A5018565057- Magnetic confinement fusion research
- Fusion materials and technologies
- Nuclear reactor physics and engineering
- Thermography and Photoacoustic Techniques
- Laser-Plasma Interactions and Diagnostics
- Calibration and Measurement Techniques
- Radiative Heat Transfer Studies
- Nuclear Physics and Applications
- Heat and Mass Transfer in Porous Media
- Gas Dynamics and Kinetic Theory
- Thermal properties of materials
- Nuclear Materials and Properties
- Superconducting Materials and Applications
- Infrared Target Detection Methodologies
- Nanomaterials and Printing Technologies
- Numerical methods in inverse problems
- Spacecraft and Cryogenic Technologies
- Numerical methods in engineering
- Pickering emulsions and particle stabilization
- Composite Material Mechanics
- Plasma Diagnostics and Applications
- Nuclear Engineering Thermal-Hydraulics
- Diamond and Carbon-based Materials Research
- Advanced ceramic materials synthesis
- Welding Techniques and Residual Stresses
Aix-Marseille Université
2014-2024
Institut Universitaire des Systèmes Thermiques Industriels
2014-2024
CEA Cadarache
2008-2024
Centre National de la Recherche Scientifique
2013-2023
Château Gombert
2010-2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2008-2013
Culham Science Centre
2012
École Polytechnique
2005-2009
Irepa Laser (France)
1998
Abstract ITER will operate with a tungsten divertor, material featuring surface morphology changes when exposed to helium plasmas, in particular the formation of so called fuzz under specific conditions. Investigating interactions between plasma facing components and plasmas tokamak environment is therefore key point consolidate predictions for divertor performance lifetime. To this end, dedicated campaign was performed full WEST tokamak, cumulating ∼2000 s repetitive L mode discharges. It...
The continuous growth of the concrete industry requires an increased quantity cement and natural aggregates year after year, it is responsible for a major part global CO2 emissions. These aspects led to rigorous research suitable raw materials. Taking into account that these materials must have sustainable character also low impact on environmental pollution, replacement conventional components by residual waste can lead targets. This paper’s aim analyze density, compressive strength thermal...
Abstract The protection of ITER in-vessel components and the plasma-wall interaction studies will be based on a large network infrared (IR) cameras covering 70% tokamak. surface temperature measurement from IR images remains challenging due to presence metallic targets, with changes in thermo-radiative properties (emissivity) multiple reflections. paper provides an overview major progress improve interpretation image get more reliable synthetic diagnostics. presents latest development (1)...
Abstract The consequences of tungsten (W) melting on divertor lifetime and plasma operation are high priority issues for ITER. Sustained controlled W-melting experiment has been achieved the first time in WEST a poloidal sharp leading edge an actively cooled ITER-like facing unit (PFU). A series dedicated power steady state discharges were performed to reach point tungsten. was exposed parallel heat flux about 100 MW.m −2 up 5 s providing melt phase 2 without noticeable impact (radiated...
Abstract This paper summarizes the emissivity measurements performed on plasma-facing units (PFU) of WEST lower divertor during first phase running with a mix actively cooled ITER-like PFUs made bulk tungsten (W) and inertially graphite coating tungsten. In situ assessments laboratory after removing W-coated ITER-grade from device are shown. The exhibit complex pattern strong variation as function space time mainly explained magnetic equilibrium (strike point location) well plasma...
Infra-red (IR) thermography is a widely used tool in fusion devices to monitor and protect the plasma-facing component (PFC) from excessive heat loads. However, with use of all-metal walls devices, deriving surface temperature IR measurements has become more challenging. In this paper, an overview infra-red metallic tokamaks WEST ASDEX Upgrade (AUG) reported techniques carried out modeling experimental fields deal radiative fully reflective environment are presented. Experimental...
In this paper, a method was developed to estimate in-situ the emissivity of W-coated graphite divertor tiles in WEST tokamak. This is based on double heating and take advantages temperature increase after successive plasma experiments due inertial behavior facing components. Photonic calculations have been used disentangle emitted reflected parts measured radiances from infrared system. The uncertainty as well robustness investigated thanks wide IR thermocouple coverage divertor. results...
We present here experiments dealing with the hydrodynamic characterization of high-porosity metallic foam, performed on copper foam. The experimental setup and procedure used to obtain data are described. Analysis these measurements is conducted using parameter estimation method. Brazing foam channel wall found have no effects pressure drop. This study demonstrates that for this category porous material, inertial factor evaluated accurately, whereas permeability cannot be determined...
Rear face flash experiments were performed in order to determine the thermal conductivity of sintered tungsten at room temperature. Ten different samples synthesized with spark plasma sintering technique. The microstructure obtained from is porous and consists angular grains medium sphericity. average grain size (d) porosity (P) lie within ranges 2μm≤d≤7μm 0≤P≤0.35. We show that dependence on shows a critical behaviour. A theoretical explanation this behaviour predictive model for are proposed.
In this paper, using both experimental data and theoretical modelling, we investigate the degradation of thermal conductivity sintered metals due simultaneously to grain boundary resistance porosity. We show that porosity dependence material from spherical particle powder, exhibits a critical behaviour associated with second order phase transition. An analytical model single parameter is proposed describe versus
Abstract During steady state plasma operation in fusion devices, leading edges of the actively cooled plasma-facing components can be impacted by flux with nearly normal angle incidence, causing local overheating. The overheating a critical issue high-power machines, especially presence mechanical misalignments. Due to heat diffusion through material, edge power overload also leads increase temperature on top part tile that detected infrared imaging system (viewed from machine). In Tore...
The consequences of tungsten (W) damaging processes, such as cracking and melting, on divertor lifetime plasma operation are high priority issues for ITER. A sustained melting experiment was conducted in WEST using a 2 mm deep groove geometry the upstream mono-block (MB) to overexpose sharp leading edge (LE) downstream MB. W-cracking has been evidenced first time with very spatial resolution infrared camera before reached. These cracks develop when monoblock temperature is about 2600°C, thus...
The effective thermal conductivity of highly porous metal foams is measured using a photothermal method with crenel heating excitation. This based on nondestructive technique. foam sandwiched between two thin aluminum plates. front face the three-layered structure submitted to heat flux and temperature rise rear recorded an infrared camera. Measurements are reported several foams. parameter identification performed by minimization ordinary least squares objective function comparing...
Infrared (IR) images of the ITER wide angle viewing system are modeled for baseline plasma equilibrium and partially detached tungsten divertor, taking into account three-dimensional structure first wall divertor. The modeling includes a comprehensive chain calculations from heat load specifications up to synthetic, reflection-free IR surface temperature, T-surf. effect optical blur due finite detector size diffraction/aberrations-approximated by Gaussian filter-on measured T-surf is...
4 probes with Fiber Bragg Gratings (FBGs) will be integrated in Plasma Facing Component (PFC) of the WEST lower divertor order to measure bulk temperature distribution poloidal direction (11 locations equally spaced). A 2D nonlinear unsteady calculation combined Conjugate Gradient Method (CGM) and adjoint state is used estimate space time evolution surface heat flux based on measurements. Synthetic measurements are generated assuming optical projection taking into account physical effects...
In fusion devices like ITER, plasma facing components will be in metal, (Tungsten and Beryllium), with emissivity the range of 0.1–0.4. Therefore, surface temperature monitoring by infrared system become more challenging due to low consequently non negligible reflected flux. The active pyrometry method proposed this paper allows measurements independently parasitic fluxes. A local increase (ΔT(t)~10 °C) introduced a transient heating source (pulsed or modulated) results an additional...