RF current drive and plasma fluctuations

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The experimental fusion reactor ITER will feature two (or three) heating neutral beam injectors (NBI) capable of delivering 33(or 50) MW of power into the plasma. A NBI consists of a plasma source for production of negative ions (extracted negative ion cur ...

Electron beam-generated plasmas (EBPs) have been used to modify the surface properties. In certain applications, EBPs are transversely confined and their properties are of value to the treatment. In this paper, the characteristics of an electron beam-gener ...

Ion transport through biological and solid-state nanochannels is known to be a highly noisy process. The power spectrum of current fluctuations is empirically known to scale like the inverse of frequency, following the long-standing yet poorly understood H ...

Two reduced models for predicting detachment onset and divertor reattachment times are validated on MAST Upgrade (MAST-U). These models are essential for future tokamak reactor design, providing rapid calculations based primarily on engineering parameters. ...

The surface erosion of biased electrodes immersed in a radio frequency (RF) plasma was investigated in oblique magnetic fields ranging from 0.1 T to 3.5 T. The plasma potential and density in the vicinity of the biased electrode have been measured using an ...

The superconducting magnet system of the Divertor Tokamak Test (DTT) facility, composed of 18 toroidal field (TF) coils, 6 poloidal field coils and a central solenoid, has been designed and many procurements have been launched. Some manufacturing aspects a ...

While much about Alfvén eigenmode (AE) stability has been explored in previous and current tokamaks, open questions remain for future burning plasma experiments, especially regarding exact stability threshold conditions and related isotope effects; the lat ...

In certain cases of astronomical data analysis, the meaningful physical quantity to extract is the ratio R between two data sets. Examples include the lensing ratio, the interloper rate in spectroscopic redshift samples, and the decay rate of gravitational ...

There is a bias in the inference pipeline of most diffusion models. This bias arises from a signal leak whose distribution deviates from the noise distribution, creating a discrepancy between training and inference processes. We demonstrate that this signa ...

Within the context of contemporary machine learning problems, efficiency of optimization process depends on the properties of the model and the nature of the data available, which poses a significant problem as the complexity of either increases ad infinit ...

Recent results from MAST Upgrade are presented, emphasising understanding the capabilities of this new device and deepening understanding of key physics issues for the operation of ITER and the design of future fusion power plants. The impact of MHD instab ...

This study employs the established momentum transport analysis at ASDEX Upgrade [Zimmermann et al., Nucl. Fusion 63, 124003 (2023)] to investigate the parametric variations of the momentum transport coefficients in the core of H-mode plasmas. These experim ...

In this paper, we investigate federated contextual linear bandit learning within a wireless system that comprises a server and multiple devices. Each device interacts with the environment, selects an action based on the received reward, and sends model upd ...

The mission of WEST (tungsten-W Environment in Steady-state Tokamak) is to explore long pulse operation in a full tungsten (W) environment for preparing next-step fusion devices (ITER and DEMO) with a focus on testing the ITER actively cooled W divertor in ...

This paper introduces Wireless IoT-based Noise Cancellation (WINC) which defines a framework for leveraging a wireless network of IoT microphones to enhance active noise cancellation in noise-canceling headphones. The IoT microphones forward ambient noise ...

We prove global in time well-posedness for perturbations of the 2D stochastic Navier-Stokes equations partial derivative( t)u + u center dot del u = Delta u - del p + sigma + xi, u(0, center dot ) = u(0),div (u) = 0, driven by additive space-time white noi ...

The largest operating stellarator, Wendelstein 7-X, is of the quasi-isodynamic type. For this design to scale up to a fusion reactor, several criteria must be met, one of them being good fast ion confinement. The latter still has to be tested experimentall ...

For the EU DEMO conductor testing, a temperature sensor based on Fiber Bragg Grating (FBG) optical fiber is studied at the EPFL Swiss Plasma Center. The SULTAN test facility has been upgraded to use fiber optic sensor for temperature monitoring and quench ...

Higher-order asymptotics provide accurate approximations for use in parametric statistical modelling. In this thesis, we investigate using higher-order approximations in two-specific settings, with a particular emphasis on the tangent exponential model. ...

Linear-Quadratic-Gaussian (LQG) control is a fundamental control paradigm that is studied in various fields such as engineering, computer science, economics, and neuroscience. It involves controlling a system with linear dynamics and imperfect observations ...

RF current drive and plasma fluctuations

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Optimizing the ITER NBI ion source by dedicated RF driver test stand

Characterization of transversely confined electron beam-generated plasma using two-dimensional particle-in-cell simulations

Disentangling 1/f noise from confined ion dynamics

Validating reduced models for detachment onset and reattachment times on MAST-U

Plasma sputtering of biased electrodes in an oblique magnetic field

DTT toroidal field conductor samples test in Sultan: DC and AC characterization

Isotope effects and Alfvén eigenmode stability in JET H, D, T, DT, and He plasmas

An Unbiased Method of Measuring the Ratio of Two Data Sets

Exploiting the Signal-Leak Bias in Diffusion Models

Universal and adaptive methods for robust stochastic optimization

Overview of physics results from MAST upgrade towards core-pedestal-exhaust integration

Experimental validation of momentum transport theory in the core of H-mode plasmas in the ASDEX Upgrade tokamak

Federated Linear Bandit Learning via Over-the-air Computation

WEST full tungsten operation with an ITER grade divertor

WINC: A Wireless IoT Network for Multi-Noise Source Cancellation

Global existence for perturbations of the 2D stochastic Navier-Stokes equations with space-time white noise

Fast ion generation with ICRF waves and beams in the Wendelstein 7-X stellarator

Quench Detection and Temperature Measurement With Fiber Optic Sensors

Higher Order Asymptotics: Applications to Satellite Conjunction and Boundary Problems

Distributionally Robust Linear Quadratic Control