Kamenskiy, Maksim Vladislavovich

Kulygin M.L., Novikov E.A., Litovsky I.A., Kamensky M.V., Malshakova O.A., Sorokin A.A.

Samsonov S.V., Denisov G.G., Bogdashov A.A., Gachev I.G., Kamenskiy M.V., Leshcheva K.A., Savilov A.V., Novak E.M.

Kulygin M.L., Novikov E.A., Kamensky M.V., Belousov V.I., Litovsky I.A., Fokin A.P., Ananichev A.A., Orlovsky A.A., Parshin V.V., Serov E.A., Proyavin M.D., Malshakova O.A., Afanasiev A.V., Sorokin A.A.

Denisov G.G., Sobolev D.I., Proyavin M.D., Gashturi A.P., Morozkin M.V., Kotomina V.E., Kamensky M.V., Orlovsky A.A.

Samsonov S.V., Denisov G.G., Bogdashov A.A., Gachev I.G., Kamenskiy M.V., Savilov A.V., Novak E.M.

Semenov E.S., Proyavin M.D., Morozkin M.V., Zuev A.S., Kamensky M.V.

Samsonov S.V., Denisov G.G., Bogdashov A.A., Gachev I.G., Kamenskiy M.V., Leshcheva K.A., Savilov A.V., Novak E.M.

Proyavin M., Morozkin M., Manuilov V., Soluyanova E., Tai E., Kamenskiy M., Orlovskiy A., Glyavin M.

Proyavin M.D., Morozkin M.V., Manuilov V.N., Soluyanova E.A., Tai E.M., Kamenskiy M.V., Orlovskiy A.A., Sobolev D.I., Glyavin M.Y.

Samsonov S.V., Denisov G.G., Bogdashov A.A., Gachev I.G., Kamenskiy M.V., Leshcheva K.A.

Rozental R.M., Samsonov S.V., Bogdashov A.A., Gachev I.G., Ivanov A.A., Kamenskiy M.V.

For the first time, self-mode-locking regime in a continuous-wave (CW) K-band helical waveguide gyro-TWT with strong external reflections was obtained experimentally. We have registered correlated sequences of nanosecond-duration pulses with a peak intensity of more than seven times larger than the mean intensity of the output radiation.

Proyavin M.D., Morozkin M.V., Manuilov V.N., Soluyanova E.A., Tai E.M., Kamenskiy M.V., Orlovskiy A.A., Glyavin M.Y.

A series of work has been carried out to develop a new generation of technological gyrotrons on the first cyclotron harmonic with a radiation frequency of 28 GHz and a power beyond 20 kW. The generation efficiency reaches up to 55% at 6-kW power level without a system of recovery of residual electron energy. The efficiency of the entire setup is above 35% in the mode of maximum radiation power, which is achieved by using a magnetically shielded oil-cooled solenoid. The proper operation of the developed electron-optical system under conditions of a quasi-adiabatic magnetic field in the area of formation of a helical electron beam and a non-adiabatic one in the collector region is confirmed. The paper presents experimental data which is consistent with the results of numerical modeling. This allows us to further count on the implementation of generators up to the W-band frequency range using the magnetic system and high-voltage power sources.

Proyavin M.D., Morozkin M.V., Ginzburg N.S., Denisenko A.N., Kamenskiy M.V., Kotomina V.E., Manuilov V.N., Orlovskiy A.A., Osharin I.V., Peskov N.Y., Savilov A.V., Zaslavsky V.Y.

Novel additive technology of the Chemical Metallization of Photopolymer-based Structures (CMPS) is under active elaboration currently at the IAP RAS (Nizhny Novgorod). The use of this technology has made it possible to implement components of electron–optical and electrodynamic systems for high-power microwave vacuum tubes, such as a gyrotron and a relativistic Cherenkov maser, the design and experimental studies of which are described in this paper. Within the framework of the gyrotron developments, we carried out a simulation of the distribution of the heat load on the collector of high-power technological gyrotron taking into account secondary emission. The prospect of a significant reduction in the maximum power density of the deposited electron beam was shown. The experimental study of the gyrotron collector module manufactured using CMPS technology demonstrated high potential for its further implementation. Recent results of theoretical and experimental studies of a spatially extended Ka-band Cherenkov maser are presented. In this oscillator, the 2D-periodical slow-wave structure made by the proposed technology was applied and a narrow-band generation regime was observed with a sub-GW power level. The design and simulations of a novel selective electrodynamic system for a high-harmonic gyrotron with the planned application of the CMPS technology are discussed.

Leshcheva K.A., Kamenskiy M.V., Gachev I.G., Bogdashov A.A., Denisov G.G., Samsonov S.V.

Design of a proof-of-principle experiment on a broadband frequency-tunable gyrotron backward-wave oscillator (gyro-BWO) is discussed. The gyro-BWO under consideration is using a recently proposed interaction circuit in the form of quasi-optical transmission line where the mirrors direct a Gaussian wave beam along a zigzag-like path with vertical and inclined segments periodically spaced along longitudinal z-axis. A static B-field and translational electron velocity are directed along z-axis, so that the electron beam periodically intersects with the wave beam. The resonant cyclotron beam-wave interaction occurs at the regions of perpendicular beam-wave intersections resulting in low sensitivity to the particle velocity spread similar to a gyrotron. The 3D PIC simulations show prospects of this “zigzag” gyro-BWO in realization of frequency tunable oscillators capable of high power and unique (octave frequency band) tuning in the short-millimeter wavelength range. In the paper, a general layout and results of computer modeling of major experimental components (interaction circuit, electron gun, output microwave system etc.) are discussed for a CW device using a cryomagnet with the B-field of 4–8 T. According to CST simulations, the designed gyro-BWO ensures output of nearly Gaussian wave beam of kilowatt power level at any predefined frequency within 107–215 GHz range.

Morozkin M., Manuilov V., Proyavin M., Kotomina V., Kamenskiy M., Orlovskiy A.

Ding K., Bi C., Ao Y., Cheng L., Fang H., Dong Y., Zhou H., Wang X., Zhang Z., Liang S., Gong S., Zhang Y.

In this paper, we propose a sub-terahertz PAM4 modulator based on transmission characteristic reconstruction by combining meta-unit, GaAs Schottky diode, and fan branch lines. This method combined the significant electromagnetic resonant characteristics of meta-unit, the high-speed controllability of GaAs Schottky diode, and the high integration of on-chip transmission line together to realize high-speed modulation. Then, we achieve transmission characteristic reconstruction by adjusting the resonance strength under different applied voltages through fan branch lines, enabling high-order amplitude modulation of sub-terahertz waves. The experimental results show that the PAM4 modulation of sub-terahertz waves is achieved with a nearly linear variation of the transmission coefficient in the whole voltage range and a maximum modulation rate of 21 Gbps, providing a promising prospect for the development and application of integrated sub-terahertz direct high-order modulation technology.

Novak E.M., Samsonov S.V., Savilov A.V.

Gashturi A.P., Sobolev D.I., Denisov G.G., Proyavin M.D., Morozkin M.V., Chirkov A.V.

Novak E.M., Savilov A.V.

Novak E., Savilov A.

Peskov N.Y., Zaslavsky V.Y., Denisenko A.N., Abubakirov E.B., Palitsin A.V., Panin A.N., Proyavin M.D., Rodin Y.V., Ginzburg N.S.

Yang T., Chang C., Yao H., Chang T.

Starodubov A.V., Serdobintsev A.A., Galushka V.V., Kozhevnikov I.O., Amanov T.M., Titov V.N., Ozhogin I.S., Chernozubkina K.S., German S.V., Molchanov S.Y., Bahteev I.S., Ryskin N.M.

Trends concerning the acceleration of the development of novel millimeter and terahertz-band vacuum microelectronic devices highly demand rapid and cost-effective techniques that allow microfabrication of the proof-of-concept physical models. The additive manufacturing can meet the abovementioned requirements. Nowadays, vat photopolymerization is one of the most flexible and precise additive technologies that allows fabrication of microsized elements with tolerance down to tens of microns. We proposed an approach based on the liquid crystal display vat photopolymerization and vacuum magnetron sputtering for rapid and low-cost microfabrication of the key sub-terahertz-band electromagnetic components. To validate the proposed approach, several samples of single grating slow-wave structure for a W-band (75–110 GHz) vacuum-tube device were successfully microfabricated for the first time. The structure with total length of 60 mm consisted of a 20-pitch uniform section and two 11-pitch tapered sections at both ends in order to reduce the reflections. Magnetron sputtering was used to deposit the thin copper film onto the inner surface of the fabricated samples. The surface roughness was measured before and after metallization using profilometry. Morphological and profilometric analyses have shown a decrease in the surface roughness up to 30% after 1-µm-thick metallization and up to 50% after 3-µm-thick metallization. Results indicate that a 3-µm-thick metallization layer sufficiently meets requirements for suitable reflection and transmission losses in the W-band. Reflection and transmission losses in the W-band of the fabricated slow-wave structure were measured using a vector network analyzer and compared with the results of numerical simulation using 3D finite-difference time-domain code. Comparison with the numerical simulation results shows good qualitative and quantitative agreement. The measured reflections were below – 20 dB in the 88–105 GHz frequency range. The specific transmission attenuation was measured to be 0.08 dB per pitch. This study underscores the promise of the proposed method for swiftly prototyping complex electromagnetic structures, leading to significant time savings in proof-of-concept research endeavors.

Ryskin N.M., Ozhogin I.S., Starodubov A.V., Serdobintsev A.A., Kozhevnikov I.O., Galushka V.V., Emelianov V.V., Molchanov S.Y., Bakhteev I.

Zuev A., Plankin O., Semenov E., Zapevalov V.

Kulygin M.L., Novikov E.A., Litovsky I.A., Kamensky M.V., Malshakova O.A., Sorokin A.A.

Rozental R.M., Ivanov A.A.

Samsonov S.V., Denisov G.G., Bogdashov A.A., Gachev I.G., Kamenskiy M.V., Leshcheva K.A., Savilov A.V., Novak E.M.

Novak E.M., Savilov A.V., Kalynova G.I.

Bandurkin I.V., Bylinsky N.A., Zaslavsky V.Y., Kalynov Y.K., Osharin I.V., Proyavin M.D., Peskov N.Y., Savilov A.V., Semenov E.S.

Kulygin M.L., Novikov E.A., Kamensky M.V., Belousov V.I., Litovsky I.A., Fokin A.P., Ananichev A.A., Orlovsky A.A., Parshin V.V., Serov E.A., Proyavin M.D., Malshakova O.A., Afanasiev A.V., Sorokin A.A.

Novak E.M., Samsonov S.V., Savilov A.V.

Li G., Claveau E.L., Jawla S.K., Schaub S.C., Shapiro M.A., Temkin R.J.

Samsonov S.V., Denisov G.G., Bogdashov A.A., Gachev I.G., Kamenskiy M.V., Leshcheva K.A.

Gashturi A.P., Sobolev D.I.

Novak E.M., Samsonov S.V., Savilov A.V.

We present the quasi-analytical spatiotemporal theory, which describes the process of establishing generation in a backward-wave gyro-oscillator based on the use of a sectioned quasi-optical system with the zigzag path of the operating wave beam. This theory explains peculiarities (namely, a piecewise character) of changing the operating frequency and power of the output signal in the process of the broadband frequency tuning provided by changing the operating magnetic field. This theory also describes competition of different modes of the system in the process of excitation of auto-oscillators and predicts the possibility for realization of the regime of automodulations of the output power, as well as the regime of formation of a short powerful super-radiant pulse.

Proyavin M.D., Morozkin M.V., Manuilov V.N., Soluyanova E.A., Tai E.M., Kamenskiy M.V., Orlovskiy A.A., Glyavin M.Y.

A series of work has been carried out to develop a new generation of technological gyrotrons on the first cyclotron harmonic with a radiation frequency of 28 GHz and a power beyond 20 kW. The generation efficiency reaches up to 55% at 6-kW power level without a system of recovery of residual electron energy. The efficiency of the entire setup is above 35% in the mode of maximum radiation power, which is achieved by using a magnetically shielded oil-cooled solenoid. The proper operation of the developed electron-optical system under conditions of a quasi-adiabatic magnetic field in the area of formation of a helical electron beam and a non-adiabatic one in the collector region is confirmed. The paper presents experimental data which is consistent with the results of numerical modeling. This allows us to further count on the implementation of generators up to the W-band frequency range using the magnetic system and high-voltage power sources.

Leshcheva K.A., Kamenskiy M.V., Gachev I.G., Bogdashov A.A., Denisov G.G., Samsonov S.V.

Design of a proof-of-principle experiment on a broadband frequency-tunable gyrotron backward-wave oscillator (gyro-BWO) is discussed. The gyro-BWO under consideration is using a recently proposed interaction circuit in the form of quasi-optical transmission line where the mirrors direct a Gaussian wave beam along a zigzag-like path with vertical and inclined segments periodically spaced along longitudinal z-axis. A static B-field and translational electron velocity are directed along z-axis, so that the electron beam periodically intersects with the wave beam. The resonant cyclotron beam-wave interaction occurs at the regions of perpendicular beam-wave intersections resulting in low sensitivity to the particle velocity spread similar to a gyrotron. The 3D PIC simulations show prospects of this “zigzag” gyro-BWO in realization of frequency tunable oscillators capable of high power and unique (octave frequency band) tuning in the short-millimeter wavelength range. In the paper, a general layout and results of computer modeling of major experimental components (interaction circuit, electron gun, output microwave system etc.) are discussed for a CW device using a cryomagnet with the B-field of 4–8 T. According to CST simulations, the designed gyro-BWO ensures output of nearly Gaussian wave beam of kilowatt power level at any predefined frequency within 107–215 GHz range.

Kulygin M.L., Litovsky I.A., Gospodchikov E.D., Denisov G.G.

Antipov S., Kuzikov S. ., Vikharev A. .

Recently, gradients on the order of $1\text{ }\text{ }\mathrm{GV}/\mathrm{m}$ have been obtained with single-cycle ($\ensuremath{\sim}1\text{ }\text{ }\mathrm{ps}$) THz pulses produced by the conversion of high peak power laser radiation, in nonlinear crystals ($\ensuremath{\sim}1\text{ }\text{ }\mathrm{mJ}$, 1 ps, up to 3% conversion efficiency). Such high intensity radiation can be utilized for charged particle acceleration. For efficient acceleration, a large number of accelerating cells have to be stacked together with delay lines in order to provide proper timing between accelerating fields and moving electrons. Additionally, THz pulses in individual cells need to be focused transversely to maximize the accelerating gradient. This focusing is currently done by the tapering of the waveguide. In this paper, we propose instead to use dielectric lenses for the robust focusing of THz pulses in accelerating cells. Each lens is made from the same material as the delay line in a monolithic unit. We have fabricated prototype units from quartz and silicon. Such an approach simplifies the fabrication and alignment of the multicell accelerating structure. We present a design in which a 100 microJoule THz pulse produces a 600 keV energy gain in a 5-mm long 10-cell accelerating structure for an ultrarelativistic electron. This approach can be extended to nonrelativistic particles.

Novak E.M., Samsonov S.V., Savilov A.V.

We describe the small-signal theory of a backward-wave gyro-oscillator with a sectioned quasi-optical system with the zigzag path of the operating wave beam. This theory explains peculiarities (namely, a piecewise character) of changing the operating frequency and power of the output signal in the process of the broadband frequency tuning provided by changing the operating magnetic field.

Marek A., Feuerstein L., Illy S., Thumm M., Wu C., Jelonnek J.

Marek A., Feuerstein L., Illy S., Thumm M., Wu C., Jelonnek J.

A novel type of frequency doubling gyrotron traveling wave amplifier (FD-GTWT) for applications that require high-power microwave in the sub-THz frequency range is presented. The proposed FD-GTWT delivers high power and high gain over a broad bandwidth and simultaneously doubling the frequency of the input signal. Simulations of a first 263GHz FD-GTWT design are presented, which show for a 10mW driving signal at 131.5GHz an RF output power of 250W at 263GHz and a gain of >40dB over a bandwidth of 17.5GHz. The basis of the FD-GTWT are two interaction circuits separated by a long drift section. In the first circuit, the electron beam is pre-bunched at the fundamental cyclotron harmonic. In the second one, high-power RF is induced by the pre-bunched electron beam at the 2nd cyclotron harmonic. Both sections consist of helically corrugated waveguides that efficiently suppress parasitic interactions and allow broad bandwidth.

Liu G., Cao Y., Wang Y., Jiang W., Wang W., Wang J., Luo Y.

Overall design and cold test of a G-band gyrotron traveling-wave tube (gyro-TWT) amplifier are presented. This gyro-TWT aims at achieving a goal of 10-kW pulse output power in the range of 210–220 GHz. It is operated in a circular TE 01 mode at the fundamental cyclotron harmonics, which is driven by a 50-kV, 3-A gyrating electron beam. Low velocity spread diode-type magnetron injection gun (MIG), multichannel TE 01 mode input coupler, broadband metasurface output window, and lossy material loaded beam–wave interaction circuit are simulated and partially measured. Particle-in-cell (PIC) simulation shows that the designed gyro-TWT can achieve a saturated output power over 10 kW in the range of 210–228 GHz with a beam velocity spread of 2.29%.

Denisov G., Palitsin A., Sobolev D., Morozov S., Parshin V., Glyavin M.