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The planar coil stellarator design is a novel approach to producing the confining magnetic field of a stellarator plasma. The work presented here details the optimization of the two types of planar coils that are used in the planar coil design: the plasma encircling coils, and the shaping coils. The plasma encircling coils provide the mean magnetic field and linking current, similar to the toroidal field (TF) coils in a tokamak. The plasma encircling coils can be rotationally symmetric TF-like coils and produce a B∝1/R field, but optimizing their placement, tilt, and shaping can substantially reduce the magnetic field error. In addition, an array of dipole-like shaping coils, that lie on a surface between the plasma boundary and the encircling coils, correct for the residual magnetic field error following encircling coil optimization. As a proof-of-concept, it is shown that by optimizing both types of coils, subject to realistic engineering constraints, reasonable magnetic field errors of ∼1% have been achieved. Comparison to a traditional modular coil set reveals that similarly low magnetic field errors can be attained with the planar coil stellarator.

In order to optimize the structure of high temperature superconducting coils for linear motor applications, three separate coils with different shapes made of Re-BCO coated conductor were studied: circular shaped single pancake, circular shaped double-pancake and racetrack shaped single-pancake. The thrust and vertical forces of the three coils above a conventional flat linear three-phases winding were investigated experimentally. With the aid of the experimentally obtained values, it was found that single-pancake coil in the shape of a racetrack was the best selection for a flat single-sided linear motor system. Studies were also made on the frequency characteristics of the vertical force of the racetrack shaped single-pancake coil.

In this article, we survey a complete MRI systematic pipeline from theoretical modelling and numerical simulations to analysis and optimization of three different types of MRI coils. After a preliminary parametric exploration using generic models based on standard equations, a Method of Moments (MoM) study of geometrically representative coil structures was conducted to explore the nearer field effects. Then, Finite Difference Time Domain (FDTD) analysis was performed to realize the optimized-designed devices to be fabricated using MEMS process and confirmed its performance by using Vector Network Analyzer (VNA) and an anechoic chamber measurement. Performance comparisons based on parameters like resonance frequency, gain and radiated power were performed. Then for the Roger’s 6010TM RT/Duroid substrate material (ε=10.5) thickness 1.6 mm, the rectangular resonance frequency and return loss for the MRI coil are 8.06 GHz and 52.73 dB respectively. The gain on this coil is 36.45 dBm and the radiated powers were 59.25 dBi and 53.56 dBi. In comparison, using similar substrate material, it obtained a return loss of 52.73 dB and a gain of 45.89 dBm, while the circular MRI coil works at the same resonance frequency and could be found in the literature. Using Teflon-PTFE substrate with dielectric constant of 2.1, the resultant triangular MRI coil is fabricated which shows resonance frequency of 8 GHz return loss of 45.81 dB and gains of 49.35 dBm. This study’s performance metrics are closure with regularization results, and the closure is the validation of the enhanced performance of the proposed resonators for medical imaging applications. The designs were also extrapolated to bio-phantom models for further exploration. These RF coils could improve MRI diagnostic technologies as confirmed by the electromagnetic simulation results.

In order to design a high efficiency Wireless Electric Vehicle Charging (WEVC) system, the design of the different system components needs to be optimized, particularly the design of a high-coupling, misalignment-tolerant inductive link (IL), comprising primary and secondary charging coils. Different coil geometries can be utilized for the primary and the secondary sides, each with a set of advantages and drawbacks in terms of weight, cost, coupling at perfect alignment and coupling at lateral misalignments. In this work, a Finite Element Method (FEM)-based systematic approach for the design of double-D (DD) charging coils is presented in detail. In particular, this paper studies the effect of different coil parameters, namely the number of turns and the turn-to-turn spacing, on the coupling performance of the IL at perfect alignment and at ±200 mm lateral misalignment, given a set of space constraints. The proposed design is verified by an experimental prototype to validate the accuracy of the FEM model and the simulation results. Accordingly, FEM simulations are utilized to compare the performance of rectangular, DD and DDQ coils. The FEM results prove the importance of utilizing an additional quadrature coil on the secondary side, despite the added weight and cost, to further improve the misalignment tolerance of the proposed inductive link design.

The use of 3D magnetic fields is one of the promising approaches to control edge localized modes (ELMs), and ITER has plans to utilize a flexible 3D coil set for ELM suppression using 3D fields. This study focuses on optimizing the 3D field spectrum to expand the operational window for n = 1 resonant magnetic perturbation (RMP) ELM suppression in KSTAR. The optimized n = 1 RMP effectively suppresses ELMs throughout the entire H-mode discharge, including the first ELM crash, while avoiding the onset of disruptive locked modes in low-density L-mode plasmas. The predicted suppression window aligns well with experimental data, highlighting the challenges and solutions of using n = 1 RMP at low densities. Moreover, the optimization successfully achieved n = 1 RMP ELM suppression for the first time in ITER-relevant q95 and shaping conditions, including cases with q95 as low as 3.6, as well as other q95 and shape configurations. This highlights the importance and utility of 3D coil optimization while emphasizing the potential of long-wavelength low-n RMP, which will be valuable for ex-vessel coils designed to avoid complications of nuclear degradation.

• Powdery mildew, a fungal disease caused by Blumeria graminis f. sp. tritici (Bgt), has a serious impact on wheat production. Loss of resistance in cultivars prompts a continuing search for new sources of resistance. • Wild emmer wheat (Triticum turgidum ssp. dicoccoides, WEW), the progenitor of both modern tetraploid and hexaploid wheats, harbors many powdery mildew resistance genes. We report here the positional cloning and functional characterization of Pm41, a powdery mildew resistance gene derived from WEW, which encodes a coiled-coil, nucleotide-binding site and leucine-rich repeat protein (CNL). Mutagenesis and stable genetic transformation confirmed the function of Pm41 against Bgt infection in wheat. • We demonstrated that Pm41 was present at a very low frequency (1.81%) only in southern WEW populations. It was absent in other WEW populations, domesticated emmer, durum, and common wheat, suggesting that the ancestral Pm41 was restricted to its place of origin and was not incorporated into domesticated wheat. • Our findings emphasize the importance of conservation and exploitation of the primary WEW gene pool, as a valuable resource for discovery of resistance genes for improvement of modern wheat cultivars.

In this work, we utilize new coil objectives for stellarator optimization with autodifferentiation, including pointwise and net coil–coil forces and torques. We use these methods to perform the first large-scale optimization of planar dipole coil arrays, since arrays of small and geometrically simple coils have been proposed to partially produce the 3D magnetic fields for stellarators, generate advantageous magnetic field perturbations in tokamaks, and provide active, real-time control capabilities. We perform an ablation study to show that minimizing the orientation and location of each coil may be essential to get coil forces, coil torques, and field errors to tolerable levels. We conclude with solutions for three reactor-scale quasi-symmetric stellarators by jointly optimizing nonplanar TF coils and planar coil arrays.

All 19 ITER toroidal field coil structures (TFCSs) were successfully fabricated by the Japan Domestic Agency with solving technical challenges. This study presents the results of the welding-deformation control process, which is a remarkable challenge in an efficient fabrication of the TFCSs.

Magnetic fields with quasi-symmetry are known to provide good confinement of charged particles and plasmas, but the extent to which quasi-symmetry can be achieved in practice has remained an open question. Recent work [M. Landreman and E. Paul, Phys. Rev. Lett. 128, 035001, 2022] reports the discovery of toroidal magnetic fields that are quasi-symmetric to orders-of-magnitude higher precision than previously known fields.We show that these fields can be accurately produced using electromagnetic coils of only moderate engineering complexity, that is, coils that have low curvature and that are sufficiently separated from each other.Our results demonstrate that these new quasi-symmetric fields are relevant for applications requiring the confinement of energetic charged particles for long time scales, such as nuclear fusion. The coils’ length plays an important role for how well the quasi-symmetric fields can be approximated. For the longest coil set considered and a mean field strength of 1 T, the departure from quasi-symmetry is of the order of Earth’s magnetic field. Additionally, we find that magnetic surfaces extend far outside the plasma boundary used by Landreman and Paul, providing confinement far from the core. Simulations confirm that the magnetic fields generated by the new coils confine particles with high kinetic energy substantially longer than previously known coil configurations. In particular, when scaled to a reactor, the best found configuration loses only 0.04% of energetic particles born at midradius when following guiding center trajectories for 200 ms.