Unique developments

The new-generation high-power gyrotrons developed in cooperation with the closed joint-stock company GYCOM are capable of generating radiation with a power of up to 1 MW and an efficiency of 50 to 55% by pulses with a duration of up to 1000 s in quasi-continuous regime at frequencies of 30 to 170 GHz. The most powerful gyrotrons have artificial diamond output windows, high-efficiency quasi-optical converters of the operating mode into a paraxial wave beam and systems of recovery of the residual energy of the electron beam. High-power gyroklystrons and broadband gyro-BWOs at frequencies of about 35 and 94 GHz have been developed and brought to a high technical level for use in radar systems of a new type.

Gyrotron microwave complexes for processing of a wide class of dielectric, semiconductor, and metal powder materials. Methods for creating new materials (including nano materials) and methods for pilot testing of the processes have been developed. By microwave radiation heating without using the external pressure, dense (more than 98% of the theoretical value) nano-structural aluminum-oxide and laser-oxide ceramics have been obtained.

A series of stabilized high-voltage power-supply sources with an output voltage of 5 to 50 kV and a power of up to 60 kW. They have a unified modular design based on modern power semiconductor devices. The sources ensure operation of high-power microwave devices (magnetrons, gyrotrons, etc.) both in CW and pulse-periodic oscillation modes.

Hydroacoustic measuring complex "Neva-IAP" has been developed and constructed for measuring the underwater noise level of ships and submarines in shallow-water test areas in the presence of neighboring-navigation noise. The complex provides measurements of objects with underwater noise levels below the background acoustic noise of the sea. The complex and its metrological equipment are certified as a measuring facility in the Navy test areas.

High-power low-frequency hydroacoustic sound sources. Piezoceramic longitudinal-flexural transducers at resonant frequencies of 100 to 1000 Hz. The efficiency is more than 70%. The operating frequency band is more than 50% of the resonant frequency. The vibrators are used for exciting sound fields on routes over hundreds or thousands of miles. The high output power (up to 30 kW) is sufficient to address a number of basic and applied problems of ocean acoustics, in the first place, the problems of remote sensing and underwater lighting conditions. The technology makes it possible to create vibrators that are unrivaled in acoustic parameters and mass-size characteristics.

Hydroacoustic data collection system for multichannel antenna arrays and spatially distributed antenna groups in a wide range of 5 Hz to 10 kHz provides coherent signal processing and beamforming to the nearest tenth of a degree at the maximum frequency of the operating range with dynamic range no worse than 105 dB in all one-third octave bands. The Ethernet protocol capabilities and transmission of digital streams over fiber-optic and radio channels are employed. A pilot batch of products has been manufactured and their testing and trial operation in marine experiments have been performed.

A set of technical tools for a study of vibration and acoustic characteristics of complex mechanical and acoustic systems in the shipbuilding, aerospace, and construction areas. The equipment is designed for automatic polling of the vibration sensor systems and solution of diagnostic problems and operates as a full-scale multi-channel signal analyzer with an extensible set of functions and as a multichannel digital data logger. It is used in the control systems of power equipment, research problems in vibroacoustics, and for measurement of the vibration and noise levels.

Dual-band (3 and 2 mm) atmospheric absorption meter for monitoring of atmospheric moisture content and water content of clouds is a radiometric system composed of two radiometers (in the same housing) at frequencies of 84 to 99 GHz and 132 to 148 GHz, a positioner, and a data control, acquisition, and processing system based on a PC and a USB-4716 module. The data control, acquisition, and processing system provides fully automatic control of the complex in cyclic observation mode at a given time.

Mobile microwave ozonometer (of size 500×225×125 mm and mass 10 kg) is designed for a study of the ozone layer at altitudes of 20 to 60 km under field conditions. The device performance is as follows: single-sideband noise temperature 2500 K, analysis bandwidth 240 MHz, spectral resolution from 1 to 10 MHz, and 32 channels. The ozonometer sensitivity permits recording the spectrum of the atmospheric ozone radiation line (the resonant frequency is 110836.04 MHz) for a signal-accumulation time of 5 min.

Millimeter- and submillimeter-wave resonator spectrometer (36—520 GHz) based on a series of BWOs with synthesized frequency. It significantly exceeds all counterparts known to date in bandwidth and measurement accuracy. A record-breaking sensitivity of 4 · 10—9 cm—1 to absorption-coefficient variation is achieved. The spectrometer is equipped with a thermal pressure chamber for studying the dielectric properties of solid, liquid, and gaseous dielectrics, including the atmospheric gas spectra, under pressures from a few millitorr to atmospheric pressure in the temperature range from —253 to +50°С. Moreover, the spectrometer permits one to explore the reflection coefficients of metals and coatings.

Millimeter- and submillimeter-wave sub-Doppler spectrometer allows obtaining (by the Lamb dip method) narrow nonlinear resonances with a minimum width of up to 8—10 kHz in the Doppler circuit of rotational transitions of molecules and measurement of their frequencies with absolute accuracy better than 1 kHz (±500 Hz) without using the resonator.

Radioastronomic SiS (superconductor-insulator-semiconductor) receiver. The device has two bands (the wavelengths are 2 and 3 mm), two (left- and right-hand circular) polarizations and a noise temperature of ~60 K in each channel.

Technology for growing combined substrates containing polycrystalline and single-crystal CVD diamonds from the gaseous phase makes it possible to obtain epitaxial layers of required quality for the formation of semiconductor diamond structures. Plates of combined diamond 200—500 μm thick and up to 100 mm in diameter are suitable for producing electronic devices on a single-crystal surface in the existing technological lines developed for the silicon technology. This technology will permit creating electronic devices with the best performance due to a higher carrier mobility than in silicon and stability of the CVD diamond to external radiation, high pressure, and temperature differences. The technology was developed in cooperation with the scientific and production enterprise "Istok".

Technology for deposition of thin layers of semiconductor materials (including broadband) using the plasma maintained by the gyrotron microwave radiation at a frequency of 24 GHz under the ECR discharge conditions. Use of such a high-frequency heating (the frequency is usually 2.45 GHz) makes it possible to create a non-equilibrium plasma with high density (~1012 cm—3), which provides a high rate of plasma-chemical reactions with relatively low energies of ions and neutral particles. The as-grown structures are promising for use in optoelectronic devices.

Prototype industrial plant (reactor) for high-speed growing of polycrystalline diamond in the plasma created by a CW gyrotron at a frequency of 28 GHz. The plant is used for growing polycrystalline diamond films and plates of large area (more than 100 cm2) at a growth rate of no less than 10 μm/h, which significantly exceeds the growth rate in the existing magnetron-based microwave reactors. The diamond films synthesized in the reactor will be used in electronics, nuclear engineering, laser engineering, synchrotron radiation optics, electrochemistry, and manufacturing industry, as well as for fabricating radiation-resistant detectors of ionizing radiation, windows for megawatt-power gyrotrons, and high-power technological lasers (in cooperation with GYCOM).

Faraday isolators with short magneto-optical elements are among the key elements in lasers. They are used for isolation (shielding) of low-power laser elements from high-power radiation or for suppression of self-excitation of amplifiers and reliably operate at an average optical power of 1 kW or more (cf. with a conventional value of less than 100 W). Specific features include a much higher magnetic field, which has a maximum of 2.5 T (versus ~1.5 T), and original optical circuits which drastically attenuate spurious thermal effects.

Cryogenic Faraday isolator for use in lasers with an average power of more than 10 kW is an optical cryostat, in which a permanent-magnet Faraday rotator is cooled down to the liquid-nitrogen temperature. This makes it possible to use the advantages of the disk geometry (frontal heat sink, composite materials, etc.) and also increases the number of media for use as a magneto-optical element or a compensator for spurious thermal effects. This radically new line in creating Faraday isolators allows utilizing them in high-power lasers.

Diffuse fluorescence tomograph for in vivo studies of tumor tissues based on the detection of a weak fluorescent signal and solution of the inverse problem of reconstructing the distribution of fluorophore in tissue with allowance for the diffuse light propagation. Diffuse fluorescence tomography provides three-dimensional images of tumors labeled with fluorophores, including fluorescent proteins.

Endo ocular OCT device for intraoperative monitoring of surgery of the retina and visual nerve. The OCT device has a replaceable probe with an outer diameter of the tip of 0.62 mm. The resolution of 20 μm at imaging depth of 1.5 mm was obtained by scanning the studied objects with a superluminescent source at a wavelength of 1310 nm. The device provides endoscopic monitoring during surgical intervention and real-time imaging of multilevel structures of the posterior eye chamber in the area of the nerve fiber layer of the retina and visual nerve. The device has been successfully tested in clinical practice.

Endoscopic optical coherence tomographs for clinical applications, such as imaging of the surface structure of mucous and serous tissues of human internal organs, including the devices for polarization-sensitive measurements (increasing the diagnostic value of the method), the devices with thin probes compatible with a wide class of medical endoscopic tools, as well as a high-speed version of an endoscopic tomograph with 8 frames per second imaging for real-time observation of the internal state and mobility of the living biological tissue under study.

Microwave thermodestruction system (MTDC-1) is designed for microwave tumor ablation (MTA), i.e., destruction of focal deep-seated (liver, kidney, etc.) tumor nodes and superficial tumors of the gastro-intestinal tract. It can be used as an intraoperative ultrasound-guided tool in endoscopic interventions with a system of removable needle probes and flexible antennas. A microwave oscillator (2.45 GHz) with controlled average output power of up to 500 W is used for the local destruction of biological tissues. A cooled needle 3 mm in diameter and 150—200 mm long, which is connected to the oscillator via a flexible radio-frequency cable, is used as a tool for direct impact on tumor tissue. The method has found its place in the arsenal of surgical techniques for the treatment of focal liver diseases. The system was developed by researcher of the Institute of Applied Physics and of the Volga District Medical Center.

Rail flaw detector for nondestructive rail testing. Operated unattended with a built-in recorder, the device records information on the rail structure, tuning parameters, and operator's manipulations and also permits visualization of echographic information.

High-speed millimeter-wave digital frequency meter (70—170 GHz). The frequency meter has continuous and slave modes, direct reading without an external mixer, built-in memory for measurement results, and connection to the PC via RS-232 channel.
It measures the frequencies of a continuous signal and single microwave pulses having a duration of no less than 30 ms and a frequency drift of up to 8 GHz/s with
1 MHz accuracy.