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View article: Operation of a lithium beam diagnostic in tritium and deuterium–tritium experiments at JET
Operation of a lithium beam diagnostic in tritium and deuterium–tritium experiments at JET Open
A fast neutral lithium beam has been used at JET for more than 30 years to measure profiles of electron density in the pedestal and scrape off layer. The diagnostic was not designed for tritium operation. In this paper, we describe the mod…
View article: The core–edge integrated neon-seeded scenario in deuterium–tritium at JET
The core–edge integrated neon-seeded scenario in deuterium–tritium at JET Open
This paper reports the first experiment carried out in deuterium–tritium addressing the integration of a radiative divertor for heat-load control with good confinement. Neon seeding was carried out for the first time in a D–T plasma as par…
View article: Production and launch studies of cryogenic pellets for the ITER disruption mitigation system
Production and launch studies of cryogenic pellets for the ITER disruption mitigation system Open
A support laboratory has been set up to study pellet production, launch and shattering of cryogenic protium, deuterium, and neon pellets for the ITER disruption mitigation system, which plans to use 28.5 × 57 mm (diameter × length) protium…
View article: Exploring the physics of a high-performance H-mode scenario with small ELMs at low collisionality in JET with Be/W wall
Exploring the physics of a high-performance H-mode scenario with small ELMs at low collisionality in JET with Be/W wall Open
A new H-mode regime at low density and low edge safety factor ( q 95 = 3.2, with = 3 MA) that combines high energy confinement, stationary conditions for density and radiation and small Edge Localized Modes (ELMs) have been found in …
View article: Charge exchange recombination spectroscopy on the alkali beam of Wendelstein 7-X
Charge exchange recombination spectroscopy on the alkali beam of Wendelstein 7-X Open
Measurements of ion temperature profiles are required to assess the energy and particle transport processes in the Wendelstein 7-X stellarator. This device is equipped with a diagnostic alkali beam, which can be utilized to determine local…
View article: Fuelling of deuterium–tritium plasma by peripheral pellets in JET experiments
Fuelling of deuterium–tritium plasma by peripheral pellets in JET experiments Open
A baseline scenario of deuterium–tritium (D–T) plasma with peripheral high-field-side fuelling pellets has been produced in JET in order to mimic the situation in ITER. The isotope mix ratio is controlled in order to target the value of 50…
View article: Eddy current actuated fast valve development for disruption mitigation applications
Eddy current actuated fast valve development for disruption mitigation applications Open
Shattered Pellet Injection (SPI) is a common technique used in Disruption Mitigation Systems to prevent or minimize the effect of plasma disruptions in Tokamaks. To operate an SPI system, a fast-acting valve is needed for accelerating pell…
View article: Mechanical design of a Fast Shutter for the ITER disruption mitigation system
Mechanical design of a Fast Shutter for the ITER disruption mitigation system Open
ITER is a large-scale experimental nuclear fusion reactor currently under construction. To protect the first wall components of the machine against damages due to a plasma disruption event, ITER needs a Disruption Mitigation System (DMS). …
View article: Fast Shutter optioneering study for the ITER Disruption Mitigation System
Fast Shutter optioneering study for the ITER Disruption Mitigation System Open
ITER needs a Disruption Mitigation System (DMS) for protection from the consequences of plasma disruptions during high-power operation. The current DMS for ITER is based on the Shattered Pellet Injection (SPI) technology. This works on the…
View article: First measurements of an imaging heavy ion beam probe at the ASDEX Upgrade tokamak
First measurements of an imaging heavy ion beam probe at the ASDEX Upgrade tokamak Open
The imaging heavy ion beam probe (i-HIBP) diagnostic has been successfully commissioned at ASDEX Upgrade. The i-HIBP injects a primary neutral beam into the plasma, where it is ionized, leading to a fan of secondary (charged) beams. These …
View article: Experimentally corroborated model of pressure relaxation limit cycle oscillations in the vicinity of the transition to high confinement in tokamaks
Experimentally corroborated model of pressure relaxation limit cycle oscillations in the vicinity of the transition to high confinement in tokamaks Open
An analytical formula systematically predicts the observed frequency of pressure relaxation limit cycle oscillations in the vicinity of the transition to high confinement in four tokamaks (JET, ASDEX Upgrade, COMPASS, Globus-M). The experi…
View article: Statistical analysis of plasma filaments in the island divertor of Wendelstein 7-X
Statistical analysis of plasma filaments in the island divertor of Wendelstein 7-X Open
Plasma filaments have been measured with alkali beam emission spectroscopy in the plasma edge, divertor island, and scrape-off layer of Wendelstein 7-X. Due to the high intensity of a 1–2 kHz plasma mode, a new, correlation based condition…
View article: L-H transition studies in tritium and deuterium–tritium campaigns at JET with Be wall and W divertor
L-H transition studies in tritium and deuterium–tritium campaigns at JET with Be wall and W divertor Open
The recent deuterium–tritium campaign in JET-ILW (DTE2) has provided a unique opportunity to study the isotope dependence of the L-H power threshold in an ITER-like wall environment (Be wall and W divertor). Here we present results from de…
View article: Effect of the isotope mass on pedestal structure, transport and stability in D, D/T and T plasmas at similar β <sub>N</sub> and gas rate in JET-ILW type I ELMy H-modes
Effect of the isotope mass on pedestal structure, transport and stability in D, D/T and T plasmas at similar β <sub>N</sub> and gas rate in JET-ILW type I ELMy H-modes Open
The work describes the pedestal structure, transport and stability in an effective mass ( A eff ) scan from pure deuterium to pure tritium plasmas using a type I ELMy H-mode dataset in which key parameters that affect the pedestal behaviou…
View article: Pedestal particle balance studies in JET-ILW H-mode plasmas
Pedestal particle balance studies in JET-ILW H-mode plasmas Open
JET-ILW type I ELMy H-modes at 2.5 MA/2.8 T with constant NBI heating (23 MW) and gas fuelling rate were performed, utilising edge localised mode (ELM) pacing by vertical kicks and plasma shaping (triangularity, δ ) as tools to disentangle…
View article: Experimental study on the role of the target electron temperature as a key parameter linking recycling to plasma performance in JET-ILW*
Experimental study on the role of the target electron temperature as a key parameter linking recycling to plasma performance in JET-ILW* Open
Changes in global and edge plasma parameters ( H 98(y,2) , dimensionless collisionality ν * , core density peaking, separatrix density n e,sep ) with variations in the D 2 fueling rate and divertor configuration are unified into a single t…
View article: Recent progress in L–H transition studies at JET: tritium, helium, hydrogen and deuterium
Recent progress in L–H transition studies at JET: tritium, helium, hydrogen and deuterium Open
We present an overview of results from a series of L–H transition experiments undertaken at JET since the installation of the ITER-like-wall (JET-ILW), with beryllium wall tiles and a tungsten divertor. Tritium, helium and deuterium plasma…
View article: Overview of the COMPASS results <sup>*</sup>
Overview of the COMPASS results <sup>*</sup> Open
COMPASS addressed several physical processes that may explain the behaviour of important phenomena. This paper presents results related to the main fields of COMPASS research obtained in the recent two years, including studies of turbulenc…
View article: TECXY simulations of Ne seeding in JET high power scenarios
TECXY simulations of Ne seeding in JET high power scenarios Open
Preparation of D-T experiments on JET device raises a question about the mitigation of assumed high power entering the SOL. JET DT scenarios aim to achieve good plasma confinement and the heat loads reduction to the divertor at the same ti…
View article: Synthetic edge and scrape-off layer diagnostics—a bridge between experiments and theory
Synthetic edge and scrape-off layer diagnostics—a bridge between experiments and theory Open
The scrape off layer (SOL) plasma in a Tokamak device and its coupling with the edge dictate the performance of a discharge to a high degree—especially as all plasma has to go through the SOL, which is the main exhaust channel for the hot …
View article: Micro-Faraday cup matrix detector for ion beam measurements in fusion plasmas
Micro-Faraday cup matrix detector for ion beam measurements in fusion plasmas Open
Atomic beam probe is an extension of the routinely used beam emission spectroscopy diagnostic for the plasma edge current fluctuation measurement at magnetically confined plasmas. Beam atoms ionized by the plasma are directed to a curved t…
View article: Publisher’s Note: “Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system” [Rev. Sci. Instrum. 89, 043509 (2018)]
Publisher’s Note: “Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system” [Rev. Sci. Instrum. 89, 043509 (2018)] Open
This article was originally published online on 20 April 2018 with an error in the last sentence of the second to last paragraph before the Acknowledgments. The sentence should have read, Determining SOL and edge turbulence spectra and cor…
View article: Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system
Sub-millisecond electron density profile measurement at the JET tokamak with the fast lithium beam emission spectroscopy system Open
Diagnostic alkali atom (e.g., lithium) beams are routinely used to diagnose magnetically confined plasmas, namely, to measure the plasma electron density profile in the edge and the scrape off layer region. A light splitting optics system …
View article: Axisymmetric oscillations at L–H transitions in JET: M-mode
Axisymmetric oscillations at L–H transitions in JET: M-mode Open
L to H transition studies at JET have revealed an n = 0, m = 1 magnetic oscillation starting immediately at the L to H transition (called M-mode for brevity). While the magnetic oscillation is present a weak ELM-less H-mode regime is obtai…