Publications de Basil Duval | EPFL Graph Search

Chattez avec Graph Search

Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.

AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.

A diagnostic neutral beam injector (DNBI) [CRPP report LRP 710/01, CRPP-EPFL, 200 1; EPS Conf. Comr. Fusion Plasma Phys., 25A (2001) 365] has been installed on tokamak A configuration variable (TCV) [Plasma Phys. Control Fusion, 36 (1994) 13277; Plasma Phys. Control Fusion, 43 (200 1) A 16 1; Plasma Phys. Control Fusion, to be published] for the purpose of providing local measurements of plasma ion temperature, velocity and impurity density by Charge exchange recombination spectroscopy (CXRS) [EPS Conf. Con

A set of seven twin slit cameras, each containing two 20-element linear absolute extreme ultraviolet photodiode arrays, has been installed on the Tokamak a Configuration Variable. One array in each camera will operate as a bolometer and the second as a Lyman-alpha (L-alpha) emission monitor for estimating the recycled neutral flux. The camera configuration was optimized by simulations of tomographic reconstructions of the expected L-alpha emission. The diagnostic will provide spatial and temporal resolution

A rapid algorithm for tomographic inversion is presented that allows post-discharge reconstruction of the soft x-ray (SXR) emissivity evolution in the Tokamak a configuration variable (TCV). Simultaneously, it determines the centre of gravity of the emissivity that may serve as a reliable measurement of the plasma position, that is independent of magnetic measurements. Tests of the algorithm were performed using shaped phantom datasets and all past SXR measurements were processed to obtain plasma position s

A calibration of the JET neutron detectors was carried out prior to the upcoming deuterium-tritium experimental campaign. Two Compact DT neutron generators (NGs) were purchased for this purpose from VNIIA, Russia. These generators are capable of producing ...

Fluid simulations of the boundary of fusion plasmas predict the formation of an electric potential well in the vicinity of the X-point in detached divertor conditions with Bt in the unfavorable direction for H-mode access. This potential well arises when t ...

The present status of operation and upgrades of the 50 keV / 3 A Diagnostic Neutral Beam Injector (DNBI) at TCV tokamak are described. The plasma grid was replaced by a new re-manufactured one with its existing design. The technology and production were performed within SPC-EPFL. The further redesign of the plasma grid was done to improve the strength and stability, accounting for the results of grid deformation measurements, and considering ANSYS thermomechanical analysis in combination with IBSimu beam si

Within the range of plasma shapes and plasma currents investigated, the electron confinement time, tau_Ee, increases with safety factor, density and negative triangularity similar to the Ohmic heating case. There is little dependence of tau_Ee on the heating location provided power deposition occurs inside the q=1 surface; as power deposition moves out of the inversion surface, tau_Ee decreases. The power-induced energy confinement degradation exponent (tau_Ee~PaP) is as usual: alpha_P ~-0.5. As a general t

Early tokamaks with circular cross-section plasmas were vertically stable in nature and no problems were reported on the control of the vertical position. However, the concept of vertically elongated plasma cross-section, with benefits to the energy confin ...

The design and operation of ITER experimental fusion reactor requires the development of neutron measurement techniques and numerical tools to derive the fusion power and the radiation field in the device and in the surrounding areas. Nuclear analyses prov ...

The total emission of radiation is a crucial quantity to calculate the power balances and to understand the physics of any Tokamak. Bolometric systems are the main tool to measure this important physical quantity through quite sophisticated tomographic inv ...

In the published paper titled 'Model-based impurity emission front control using deuterium fueling and nitrogen seeding in TCV' (2023 Nucl. Fusion 63 026006), the legend of figure 5 shows the wrong colors: red and blue are switched. This corrigendum provid ...

A systematic study of the power threshold for L-H transition has been conducted in TCV. Only results from NB heated plasmas are reported. The dependencies of PLH on plasma current, plasma density and main ion species have been investigated. For Deuterium&# ...

Predictability of burning plasmas is a key issue for designing and building credible future fusion devices. In this context, an important effort of physics understanding and guidance is being carried out in parallel to JET experimental campaigns in H and D ...

The intensity of Be-9 + p nuclear fusion reactions was experimentally studied during second harmonic (2 omega CH) ion-cyclotron resonance heating (ICRH) and further analyzed during fundamental hydrogen minority ICRH of JET-ILW hydrogen and deuterium plasma ...

Compact DT neutron generators based on accelerators are often built on the principle of a mixed beam operation, meaning that deuterium (D) and tritium (T) are both present in the ion beam and in the target. Moreover, the beam consists of a mixture of ions ...

An effect due to fusion born triton production has been observed in JET high-performance deuterium plasma discharges with neutral beam injection (NBI) and H-minority ion cyclotron range of frequencies (ICRF) heating, using DD and deuterium tritium (DT) neu ...

Geodesic acoustic modes (GAMs) may generate strong oscillations in the radial electric field and therefore are considered as a possible trigger mechanism for the L-H transition. This contribution focuses on the characterization of GAMs in JET plasmas when ...

This paper reports simultaneous measurements of intrinsic toroidal and poloidal plasma rotation during the evolution of electron Internal Transport Barriers (eITBs) on TCV. A CXRS diagnostic-beam system provides ion parameter profiles for stationary pre-barrier formation and eITB sustainment phases with a 15mm spatial resolution across the entire barrier width. This special configuration is used to assess the role of Er and E ×B shearing for the eITBs sustainment and formation in TCV. Two eITBs targets were

The unique flexibility of TCV in plasma shaping has been exploited to address different aspects of tokamak physics in which the plasma shape may play a role. This paper summarizes the experiments undertaken in the TCV tokamak ("Tokamak à Configuration Variable") over the last decade in stability and transport and offers a comprehensive and integrated view of the various effects of plasma shape observed. For each of these effects, the relation between experimental results and theoretical predictions is stres

A new mechanism has recently been proposed that generates a radial flux of parallel momentum in toroidal plasmas. Namely, by considering up-down asymmetric flux surfaces, the symmetry following the magnetic field can be broken and an additional contributio ...

Basil Duval

Chattez avec Graph Search

Upgrade of the diagnostic neutral beam injector for the TCV tokamak

AXUV bolometer and Lyman-alpha camera systems on the TCV tokamak

Investigation of the consistency of magnetic and soft X-ray plasma position measurements on TCV by means of a rapid tomographic inversion algorithm

Characterisation of neutron generators and monitoring detectors for the in-vessel calibration of JET

X-point potential well formation in diverted tokamaks with unfavorable magnetic field direction

Recent progress with Diagnostic Neutral Beam Injector at TCV tokamak

EFFECT OF LOCALISED ELECTRON CYCLOTRON HEATING ON ENERGY CONFINEMENT AND MHD IN TCV

Using APCS for Plasma Vertical Control at TCV

Overview Of Neutron Measurements In Jet Fusion Device

Maximum likelihood bolometric tomography for the determination of the uncertainties in the radiation emission on JET TOKAMAK

Model-based impurity emission front control using deuterium fueling and nitrogen seeding in TCV (vol 63, 026006, 2023)

L-H power threshold for neutral beam heated plasmas with Deuterium, Hydrogen, Helium and mixed ion species in TCV

First principles and integrated modelling achievements towards trustful fusion power predictions for JET and ITER

Evidence of Be-9 + p nuclear reactions during 2 omega(CH) and hydrogen minority ICRH in JET-ILW hydrogen and deuterium plasmas

Modelling of the neutron production in a mixed beam DT neutron generator

On a fusion born triton effect in JET deuterium discharges with H-minority ion cyclotron range of frequencies heating

Geodesic acoustic mode evolution in L-mode approaching the L-H transition on JET

Rotation studies in electron Internal Transport Barriers on TCV

Physics Insight and Performance Benefit from Plasma Shaping Experiments in MHD and Energy Transport in the TCV Tokamak

Experimental demonstration of an up-down asymmetry effect on intrinsic rotation in the TCV tokamak