Transport and turbulence reduction with negative triangularity : Correlation ECE measurements in TCV

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JET, the only tokamak capable of operating with deuterium-–tritium (D-T) fuel (since TFTR was shutdown in 1999), has provided essential experimental data to support ITER and DEMO design and operation. Within the EUROfusion Tokamak Exploitation Work Package, JET completed its final campaigns (2022--2023), culminating in the third D-T campaign (DTE3). These experiments addressed key challenges in plasma scenarios, exhaust control, and tritium management under reactor-relevant conditions. Significant progress

Research on the Tokamak à Configuration Variable (TCV) addresses a wide range of key questions relevant to ITER and future fusion power plants. Over the past two years, highly productive experimental campaigns have led to major advances across several areas: the ITER baseline scenario; pedestal properties in low-collisionality, peeling-limited conditions; and the development of high-

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, non-inductive regimes. Alternative high-confinement scenarios have likewise received significant attention, with re

Helicon waves (also known as whistler waves) satisfying the normal wave-particle cyclotron resonance are observed to limit the growth and maximum energy of relativistic electrons (REs) in low-density Ohmic DIII-D tokamak plasmas. Following the application of helicon waves, pitch-angle scattering of high-energy REs causes an increase in both synchrotron and electron-cyclotron emissions. The hard x-ray emission, a proxy for the RE population, ceases to grow. Energy-resolved hard x-ray measurements also show a

The role of plasmoid drifts towards the tokamak low field side (LFS) and associated rocket motion of solid fragments in the material assimilation of shattered pellet injection (SPI) is investigated. In particular, a trace neon SPI scheme, where a small amount of neon is added to the pellet, envisaged to suppress plasmoid drifts via stronger radiation in the plasmoid, is examined combining experiments on JET and modelling with the non-linear MHD code JOREK. In the JET experiments, pure deuterium (D2) pellet

Utilizing the TokaMaker code, this manuscript presents a scheme for determining the optimal locations of poloidal field coils in tokamak configurations, aimed at reducing the currents required to reproduce target equilibrium in future devices. The definition of the coil position space is described, as well as the cost function is to be minimized, which incorporates the constraints of the problem. The MANTA reactor design, featuring strong negative triangularity shaping, is considered as a test example, wher

The present status of operation and upgrades of the 50 keV / 3 A Diagnostic Neutral Beam Injector (DNBI) at TCV tokamak are described. The plasma grid was replaced by a new re-manufactured one with its existing design. The technology and production were performed within SPC-EPFL. The further redesign of the plasma grid was done to improve the strength and stability, accounting for the results of grid deformation measurements, and considering ANSYS thermomechanical analysis in combination with IBSimu beam si

The transition of the energy system towards decentralized renewable energy sources poses both opportunities and challenges for quarters, districts, and municipalities. To aid local authorities and policy makers in navigating this complex topic, we present a decision-support and pathway recommendations tool. The tool is preloaded with publicly available data and offers modeled data for missing aspects to both display the status quo and enable an assessment of different options in future scenarios. These scen

JT-60SA is currently the world's largest superconducting tokamak. It accelerates the realization of fusion energy by supporting ITER exploitation and complementing it in addressing key physics and engineering issues for DEMO reactors. The main targets of JT-60SA are breakeven-equivalent high-temperature deuterium plasmas and high-βsteady-state plasmas. To achieve these goals, laser-aided diagnostics with high spatial resolution are essential for detailed physics studies. In Operation Phase 1, a tangential s

This thesis focuses on the analysis and reproduction of integral experiments for validating stainless-steel nuclear data, through two complementary programs conducted in the CROCUS zero-power reactor at EPFL. These programs are the semi-integral PETALE program, which includes criticality and transmission experiments with heavy reflectors, and the hybrid pile-oscillation program BLOOM. Both belong to HARVEST X, an EPFL coordinated initiative to reproduce, extend, and cross-validate experiments for stainless-

The engineering of aluminum nitride (AlN) waveguides allows for broad supercontinuum generation (SCG) within its wide transparency window (200 nm - 5.5 μm) enabling applications in precision spectroscopy and metrology fields. An efficient coverage from 500 to 3500 nm was shown by pumping crystalline AlN waveguides with a femtosecond laser centered at 1560 nm [1]. UV and visible coverage was reached by pumping around 800 nm and by chirping the waveguide [2] or by exploiting the modal dispersion of higher-ord

Estimation of the dynamic evolution of electron plasma density during a tokamak discharge is cru- cial since it directly affects the plasma performance, confinement and stability, therefore it needs to be monitored and controlled. Knowledge of the density profile can also be used to control in a more direct way the desired aspects of the plasma density, for example choosing to control the core, volume averaged or edge density, replacing control methods that rely e.g. on a single line-averaged electron densi

Geothermal energy is heat energy generated and stored in the Earth. With the awareness of the society about environmental issues, geothermal power is developing worldwide. It is cost-effective, reliable, sustainable, and environmentally friendly but has historically been extracted from the depth of the earth. Recent technological advances permits to use this energy from the shallow depth of the earth. Thanks to infrastructure foundations combined with heat pump technology, we are able to use this geothermal

Gyrokinetic simulations are extensively used as a tool to describe various phenomena in magnetically confined plasmas. Among others, turbulent transport induced by drift-wave type instabilities such as Ion Temperature Gradient (ITG), Trapped Electron Mode (TEM) and Electron Temperature Gradient (ETG) plays a central role in fusion research. While the ITG mode in first approximations can be modeled using a reduced adiabatic electron model, the TEM and ETG modes require a kinetic description. The global delta

Magnetic-fusion plasmas are complex self-organized systems with an extremely wide range of spatial and temporal scales, from the electron-orbit scales (similar to 10(-11) s, similar to 10(-5) m) to the diffusion time of electrical current through the plasma (similar to 10(2) s) and the distance along the magnetic field between two solid surfaces in the region that determines the plasma-wall interactions (similar to 100 m). The description of the individual phenomena and of the nonlinear coupling between the

A novel first-principles self-consistent model that couples plasma and neutral atom physics suitable for the simulation of turbulent plasma behaviour in the tokamak edge region has been developed [1] and implemented in the GBS code [2]. While the plasma is modelled by the drift-reduced two fluid Braginskii equations, a kinetic model is used for the neutrals, valid in short and in long mean free path scenarios. The model includes ionization, charge-exchange, recombination, and elastic collisional processes.

The mechanism regulating the equilibrium electrostatic potential in the scrape-off layer (SOL) of magnetic confinement devices is elucidated. Based on a generalized Ohm's law and the boundary conditions at the magnetic presheath entrance, an analytical expression for the equilibrium electrostatic potential is derived. Results imply that the relative importance of the plasma dynamics at the sheath and far away from the wall in setting the value of the electrostatic potential depends on the density and temper

Simulations of edge turbulence are particularly challenging due to the presence of large amplitude fluctuations and to the coupling of equilibrium and fluctuating scales. While validating edge simulations is necessary to assess the accuracy of our understanding, difficulties in experimental diagnostics and the lack of a precise validation methodology have, to date, severely limited the process. The Global Braginskii Solver (GBS) code has been developed to simulate plasma turbulence in edge-relevant conditio

We present non-linear self-consistent 3D global fluid simulations of the SOL plasma dynamics using the Global Braginskii Solver (GBS) code. The code solves the drift-reduced Braginkii equations in a collisional plasma, with cold ions. The GBS code, originally developed for an electrostatic, 2D configuration has been recently upgraded to describe the SOL turbulence with the introduction of the variable curvature along the magnetic field lines, the magnetic shear, and the electromagnetic effects. The code pec

Recent advances in the suprathermal ion diagnostic in the basic plasma experiment TORPEX have inspired our comprehensive theoretical study of suprathermal ion transport. TORPEX, an example of a simple magnetized toroidal plasma (SMT), is equipped with a flexible fast ion source and detector capable of exploring fast ion dynamics in a wide range of positions and energies. We simulate an ensemble of ion tracer trajectories as specified by ideal interchange-mode turbulence imported from a validated numerical s

One of the most important open issue for the realization of a fusion reactor is the understanding of the turbulence that develops at the periphery of the device, in the region called the edge. Turbulence is the major cause of particles and energy losses and it is driven by the presence of plasma and magnetic field inhomogeneities. We present non-linear self-consistent simulations of the edge plasma dynamics and we interpret them by means of linear studies of the fluid equations modeling the system. The line

Transport and turbulence reduction with negative triangularity : Correlation ECE measurements in TCV

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Results from the last DD and DT JET campaigns in the framework of the EUROfusion Tokamak Exploitation Work Package Activity

Progress and innovations in the TCV tokamak research programme

First Demonstration of Resonant Pitch-Angle Scattering of Relativistic Electrons by Externally Launched Helicon Waves

Role of plasmoid drift in the efficiency and reliability of shattered pellet injection

Poloidal field coils optimization for the MANTA tokamak using TokaMaker

Recent progress with Diagnostic Neutral Beam Injector at TCV tokamak

Supporting the Integration of Renewable Energy in Communities and Districts by Automated, Online Impact Assessment

Laser-aided diagnostics of JT-60SA

Analysis and Reproduction of Stainless-steel Integral Experiments Towards Nuclear Data Assimilation

Extending the Supercontinuum Spectrum in Fully Etched Thick Aluminum Nitride Waveguides

Model-based electron density estimation using multiple diagnostics on TCV

Numerical simulation of deck de-icing using energy pile systems

An improved hybrid electron model for global gyrokinetic simulations using the ORB5 PIC code

Computational challenges in magnetic-confinement fusion physics

Impact of neutral atoms on plasma turbulence in the tokamak edge region

On the electrostatic potential in the scrape-off layer of magnetic confinement devices

Progressive steps towards global validated simulation of edge plasma turbulence

Global two-fluid simulations of tokamak Scape-Off-Layer turbulence

Suprathermal ion transport theory and experiments in the SMT

Simulation of tokamak SOL turbulence