A5016751670- Magnetic confinement fusion research
- Nuclear Physics and Applications
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Nuclear physics research studies
- Particle accelerators and beam dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- Plasma Diagnostics and Applications
- Radioactive contamination and transfer
- High-Energy Particle Collisions Research
- Particle Accelerators and Free-Electron Lasers
- Internet of Things and Social Network Interactions
- Magnetic Field Sensors Techniques
- Laser-induced spectroscopy and plasma
- Particle physics theoretical and experimental studies
- Graphite, nuclear technology, radiation studies
Ioffe Institute
2016-2025
Physico-Technical Institute
2008-2024
St. Petersburg Department of Steklov Institute of Mathematics
2024
Plasma (Russia)
2023
Royal Military Academy
2020
Culham Science Centre
2012-2019
Physical and Technical Institute
1998-2015
Russian Academy of Sciences
2004-2013
Disruptions are a major operational concern for next generation tokamaks, including ITER.They may generate excessive heat loads on plasma facing components, large electromagnetic forces in the machine structures and several MA of multi-MeV runaway electrons.A more complete understanding processes methods to suppress them is necessary ensure safe reliable operation future tokamaks.Runaway electrons were studied at JET-ILW showing that their dependencies (accelerating electric field, avalanche...
The targeted plasma parameters of the compact spherical tokamak (ST) Globus-M have basically been achieved. reasons that prevent further extension operating space are discussed. operational limits together with an understanding limiting form basis for defining design requirements next-step, Globus-M2. recent experimental and theoretical results achieved discussed, problems research programme summarized finally, Globus-M2 presented. magnetic field current in will be increased to 1 T 0.5 MA,...
At present, magnetic confinement fusion devices rely solely on absolute neutron counting as a direct way of measuring power. Absolute deuterium-tritium gamma rays could provide the secondary neutron-independent technique required for validation scientific results and licensing tool future power plants. However, this approach necessitates an accurate determination gamma-ray-to-neutron branching ratio. The ratio reaction ^{3}H(^{2}H,γ)^{5}He/^{3}H(^{2}H,n)^{4}He was determined in plasmas at...
The spectral 𝛾 ray emission from the reaction 3H(2H,𝛾)5He has been measured for first time in a magnetic confinement deuterium-tritium plasma experiment at Joint European Torus. A custom developed gamma spectrometer system based on LaBr3 scintillator combined to LiH neutron attenuator and zero dead fast digital data acquisition allowed measure weak under ≈105 more intense 14MeV field. 𝑅-matrix analysis of 5He nucleus used predict expected spectrum which compared with measurement, but...
A new high efficiency, resolution, fast γ-ray spectrometer was recently installed at the JET tokamak. The is based on a LaBr3(Ce) scintillator coupled to photomultiplier tube. digital data acquisition system used allow spectrometry with event rates in excess of 1 MHz expected future DT plasmas. However, lower typical present day experiments, digitization can degrade energy resolution system, depending algorithms for extracting pulse height information from digitized pulses. In this paper,...
High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out nuclear accelerators, combining a LaBr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (Ce) detector with dedicated hardware and software solutions based on digitization off-line analysis. Spectra measured up to 4 MHz, little or no degradation of the energy resolution, adopting pile rejection algorithm. The reported results represent step forward...
Gamma-ray spectrometry on ITER can provide information both confined fusion alpha particles for optimization of plasma heating and runaway electrons, which is important safe reactor operations. For the purpose deconvolution gamma-ray spectra recorded in experiments DeGaSum code has been developed. The be applied processing monoenergetic gamma rays, are born nuclear reactions produced by other fast ions, continuous bremsstrahlung generated electrons MeV range structure materials. spectrometer...
Dedicated experiments to generate energetic D ions and fusion-born alpha particles were performed at the Joint European Torus (JET) with ITER-like wall (ILW). Using 3-ion radio frequency (RF) heating scenario, deuterium from neutral beam injection (NBI) accelerated in core of mixed plasmas higher energies ion cyclotron resonance (ICRF) waves, turn leading a core-localized source particles. The fast-ion distribution RF-accelerated D-NBI was controlled by varying ICRF NBI power ( 4–6 MW, 3–20...
Abstract The fusion reaction between deuterium and tritium, D ( T,n ) 4 He is the main source of energy in future thermonuclear reactors. Alpha-particles -ions) born with an average 3.5 MeV transferring to thermal plasma during their slowing down, should provide self-sustained D–T burn. adequate confinement α -particles essential efficient heating bulk steady burning a reactor plasma. That why fusion-born -particle studies have been priority task second experiments (DTE2) on Joint European...
Abstract High-resolution γ-ray measurements were carried out on the Joint European Torus (JET) in an experiment aimed at accelerating 4 He ions MeV range by coupling third harmonic radio frequency heating to injected beam. For first time, Doppler broadening of peaks from 12 C(d, pγ) 13 C and 9 Be(α, nγ) reactions was observed interpreted with dedicated Monte Carlo codes based detailed nuclear physics processes. Information confined deuteron energy distribution inferred, energies as high 6...
Ion cyclotron emission (ICE) observation in neutral beam injection (NBI)-heated plasma the TUMAN-3M tokamak is reported. Experiments were performed deuterium or hydrogen target plasmas, with heating consisting of 60% and 40% atoms accelerated up to 16 keV. High-frequency internal magnetic probes used as a diagnostic tool for ICE detection. In ~13 MHz frequency was observed, 1–2 ms delay after NBI pulse front; this corresponds approximately fundamental ion (IC) resonance near axis. ~7...
We discuss α-particle velocity-space diagnostic in ITER based on the planned collective Thomson scattering (CTS) and γ-ray spectrometry (GRS) systems as well ASCOT simulations of distribution function. GRS is sensitive to α-particles with energies MeV at all pitches p, CTS for . The remaining velocity space not observed. view plasma (almost) perpendicularly magnetic field. Hence we cannot determine sign pitch distinguish co- counter-going currently diagnostics. Therefore can only infer...
The paper provides an overview of the results obtained on spherical tokamak Globus-M2 in 2019–2020. experiments were performed with toroidal magnetic field up to 0.8 T and plasma current 0.4 MA (80% design values). temperature electrons 1 keV ions 800 eV at density 1020 m−3 recorded neutral beam injection (850 kW, 28.5 keV). Heat conductivity analysis was made by means codes ASTRA 7.0, NCLASS, SPIDER, NUBEAM, 3D fast ion tracking algorithm basis experimental data. A scaling for tokamaks,...
Abstract Runaway electrons (REs) created during tokamak disruptions pose a threat to the reliable operation of future larger machines. Experiments using shattered pellet injection (SPI) have been carried out at JET investigate ways prevent their generation or suppress them if avoidance is not sufficient. Avoidance possible SPI contains sufficiently low fraction high-Z material, it fired early in advance disruption prone runaway generation. These results are consistent with previous similar...
Abstract NBI-assisted plasma heating with one or two injectors of fast neutral atoms was studied at the Globus-M2 spherical tokamak toroidal magnetic fields 0.8–0.9 T and currents 0.35–0.4 MA. Measurements spatial temperature electron density distributions, performed using Thomson scattering diagnostics, showed a twofold increase in electrons during injection particles energies up to 45 keV beam power 0.75 MW, as compared ohmic regime. Switching on second additional particle energy 30 0.5 MW...
Gamma-ray spectrometry is a diagnostic tool for fast ions in large tokamak plasmas. The information provided allows us to identify and simultaneously distinguish the presence of α-particles other (H, D, T, 3 He) obtain on their energy distribution relative densities, addition performing tomographic radial profile reconstruction γ-emission sources. lack vertical ports ITER makes implementation neutron γ-ray systems more complicated. use divertor port viewpoint currently suggested. strong...
Abstract Recent JET experiments have been dedicated to the studies of fusion reactions between deuterium (D) and Helium-3 ( 3 He) ions using neutral beam injection (NBI) in synergy with third harmonic ion cyclotron radio-frequency heating (ICRH) beam. This scenario generates a fast tail enhancing DD D He reactions. Modelling measuring accurately is essential for quantifying products. paper presents modelling distribution function resulting from NBI+ICRF scheme, reinforced by comparison...
Gamma-ray spectroscopy (GRS) has become an established technique to determine properties of the distribution function energetic particles in MeV range, which are fast ions from heating and fusion reactions or runaway electrons born disruptions. In this paper we present a selection recent results where GRS is key investigate physics range particles. These radio-frequency experiments, theoretical models can be tested with unprecedented degree accuracy, disruption mitigation studies, sheds...
To study the runaway electron (RE) dynamics during plasma discharge and develop scenarios for disruption mitigation, a hard x-ray (HXR) spectrometric system has been developed commissioned at ASDEX Upgrade tokamak (AUG). The diagnostic consists of two high-performance spectrometers based on LaBr3(Ce) scintillation detectors supplied with advanced electronics analysis algorithms. These view AUG chamber quasi-radially equatorial plane. measurements were carried out in RE beam generation...
Abstract Runaway electron gamma-ray detection system, a novel hard x-ray (HXR) spectrometer optimized for bremsstrahlung radiation measurement from runaway electrons in fusion plasmas, has been developed. The detector is based on 1‘×1’ LaBr 3 :Ce scintillator crystal coupled with photomultiplier tube. system an energy dynamic range exceeding 20 MeV resolution of 3% at 661.7 keV. gain stable even under severe loads, shift that stays below HXR counting rates excess 1 MCps. performance the...
A new gamma-ray spectrometer with MHz capabilities has been developed to measure the bremsstrahlung emission spectrum in energy band generated by MeV range runaway electrons disruption experiments at ASDEX Upgrade. Properties of are inferred from measured a deconvolution technique, particularly regard their maximum energy. Changes induced electron velocity space unambiguously observed both massive gas injection and resonant magnetic perturbation detector.
Studies of the super-thermal and runaway electron behavior in ohmic lower hybrid current drive FT-2 tokamak plasmas have been carried out using information obtained from measurements hard x-ray spectra non-thermal microwave radiation intensity at frequency 10 GHz range (53 ÷ 78) GHz. A gamma-ray spectrometer based on a scintillation detector with LaBr3(Ce) crystal was used, which provides counting rates up to 107 s−1. Reconstruction energy distribution RE interacting poloidal limiter chamber...
In fusion plasmas gamma ray emission is caused by reactions of fast particles, such as alpha with impurities. Gamma spectroscopy at JET has provided valuable diagnostic information on fuel well product ions. Improvements these measurements are needed to fully exploit the flux increase future high power experiments and ITER. Limiting aspects are, for instance, count rate capability due a neutron/gamma background combined slow detector response modest energy resolution low light yield...