A5054548256- Magnetic confinement fusion research
- Fusion materials and technologies
- Nuclear Materials and Properties
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Laser-induced spectroscopy and plasma
- Dust and Plasma Wave Phenomena
- Laser Design and Applications
- Solid State Laser Technologies
ITER
2023-2025
Culham Science Centre
2024
Culham Centre for Fusion Energy
2024
KTH Royal Institute of Technology
2017-2023
Mirrors will be used as first plasma-viewing elements in optical and laser-based diagnostics ITER. Deterioration of the mirror performance due to e.g. sputtering surface by plasma particles or deposition impurities hamper entire affected diagnostic thus affect ITER operation. The Specialists Working Group on First (FM SWG) Topical Diagnostics International Tokamak Physics Activity (ITPA) plays an important role finding solutions for mirrors.
The experiments carried out in hydrogen at the TOMAS facility show possibility of controlling plasma parameters such as temperature and electron density a combined cyclotron resonance radio frequency (ECR+RF) discharge. A maximum up to ≈6 × 1016 m−3 35 eV are observed ECR+RF propagation RF waves under weak magnetic field is analyzed. Depending on experimental conditions, radial distribution field, there can be several cases: only slow wave propagate, simultaneously fast or propagate....
Abstract An assessment of the tritium (T) inventory in plasma facing components (PFC) during JET T and deuterium-tritium (DT) operations is presented based on most comprehensive ex situ fuel retention data set PFCs from 2015-2016 ILW3 operating period presented. The global 4.19 × 10 23 D atoms, 0.19% injected fuel. inner divertor remains region highest (46.5%). at end calculated as 7.48 22 atoms informative for accountancy, clean-up efficacy waste liability assessments. accumulation rate...
The First Mirror Test for ITER has been carried out in JET with mirrors exposed during: (i) the third ILW campaign (ILW-3, 2015–2016, 23.33 h plasma) and (ii) all three campaigns, i.e. ILW-1 to ILW-3: 2011–2016, 63,52 total. All from main chamber wall show no significant changes of total reflectivity initial value diffuse does not exceed 3% spectral range above 500 nm. modified layer on surface very small amount impurities such as D, Be, C, N, O Ni. divertor (inner, outer, base under bulk W...
Collection and ex situ studies of dust generated in controlled fusion devices during plasma operation are regularly carried out after experimental campaigns. Herewith results the survey per ...
The Toroidal Magnetized System device has been significantly upgraded to enable development of various wall conditioning techniques, including methods based on ion and electron cyclotron (IC/EC) range frequency plasmas, complement plasma–wall interaction research in tokamaks stellarators. toroidal magnetic field generated by 16 coils can reach its maximum 125 mT the axis. EC system is operated at 2.45 GHz with up 6 kW forward power. IC couple 10 MHz–50 MHz. direct current glow discharge a...
Abstract Mirror tests for ITER have been carried out in JET over 15 years. During the third campaign with ITER-like wall (2015–2016), comprising a total tokamak plasma exposure duration of 23.4 h and 1027 glow discharge cleaning, new experiment was performed specially designed test assembly housing six polycrystalline molybdenum mirror samples featuring trapezoidal entrance apertures simulating geometry cut-outs diagnostic first shielding blanket. The installed on vacuum vessel at outer...
Abstract This paper presents an overview of the TOMAS plasma diagnostics. The Langmuir probe method is employed to measure electron temperature, density and floating potential distributions.Two triple probes (horizontal vertical distributions) a single distribution) are used. measured parameters by compared. ion neutral atom flux energy distribution respectively characterized with Residual Field Energy Analyzer Time-of-Flight Neutral Particle Analyzer. To determine elemental/charge content...
Abstract Electron- (ECWC) and ion- (ICWC) cyclotron wall conditioning are essential means for controlled fusion to modify the surface state of plasma-facing components in order reduce impurity generation fuel accumulation wall. Development ECWC ICWC requires characterization neutral particle fluxes generated discharges, because neutrals enhance homogeneity conditioning, which may contribute remote or shadowed areas, especially presence a permanent magnetic field (e.g. W7-X, ITER). A...
Dust particles and co-deposits were sampled for the first time from beryllium limiters bulk tungsten divertor (both after ILW-3), test mirrors main chamber ILW-2 ILW-3. The focus was on morphology of molten metal outgrowths. In parallel, stability layers under impact hot water examined Be coatings. study performed by several microscopy methods including SEM, AFM, FIB, TEM Be-sensitive EDX has revealed: (i) an asymmetric distribution with largest objects (125-550 μm) side surfaces tile: (ii)...
Abstract The toroidal magnetized system (TOMAS) plasma facility aims at complementary research on wall conditioning methods, production and plasma–surface interaction studies. This paper explores for the first time parameters in helium electron-cyclotron resonance (ECR) combined ECR + radio-frequency (RF) discharges TOMAS. discharge this work, 2.45 GHz 87.6 mT, is main one creating maintaining plasma, while addition of RF power 25 MHz allows to broaden achievable electron temperature density...
Silicon plates were installed above the inner and outer divertor of JET with ITER-like wall (ILW) after second third ILW campaigns to monitor dust generation deposition aim determine morphology content individual particles co-deposits, including deuterium content. Particular interest was in metal-based particles: Be, W, steel, Cu. Ex-situ examination two performed by a set microscopy ion beam methods micro-beam nuclear reaction analysis particle-induced X-ray emission. Different categories...
Plasma edge cooling, ion cyclotron wall conditioning and disruption mitigation techniques involve massive gas injection (by puffs or pellets) to the torus. A certain fraction remains in plasma-facing components (PFC) due co-deposition implantation. An uncontrolled release/desorption of such retained species affects stability plasma operation. The aim this work was determine lateral depth distribution noble (3He, 4He, Ne, Ar), seeded (N2, Ar) tracer gases (15N, 18O) PFC retrieved from JET...
Plasma-facing components have castellated structure for thermo-mechanical durability and integrity under high heat flux loads. However, fuel co-deposition in the grooves of castellation may enh ...
The paper provides a concise overview of ion beam analysis methods and procedures in studies materials exposed to fusion plasmas controlled devices with magnetic confinement. An impact erosion–deposition processes on the morphology wall is presented. In particular, results for deuterium analyses are discussed. Underlying physics, advantages limitations addressed. role diagnostics material migration fuel retention explained. A brief note research handling radioactive beryllium-contaminated also given.