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Deep learning approaches have shown promising performance for compressed sensing-based Magnetic Resonance Imaging. While deep neural networks trained with mean squared error (MSE) loss functions can achieve high peak signal to noise ratio,…

Computer Vision and Pattern Recognition · Computer Science 2018-07-02 Maximilian Seitzer , Guang Yang , Jo Schlemper , Ozan Oktay , Tobias Würfl , Vincent Christlein , Tom Wong , Raad Mohiaddin , David Firmin , Jennifer Keegan , Daniel Rueckert , Andreas Maier

Reliable position and shape control in tokamak plasmas requires accurate real-time regulation of several strongly coupled shape parameters. The control vectors that disentangle these couplings, referred to as \textit{virtual circuits}…

We propose a quantum-Hamiltonian-learning-based sequential reconstruction framework for dynamic two-dimensional magnetic-field maps using a local likelihood model derived from a nitrogen-vacancy-center spin-1 Hamiltonian. Local measurements…

Quantum Physics · Physics 2026-05-26 Hiroshi Yamauchi , Sophie Colleen Stearn , Samuel Tovey

Edge-Localized-Mode (ELM) suppression by resonant magnetic perturbations (RMPs) generally occurs over very narrow ranges of the plasma current (or magnetic safety factor q95) in the DIII-D tokamak. However, wide q95 ranges of ELM…

Plasma Physics · Physics 2020-08-03 Q. M. Hu , R. Nazikian , B. A. Grierson , N. C. Logan , D. M. Orlov , C. Paz-Soldan , Q. Yu

A two-fold analysis of electromagnetic core tokamak instabilities in the framework of the gyrokinetic theory is presented. First principle theoretical foundations of the gyrokinetic theory are used to explain and justify the numerical…

A mechanism for fast magnetic reconnection in collisionless plasma is studied for understanding sawtooth collapse in tokamak discharges. Nonlinear growth of the tearing mode driven by electron inertia is analytically estimated by invoking…

Plasma Physics · Physics 2012-10-03 M. Hirota , P. J. Morrison , Y. Ishii , M. Yagi , N. Aiba

Quantum systems have shown great promise for precision metrology thanks to advances in their control. This has allowed not only the sensitive estimation of external parameters but also the reconstruction of their temporal profile. In…

Quantum Physics · Physics 2014-03-20 Easwar Magesan , Alexandre Cooper , Honam Yum , Paola Cappellaro

A local magnetic equilibrium model is presented, with finite aspect ratio and up-down asymmetrically shaped cross section, that depends on eight free parameters. In contrast with other local equilibria, which provide simple magnetic-surface…

Plasma Physics · Physics 2018-08-22 Paulo Rodrigues , André Coroado

The emergence and dynamics of filamentary structures associated with edge-localized modes (ELMs) inside tokamak plasmas during high-confinement mode is regularly studied using Electron Cyclotron Emission Imaging (ECEI) diagnostic systems.…

Plasma Physics · Physics 2022-04-05 Cooper Jacobus , Minjun J. Choi , Ralph Kube

The physical sciences require models tailored to specific nuances of different dynamics. In this work, we study outcome predictions in nuclear fusion tokamaks, where a major challenge are \textit{disruptions}, or the loss of plasma…

Plasma Physics · Physics 2024-01-02 Lucas Spangher , William Arnold , Alexander Spangher , Andrew Maris , Cristina Rea

The integrity of plasma-facing components (PFCs) in tokamaks is critically challenged by transient events such as runaway electron (RE) impacts. We report the first systematic analysis of the thermal damage to tungsten-based PFC tiles…

Plasma Physics · Physics 2026-03-05 T. Rizzi , K. Paschalidis , S. Ratynskaia , P. Tolias , I. Ekmark , M. Hoppe , R. A. Tinguely , A. Feyrer , T. Looby

Fast and accurate MRI reconstruction is a key concern in modern clinical practice. Recently, numerous Deep-Learning methods have been proposed for MRI reconstruction, however, they usually fail to reconstruct sharp details from the…

Image and Video Processing · Electrical Eng. & Systems 2023-06-21 Hanhui Yang , Juncheng Li , Lok Ming Lui , Shihui Ying , Jun Shi , Tieyong Zeng

This paper presents a novel approach for simulating plasma instabilities in tokamak plasmas using the piecewise field-aligned finite element method in combination with the particle-in-cell method. Our method traditionally aligns the…

The EXL-50U spherical tokamak was built by Energy iNNovation to develop technologies for proton-boron fusion in spherical tokamaks (Liu et al., Phys. Plasmas 2024). We present a conceptual design of the Doppler backscattering (DBS)…

A disrupting plasma in a high-performance tokamak such as ITER or SPARC may generate large runaway electron currents that, upon impact with the tokamak wall, can cause serious damage to the device. To quickly identify regions of safe…

Plasma Physics · Physics 2026-03-24 Björn Zaar , István Pusztai , Ida Ekmark , Tünde Fülöp

Synthetic aperture radar tomography (TomoSAR) has been extensively employed in 3-D reconstruction in dense urban areas using high-resolution SAR acquisitions. Compressive sensing (CS)-based algorithms are generally considered as the state…

Signal Processing · Electrical Eng. & Systems 2022-05-04 Kun Qian , Yuanyuan Wang , Yilei Shi , Xiao Xiang Zhu

Methods from soft-collinear effective theory are used to perform the threshold resummation of Sudakov logarithms for the deep-inelastic structure function F_2(x,Q^2) in the endpoint region x->1 directly in momentum space. An explicit…

High Energy Physics - Phenomenology · Physics 2008-11-26 Thomas Becher , Matthias Neubert

We use beam tracing -- implemented with a newly-written code, Scotty -- and the reciprocity theorem to derive a model for the linear backscattered power of the Doppler Backscattering (DBS) diagnostic. Our model works for both the O-mode and…

Plasma Physics · Physics 2022-10-03 Valerian H Hall-Chen , Felix I Parra , Jon C Hillesheim

Motivated by evidence for core-edge coupling in the form of double-peaked fishbone-like low-frequency modes ($\lesssim 20\,{\rm kHz}$) in KSTAR, which exhibit synchronized Alfv\'{e}nic activity both in the central core and near the plasma…

The image reconstruction problem of the tomographic imaging technique magnetic particle imaging (MPI) requires the solution of a linear inverse problem. One prerequisite for this task is that the imaging operator that describes the mapping…

Computational Physics · Physics 2019-07-12 Tobias Kluth , Patryk Szwargulski , Tobias Knopp