A5003281971- Fusion materials and technologies
- Magnetic confinement fusion research
- Nuclear reactor physics and engineering
- Nuclear Materials and Properties
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Advanced Fiber Optic Sensors
- Numerical methods in inverse problems
- Plasma Diagnostics and Applications
- Thermography and Photoacoustic Techniques
- Particle accelerators and beam dynamics
- Magneto-Optical Properties and Applications
- Solar Thermal and Photovoltaic Systems
- Gas Dynamics and Kinetic Theory
- Advanced Sensor Technologies Research
- Computational Fluid Dynamics and Aerodynamics
- Heat Transfer and Boiling Studies
- Calibration and Measurement Techniques
- Nuclear Engineering Thermal-Hydraulics
- Radiative Heat Transfer Studies
- Nuclear materials and radiation effects
- Metallurgical Processes and Thermodynamics
- Infrared Target Detection Methodologies
- Thermal Analysis in Power Transmission
Aix-Marseille Université
2014-2024
Institut Universitaire des Systèmes Thermiques Industriels
2013-2024
Centre National de la Recherche Scientifique
2014-2024
Château Gombert
2012-2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2010-2019
Institut de Recherche sur la Fusion par Confinement Magnétique
2019
CEA Cadarache
2010-2018
Culham Science Centre
2012
The key remaining physics design issue for the ITER tungsten (W) divertor is question of monoblock (MB) front surface shaping in high heat flux target areas actively cooled targets. Engineering tolerance specifications impose a challenging maximum radial step between toroidally adjacent MBs 0.3 mm. Assuming optical projection parallel loads, magnetic shadowing these edges required if quasi-steady state melting to be avoided under certain conditions during burning plasma operation and...
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...
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...
Abstract The full W environment that is now foreseen for ITER puts strong emphasis on experimental results obtained in present devices similar conditions. In this context, the WEST tokamak well equipped to bring key contributions preparation of operation, thanks its capability perform long pulses dominant electron heating, torque-free scheme based RF systems, and ITERgrade actively cooled divertor. Recent interest cover understanding tungsten contamination evaluation conditioning methods,...
Plasma Facing Components (PFC) temperature measurement is mandatory to ensure safe high power and long pulse tokamak operation. IR thermography systems which are widely used in magnetic fusions devices become challenged with the choice of tungsten as a PFC material ITER tokamak, mainly due emissivity uncertainties reflection issues hot environment. Embedded measurements foreseen cross-check measurements. Fiber Bragg grating sensors potentially great interest for this application because they...
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...
Studying the ageing of tungsten monoblocks, their erosion and fuel inventory is priority WEST post-mortem analyses programme. Actively-cooled ITER-like plasma-facing units (PFUs) special W-coated marker lower divertor tiles were retrieved from after C3 C4 experimental campaigns to perform ex-situ analyses. The erosion/deposition pattern on was determined. deposition found mainly inner side which covered by layered deposits that increase in thickness radial direction a few hundreds nm maximum...
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...
WEST is a full W tokamak with an extensive set of diagnostics for heat load measurements especially in the lower divertor.It composed by infrared thermography, thermal measurement thermocouples and fiber Bragg grating embedded few mm below surface flush mounted Langmuir probes.A large database including different magnetic equilibrium input power investigated to compare pattern (location, amplitude peak flux decay length) on inner outer strike point regions : from first ohmic diverted plasma...
In the WEST tokamak, ITER-like divertor targets consisting of tungsten monoblocks bonded via an OHFC-Cu compliance layer to CuCrZr cooling tubes were exposed plasma during 2018 experimental campaign in which modest heating power was available. Up 2.5 MW/m2 surface heat flux attained. Inspection components after revealed a wide variety damage at both leading and trailing monoblock edges, optical hot spots are projections along magnetic field lines toroidal gaps between onto poloidal edges....
Assessing the performance of ITER design for tungsten (W) divertor Plasma Facing Units (PFUs) in a tokamak environment is high priority issue to ensure efficient plasma operation. This paper reviews most recent results derived from experiments and post-mortem analysis ITER-grade PFUs exposed WEST associated modelling, with focus on understanding heat loading damage evolution. Several shaping options, sharp or chamfered leading edge (LE), unshaped shaped blocks toroidal bevel as foreseen...
Melting is one of the major risks associated with tungsten (W) plasma-facing components (PFCs) in tokamaks like JET or ITER. These are designed such that leading edges and hence excessive plasma heat loads deposited at near normal incidence avoided. Due to high stored energies ITER discharges, shallow surface melting can occur under insufficiently mitigated disruption so-called edge localised modes—power load transients. A dedicated program was carried out study physics consequences W...
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...
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...
Twelve ITER-like plasma-facing units made of tungsten were exposed in the WEST tokamak divertor, with three (PFUs) significantly overexposed to plasma heat flux: one sharp-edged PFU (vertical misalignment h = 0.8 mm) and two chamfered PFUs (h =0.6 mm 0.3 mm, respectively). This paper describes first temperature analysis obtained a very high spatial resolution infrared camera (pixel size ∼ 0.1 on misaligned edges shows consistency parallel flux derived from these measurements. The is focused...
The pre-fusion power operation (PFPO) phase of ITER, as described in the ITER research plan with Staged Approach2, includes both hydrogen (H) and helium (He) plasma operations. In preparation for PFPO, WEST JET ran He campaigns to study plasma-wall interactions a tungsten environment. included back-and-forth transition between H or deuterium (D) allowing assessment achievable content well accessible wall reservoirs respective species. changeovers tokamak pulses fixed divertor configuration....
Abstract Understanding impurity transport in tokamak plasmas is crucial to control radiative losses and material migration future magnetic fusion reactors. In this work we deploy the SolEdge2D-EIRENE code model boundary plasma a WEST discharge, satisfactorily reproducing measurements of both upstream divertor conditions. The spatial distribution oxygen, studied here as representative light impurity, compared vacuum ultraviolet spectroscopy acquired with an oscillating line sight. simulation...