AI Article Synopsis
- A "current hole" phenomenon occurs in the central region of a tokamak plasma when the current density drops close to zero, despite high electric conductivity.
- Experiments conducted on the JT-60U tokamak demonstrate that neither toroidal electric fields nor radio-frequency waves can drive current in this region.
- This behavior indicates the formation of a new, rigidly structured self-organized magnetic field within the axisymmetric toroidal plasma.
Article Abstract
It is found that no current is driven in a central region of a tokamak plasma once the central current density becomes nearly zero ("current hole"), in spite of high electric conductivity, at the current drive by a toroidal electric field and a radio-frequency wave in experiments on the JT-60U tokamak. This is a new, stiff, self-organized structure of a magnetic field in an axisymmetric toroidal plasma.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.95.075001 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Surface induced crystallization/amorphization of phase change materials.
Nanotechnology
January 2025
MME, Wright State University, 3640 Colonel Glenn Hwy, Lake Campus, 7600 Lake Drive, Lake Campus, Fairborn, Ohio, 45435, UNITED STATES.
Surface induced crystallization/amorphization of a Germanium-antimony-tellurium (GST) nanolayer is investigated using the phase field model. A Ginzburg-Landau (GL) equation introduces an external surface layer (ESL) within which the surface energy and elastic properties are properly distributed. Next, the coupled GL and elasticity equations for the crystallization/amorphization are solved.
View Article and Find Full Text PDFMatched Guiding and Controlled Injection in Dark-Current-Free, 10-GeV-Class, Channel-Guided Laser-Plasma Accelerators.
Phys Rev Lett
December 2024
Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
We measure the high-intensity laser propagation throughout meter-scale, channel-guided laser-plasma accelerators by adjusting the length of the plasma channel on a shot-by-shot basis, showing high-quality guiding of 500 TW laser pulses over 30 cm in a hydrogen plasma of density n_{0}≈1×10^{17} cm^{-3}. We observed transverse energy transport of higher-order modes in the first ≈12 cm of the plasma channel, followed by quasimatched propagation, and the gradual, dark-current-free depletion of laser energy to the wake. We quantify the laser-to-wake transfer efficiency limitations of currently available petawatt-class lasers and demonstrate via simulation how control over the laser mode can significantly improve beam parameters.
View Article and Find Full Text PDFCurvature Dependence of Gravitational-Wave Tests of General Relativity.
Phys Rev Lett
December 2024
Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA.
High-energy extensions to general relativity modify the Einstein-Hilbert action with higher-order curvature corrections and theory-specific coupling constants. The order of these corrections imprints a universal curvature dependence on observations while the coupling constant controls the deviation strength. In this Letter, we leverage the theory-independent expectation that modifications to the action of a given order in spacetime curvature (Riemann tensor and contractions) lead to observational deviations that scale with the system length scale to a corresponding power.
View Article and Find Full Text PDFInter- and Intrasublattice Spin Mixing Conductance of the Antiferromagnetic Spin Pumping Effect in α-Fe_{2}O_{3}/Pt.
Phys Rev Lett
December 2024
Department of Materials Physics, Nagoya University, Nagoya, Aichi 464-8603, Japan.
The spin pumping effect in antiferromagnets, which ultimately converts THz waves into a spin current, is the key physical mechanism leading to an essential function which harnesses the THz technology and spintronics. Here, we report thorough experimental investigations of the spin current induced by the antiferromagnetic spin pumping effect in epitaxial α-Fe_{2}O_{3} thin films having two distinct dynamic modes and unambiguously show that both the inter- and intrasublattice spin mixing conductance are equally substantial. Our experimental insight is an important advance for understanding the physics of transduction between the spin current and the staggered magnetization dynamics at THz frequency.
View Article and Find Full Text PDFPhase Diagram, d-Wave Superconductivity, and Pseudogap of the t-t^{'}-J Model at Finite Temperature.
Phys Rev Lett
December 2024
Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China.
Recently, robust d-wave superconductive (SC) order has been unveiled in the ground state of the 2D t-t^{'}-J model-with both nearest-neighbor (t) and next-nearest-neighbor (t^{'}) hoppings-by density matrix renormalization group studies. However, there is currently a debate on whether the d-wave SC holds up strong on both t^{'}/t>0 and t^{'}/t<0 cases for the t-t^{'}-J model, which correspond to the electron- and hole-doped sides of the cuprate phase diagram, respectively. Here, we exploit state-of-the-art thermal tensor network approach to accurately obtain the phase diagram of the t-t^{'}-J model on cylinders with widths up to W=6 and down to low temperature as T/J≃0.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!