Y. Kazakov
A5004957119- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Astro and Planetary Science
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Advanced Data Storage Technologies
- Electromagnetic Launch and Propulsion Technology
- Dust and Plasma Wave Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Rocket and propulsion systems research
- Inorganic Fluorides and Related Compounds
- Laser-induced spectroscopy and plasma
- Spacecraft and Cryogenic Technologies
- Earthquake Detection and Analysis
- High-Energy Particle Collisions Research
Laboratoire de Physique des Plasmas
2025
Plasma (Russia)
2025
Royal Military Academy
2014-2023
Uppsala University
2020
Max Planck Society
2018-2019
Max Planck Institute for Plasma Physics
2018-2019
European Steel Association
2017
Culham Science Centre
2016
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016
Culham Centre for Fusion Energy
2016
Wendelstein 7-X is the first comprehensively optimized stellarator aiming at good confinement with plasma parameters relevant to a future power plant. Plasma operation started in 2015 using limiter configuration. After installing an uncooled magnetic island divertor, extending energy limit from 4 80 MJ, continued 2017. For this phase, electron cyclotron resonance heating (ECRH) capability was extended 7 MW, and hydrogen pellet injection implemented. The enhancements resulted highest triple...
Wendelstein 7-X is a highly optimized stellarator that went into operation in 2015. With 30 cubic meter volume, superconducting coil system operating at 2.5 T, and steady-state heating capability of eventually up to 10 MW, it was built demonstrate the benefits stellarators parameters approaching those fusion power plant. We report here on first results with test divertor installed, during second phase, which performed half 2017. Operation divertor, addition several new fueling systems,...
A significant improvement of plasma parameters in the optimized stellarator W7-X is found after injections frozen hydrogen pellets. The ion temperature post-pellet phase exceeds 3 keV with 5 MW electron heating and global energy confinement time surpasses empirical ISS04-scaling. realized such experiments are significantly above those comparable gas-fuelled discharges. In this paper, we present details these pellet discuss main properties during enhanced phases. Local power balance applied...
Abstract In JET deuterium-tritium (D-T) plasmas, the fusion power is produced through thermonuclear reactions and between thermal ions fast particles generated by neutral beam injection (NBI) heating or accelerated electromagnetic wave in ion cyclotron range of frequencies (ICRFs). To complement experiments with 50/50 D/T mixtures maximizing reactivity, a scenario dominant non-thermal reactivity has been developed successfully demonstrated during second campaign DTE2, as it was predicted to...
Abstract Ion cyclotron resonance frequency (ICRF) heating has been an essential component in the development of high power H-mode scenarios Jet European Torus ITER-like wall (JET-ILW). The ICRF performance was improved by enhancing antenna-plasma coupling with dedicated main chamber gas injection, including preliminary minimization RF-induced plasma-wall interactions, while RF where optimized for core impurity screening terms ion position and minority hydrogen concentration. impact on...
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...
Plasma production in stellarators with ion cyclotron heating is complementary to the widely used electron (ECRH). The prospective light minority scenario developed and tried on Uragan-2M Large Helical Device (LHD) had been reexamined at LHD. distinctive feature of this attempt that parameters plasma produced are better than before comparable those by ECRH. This new possibility heating, if it becomes practical, motivates rethinking role stellarator machines.
For stellarators, which need no or only small amounts of current drive, electron-cyclotron-resonance heating (ECRH) is a promising method even for the envisaged application in fusion power plant. Wendelstein 7-X (W7-X) equipped with steady-state capable ECRH system, operating at 140 GHz, corresponds to 2nd cyclotron harmonic electrons magnetic field 2.5 T. Ten gyrotrons are operational and already delivered 7 MW W7-X plasmas. Combined pellet injection, highest triple product (0.68 × 1020 keV...
Abstract The reference ion cyclotron resonance frequency (ICRF) heating schemes for ITER deuterium–tritium (D-T) plasmas at the full magnetic field of 5.3 T are second harmonic and 3 He minority heating. wave-particle location these coincide central a wave 53 MHz T. Experiments have been carried out in major D-T campaign (DTE2) JET, its prior D campaigns, to integrate ICRF scenarios JET high-performance compare their performance with commonly used hydrogen (H) In 50:50 D:T plasmas, up 35% 5%...
Abstract JET returned to deuterium-tritium operations in 2023 (DTE3 campaign), approximately two years after DTE2. DTE3 was designed as an extension of JET's 2022-2023 deuterium campaigns, which focused on developing scenarios for ITER and DEMO, integrating in-depth physics understanding control schemes. These were evaluated with mixed D-T fuel, using the only remaining tritium-capable tokamak until its closure 2023. A core-edge-SOL integrated H-mode scenario developed tested D-T, showing...
We report the first experimental detection of a zero-frequency fluctuation that is pumped by an Alfvén mode in magnetically confined plasma. Core-localized modes frequency inside toroidicity-induced gap (and its harmonics) exhibit three-wave coupling interactions with fluctuation. The observation consistent theoretical and numerical predictions zonal modes, correlated increase deep core ion temperature, temperature gradient, confinement factor <a:math...
Abstract The fast-ion distribution function in fusion plasmas can be inferred by inverting Doppler-shifted measurements from diagnostics. full parametrised three constants of motion with the addition a binary index. However, limited number measurements, cogent prior information must added to regularise inverse problem, enabling reconstruction function. In this paper, we demonstrate how incorporate wave-particle interactions ion cyclotron range frequencies (ICRF) as future ITER tokamak test...
Abstract We review the physics of energetic particles (EPs) in magnetically confined burning fusion plasmas with focus on advances since last update ITER Physics Basis (Fasoli et al 2007 Nucl. Fusion 47 S264). Topics include basic EP physics, generation, diagnostics EPs and instabilities, interaction thermal plasma EP-driven particle modes (EPMs), turbulence, linear nonlinear stability simulation instabilities EPMs, 3D effects, scenario optimization strategies based phase-space control,...
In stellarators, increasing the density is beneficial for energy confinement. While there no single reason this observation, it still very robust across different devices and reflected in empirical confinement time scaling ISS04. order to study whether also true Wendelstein 7-X, of analyzed compared ISS04 first divertor experiments. When increased beyond a critical density, however, radiative collapses are frequently observed. Existing analytical models revisited assess they can predict...
A new deuterium-tritium experimental, DTE2, campaign has been conducted at the Joint European Torus (JET) between August 2021 and late December 2021. Motivated by significant enhancements in past decade JET, such as ITER-like wall enhanced auxiliary heating power, achieved a fusion energy world record performed broad range of fundamental experiments to inform ITER physics scenarios operations. New capabilities area product measurements nuclear diagnostics were available result long...
Abstract During the two most recent experimental campaigns in advanced stellarator Wendelstein 7-X (W7-X) (Klinger et al 2017 Plasma Phys. Control. Fusion 59 014018; Bosch Nucl. 57 116015; Wolf 102020; Pedersen Plasmas 24 0555030) hydrogen ice pellet injection was performed for first time. In order to investigate potential of fueling W7-X and study particle deposition a large stellarator, blower-gun system installed with 40 pellets capability. The experience gained this will be used...
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...
Abstract A series of ice pellets was injected into the advanced stellarator Wendelstein 7-X (W7-X). Although were small and slow, deep efficient particle fueling could be observed experimentally. The most striking feature appearing after injection pellets, however, a transient increase in energy confinement time. This phase resembled several aspects modes enhanced gas-puff or pellet injection, as other fusion experiments. All experimental attempts, to prolong this phase, failed. In paper,...
Beam-target reactions are responsible for a substantial fraction of the fusion power generated in D-T plasmas JET-ILW (Be/W-wall), with ion temperatures 10-12keV and large neutral-beam injection (NBI) power.It is known that injecting D beam ions energies ~100-150keV T-rich has larger potential beam-target than 50:50 D:T plasmas, but such scenario was never developed past experiments performed JET-C (Carbon-wall) TFTR 90's.On top intrinsic advantages using beams neutron production,...
Abstract Recent results from MAST Upgrade are presented, emphasising understanding the capabilities of this new device and deepening key physics issues for operation ITER design future fusion power plants. The impact MHD instabilities on fast ion confinement have been studied, including first observation losses correlated with Compressional Global Alfvén Eigenmodes. High-performance plasma scenarios developed by tailoring early current ramp phase to avoid internal reconnection events,...
The results of the plasma start-up with ICRH U-2M RF discharges in H2+He mixture newly implemented controlled gas H2 concentration are presented. W7-X like antenna operated monopole phasing applied power ∼ 100 kW. We investigated pressure range p = 6×10−4 - 9 × 10−2 Pa. Plasma production an average density up to Ne 1013 cm−3 was observed at frequencies fundamental harmonic hydrogen cyclotron frequency.