Introduction – Achieving safe power and particle exhaust compatible with a high-performance core plasma is one of the main challenges towards commercial fusion power. Currently, the most promising solution is to operate a diverted tokamak in detached conditions with high divertor neutral pressure, high volumetric power dissipation, and a strong temperature and pressure gradient along the...
Power exhaust is one of the big challenges for future fusion reactors. In the EU programme, both conventional and alternative divertor approaches are studied. For a conventional divertor in EU-DEMO (1), more than 80% of the exhaust power needs to be dissipated before entering the SOL to keep the divertor in the detached regime, where the interaction of the plasma with the wall is significantly...
A promising repeatable laser system producing multi-kilojoule of pulse energy has been basically designed for realization of the fast-ignition-based inertial fusion energy (IFE) reactor. Two cultivated core key technologies ensure high reliability of the proposed design. First, using our novel bonding technology, a cryogenic active-mirror amplifier has been developed to enable 100 Hz...
Successful operation of ITER depends critically on disruption management for the Pre-Fusion Power Operation (PFPO) phase up through Fusion Power Operations (DT). The power-handling capabilities of the beryllium (Be) first-wall panels (FWP) and other plasma-facing components (PFC) must be preserved in the face of disruptions and vertical displacement events (VDE). This need should account for...
Positive plasma potential was observed for the first time in a core tokamak plasmas, conventionally characterized by negative potential. Direct measurement of the electric potential in the core plasma is of paramount importance for the understanding of the role of radial electric field E_r in the mechanisms regulating the toroidal plasma confinement. New experimental observations and...
High performance advanced tokamak scenarios are very attractive for future burning plasmas. They can be achieved by elevating the central $q$-profile to values around unity to stabilize the sawtooth instability, which would otherwise reduce performance and could trigger deleterious instabilities. High-$\beta$ plasmas can develop such a flat elevated central $q$-profile in the presence of MHD...
Substantial seeding of impurities into the divertor has been used for a long time in tokamaks to reduce the power and particle fluxes impacting on the divertor targets and is one of the main techniques to be utilised on ITER to facilitate stationary divertor operation [$1$]. There have been attempts to predict how the impurity concentration required for detachment should scale with different...
Here we report recent progresses of laser fusion energy research in Japan, especially on the fast ignition scheme. For the fast-track to the laser fusion energy, we are investigating the fast-ignition plasma physics to realize optimal compression of a fusion fuel as well as efficient heating of the compressed fuel. In this scheme, we have demonstrated the efficient heating of high density...
Inertial Confinement Fusion (ICF) schemes are designed to heat and compress DT fuel to conditions exceeding the Lawson criterion ($p \tau$) using implosion, which greatly amplifies the pressure of a driver (~100 MBar) to the conditions necessary for laboratory-scale ICF (~100s GBar). The National Ignition Facility (NIF) focuses on the laser indirect drive approach to ICF, in which laser energy...
During burning plasma operation on ITER, extrinsic impurity seeding will be mandatory for heat flux control at the tungsten (W) divertor vertical targets [1]. A very extensive database of SOLPS plasma boundary code simulations has been compiled for ITER [1], including the most recent advances, obtained with the SOLPS-ITER version, in which for the first time, fluid drifts have been included...
TAE Technologies, Inc. (TAE) is a privately funded company pursuing an alternative approach to magnetically confined fusion, which relies on field-reversed configuration (FRC) plasmas composed of mostly energetic and well-confined particles by means of a state-of-the-art tunable energy neutral-beam (NB) injector system. TAE’s current experimental device, C-2W (also called “Norman”) shown in...
Outline. We report on major progress regarding simulations of edge localized modes (ELMs). First of a kind simulations of realistic repetitive type-I ELM cycles are presented, reproducing in particular the explosive onset of the ELM crashes for the first time. Key to this achievement were numerical improvements, fully realistic plasma parameters and flows, a self-consistent evolution of...
Introduction. Extrapolations to ITER and DEMO from existing smaller experiments alone are unreliable, especially for turbulent transport - requiring the aid of predictive simulations. The 3D fluid turbulence code GRILLIX [1–4] is used to study confinement improvement through turbulence suppression that is compatible with power exhaust. This contribution describes the validation against...
Introduction – Negative triangularity discharges were first studied on TCV to examine the effect of plasma shaping on energy confinement in ohmic, L-mode discharges [1]. Subsequent experiments, using ECRH to stabilize MHD instabilities, showed an improvement of energy confinement in negative triangularity as compared to similar positive triangularity discharges [2]. Modulated ECRH to allow...
In the laser-driven indirect drive scheme for inertial confinement fusion (ICF), the capsule diameter is typically limited to ~2 mm in order to attain quasi-round implosions with currently available laser energy in cylindrical hohlraums. This geometrical factor restricts the energy coupling efficiency from the hohlraum to the capsule to be ~10% [Ref.1]. We report the first series of...
We propose a novel heating mechanism for ions in overdense plasmas by introducing two whistler waves along a strong magnetic field in the counter-beam configuration [A]. The essential process is the collapse of standing whistler waves within a short timescale comparable to the wave oscillation period. During the collapse, ions are accelerated by a static electric field and acquire a large...
The uncertainties surrounding the physics of plasma exhaust and its centrality in reactor design require a thorough evaluation of promising alternatives as a precautionary measure to avoid delays in DEMO, if the ITER solution for the divertor could not extrapolate to reactor relevant machines. In this contribution, we review the physics and engineering work carried out within EUROfusion’s work...
The Japan Establishment for a Power-laser Community Harvest (J-EPoCH) is proposed as a next generation laser facility having multi-purpose high repetition laser beams at the maximum rate of 100 Hz. The omnidirectional 12 laser beams with 8 kJ would yield ~$10^{13}$ neutrons with a Large High Aspect Ratio Target (LHART) (1). As one of the applications of J-EPoCH, a laser fusion subcritical...
Divertor detachment is a scenario characterized by the dominance of neutral interactions to mitigate the extreme plasma heat flux that would otherwise be incident upon solid walls of fusion reactors. Despite the critical role theory will play in predicting divertor performance, rigorous modelling of neutrals is plagued by the difficulty of directly solving the nonlinear Boltzmann equation....
A world-class ultraintense laser LFEX at ILE, Osaka University directly heated a CD shell target, imploded by GEKKO XII(GXII) laser. Illuminating LFEX energy of 246 J increased the core internal energy by $23\pm 3$ J, leading to the conclusion that the heating efficiency is $9\pm 0.8$ %. The results encourage the fast ignition scheme fusion as a hopeful candidate of the fusion...
Introduction
An interesting phenomenon known as density incrustation at the interface of high Z / low Z plasmas was recently reported in high energy density (HED) systems like inertial confinement fusion (ICF) [1]. Radiation transport and hydrodynamic motion of materials are intricately coupled in HED systems and their interplay gives rise to several interesting phenomena. Density...
The divertor target is the most intense plasma-surface interaction area in tokamaks. Currently, the control of power load on the targets becomes to one of the most important issue for high performance long-pulse discharges. EAST has achieved over 100 s high performance operation, however, its lower graphite divertor prevents its achievement of further high-power long-pulse discharges $[1]$....
A new fluid plasma transport solver MAPS (MFEM [1] Anisotropic Plasma Solver) is being developed for the simulation of far scrape-off-layer (SOL) radio frequency antenna simulations. MAPS solves a coupled set of particle, parallel momentum, and energy equations for plasma and neutral species using a finite element approach based on the MFEM (Finite Element Discretization Library) framework...
We developed a hydrogen population code by combining the Neutral-Transport code with the rovibrationally resolved Collisional-Radiative model (NT-CR), EMC3-EIRENE code, and the Molecular Dynamics (MD) simulation of carbon (C) and tungsten (W) divertor plates. Using this code, (i) we successfully treated hydrogen molecule H$_2$ reactions relating to the molecular assisted recombination (MAR),...
First-principles helicon wave and scrape-off-layer (SOL) turbulence models show that turbulence can significantly modify the helicon wave behavior and may significantly reduce the helicon current drive efficiency. From previous ray tracing (1) and full-wave modeling (2) efforts without turbulence, helicon waves are expected to be an efficient off-axis current drive actuator for advanced...
Here we report the mechanism of plasma heating by magnetized fast-isochoric (MFI) heating scheme (1). The mechanism was visualized experimentally by combining spectroscopic and spatially- and temporally-resolved X-ray imaging techniques. The MFI scheme employs an external magnetic field for guiding a high-intensity relativistic electron beam (REB) generated by relativistic laser-plasma...
Here we report theoretical and numerical studies for efficient plasma heating by high intensity lasers with a lateral confinement of the laser-accelerated fast electrons in the laser spot area. Recent experiments using kilojoule (kJ) petawatt lasers show efficient particle accelerations and plasma heating, indicating that the lateral loss of fast electrons is considerably small. We here found...
Laser Magneto-Inertial fusion is a recently developed approach for the thermonuclear fusion. It consists in applying to the laser inertial fusion plasma a strong magnetic field whose the role is to limit the diffusion of the formed plasma during the impact of an intense laser pulse with a target containing the thermonuclear fuel, as well as the confinement of produced alpha particles by the...
Erosion of plasma-facing components (PFC) due to sputtering by impinging ions and neutrals is one of the key challenges on the road to fusion power. Erosion will be a contributor to the overall PFC lifetime estimation, and to impurity production that can potentially lead to radiative collapse. Moreover, PFC erosion is directly linked to the key issues of fuel retention by co-deposition and...
Anomalous plasma transport in the boundary region of a tokamak plasma is normally associated with density structures. These density structures are commonly termed as plasma blobs. Recently, a theory for a universal mechanism of plasma blob formation has been put forward that is based on a breaking process of a radially elongated streamer [1] in the presence of poloidal and radial velocity...
In magnetic confinement fusion devices, the plasma density is largely self-sustaining through internal recycling processes. While refueling the plasma, the recycling neutrals can also considerably affect the energy transport in both the plasma confinement and exhaust regions. A quantitative understanding of the neutral-related effects first requires a precise knowledge of the origin and source...
Tungsten (W) and tungsten based alloys are candidate materials for plasma-facing components (PFCs) in future fusion reactors, largely due to their low erosion yield by physical sputtering and low retention of plasma fuel in them. The present work concentrates on erosion results obtained from two European tokamaks, ASDEX Upgrade (AUG) and WEST, which have operated with full-W first walls since...
Introduction – The H-mode confinement regime will be the main operational scenario on ITER and also the current foreseen scenario for fusion reactors. A continuous effort towards better predictive capabilities of H-mode confinement is being pursued on both experimental and theoretical fronts. The H-mode is characterised by the formation of a pedestal near the plasma edge and as the fusion...
Introduction -- Power exhaust solutions for a next step device must be compatible with good plasma performance. To reach sufficiently low divertor power loading impurity seeding is necessary. The amount of injected impurities required depends critically on both the maximum achievable separatrix density and the scrape-off layer width. Transient power loads due to type-I edge localised modes...
The high coupling efficiency ($\eta_c$) can be achieved by using a shell target with holes in the direct fast ignition. Here, we have made it clear that a diffusive heating is not negligible compared with a collisional and a resistive heating. In order to obtain high $\eta_c$, it is important to maintain the low effective hot electron temperature ($T_{eff}$). In the shell target with holes,...
Numerical simulations by the integrated divertor code SONIC show that the screening effect on the seeded high-Z impurity in the SOL plasma is improved through the enhancement of plasma flow induced by additional low-Z impurity injection. A single impurity injection of Ar into a steady-state high-beta plasma of JT-60SA results in a high Ar density at the top of SOL plasma, leading to an...
For a laser fusion reactor of fast ignition$^{1,2}$, we design an optimum implosion with solid spherical target and inserted conical gold target, where we achieve the maximum areal density $\rho R_{\rm max}=0.46$ g/cm$^2$. According to the hydro-equivalent, the results correspond to the re-quired laser energies for the implosions are 82 kJ for the ignition-scale-target ($\rho R_{\rm max}$=1.1...
Electric fields in plasma plays a key role in understanding many plasma phenomena from confinement to particle flows. In fusion machines like tokamak, changes in the edge radial electric field are also correlated with changes in many edge phenomena such as L-H transition, rotation, transport, and the suppression of large magnetohydrodynamic (MHD) instabilities called ELMs (Edge Localized...
Present and future long-pulse tokamaks such as JT60-SA, ITER and DEMO will require increasingly advanced control methods to maximize the plasma performance and pulse duration while avoiding plasma disruptions. Given the cost and complexity of a single discharge, maximal use of automated approaches is strongly preferred above costly and error-prone trial-and-error discharge development...
The contamination of core plasma by high-Z impurities, especially tungsten (W), is the main reason of very high level of radiated power in WEST [1] experiments. Determining the main sources of core contamination is indeed a key aspect in preparing a high confinement scenario for the second phase of WEST operation that will start at the end of 2020. Intrinsic light impurities, mainly oxygen and...
Magnetic reconnection (MR) is a process which occurs in many astrophysical plasmas, e.g. in solar flares, in coronal mass ejecta, or at the outer boundary of the Earth magnetosphere, as well as in man-made plasmas, e.g. fusion plasmas. However, as of now, the fundamental microphysics implied in this process is far from being well understood. Most of the investigations on this long-standing...
Executive summary: We report on the results of a quantitative study, based on experimental data, of the role plasma-atom and plasma-molecule interactions in power, particle and momentum balance during detachment. Important implications emerge for: 1) our understanding of detachment; 2) the interpretation of divertor spectroscopy measurements and 3) plasma-edge modelling, where the...
Efficient RF current drive is essential for developing a steady-state operation scenario in a tokamak. This paper investigates the impact of lower hybrid wave interaction with the tokamak boundary plasma on wave power deposition on the Alcator C-Mod and EAST tokamaks. The results presented here suggest that the presence of edge density fluctuations in a tokamak may need to be considered in...
Tokamak plasmas are mostly optically thin for visible radiation-emitting out of the plasma as the density of the emitter in the plasma is not sufficiently high to produced self-absorption of spectral lines in the visible region. However, in certain conditions, such as during pellet ablation inside plasma and massive gas injection signatures of absorption in the emission spectra might be...
In the ADITYA-U tokamak [1], impurity seeding experiments were carried out to achieve transitions to radiative improved (RI) modes [2], which is usually characterized by the increased confinement along with increased plasma density, temperature and toroidal velocity shear profile as compared to the Ohmic mode. In this type of discharges, radiation from the edge region of the plasma is...
EX
The new results of the experimental study of the ion cyclotron emission (ICE) characteristic features in the NBI heated plasma of the TUMAN-3M tokamak [1] are presented. Figure 1 shows an example of the NBI ICE spectrum in deuterium plasma with deuterium NBI, comprising fundamental cyclotron resonance (IC) frequency and its harmonics. For the first time, a dispersion relation for the...
The paper reports unique observation of an ion cyclotron emission (ICE) from the ohmically heated plasma in the absence of energetic ions. The possibility to use the ohmic ICE for determination of the hydrogen isotopes ratio is discussed.
Described experiments were performed in the compact circular shaped limiter tokamak TUMAN-3M $(R(0)=0.53\:m$, $a=0.22\:m$, $B_T=1\:T$, $I_p=150\:kA$,...
In contrast to theory expectations, in numerous experiments the isotope effect results in the improvement of tokamak energy confinement as the hydrogen isotope mass increases [1]. This effect is beneficial and important for the success of Iter, where a mixture of heavy hydrogen isotopes will be used as a fuel.
The influence of the plasma isotope content on turbulence parameters and,...
Under the auspices of EUROfusion, the ITER baseline scenario (IBL, [1]) is jointly investigated on AUG and TCV. While AUG results were presented at the last IAEA [2], this contribution focuses on recent results obtained in TCV. Such developments in TCV were only possible with the installation of an NBI heating source [3], allowing ELMy H-modes at ITER relevant $\beta_N$. The IBL scenario is...
The theoretical model of the feedback instability is proposed to explain the mechanism of the correlation between the detachment and the cross-field plasma transport. It is shown that (1) the feedback instability on the detached divertor plasma can be induced in a certain condition in which the recombination frequency $\nu_{\textrm{rec}}$ is larger than the ion cyclotron frequency...
ADITYA tokamak has been upgraded to ADITYA-U tokamak which is equipped to have shaped plasma operations. The main structural modification is the replacement of an old rectangular cross-section vacuum vessel by a new circular cross-section vacuum vessel. New poloidal coils (six) have been installed in between new vessel and toroidal field coils [1]. Additionally, as per the design requirement,...
In the last few years it was demonstrated experimentally on tokamak ASDEX Upgrade that with a big amount of seeded radiant (nitrogen) the outer target fully detaches, and the high radiation zone appears in the confined region up to 10 cm above the X-point. The location of such a spot may be controlled in real time by variation of the impurity seeding rate [1]. Such regimes might be promising...
Magnetic equilibrium modeling using the FIESTA code shows that steady-state snowflake (SF) divertor (1) configurations can be created and maintained with the existing poloidal field coil set in the MAST-U tokamak. A full multi-fluid plasma transport model with a computational grid encompassing two poloidal magnetic field nulls, with charge-state-resolved carbon impurities sputtered at material...
After the IAEA-FEC 2016 presentation (1) showing that the midplane-mapped heat-load width $\lambda_q^{XGC}$ predicted by the XGC1 edge-gyrokinetic-code (2) for the full-current ITER is $\stackrel{>}{\sim}6\times$ wider than the experimental-data based formula $\lambda_q^{Eich}$ (PRL 2011) while the same code reproduces $\lambda_q^{XGC}\simeq\lambda_q^{Eich}$ for the present experiments, a...
Tokamak is a toroidal device where plasma is confined by means of appropriate magnetic field configurations. Tokamak plasma is home to several magnetic Instabilities, which can lead to loss of confinement and even termination of plasma delivering very high heat load on the plasma facing components [1]. As these magnetic instabilities are dependent on the magnetic field configurations inside...
Implementation of suitable disruption mitigation technique remains the topmost priority for larger tokamaks including the ITER. The spontaneous disruption in ITER may probably be an unavoidable part, while operated with high performance D-T fuel [1]. Disruptions in ITER could produce very large heat loads on divertor targets and other Plasma Facing Components (PFC), and large electromagnetic...
Control and/or mitigation of runaway electrons (REs) is necessary for the operation of larger fusion devices including ITER [1]. The disruption generated REs, in particular, pose a serious threat for the plasma facing components in ITER as they are predicted to acquire very energy (~ tens of MeV). Many RE mitigation mechanisms like Massive Gas Injection (MGI) [2] and Resonant Magnetic...
The high-power reconnection heating of merging spherical tokamak (ST) plasmas has been developed by TS-3U, TS-4U$[1]$, UTST, MAST$[2]$ and ST-40 experiments and PIC simulations$[3]$, leading us to direct access to burning and high-beta ST often with absolute minimum-B without using any additional heating like neutral beam injection (NBI). All of them confirmed, (i) the promising scaling of ion...
Disruption instability and formation of the accelerated electron beams represent one of the main problems in design of the cost-effective fusion reactor. To minimize consequences of the disruptions in tokamaks, several methods for predicting disruption, controlling plasma discharge at the initial stage of the instability, and fast quenching (stopping) a plasma discharge are considered...
New concept of the longitudinal losses suppression for linear magnetic traps have experimentally demonstrated the reduction of the plasma flow by the factor of 2–2.5. This factor is in a good agreement with the theory. Preliminary scalings show the possibility of the further improvement of the suppression efficiency.
High relative pressure (β ≈ 60%), mean energy of hot ions of 12 keV and...
Accurate modelling of cross-field turbulent transport in tokamak’s edge plasma remains a challenge, many key experimental features such as edge transport barriers formation being still hard to simulate, especially for ITER size tokamaks. Being able to predict the SOL width or the power load imbalance between inner and outer divertor legs even for today’s JET size tokamaks is still an open...
Fundamental mechanisms governing the prompt redeposition of tungsten impurities sputtered in tokamak divertors have been identified and analyzed to enable quantitative estimations and in-situ monitoring of the net erosion and lifetime of tungsten divertor plasma-facing components in ITER [1]. The net erosion of tungsten divertor PFCs is primarily determined by the prompt redeposition of...
A mini-reactor called CANDY that based on kJ-class diode-pumped solid-state laser (DPSSL) is proposed to perform feasibility studies of the power plant in fast ignition scheme fusion. In order to implement CANDY, we have adressed two issues. First is a repetitive operation of pellet injection and laser illumination, second is target physics related to inertial confinement fusion plasma. First...
Pulsed power technology of switched-mode has been employed to design and build a high-
voltage pulsed-power supply as an efficient pulse drive unit for low energy plasma focus
devices (PFDs). The plasma focus has been widely investigated as a radiation source,
including as ion-beams, electron-beams and as a source of x-ray and neutron production,
providing considerable scope for use in...
Reaching good-quality H-mode and the development of ELM control techniques are among the main priorities for ITER during its non-active operations [1']. Recent encouraging experimental results at JET-ILW demonstrated a significant reduction in the H-mode power threshold for NBI-heated plasmas when a small amount of $^{4}{\rm He}$ ions, $n(^{4}{\rm He})/n_{e} \approx 10\%$, was added to...
Scoping the possible operational regimes of a DEMO reactor requires reliable models of power exhaust processes. The scrape-off layer (SOL) and divertor in DEMO will need a higher radiated power fraction than present-day devices, and strong asymmetries in the SOL power fluxes entering the divertor regions may reduce the operational window in which the targets can be protected from excessive...
Sustained fusion reactions have been measured in a quiescent deuterium Z-pinch plasma, wherein unity beta was achieved, and sheared flows alone provided stability. Measurements from multiple scintillator neutron detectors demonstrated that 2.45 MeV neutrons were emitted uniformly along the majority of the 50-cm plasma column and that the neutrons were produced from a thermonuclear process with...
SIMULATION OF DIRECT - DRIVE TARGETS FOR MEGAJOULE LASERFACILITIES WITH ACCOUNT FOR NONLOCAL ELECTRON TRANSPORT, FAST ELECTRON GENERATION AND STIMULATED STATTERING OF LASER RADIATION
Karlykhanov N.G., Khimich I.A., Lykov V.A., Rykovanov G.N.
FSUE “RFNC-VNIITF named after academician E.I. Zababakhin”
Snezhisk, Chelyabinsk reg., Russia
n.g.karlykhanov@vniitf.ru
The review of theoretical...
We have recently developed a kinetic neutral code for understanding the hydrogen neutral gas dynamics in the divertor region. The Linear Divertor Analysis with fluid model (LINDA) code [A] has been successfully coupled with Kinetic Monte-Carlo Neutral Code (KMNC) in the present study. This is the first attempt for the GAMMA 10/PDX detached plasmas to perform such a self-consistent and detailed...
It is critical to solve the power exhaust issue for future fusion devices, such as China Fusion Engineering Test Reactor (CFETR) [1]. In case of the steady-state operation, the divertor plasma is expected to be in the detachment regime. Thus, the heat load onto the targets can be reduced within the engineering limits and the sputtering can also be mitigated. Radiative snowflake divertor [2] is...
Power exhaust is considered as one of the most critical issues for future fusion devices. It is considered as an indispensable way for reducing divertor heat load to a tolerable level by seeding impurity and achieving a radiative divertor, especially for the future tokamaks with full metal walls. For China Fusion Engineering Test Reactor (CFETR) [1], which aims to achieve a fusion power ~1 GW,...
Hailong Du1*, Guoyao Zheng1, Xuru Duan1, Houyang Guo2, Jiaxian Li1, Lei Xue1 and Yue Zhou1
1Southwestern Institute of Physics, Chengdu, 610041, China
2General Atomics, PO Box 85608, San Diego, CA 92186-5608, United States of America
Email: duhl@swip.ac.cn
A new mid-size device, HL-2M $[$ 1$]$, is being installed at SWIP to address critical physics and technology issues towards advanced...
During non-local (“global”) L-H transitions found in various regimes of JET and JT-60U tokamaks earlier [1-3], the rise of Te,i and ne starts simultaneously in the spatial zone ≈0.3< r/a <1, while heat and density fluxes fall simultaneously in the same region. At the ITB-events in JT-60U and T-10 (circular tokamak with a limiter =30 cm, R=150 см, Вт= 2.5 Т), heat and density fluxes fall in a...
Finding an optimized Inertial Confinement Fusion1–3 experimental design is a challenge due to the large number of physical parameters that can be modified from experiment to experiment, and the inability of simulations to accurately
and rapidly a priori predict experimental results when these changes are made. Recently, a novel method[4] has been developed to address this issue by...
The paper will present current results from the GOL-NB experimental program [1] that is a part of broader activities on developing the physics basis for a next-generation sub-fusion-grade GDMT linear confinement system [2] in the Budker Institute of Nuclear Physics. The current understanding of physics of open confinement systems requires a significant improvement of the longitudinal energy...
To study the runaway electron (RE) dynamics during plasma discharge, as well as to develop scenarios for disruption mitigation, a gamma-spectrometric system has been developed and commissioned at the ASDEX Upgrade tokamak (AUG). The diagnostic system consists of two scintillation gamma-ray spectrometers based on the fast LaBr3(Ce) crystals. These spectrometers observe the AUG tokamak chamber...
![Tungsten removal scenario in discharge 70358: $I_{pl} = 220$ kA, $P_{EC} = 0.75$ MW (on-axis, co-ECCD)][1]
![Calculations results for discharge 70358:(a) predictions of experimental W removal (b) diffusion coefficient, (c) pinching rate.][2]
An increasing number of installations for magnetic plasma confinement implement tungsten as a material for the plasma-facing components. For...
A D-D fusion reaction during the Alfvénic collisional merging formation process of a field-reversed configuration (FRC) plasma has been detected by the developed fast response neutron detector in the FAT-CM device at Nihon University [A]. The neutron radiation and its dependency on the translation velocity of FRC plasma have been observed as an experimental evidence of an excited shock heating...
3/15/2020
Dear Sirs and Madams,
Synopsis Unified Field Theory
Sustainable fusion is now possible and achieved through a new model of science, known as the unified field theory.
The Unified Field Theory, by Gordon L. Ziegler (published in the Summer of 2014 Edition of The Galilean Electrodynamics Journal), and the Unified Particle Theory—(yet to be published)...
In the context of the inertial fusion energy (IFE) programme, the researches have embarked on a new stage which provides an opportunity to produce pure fusion ignition and burn by using power laser facilities and appropriate scale targets. The ignition and high gain target design requires free standing cryogenic target with an isotropic hydrogen fuel on the inside surface of a spherical...
The dependence of particle and energy confinement in fusion plasmas on the main ion mass still challenges the current theoretical understanding of tokamak physics, although it represents one of the aspects of paramount relevance for the extrapolation to a fusion reactor. Moreover, knowledge is required in order to allow the experience developed in hydrogen (H) operation to be directly...
The Gas-Dynamic Multimirror Trap Project
D.V. Yakovlev, P.A. Bagryansky, A.D. Beklemishev, A.V. Burdakov, I.S. Chernoshtanov, A.A. Ivanov, M.S. Khristo, I.A. Kotelnikov, S.V. Polosatkin V.V. Postupaev, V.V. Prikhodko, V.Ya. Savkin, D.I. Skovorodin, E.I. Soldatkina, A.L. Solomakhin, A.A.Molodyk¹, V.I. Scherbakov², S.V.Samoilenkov², A.P.Vavilov²
Budker Institute of Nuclear Physics SB RAS,...
There are two relativistic electron beam (REB) heating mechanisms, resistive heating (Joule heating) and drag heating (direct collision between REB and bulk electrons). These REB heatings have been discussed intensively to assess the fast ignition (FI). However, such assessment had been done based on the experimental results using a sub-picosecond (ps) laser pulse and theories for them. Here...
A large effort is currently under way to demonstrate thermonuclear ignition in the laboratory via inertial confinement fusion (ICF) [1]. In laser driven inertial confinement fusion (ICF), a spherical capsule of deuterium and tritium (DT) is driven to high velocities by direct irradiation of laser energy (direct drive) or an x-ray bath of an irradiated hohlraum (indirect drive) [2]. At...
Neutrons along with x-rays emission have been reported in plasma focus (PF) devices, if the filled gas is deuterium [1]. The origin of neutron emission is the subject of debate, due to occurring of complex physical phenomena during pinch phase. Most of the PF scientific community believe that neutron production takes place due to beam-target fusion mechanism [2]. Some investigators reported a...
Some years ago concepts such as European HiPER gave an opportunity to study in common the physics of the many components for an efficient IFE Reactor. The integral scheme then proposed allows understanding the interconnection among the different components when approaching a realistic design. A common vision for nuclear fusion in general.
The work presented here will remark new research in...
