24–84-GHz Gyrotron Systems for Technological Microwave Applications

Богдашов, А. А.; Bykov, Yu. V.; Денисов, Г. Г.; Eremeev, A. G.; Glyavin, M. Yu.; Kalynova, G. I.; Kholoptsev, V. V.; Лучинин, А. Г.; Plotnikov, I. V.; Semenov, V. E.; Zharova, N. A.

doi:10.1109/tps.2004.823904

Cited by 118 publications

(18 citation statements)

References 11 publications

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“…Analysis of the gyro-BWO capabilities showed that this device may be attractive for a number of technological applications, for which CW kilowatt-power gyrotrons are actively used [13]. This was the motivation to start a project aimed at realizing a CW tunable gyro-BWO with a power of several kilowatts at a frequency of about 24 GHz [12].…”

Section: Introductionmentioning

confidence: 99%

Frequency-Tunable CW Gyro-BWO With a Helically Rippled Operating Waveguide

Самсонов

Денисов

Bratman

et al. 2004

IEEE Trans. Plasma Sci.

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Operation of a continuous wave gyrotron backward-wave oscillator (gyro-BWO) with a helically rippled operating waveguide has been experimentally studied. The gyro-BWO exploits a dc oil-cooled magnet with magnetic field up to 0.5 T and utilizes a weakly relativistic (20 keV) electron beam produced by a magnetron injection gun. Stable generation at the second cyclotron harmonic with a maximum power of 7 kW and an efficiency of 15% at a frequency of 24.7 GHz was achieved. Smooth oscillation frequency tuning by varying the magnetic field was measured to be as wide as 5% at the half-power level. The first gyro-BWO operation with a single-stage energy recovery system was realized. The use of a depressed collector provided an efficiency increase up to 23% and an opportunity for reduction of the main power supply voltage down to 10 kV.Index Terms-Continuous wave (CW) high-power microwave device, cyclotron-resonance maser, gyrotron backward-wave oscillator (gyro-BWO), smooth-frequency tuning.

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Section: Introductionmentioning

confidence: 99%

Frequency-Tunable CW Gyro-BWO With a Helically Rippled Operating Waveguide

Самсонов

Денисов

Bratman

et al. 2004

IEEE Trans. Plasma Sci.

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“…28 GHz Cyclotron harmonic s 1 Accelerating voltage U 0 23 kV Operating current I 0 2.4 A Operating mode TE 1,3 Beam radius in the cavity R 0 6.6 mm At the same time ferromagnetic screens substantially increases the inhomogeneity of the magnetic field outside the screens, in particular in the collector region. So here the coefficient of non-adiabaticity H = h/L B (here h is the step of electron trajectory, L B is the scale of the magnetic field) exceeds 2 (see Fig.…”

Section: Frequency Fmentioning

confidence: 99%

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confidence: 99%

Collector system of a gyrotron with magnetically shielded solenoid

et al. 2017

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The gyrotron-based complexes developed by IAP RAS are used now for many applications, such as sintering of nanostructured ceramics, metal compacts and metal-ceramic composites, CVD growth of diamond films and disks, and generation of multi-charged ion beams [1][2][3]. These systems typically operate in 24-28 GHz frequency range with a power of 5-15 kW. As a source of microwave radiation, the systems use CW gyrotrons operating in magnets with oil or water cooling (so called technological gyrotrons). To reduce power consumption of magnets, gyrotrons operate on second cyclotron harmonic.Nowadays applications of gyrotron-based setups become more demanding in terms of output power. Also new applications appear that require high power, for example fabrication of metal oxides nanopowders [4] or production of oversized diamond disks for vacuum windows.At present, a powerful gyrotron complex is being developed at the Institute of Applied Physics of the Russian Academy of Sciences, which includes a "warm" solenoid with magnetic shielding [5,6] (see Fig. 1). Due to ferromagnetic screens, it is possible either to reduce the energy consumption of the solenoid in more than two times, or to increase the frequency of radiation while maintaining the energy of the magnetic system. The main parameters of the gyrotron are: At the same time ferromagnetic screens substantially increases the inhomogeneity of the magnetic field outside the screens, in particular in the collector region. So here the coefficient of non-adiabaticity H = h/L B (here h is the step of electron trajectory, L B is the scale of the magnetic field) exceeds 2 (see Fig. 2).Due to nonstandard distribution of the magnetic field in such systems and increased energy of an electron beam, collector of a gyrotron with magnetically shielded solenoid would differ significantly from collector of a standard technological gyrotron. The intensity of the magnetic field outside the shielding decays very rapidly; due to this, the motion of the electrons will be nonadiabatic. In this report, a collector design is presented and the simulation of the motion of electrons in the collector region is carried out. The results of the simulation (see Fig. 3) show that, due to the rapid decay of the magnetic field, electrons, falling into the region of the nonadiabatic field, acquire a transverse velocity and twist, starting to move downward along the radius. Then, when the magnetic field almost completely decays, the electron beam continues to fly apart inertially, while the direction of motion of the electrons is determined by the angle of the velocity vector at the exit from the region where the magnetic field is still significant. The inertial expansion of the electron beam provides a large ratio of the beam track length to the radius of the collector Rc and a smooth energy density distribution within the track. However it is possible to use this effect

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“…[6][7][8][9][10] The gyrotron consists of several major components including a magnetron injection gun (MIG), open-ended cavity, mode converter, and collector. [11][12][13] The mode converter is critical: it converts a higher-order mode from the interaction circuit into a Gaussian-like beam, which effectively transmits RF power through free space.…”

Section: Introductionmentioning

confidence: 99%

Cold testing of quasi-optical mode converters using a generator for non-rotating high-order gyrotron modes

Kim

Choe

et al. 2014

Review of Scientific Instruments

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Selective suppression of high order axial modes of the gyrotron backward-wave oscillator Phys. Plasmas 14, 093301 (2007) In this paper, we test the performance of a quasi-optical, internal-gyrotron mode converter. When cold testing mode converters, a rotating higher-order mode is commonly used. However, this requires a nontrivial design and precise alignment. We thus propose a new technique for testing gyrotron mode converters by using a simple, non-rotating, higher-order mode generator. We demonstrate the feasibility of this technique for a W-band gyrotron quasi-optical mode converter by examining the excitation of a TE 6,2 mode from a non-rotating mode generator. Our results demonstrate that this new cold-test scheme is an easy and efficient method for verifying the performance of quasi-optical mode converters.

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24–84-GHz Gyrotron Systems for Technological Microwave Applications

Cited by 118 publications

References 11 publications

Frequency-Tunable CW Gyro-BWO With a Helically Rippled Operating Waveguide

Frequency-Tunable CW Gyro-BWO With a Helically Rippled Operating Waveguide

Collector system of a gyrotron with magnetically shielded solenoid

Cold testing of quasi-optical mode converters using a generator for non-rotating high-order gyrotron modes

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