I. Monakhov
A5017688985- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Long-Term Effects of COVID-19
- Geriatric Care and Nursing Homes
- Health disparities and outcomes
- SARS-CoV-2 and COVID-19 Research
- Vaccine Coverage and Hesitancy
- Nuclear Engineering Thermal-Hydraulics
- Solar and Space Plasma Dynamics
- High voltage insulation and dielectric phenomena
- COVID-19 epidemiological studies
- Photocathodes and Microchannel Plates
- Electromagnetic Scattering and Analysis
- Precipitation Measurement and Analysis
- Electromagnetic Launch and Propulsion Technology
- Frailty in Older Adults
- Coal Properties and Utilization
- Economic and Technological Developments in Russia
UK Health Security Agency
2023-2024
Culham Science Centre
2015-2024
Culham Centre for Fusion Energy
2011-2024
United Kingdom Atomic Energy Authority
2003-2024
Joint European Torus
2024
Royal Military Academy
2020
Tver State University
2020
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
1999-2016
Max Planck Institute for Plasma Physics
2014-2016
Max Planck Society
2014
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...
This paper summarizes the physical principles behind novel three-ion scenarios using radio frequency waves in ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for and fast-ion generation multi-ion species plasmas. The theoretical section provides practical recipes selecting plasma composition realize scenarios, including two equivalent possibilities choice resonant absorbers that have been identified....
Abstract After the second Deuterium–Tritium Campaign (DTE2) in JET tokamak with ITER-Like Wall (ILW) and full tritium campaigns that preceded followed after DTE2, a sequence of fuel recovery methods was applied to promote removal from wall components. The started several days baking main chamber walls at 240 °C 320 °C. Subsequently, superimposed Ion-Cyclotron Conditioning (ICWC) Glow Discharge (GDC) cleaning cycles deuterium. Diverted plasma operation deuterium different strike point...
In JET, lower hybrid (LH) and ion cyclotron resonance frequency (ICRF) wave absorption in the scrape-off layer can lead to enhanced heat fluxes on some plasma facing components (PFCs). Experiments have been carried out characterize these loads order to: (i) prepare JET operation with Be wall which has a reduced power handling capability as compared carbon (ii) better understand physics driving phenomena propose solutions for next generation systems reduce them. When using ICRF, hot spots are...
Abstract We present an overview of results from a series L–H transition experiments undertaken at JET since the installation ITER-like-wall (JET-ILW), with beryllium wall tiles and tungsten divertor. Tritium, helium deuterium plasmas have been investigated. Initial in tritium show ohmic transitions low density power threshold for ( P LH ) is lower than ones densities, while we still lack contrasted data to provide scaling high densities. In there notable shift which minimum <?CDATA...
Abstract The recent deuterium–tritium campaign in JET-ILW (DTE2) has provided a unique opportunity to study the isotope dependence of L-H power threshold an ITER-like wall environment (Be and W divertor). Here we present results from dedicated transition experiments at JET-ILW, documenting tritium plasmas, comparing them with matching deuterium hydrogen datasets. From earlier it is known that as plasma isotopic composition changes deuterium, through varying deuterium/hydrogen concentrations,...
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%...
We have previously demonstrated that older residents of long-term care facilities (LTCF) in the UK show levels anti-spike antibodies are comparable to general population following primary series and booster vaccination for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, data on humoral response other SARS-CoV-2 proteins associated with natural infection scarce this vulnerable population.
This paper summarizes the operational experience of ion cyclotron resonant frequency (ICRF) ITER-like antenna on JET aiming at substantially increasing power density in range requirements for ITER combined with load resiliency. An in-depth description its commissioning, aspects and achieved performances is presented.
Recent achievements in studies of the effects ICRF (Ion Cyclotron Range Frequencies) power on SOL (Scrape-Off Layer) and PWI (Plasma Wall Interactions) ASDEX Upgrade (AUG), Alcator C-Mod, JET-ILW are reviewed. Capabilities to diagnose model effect DC biasing associated impurity production at active antennas magnetic field connections described. The experiments show that near-fields can lead not only E × B convection, but also modifications density, which for C-Mod limited a narrow region...
Ion cyclotron resonance heating (ICRH) in the hydrogen minority scheme provides central ion and acts favorably on core tungsten transport. Full wave modeling shows that, at medium power level (4 MW), after collisional redistribution, ratio of transferred to ions electrons vary little with (hydrogen) concentration nH/ne but high-Z impurity screening provided by fast temperature increases concentration. The radiated JET discharges has been analyzed a large database covering 2013–2014 campaign....
Experimental evidence from the JET tokamak is presented supporting predictions of a recent theory (Graves et al 2009 Phys.Rev. Lett.102 065005) on sawtooth instability control by toroidally propagating ion cyclotron resonance waves.Novel experimental conditions minimized possible alternate effect magnetic shear modification current drive, and enabled dependence new energetic mechanism to be tested over key variables.The results have favourable implications waves in fusion reactor.
Additional heating systems can be a source of impurities in fusion plasmas. Studying the behaviour such is important to understand and minimize their effects on tokamak plasma performance. In this paper we present detailed study influence ion cyclotron resonance (ICRH) impurity content JET Using spectroscopic methods monitor Ni release by two ICRH antenna types JET: so-called ITER-like A2 antennas. The during presented as function power density, total applied, relative phasing straps, D2 gas...
Abstract A sequence of fuel recovery methods was tested in JET, equipped with the ITER-like beryllium main chamber wall and tungsten divertor, to reduce plasma deuterium concentration less than 1% preparation for operation tritium. This also a key activity regard refining clean-up strategy be implemented at end 2nd DT campaign JET (DTE2) assess tools that are envisaged mitigate tritium inventory build-up ITER. The began 4 days baking 320 °C, followed by further which Ion Cyclotron Wall...
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,...
Ion cyclotron resonance frequencies (ICRF) mode conversion has been developed for localized on-axis and off-axis bulk electron heating on the JET tokamak. The fast magnetosonic waves launched from low-field side ICRF antennas are mode-converted to short-wavelength high-field of 3He ion layer in D 4He plasmas subsequently damped electrons. resulting power deposition, measured using modulation, is narrow with a typical full-width at half-maximum ≈30 cm (i.e. about 30% minor radius) total...
ITER as a superconducting fusion machine needs efficient wall conditioning techniques for application in the presence of permanent high toroidal magnetic field (i) reducing in-vessel impurity content, (ii) controlling surface hydrogen isotopic ratio and (iii) mitigating long-term tritium inventory build-up. Encouraging results recently obtained with ion-cyclotron (ICWC) present-day tokamaks stellarators have raised ICWC to status one most promising available routine inter-pulse overnight...
Abstract Local gas injection has recently been tested as a tool to improve coupling of ion cyclotron range frequency (ICRF) waves tokamak plasmas, which relies on the tunnelling fast wave between antenna structure and cut-off layer within plasma. It is found that loading resistance substantially increased when using local inlet at deuterium rate 5 × 10 21 el s −1 or higher, proximity key factor optimize improvement in due injection.
The paper summarizes the continuous developments made to ion cyclotron resonant frequency (ICRF) system at JET in order improve reliability of power coupled plasma. It details changes and improvements so that more is during ELMy plasmas as well increasing density demonstrate reliable operation range requirements for ITER. Results obtained using conventional matching (stubs trombones) system, 3 dB couplers conjugate-T scheme with variable elements outside wave launching structure (external...
A load-tolerant External Conjugate-T (ECT) impedance matching system for two A2 Ion Cyclotron Resonance Heating (ICRH) antennas has been successfully put into operation at JET.The allows continuous injection of the RF power plasma in presence strong antenna loading perturbations caused by Edge Localized Modes (ELMs).Reliable ECT performance demonstrated under a variety conditions including H-mode plasmas with Radial Outer Gaps (ROG) range 4-14 cm.The high resilience to ELMs predicted during...
In ASDEX Upgrade H-modes with H98≈0.95, similar effect of the ICRF antenna loading improvement by local gas injection was observed as previously in L-modes. The resistance Ra between and during ELMs can increase more than 25% after a switch-over from deuterium rate 7.5⋅1021 D/s injected toroidally remote location to same amount close an antenna. However, contrast L-mode, this is small H-mode when valve downstream w.r.t. parallel plasma flows used. non-linearity at PICRP<30 kW using...
New experiments at JET with the ITER like wall show for first time that ITER-relevant low field side resonance harmonic ICRH can be used to control sawteeth have been initially lengthened by fast particles.In contrast previous [J.P. Graves et al, Nature Communs 3, 624 (2012)] high sawtooth undertaken JET, it is found of L-mode plasmas controlled less accurate alignment between layer and inversion radius.This advantage, as well discovery shortened various antenna phasings, including dipole,...