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Full-Text Articles in Physics
Analysis Of Drift Effects On The Tokamak Power Scrape-Off Width Using Solps-Iter, E. T. Meier, R. J. Goldston, E. G. Kaveeva, M. A. Makowski, Saskia Mordijck, V. A. Rozhansky, I. Yu Senichenkov, S. P. Voskoboynikov
Analysis Of Drift Effects On The Tokamak Power Scrape-Off Width Using Solps-Iter, E. T. Meier, R. J. Goldston, E. G. Kaveeva, M. A. Makowski, Saskia Mordijck, V. A. Rozhansky, I. Yu Senichenkov, S. P. Voskoboynikov
Arts & Sciences Articles
SOLPS-ITER, a comprehensive 2D scrape-off layer modeling package, is used to examine the physical mechanisms that set the scrape-off width (lambda(q)) for inter-ELM power exhaust. Guided by Goldston's heuristic drift (HD) model, which shows remarkable quantitative agreement with experimental data, this research examines drift effects on lambda(q) in a DIII-D H-mode magnetic equilibrium. As a numerical expedient, a low target recycling coefficient of 0.9 is used in the simulations, resulting in outer target plasma that is sheath limited instead of conduction limited as in the experiment. Scrape-off layer (SOL) particle diffusivity (D-SOL) is scanned from 1 to 0.1 m(2) s(-1). …
Enhanced Superconductivity In Aluminum-Based Hyperbolic Metamaterials, Vera N. Smolyaninova, Christopher Jensen, William Zimmerman, (...), M. M. Qazilbash, Et Al.
Enhanced Superconductivity In Aluminum-Based Hyperbolic Metamaterials, Vera N. Smolyaninova, Christopher Jensen, William Zimmerman, (...), M. M. Qazilbash, Et Al.
Arts & Sciences Articles
One of the most important goals of condensed matter physics is materials by design, i.e. the ability to reliably predict and design materials with a set of desired properties. A striking example is the deterministic enhancement of the superconducting properties of materials. Recent experiments have demonstrated that the metamaterial approach is capable of achieving this goal, such as tripling the critical temperature T-C in Al-Al2O3 epsilon near zero (ENZ) core-shell metamaterial superconductors. Here, we demonstrate that an Al/Al2O3 hyperbolic metamaterial geometry is capable of a similar T-C enhancement, while having superior transport and magnetic properties compared to the core-shell metamaterial …
Role Of Electron-Electron Interactions In The Charge Dynamics Of Rare-Earth-Doped Cafe2as2, Zhen Xing, T. J. Huffman, Peng Xu, (...), M. M. Qazilbash, Et Al.
Role Of Electron-Electron Interactions In The Charge Dynamics Of Rare-Earth-Doped Cafe2as2, Zhen Xing, T. J. Huffman, Peng Xu, (...), M. M. Qazilbash, Et Al.
Arts & Sciences Articles
We have investigated the charge dynamics and the nature of many-body interactions in La- and Pr-doped CaFe2As2. From the infrared part of the optical conductivity, we discover that the scattering rate of mobile carriers above 200 K exhibits saturation at the Mott-Ioffe-Regel limit of metallic transport. However, the dc resistivity continues to increase with temperature above 200 K due to the loss of Drude spectral weight. The loss of Drude spectral weight with increasing temperature is seen in a wide temperature range in the uncollapsed tetragonal phase, and this spectral weight is recovered at energy scales about one order of …
Line Parameters Including Temperature Dependences Of Air- And Self-Broadened Line Shapes Of (Co2)-C-12-O-16: 2.06-Mu M Region, D. Chris Benner, V. Malathy Devi, Keeyoon Sung, Linda R. Brown, Et Al.
Line Parameters Including Temperature Dependences Of Air- And Self-Broadened Line Shapes Of (Co2)-C-12-O-16: 2.06-Mu M Region, D. Chris Benner, V. Malathy Devi, Keeyoon Sung, Linda R. Brown, Et Al.
Arts & Sciences Articles
This study reports the results from analyzing a number of high resolution, high signal-to-noise ratio (S/N) spectra in the 2.06-μm spectral region for pure CO2 and mixtures of CO2 in dry air. A multispectrum nonlinear least squares curve fitting technique has been used to retrieve the various spectral line parameters. The dataset includes 27 spectra: ten pure CO2, two 99% 13C-enriched CO2 and fifteen spectra of mixtures of 12C-enriched CO2 in dry air. The spectra were recorded at various gas sample temperatures between 170 and 297 K. The absorption path lengths range from 0.347 to 49 m. The sample pressures …
Controlling Excited-State Contamination In Nucleon Matrix Elements, Boram Yoon, Rajan Gupta, (...), Kostas Orginos, Et Al.
Controlling Excited-State Contamination In Nucleon Matrix Elements, Boram Yoon, Rajan Gupta, (...), Kostas Orginos, Et Al.
Arts & Sciences Articles
We present a detailed analysis of methods to reduce statistical errors and excited-state contamination in the calculation of matrix elements of quark bilinear operators in nucleon states. All the calculations were done on a 2 + 1-flavor ensemble with lattices of size 32(3) x 64 generated using the rational hybrid Monte Carlo algorithm at a = 0.081 fm and with M-pi = 312 MeV. The statistical precision of the data is improved using the all-mode-averaging method. We compare two methods for reducing excited-state contamination: a variational analysis and a 2-state fit to data at multiple values of the source-sink separation …
Turbulent Particle Transport As A Function Of Toroidal Rotation In Diii-D H-Mode Plasmas, X. Wang, Saskia Mordijck, L. Zeng, L. Schmitz, Et Al.
Turbulent Particle Transport As A Function Of Toroidal Rotation In Diii-D H-Mode Plasmas, X. Wang, Saskia Mordijck, L. Zeng, L. Schmitz, Et Al.
Arts & Sciences Articles
In this paper we show how changes in toroidal rotation, by controlling the injected torque, affect particle transport and confinement. The toroidal rotation is altered using the co- and counter neutral beam injection (NBI) in low collisionality H-mode plasmas on DIII-D (Luxon 2002 Nucl. Fusion 42 614) with dominant electron cyclotron heating (ECH). We find that there is no correlation between the toroidal rotation shear and the inverse density gradient, which is observed on AUG when T-e/T-i is varied using ECH (Angioni et al 2011 Phys. Rev. Lett. 107 215003). In DIII-D, we find that in a discharge with balanced …
A Sonic Net Excludes Birds From An Airfield: Implications For Reducing Bird Strike And Crop Losses, John P. Swaddle, Dana L. Moseley, Mark H. Hinders, Elizabeth P. Smith
A Sonic Net Excludes Birds From An Airfield: Implications For Reducing Bird Strike And Crop Losses, John P. Swaddle, Dana L. Moseley, Mark H. Hinders, Elizabeth P. Smith
Arts & Sciences Articles
Collisions between birds and aircraft cause billions of dollars of damages annually to civil, commercial, and military aviation. Yet technology to reduce bird strike is not generally effective, especially over longer time periods. Previous information from our lab indicated that filling an area with acoustic noise, which masks important communication channels for birds, can displace European Starlings (Sturnus vulgaris) from food sources. Here we deployed a spatially controlled noise (termed a “sonic net”), designed to overlap with the frequency range of bird vocalizations, at an airfield. By conducting point counts, we monitored the presence of birds for four …
Unitary Limit Of Two-Nucleon Interactions In Strong Magnetic Fields, William Detmold, Kostas Orginos, Assumpta Parreño, Martin J. Savage, Et Al.
Unitary Limit Of Two-Nucleon Interactions In Strong Magnetic Fields, William Detmold, Kostas Orginos, Assumpta Parreño, Martin J. Savage, Et Al.
Arts & Sciences Articles
Two-nucleon systems are shown to exhibit large scattering lengths in strong magnetic fields at unphysical quark masses, and the trends toward the physical values indicate that such features may exist in nature. Lattice QCD calculations of the energies of one and two nucleons systems are performed at pion masses of mπ∼450 and 806 MeV in uniform, time-independent magnetic fields of strength |B|∼1019–1020 G to determine the response of these hadronic systems to large magnetic fields. Fields of this strength may exist inside magnetars and in peripheral relativistic heavy ion collisions, and the unitary behavior at large scattering lengths may have …
Effects Of Resonant Magnetic Perturbations On Turbulence And Transport In Diii-D L-Mode Plasmas, Saskia Mordijck, T. L. Rhodes, L. Zeng, E. J. Doyle, Et Al.
Effects Of Resonant Magnetic Perturbations On Turbulence And Transport In Diii-D L-Mode Plasmas, Saskia Mordijck, T. L. Rhodes, L. Zeng, E. J. Doyle, Et Al.
Arts & Sciences Articles
In this paper we show that resonant magnetic perturbations (RMPs) affect the L- to H-mode power threshold. We find that during the L-mode phase, RMPs cause the particle pinch to reverse from traditionally inward to outward. As a result, the density at the plasma edge increases, while the density in the plasma core is reduced. Linear stability calculations indicate that the plasma transitions from an ion temperature gradient (ITG) to trapped electron mode (TEM) regime at the plasma edge. If the applied RMP current is below the threshold for penetration and island formation, we find that the changes in the …
Local, Global, And Nonlinear Screening In Twisted Double-Layer Graphene, Chih-Pin Lu, Martin Rodriguez-Vega, (...), Enrico Rossi, Et Al.
Local, Global, And Nonlinear Screening In Twisted Double-Layer Graphene, Chih-Pin Lu, Martin Rodriguez-Vega, (...), Enrico Rossi, Et Al.
Arts & Sciences Articles
One-atom-thick crystalline layers and their vertical heterostructures carry the promise of designer electronic materials that are unattainable by standard growth techniques. To realize their potential it is necessary to isolate them from environmental disturbances, in particular those introduced by the substrate. However, finding and characterizing suitable substrates, and minimizing the random potential fluctuations they introduce, has been a persistent challenge in this emerging field. Here we show that Landau-level (LL) spectroscopy offers the unique capability to quantify both the reduction of the quasiparticles' lifetime and the long-range inhomogeneity due to random potential fluctuations. Harnessing this technique together with direct scanning …