A5044932952- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Plasma Diagnostics and Applications
- Geomagnetism and Paleomagnetism Studies
- Nuclear reactor physics and engineering
- Atomic and Subatomic Physics Research
- Engineering Applied Research
- Geophysics and Gravity Measurements
Aalto University
2018-2025
Max Planck Institute for Plasma Physics
2024
Abstract The impact of the SOL (Scrape-Off Layer) plasma on deposition, confinement and losses NBI fast ions was investigated in W7-X plasma. effect width, density, temperature profiles, radial electric field, charge-exchange reactions (CX) explored. Ionization slowing down partly counterbalance each other, as cold compensates for ionization effects radially decaying model profiles. However, more vulnerable steel components is mitigating over wide range
of different profiles those...
Abstract Dedicated experiments were performed on MAST Upgrade to study beam-ion losses caused by charge exchange (CX) with edge neutrals. The fuelling was switched from the high-field side low-field mid-discharge. Direct measurements suggest a strong increase in neutral density around plasma and decrease density, which is qualitatively explained CX losses. Measurements resistive bolometer have suggested particle bombardment during beam injection, providing unique opportunity separate other...
We present a novel implementation of Monte Carlo particle-following code for solving the distribution function minority species in fusion plasmas, called ASCOT5, and verify it using theoretical results neoclassical transport. The has been developed from ground up with an OpenMP-MPI hybrid paradigm to take full advantage current next generation many-core CPUs multithreading SIMD operations. Up 6-fold increase performance is demonstrated compared previous version which only utilizes MPI....
Abstract MAST-U is equipped with on-axis and off-axis neutral beam injectors (NBI), these external sources of super-Alfvénic deuterium fast-ions provide opportunities for studying a wide range phenomena relevant to the physics alpha-particles in burning plasmas. The MeV D-D fusion product ions are also produced but not confined. Simulations ASCOT code show that up 20% fast by NBI can be lost due charge exchange (CX) edge neutrals. Dedicated experiments employing low field side (LFS) gas...
Abstract A novel high-performance computing algorithm, developed in response to the next generation of computational challenges associated with burning plasma regimes ITER-scale tokamak devices, has been tested and is described herein. The Lorentz-orbit code for use stellarators tokamaks ( LOCUST ) designed computationally scalable modelling fast-ion dynamics, presence detailed first wall geometries fine 3D magnetic field structures. It achieves this through multiple levels single...
Abstract Simulation of the impact charge-exchange (CX) reactions on beam ions in Mega Amp Spherical Tokamak (MAST) Upgrade was compared to measurements carried out with a fission chamber (neutron fluxes) and fast ion deuterium-alpha (FIDA) diagnostic. A simple model developed reconstruct outer-midplane neutral density based emission from edge neutrals, Thomson scattering electron temperature. The main computational tools used were ASCOT orbit-following code FIDASIM for producing synthetic...
Abstract A model for simulating charge exchange (CX) of fast ions with background atoms in magnetically confined fusion plasmas has been implemented the ASCOT orbit-following code. The was verified by comparing simulated reaction mean free paths to analytical values across a range fusion-relevant parameters. used simulate beam slowing down presence CX reactions MAST-U target scenario. predicts CX-induced loss power be <?CDATA $22 \%$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
High-energy ions, such as fusion alphas and ions from external heating, can be very sensitive to any non-axisymmetric features in the confining magnetic field due their collisionless nature. Since understanding confinement properties of these is crucial for ITER (the first reactor currently under construction Cadarache, France) beyond, it ultimate importance that predictive simulations are accurate free numerical distortions. Adding third dimension comes at substantial computational cost,...