Search

The results of a study of the chemical composition, vacuum and thermal properties of boron carbide ceramics, which is planned to be used in ITER diagnostic ports, are presented. The measured boron carbide content in sintered and hot pressed ceramics is 99,0÷99,7%, they do not contain unauthorized impurities, which in accordance to ITER requirements. The outgassing rate of sintered and hot pressed boron carbide produced by Virial Ltd meets the requirements of the ITER Vacuum Handbook. Sintered ceramic is cheaper than hot pressed, and it is produced in large volumes, which it would be preferable for use in ITER ports, but with its massive use may create a significant gas load on the vacuum system that requires accurate analysis and outgassing tests on all candidated ceramics.

Measurement of the ionization yields for nuclear recoils is related to the energy calibration of dark matter and low-energy neutrino detectors. In this study, some results of the previous measurements of the ionization yields for nuclear recoils in liquid argon using the neutron scattering technique in the two-phase detector are discussed. The methods to increase light collection of scintillation (S1) and ionization (S2) signals in the two-phase detector using SiPM matrices and THGEM electrodes with increased optical transparency are proposed. These steps are necessary to implement the neutron double-scattering technique, which will provide measurement of the ionization yield of recoiling nuclei in the unexplored energy range.

The results of long-term outgassing test of large quantities of ceramics, which is planned to be used in ITER diagnostic ports, are presented. The outgassing rate of boron carbide ceramics produced by Virial Ltd meets the requirements of the ITER Vacuum Handbook. Massive use of ceramics in ITER may create a significant gas load on the vacuum system that requires accurate analysis. Calculations of gas emission of Equatorial Port #11 were performed and it was demonstrated that a significant amount of ceramics can be used for neutron protection. Experiments on activation of ceramics and stainless steels by fast neutrons were carried out, which showed a rapid reduction of residual radioactivity and absence of hazardous impurities.

Results of spectral and magnetic diagnostics of plasma differential rotation in the GOL-3 multiplemirror trap are presented. It is shown that the maximum frequency of plasma rotation about the longitudinal axis reaches 0.5 MHz during the injection of a relativistic electron beam into the plasma. The data of two diagnostics agree if there is a region with a higher rotation frequency near the boundary of the electron beam. Plasma differential rotation can be an additional factor stabilizing interchange modes in the GOL-3 facility.

The review presents experimental studies of plasma-surface interaction and materials behavior under plasma loads done in the multiple-mirror trap of the GOL-3 facility. In the experiments for the PSI, the energy density in the extracted plasma stream varies from 0.5 to 30 MJ/m2. Parameters of near-surface plasma measured by a set of diagnostics are reviewed. Surface patterns of targets exposed to the plasma are analyzed. The erosion depth depends on the energy loads—it rises from 0 to 600 μm at 0.5 and 30 MJ/m2, correspondingly. Cracking and evolution of graphite and tungsten surface morphology are discussed. The enthalpy of brittle destruction of graphite (10 kJ/g), which determines the threshold of bulk damage of targets irradiated with a charged-particle flux with large penetration depth, was determined. Comparison of different facilities for PSI studies are presented. Heat flux play a key role to the target surface erosion.

Residual stresses in rolled tungsten after pulsed irradiation with a plasma and an electron beam at the GOL-3 facility were measured. The mechanical stresses were derived from the strain, which was measured by the change in the interplanar distance in different directions. The interplanar distance was gaged from the shift of the peak of diffraction scattering of X-rays. The measured tension turned out to be a tensile stress along the surface. The tension along the direction of rolling and grinding was approximately three times larger than that in the perpendicular direction. The work was carried out at the VEPP-3/VEPP-4 complex.

The study is devoted to tungsten surface modification after irradiation at the GOL-3 facility with plasma loads corresponding to the ITER type I ELMs. In order to emulate heating with a steady plasma flux in the ITER divertor, some of the tungsten samples were preheated up to 500 °C. It was found out that the behavior of the surface modification (the crack pattern and the number of bubbles) depends on the initial temperature of the targets. While the orientation of major crack networks correlates with the direction of machining of the samples. Afterwards we have observed the process of craters’ formation caused by dust particle impacts.

Project of powerful submillimeter wave generator based on intense interaction of a relativistic electron beam with a magnetized plasma is developed at BINP RAS in collaboration with NSU. In presented experiments, the beam with parameters 0.8 MeV/15 kA/6 μs is injected into a plasma column with the density ∼ 1015 cm-3. Spectral composition of the emission from the plasma column is studied in the frequency band 0.1 – 1 THz. In the analysis of the results of our studies we focus on the role of strong plasma density gradients in generation of sub-mm waves.

Investigation of subthermonuclear plasma confinement and heating in magnetic fusion devices such as GOL–3 and GDT at the Budker Institute (Novosibirsk, Russia) requires sophisticated equipment for neutron-, gamma- diagnostics and upgrading data acquisition systems with online data processing. Measurement of fast neutron flux with stilbene scintillation detectors raised the problem of discrimination of the neutrons (n) from background cosmic particles (muons) and neutron-induced gamma rays (γ). This paper describes a fast neutron flux analyzer with real-time digital pulse-shape discrimination (DPSD) algorithm FPGA-implemented for the GOL–3 and GDT devices. This analyzer was tested and calibrated with the help of 137Cs and 252Cf radiation sources. The Figures of Merit (FOM) calculated for different energy cuts are presented.

This paper describes results of GOL-PET experiments on subterahertz (0.1–0.5 THz) emission from a magnetized plasma column during passing of a high-current $(\sim \hbox{10 kA})$ relativistic $(\sim \hbox{0.6 MeV})$ electron beam. The subterahertz radiation is generated in the plasma due to high-level turbulence induced by two-stream instability of the electron beam. These experiments are carried out at the specialized GOL-3T device. For the plasma density range 10 $^{14}\hbox{–10}^{15}~\hbox{cm}^{-3}$ , we have studied emission dynamics from the plasma column in its transverse and longitudinal directions. The spectral composition and polarization of the radiation was also investigated.

Hihg-power flows of plasma cause mechanical destruction of materials via non-uniform deformation and stresses. The possibility of synchrotron radiation scattering diagnostics of deformation is discussed. The experiments at the new scattering station “Plasma” on VEPP-4M demonstrated the measurements of change in the diffraction angle during pulsed heating.

A mathematical model of surface cracking under pulsed heat load was developed. The model correctly describes a smooth brittle–ductile transition. The elastic deformation is described in a thin-heated-layer approximation. The plastic deformation is described with the Hollomon equation. The time dependence of the deformation and stresses is described for one heating–cooling cycle for a material without initial plastic deformation. The model can be applied to tungsten manufactured according to ITER specifications. The model shows that the stability of stress-relieved tungsten deteriorates when the base temperature increases. This proved to be a result of the close ultimate tensile and yield strengths. For a heat load of arbitrary magnitude a stability criterion was obtained in the form of condition on the relation of the ultimate tensile and yield strengths.

A new simple predictor–corrector method for stationary self-consistent electrostatic field modeling is developed on the basis of Comsol Multiphysics 3.5 capabilities. The method is implemented in the script written in Comsol Script 1.3. The basic idea of the method is iterative computation of space charge density from a set of virtually traced trajectories of charged particles. The script is tailored for modeling of charged particle movement in a cylindrically symmetric self-consistent stationary electric field of a gas-filled DD-neutron tube with an ion source driven by a heated cathode. The proposed approach is useful for determining the mode of operation of a tube (whether plasma is formed in ion source or the mode of operation is plasmaless) and for verification of design modifications for plasmaless neutron tubes. The computed charge fields are shown to be self-consistent with a space charge adjustment error of 2.5% at worst.

The plasma system and diagnostics of the new facility GOL-3T are described. This facility is the final result of the first stage in the deep upgrade of the GOL-3 multiple-mirror system, which has operated at the Budker Institute of Nuclear Physics since 1988. The upgrade project supposes creation of two new independent facilities at the site of GOL-3. The GOL-3T facility is intended to study the physics of beam—plasma interaction and generation of subterahertz electromagnetic radiation during the collective relaxation of a high-power relativistic electron beam with a duration of 5–10 μs. Studies on the physics of multiple-mirror plasma confinement in axisymmetric magnetic systems will be continued in a new range of experiment parameters at the second facility, named GOL-NB.

Heating and confinement of plasma in a multimirror magnetic configuration have been studied at the GOL-3 facility (Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk). The experiments are aimed at estimating the densities and charge states of the main impurities in the GOL-3 plasma and determining their contribution to the effective plasma charge. Plasma with a density of ∼1015 cm−3 was heated by a relativistic electron beam (1 MeV, 8 μs, ⩽200 kJ). At the end of electron beam injection, the plasma temperature reached 1 keV. The densities of impurities were determined using VUV and visible spectroscopy, as well as mass spectrometry of the residual vacuum. To determine the effective plasma charge, the experimental data were compared with the results of numerical simulations of the ionization balance of impurities. It is shown that the effective plasma charge calculated with allowance for the contributions from the main impurities does not exceed Zeff = 1.8, which cannot explain the experimentally observed improved confinement of low-density plasma.

This paper describes results of studies on application of high current (1–10 kA) relativistic electron beams to generate millimeter and subterahertz (sub-THz) radiation in two ways. The first one is realized at the ELMI-device where the scheme of a free electron maser (FEM) with a sheet electron beam is applied for the case of a planar two-beam-channel geometry. The second way is based on emission of sub-THz radiation from plasmas with turbulence induced by a strong relativistic electron beam. These experiments are carried out at the GOL-3 facility. We present experimental results obtained at these two devices and briefly describe their theoretical analysis.

A measurement of ionization yields in noble-gas liquids is relevant to the energy calibration of nuclear recoil detectors for dark matter search and coherent neutrino-nucleus scattering experiments. In this work we further study the ionization yield of nuclear recoils in liquid Ar, using a two-phase detector with an electroluminescence gap and DD neutron generator. The ionization yields of nuclear recoils in liquid Ar were measured at 233 keV and electric fields of 0.56 and 0.62 kV/cm; their values amounted to 5.9 $\pm$ 0.8 and 7.4 $\pm$ 1 e$^-$/keV, respectively. The characteristic dependences of the ionization yield on energy and electric field were determined, while comparing the results obtained to those at lower energies and higher fields., 10 pages, 8 figures, 1 table. Submitted to the Proceedings of the Instrumentation for Colliding Beam Physics (INSTR17) Conference. To be published in JINST

A method for creation of a long magnetized column of dense hydrogen plasma in a metal chamber by means of a high-current linear discharge is considered. It is the main method for the formation of preliminary plasma in the GOL-3 multimirror trap, in which a plasma column with a length of up to 12 m and diameter of 8 cm, suitable for conducting experiments on the injection of a relativistic electron beam, was obtained. Conditions for stable discharge operation in the density range of 3 × 1019–1022 m−3 are determined, including a discharge with a uniform longitudinal plasma density profile and incomplete initial ionization of hydrogen. It is demonstrated that the system is capable of operating in a magnetic field with a variable configuration and strength of up to 6 T in the solenoidal section and up to 12 T in the end mirrors. It is shown that an important role in the development of a discharge is played by fast electrons with energies corresponding to the initial applied voltage (about 25 kV), which provide primary gas ionization. The properties of low-temperature plasma in such a discharge are discussed.

The proposal of two neutron scattering systems for calibration of two-phase cryogenic avalanche detectors with high sensitivity being developed at Budker INP is presented. This kind of detectors is designed for the search of dark matter and low energy neutrino detection, in particular, coherent neutrino scattering on nuclei. Detector calibration is made with a measurement of ionization yield and scintillation quenching factor for low energy recoiling nuclei (in 0.5 to 100 keV range) originating from elastic scattering of neutrons. To provide wide range of recoiling nuclei energies two systems of neutron scattering are proposed. The first one is based on small-sized DD generator of fast (2.45 MeV) monoenergetic neutrons operating on sealed neutron tube. The second one is based on tandem proton accelerator and lithium target and capable of generation of monoenergetic epithermal neutrons with energy up to 100 keV

The paper describes «Scattronix» code designed for modeling of recoiling nuclei spectra in cryogenic avalanche dark matter detector being calibrated with monoenergetic flow of neutrons. «Scattronix» is the code for direct Monte-Carlo modeling of fast neutrons movement in the active media of detector. The features of the task being solved (rare collisions, elastic scattering domination) allow significant simplification of code structure and consequent performance improvement in comparison with conventional codes for neutron-media interaction modeling. Physical basics of neutron scattering on 40Ar nuclei are briefly considered. Algorithm implemented in the code is described. An example of modeled spectra is given and compared with analytical estimation of spectral line width

The paper presents experimental investigations of tungsten surface modification after plasma loads at the multimirror trap GOL-3. Energy loads on tungsten surface varied from 2 up to 4 MJ/m2 per shot with sets from 1 to 9 repetitive irradiations that corresponds to loads higher than tungsten melting threshold and is close to ITER giant ELM loads. Targets surface modification and transverse microsections after irradiation was studied by optical microscopy, SEM and hardness tester. Formation on tungsten surface of three different crack networks with typical cell sizes of 1000, 10 and 0.3 μm and bubbles are identified. The network of large cracks extend perpendicularly to the irradiated sample surface to a depth of 50–350 μm. Erosion depth depends on energy loads – rises from 20 to 200 μm at 2 and 4 MJ/m2 correspondingly. Cracking, development of tungsten surface morphology and droplets splashing are discussed.

Development of a new linear device for confinement of fusion plasmas is under way in the Budker Institute of Nuclear Physics, Novosibirsk. The new device combines features of existing GOL-3 and GDT...

A numerical method of calculating the neutron yield of accelerator neutron generators using the nuclear reactions D(d, n)3He and T(d, n)4He and results are presented. For a generator with a titanium target, the neutron yield is presented for different accelerating voltages and ratios of the ion-flux components and approximate relations suitable for real-time evaluation of the neutron yield are obtained.

Sub-THz radiation can be generated by conversion of plasma waves into electromagnetic (EM) radiation in a plasma with strong Langmuir (LT) turbulence produced via a two-stream instability of a high current relativistic electron beam (REB). Nonlinear plasmon-plasmon merging results in the generation of photons nearby the 2nd harmonic of the plasma frequency 2ω p (“2ω p -process”). For plasma densities of 1014 − 1015 cm−3, these frequencies are in the range of sub-THz waves at 370–570 GHz. The specific power density of sub-THz-wave emission from plasmas in the multi-mirror magnetic trap GOL-3 (at BINP) during injection of a 10-μs-REB with a current density of about 1 kA/cm2 at plasma densities n e ≈ 5∙1014 cm−3, electron temperatures T e ≈ 1.5 keV and magnetic induction B ≈ 4 T was measured to be approx. 1 kW/cm3 in the frequency band around 300 GHz. In the case of a weakly relativistic 100-μs-electron beam (90 keV) with 250 A/cm2 the corresponding results are 700 W/cm3 around 90 GHz with an efficiency of 1–2 % at n e ≈ 3∙1013 cm−3 (total power ≈ 30 kW). Theoretical investigations show that at a density of n e ≈ 3∙1015 cm−3 and a turbulence level of 5 % the generated sub-THz power can reach ≈ 1 MW/cm3.

The processes of plasma wave transformation into electromagnetic radiation during strong interaction of a relativistic electron beam with magnetized plasma are studied in BINP in collaboration with NSU. Since 2010, experimental studies on such transformation processes were carried out on the GOL-3 facility by measuring the radiation emitted from beam-plasma system. Then after 2014 the GOL-PET device is used for these studies. Results of these experiments on emission in the frequency interval 0.1-0.5 THz from a long plasma column due to E-beam injection are described in the presented paper. The experimental results have been compared with theoretical ones obtained for EM-wave generation by the beam-plasma system.

Results from different facilities for plasma-surface interaction (PSI) studies are compared and their relevance to each other and conditions of ITER transient events are discussed. For PSI studies different types of devices were used including open traps, tokamaks, linear plasma machines including quasi-stationary plasma accelerators, electron beams and lasers. The same damage thresholds were demonstrated with different techniques. At energy loads corresponding to ITER transient events (edge localized modes (ELMs), disruptions, etc.) only macroscopic erosion mechanisms are important. They are cracking, droplet formation and macroscopic mass losses of the target. Cracking occurs during cooling stage after irradiations. Details of plasma stream parameters are of secondary importance for cracks formation; only target temperature plays a role. Macroscopic mass losses strongly correspond with melting of a thin surface layer and heat loads play a key role for melting. Heat flux defines the targets surface erosion.

The paper presents an overview of plasma-material interaction studies at the Siberian Synchrotron and Terahertz Radiation Centre. The measurements of recrystallization and surface texturing are demonstrated. The growth of grain size after the exposure by electron beam was detected using two-dimensional diffractometry. The orientation of crystal structure was detected in the tungsten irradiated by deuterium plasma. The residual stresses in irradiated tungsten were measured. The predicted structure of deformations after pulsed heat load is confirmed. First in-situ experiments confirmed the presence of crystal plane rotation effect during a pulsed heat load.

New experimental results on magnetic compression and transport of low-temperature arc plasma at ∼3 m distance are presented. The magnetic compression ratio of the plasma stream varied from 5 to 60 at the initial plasma diameter about 5 cm. Theory predicts that the multiple-mirror magnetic field should not significantly decelerate and weaken the collisional low-temperature arc plasma. In the experiments, the transport efficiency of the plasma stream in the multiple-mirror configuration of the solenoid was compared with the same in a uniform solenoidal field. As the result, the plasma with (1–4)×1020 m−3 density at the axis was obtained at ∼3 m distance from the arc plasma source. The experiments simulated the baseline scenario of GOL-NB filling by the start plasma. Finally, the experiments described in the paper validated the decisions made for the GOL-NB start plasma source.

Helicons (circularly-polarized electromagnetic waves) propagate in a plasma with density exceeded cut-off for its frequency, and provide effective energy delivery to plasma. Accordingly, helicon discharge is one of the most suitable way for production of high-density low-temperature plasma. Helicon plasma sources, operating in the MHz frequency range and respectively low magnetic fields (0.01-0.1 T), capable to create plasma with density up to 1013 cm−3. At the same time, next generation of linear plasma facilities for both for PMI studies and fusion applications requires production of plasma with density above this limit. Theoretical studies predict that such increasing of density can be achieved by application of powerful microwave sources of GHz range frequency. The aim of the presented experiments is experimental verification of theoretical predictions and search of conditions for effective delivery of electromagnetic power to plasma towards development of stationary source of dense plasma for linear ...

The MHD activity of plasma in the GOL-3 facility was studied experimentally. The complicated azimuthal structure of the profile of the longitudinal current is revealed by magnetic measurements and high-speed imaging. The azimuthal mode composition of magnetic perturbations, as well as the frequency of their rotation in different regimes, is determined. The signs of differential plasma rotation in the facility are described. Possible mechanisms responsible for the relation of differential rotation to current filamentation and magnetic reconnection in the GOL-3 plasma are proposed. These mechanisms explain the previously observed experimental evidences of these processes.

The design principles and construction of the subterahertz radiometric spectral systems developed for the GOL-3 facility are described. The spectral systems are designed according to the quasi-optical scheme and use multilayer filters based on frequency-selective surfaces. The design and manufacturing technology of such elements are discussed. The results of measuring subterahertz radiation of plasma at the frequency close to the double plasma frequency are presented.

The paper summarizes recent advances in physics of multiple-mirror confinement. GOL-3 in Novosibirsk is the only existing large-scale device of this type. Achieved plasma parameters are: n ~ 1021 m...

The paper presents experimental investigations of plasma-surface interaction and materials behavior under plasma loads relevant to type I ITER ELMs. The experiments were performed with quasi-statio...

The latest experimental campaign at the GOL-3 multiple-mirror trap was mainly aimed at features of heating and stability of the electron-beam-heated turbulent plasma. The discussed experiments feat...

Multimirror approach to plasma confinement for fusion is studied at GOL-3 facility in the Budker Institute of Nuclear Physics (Novosibirsk, Russia). The presented work is devoted to diagnostics of heavy impurities in plasma of this facility. The main purpose is quantitative measurement of density, degree of ionization of the main heavy impurities in plasma and their contribution to an effective charge of plasma at the GOL-3 facility. Density of interested elements was measured by optical spectroscopy and mass-spectroscopy of residual vacuum. A number of spectroscopic diagnostics has been developed for this purpose. Experimental data were compared with results of numerical calculations of impurities dynamics. As a result it is revealed that the contribution of heavy impurities to effective charge of plasma does not exceed 20%; thus the presence of impurities in plasma of the GOL-3 facility does not influence essentially the plasma confinement at the multimirror trap.

Results of experiments on injection of a sequence of several electron beam pulses (80–90 keV, 20–75 A, ∼30 μs) into 1019–1021 m−3 deuterium plasma are presented. The first beam pulse was injected into deuterium gas, the following pulses propagated through residual plasma that survived the inter-pulse periods. A typical pulse duration was of the order of 106 ω p − 1 that is much longer than most of the interaction-related processes. However, we noticed significant differences in plasma processes between the first pulse and the rest ones. A suggested physical factor behind those differences is longitudinal plasma current that develops during the first beam pulse.

For studying entries of impurities into thermonuclear plasma, when injecting heated neutral beams, the spectroscopic diagnostics intended for promptly monitoring the plasma composition of the radiofrequency (RF) emitter of the powerful fast neutral beam injector is designed. The analysis of plasma radiation spectra allowed us to determine the rotational temperature of the neutral hydrogen and estimate the oxygen-to-carbon impurity ratio in the RF emitter. In this work, the long-term dynamics of the neutral oxygen line brightness is studied, and the influence of the discharge chamber ageing and warming-up on the impurity content is determined.

New experimental results on magnetic compression and transport of low-temperature arc plasma are presented. In the experiments, the transport efficiency of the plasma stream in a multiple-mirror configuration was compared with the same in a uniform solenoidal field. The magnetic compression ratio of the plasma stream varied from 5 to 60 at the initial diameter of 5 cm. As the result, the plasma with (1 – 4)×1020 m-3 density at the axis was obtained at ∼3 m distance from the plasma source. Theory predicted that a multiple-mirror magnetic field should not significantly decelerate and weaken collisional plasma. The experiment confirmed this prediction. In the presented work, we simulated the baseline scenario of GOL-NB filling by cold start plasma.

The paper reviews recent experimental results from GOL-3. Currently efforts are focused on further development of a physical database for multiple-mirror confinement systems and also on an upgrade of plasma heating systems of GOL-3 device. In general, current GOL-3 parameters demonstrate good prospects of a multiple-mirror trap as a fusion reactor.

New operation regime with a high-mirror-ratio corrugation at first 2 meters of GOL-3 plasma was studied. Five corrugation periods of 44 cm length were created with mirror ratio R ≈ 2.7 by means of special configuration of a power feed of existing solenoid coils. First data on the plasma heating, confinement and features of neutron emission from the strongly corrugated plasma in the above conditions are presented.

First stage of neutral beam heating system was developed at the GOL-3 facility. Configuration of magnetic field and initial gas distribution were adopted for operation with NBI system. As a result the neutral beam with 0.5 MW power and 0.8 ms pulse duration was achieved and stable regimes suitable for beam injection experiments were found. The neutral beam system was used in first experiment as diagnostic tool for measuring the plasma density. Dynamics of plasma density and its radial distribution were studied in experiments.

Experiments involving irradiation of carbon targets with a hot electron plasma stream performed on the GOL-3 facility were aimed at the simulation of the effect of hot plasma of a thermonuclear reactor on plasma collectors in regimes close to those expected in the ITER. In these experiments, the emphasis was on the study of the surface-erosion processes exposed to the plasma stream. The graphite evaporation and chemical-erosion processes were studied with absolutely calibrated spectroscopic systems of the visible region. Spectroscopic experiments yielded data on the flow of carbon atoms from the surface of a plasma collector and on the contribution of chemical erosion to the surface-damage process. The obtained values are compared with the results of direct measurements of the erosion depth and the results of numerical calculations.

A novel diagnostic method is developed for studying the high-energy plasma electron component in the GOL-3 facility by using small-angle Thomson scattering. The method is based on the enhancement of the spectral density of scattered radiation as compared to the conventional large-angle scattering technique.

Electromagnetic emission from plasma in the vicinity of the fundamental plasma frequency and at its double value during a relativistic electron beam (REB) relaxation is studied at the GOL-3 facility [1]. In our paper we will present results of experiments carried out on the specialized GOL-PET device for the emission of terahertz radiation from plasma at its density ∼ 1015 cm−3 and the magnetic field strength 2–4 T. The plasma column created by a high-voltage discharge in the GOL-PET device has its diameter 6 cm and the length about of 250 cm. The injected electron beam has the following parameters: ∼0.8 MeV, ∼20 kA, ∼10 μs. The beam current density in the plasma is up to 3kA/cm2. The radiation in the frequency interval from 0.1 up to 0.8 THz is analyzed by fast eight-channel polychromator and polarimeter based on frequency selection quasioptical elements.