A5035746292- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Nuclear physics research studies
- Semiconductor materials and devices
- Particle Accelerators and Free-Electron Lasers
- Advanced Semiconductor Detectors and Materials
- High-Energy Particle Collisions Research
- Nuclear Materials and Properties
- Particle physics theoretical and experimental studies
- Power System Optimization and Stability
- Fault Detection and Control Systems
- Gyrotron and Vacuum Electronics Research
- Fluid Dynamics and Turbulent Flows
- Magnetic Properties and Applications
- Vacuum and Plasma Arcs
- High-pressure geophysics and materials
- Physics of Superconductivity and Magnetism
- Statistical Mechanics and Entropy
Universidade do Porto
2005-2024
Culham Science Centre
2011-2024
Culham Centre for Fusion Energy
2024
University of Lisbon
2005-2023
Royal Military Academy
2020
Institute for Atomic and Molecular Physics
1997-2002
Experiments with strong localized electron cyclotron heating (ECH) in the RTP tokamak show that heat transport is governed by alternating layers of good and bad thermal conduction. For central deposition hot filaments are observed inside q = 1 radius. Moving ECH resonance from centre to edge plasma results discrete steps temperature. The transitions occur when minimum value crosses 1,2,5/2 or 3, correspond loss a barrier situated close rational value. Close new type sawtooth activity...
The local measurement of the island width w, around resonant surface, allowed a direct test extended Rutherford model [P. H. Rutherford, PPPL Report-2277 (1985)], describing evolution radiation-induced tearing modes prior to disruptions tokamak plasmas. It is found that this accounts very well for observed exponential growth and supports radiation losses as being main driving mechanism. implies effective perpendicular electron heat conductivity in smaller than global one. Comparison...
Abstract The isotope effect on intrinsic rotation was studied at the Joint European Torus (JET) tokamak. With unique capability of JET to operate with tritium (T), for first time, experiments in hydrogen (H), deuterium (D) and T Ohmic plasmas were compared. Two reversals per type are observed plasma density scans spanning linear saturated confinement regimes. A clear mass dependence is higher densities. magnitude core found depend mass, stronger co-current H. Change characteristics coexist a...
The results of a series experiments done in RTP which had the purpose to avoid or ameliorate radiative density-limit disruptions, will be reported. Avoidance disruptions was achieved by stabilizing m = 2 radiation induced tearing mode (RTM) with electron cyclotron resonance heating (ECRH). Both continuous and modulated power deposition studied. It found that stabilization ECRH phase O-point less efficient than ECRH, contrary theoretical expectations. Detailed scans EC intensity were...
Measurements of the electron temperature, Te, and density, ne, during energy quench a major disruption showed that onset Te erosion in neighborhood m/n=2/1 O point at low field side (LFS) accelerates well-known m/n=1/1 core temperature. During this phase Te(r) is only partially flat region between q=2 q=1 surfaces ne(r) decreases increases inside island. Immediately after flattening large peak to lesser extent ne has been observed. This radially localized radius LFS, very short lived...
Experimental evidence was found in JET plasmas of a new instability at the onset minor disruptions. This is observed during growth well known m/n = 2/1 magnetic island and localized close to it, behaving as secondary island. The large heat fluxes towards plasma edge, characteristic disruptions, occur low rotation phase time amplitude suffers increase. No poloidal or toroidal mode numbers could be assigned instability.
A systematic study of COMPASS density limit disruptions (DLDs) was carried out to analyze the relation between precursor magnetic island and its secondary instability (SI). In all these plasmas, SI always found present at onset energy confinement erosion. The duration this erosion shorter for quasi-locked than rotating island, larger amplitude, duration. It also found, confinement, an inverse amplitude rotation frequency, showing that can start different values depending on what is...
An electron cyclotron emission (ECE) heterodyne radiometer and a Thomson scattering (TS) system were used to measure the temperature (T/sub e/) evolution in plasmas of Rijnhuizen Tokamak Project (RTP) during abrupt loss energy confinement high-density limit disruptions with unprecedented high resolution.