tuning within an octave. Using same voltage, orotrons can enable higher power and frequency stability than BWOs that are most widespread devices within entire terahertz range. Orotrons with relativistic electron beams, which are studied at the IAP, are capable to provide significantly higher pulse THz power (up to MW level at ns pulse duration). Both conventional and large-orbit gyrotrons (LOGs) are also under development at the IAP The LOGs are based on the same mechanism of stimulated cyclotron radiation of electrons as conventional gyrotrons, but they are more selective when operating at higher cyclotron harmonics. Correspondingly, they work at lower magnetic fields. At the same time significantly more complicated electron guns are needed for the LOGs to provide appropriate axis-encircling electron beams. Such beams with electron energy 50-250 keV and very high compression have been obtained and powerful selective generation at 1st-5th cyclot-
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ron harmonics have been demonstrated in the IAP at millimeter and submillimeter waves. When operating at the third cyclotron harmonic generation with power level of 10-20 kW has been obtained in the range of 0.3-0.42 THz. Another prospective way for developing THz sources, that will be also presented, is realization of gyro-multipliers with self-exciting LF sections and HF sections operating at high cyclotron harmonics
Plasma Science, 2006. ICOPS 2006. IEEE Conference Record - Abstracts. The 33rd IEEE International Conference on; 07/2006
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ABSTRACT: Competition of the operating modes at the second cyclotron harmonic with spurious modes at fundamental is studied numerically for the cases of gyrotron and traveling opposite spurious modes in the gyrotron FU II. This competition limits significantly the output power at the second harmonic. The results are in good agreement with experiments.
International Journal of Infrared and Millimeter Waves 09/2001; 22(10):1409-1420. · 0.58 Impact Factor
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ABSTRACT: A new variety of RF sources is studied experimentally. In the
cyclotron autoresonance maser (CARM)-gyrotron with an open
“gyrotron-type” cavity, two regimes of operation are
observed: the conventional high-harmonic gyrotron regime, and the
CARM-gyrotron regime with effective radiation of the traveling CARM
mode. The two-mode character of the electron-wave interaction in the
CARM-gyrotron regime was proved experimentally
IEEE Transactions on Plasma Science 09/2001; · 1.17 Impact Factor
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ABSTRACT: A new method of significant efficiency enhancement, which is based
on simultaneous interaction of electrons with an opposite wave at the
second cyclotron harmonic, and a forward wave of the same frequency, at
the fundamental cyclotron resonance, is proposed for the backward wave
oscillator (gyro-BWO). Excitation of the forward wave results in
significant efficiency enhancement, whereas the opposite wave provides a
broadband feedback. This allows realizing a high-efficiency,
frequency-tunable oscillator
IEEE Transactions on Plasma Science 11/2000; · 1.17 Impact Factor
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ABSTRACT: A large orbit gyrotron with a 300 keV, 30 A, 20 ns electron beam
has provided selective generation with radiation power from 1.5 MW at
fundamental (wavelength of 14 mm) to 100 kW at the fifth cyclotron
harmonic (wavelength of 4 mm). The next experiment with a unique
electron beam (250 keV, 18 A, 10 μs, 0.6 mm in diameter) is in
progress
IEEE Transactions on Plasma Science 05/1999; · 1.17 Impact Factor
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ABSTRACT: The simplest elementary source of RF space-charge field in the form of a helix rotating with the frequency of the operating wave is proposed. The use of these sources (mutually interacting) allows one to describe the main space-charge effects for different varieties of CRMs in both linear and nonlinear regimes. It is shown that, like in the subrelativistic gyrotron, due to development of the quasielectrostatic negative-mass instability, the space charge increases the increment in the amplifier and decreases the starting current in the oscillator.
International Journal of Infrared and Millimeter Waves 06/1998; 19(7):939-956. · 0.58 Impact Factor
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ABSTRACT: Large orbit gyrotron (LOG) provides output power of 40 kW at the frequency of 240 GHz. Orotrons radiate at frequencies of 100-380 GHz with power of 50-200 mW and high frequency stability. In a LOG, electron-wave interaction at high cyclotron harmonics is more selective than in conventional gyrotrons that allows achieving higher frequencies. Higher output power and higher frequency stability can be obtained in orotrons in comparison with conventional BWOs due to use of open cavities.
Infrared and Millimeter Waves, 2004 and 12th International Conference on Terahertz Electronics, 2004. Conference Digest of the 2004 Joint 29th International Conference on;
