Results 41 to 50 of about 249 (184)

Formation of a Boron‐Oxide Termination for the (100) Diamond Surface

Advanced Materials Interfaces, Volume 11, Issue 33, November 25, 2024.
A boron‐oxide termination for (100) diamond is formed under ultrahigh vacuum conditions. This is the first demonstration of a new method of introducing a boron‐based species to the diamond lattice. This result has potential for enabling new surface‐based pathways to the fabrication of high quality boron‐doped delta layers and boron‐based material ...
Alex K. Schenk, Rebecca Griffin, Anton Tadich, Daniel Roberts, Alastair Stacey   +4 more
wiley   +1 more source

Modification of ion-temperature-gradient turbulence by impurities in stellarator plasmas

Nuclear Fusion
Recent nonlinear gyrokinetic simulations have shown that impurities can strongly modify the turbulent heat flux in stellarator plasmas. Here, the ion-temperature-gradient (ITG) dispersion relation in a plasma containing impurities is analytically solved ...
Iván Calvo, Félix I. Parra, Hanne Thienpondt, José Manuel García-Regaña   +3 more
doaj   +1 more source

Methods for Color Center Preserving Hydrogen‐Termination of Diamond

Advanced Materials Interfaces, Volume 11, Issue 24, August 23, 2024.
Hydrogen‐termination of diamond by three methods. Hydrogen plasma exposure with stage heating above 700 °C yields maximal coverage but causes irr loss of shallow nitrogen‐vacancy fluorescence. Plasma exposure without heating preserves nitrogen‐vacancies at the expense of increased oxygen coverage.
Daniel J. McCloskey, Daniel Roberts, Lila V. H. Rodgers, Yuri Barsukov, Igor D. Kaganovich, David A. Simpson, Nathalie P. de Leon, Alastair Stacey, Nikolai Dontschuk   +8 more
wiley   +1 more source

Investigating long-duration plasma operation with the international multi-machine CICLOP database

Nuclear Fusion
Combined high-fusion performance and long-pulse operation is one of the key integration challenges for fusion energy development in magnetic devices. Addressing these challenges requires an integrated vision of physics and engineering aspects with the ...
X. Litaudon, E. Lerche, O. Grulke, C.T. Holcomb, J. Huang, M. Jakubowski, H.S. Kim, P. Manas, T. Morisaki, F. Turco, M. Barbarino, E. Belonohy, A. Bock, S. Brezinsek, J. Bucalossi, S. Coda, L.F. Delgado-Aparicio, P. De Vries, A. Ekedahl, L. Frassinetti, A. Garofalo, C. Giroud, X. Gong, K. Hanada, S. Ide, B.V. Kuteev, P. Maget, J. Stober, D. Van Houtte, the IEA-IAEA Coordination on International Challenges on Long duration OPeration (CICLOP) group   +29 more
doaj   +1 more source

Impact of multifold magnetic structure on spectroscopy analysis in Heliotron J based on EMC3‐EIRENE simulation

Contributions to Plasma Physics, Volume 64, Issue 7-8, August-September 2024.
Abstract The distribution pattern of the connection length in the divertor region of Heliotron J was calculated by the field line tracing method. A multifold layer structure, characterized by the range of connection length, was revealed to interpret the response of the transport of the lower‐charged impurity ions to the divertor structure.
F. Cai, S. Kado, G. Kawamura, C. Feng, R. Matoike, A. Miyashita, S. Ohshima, T. Minami, S. Inagaki, F. Kin, S. Kobayashi, A. Ishizawa, Y. Nakamura, H. Okada, S. Konoshima, T. Mizuuchi, Y. Feng, H. Frerichs, K. Nagasaki   +18 more
wiley   +1 more source

Reactor-scale stellarators with force and torque minimized dipole coils

Nuclear Fusion
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,
Alan A. Kaptanoglu, Alexander Wiedman, Jacob Halpern, Siena Hurwitz, Elizabeth J. Paul, Matt Landreman   +5 more
doaj   +1 more source

Toward plasma drifts in EMC3: Implementation of gradient, divergence, and particle tracing schemes

Contributions to Plasma Physics, Volume 64, Issue 7-8, August-September 2024.
Abstract This paper presents a first implementation of gradient, divergence, and particle tracing schemes for the EMC3 code, a stochastic 3D plasma fluid code widely employed for edge plasma and impurity transport modeling in tokamaks and stellarators.
Ruben De Wolf, Felix Reimold, Yuhe Feng, Matthieu Jacobs, Wouter Dekeyser, Giovanni Samaey, Martine Baelmans   +6 more
wiley   +1 more source

Coarse-grained gyrokinetics for the critical ion temperature gradient in stellarators

Physical Review Research, 2022
We present a modified gyrokinetic theory to predict the critical gradient that determines the linear onset of the ion temperature gradient (ITG) mode in stellarator plasmas.
G. T. Roberg-Clark, G. G. Plunk, P. Xanthopoulos   +2 more
doaj   +1 more source

MHD Convection with Joule Heating and Internal Heat Generation in a Two‐Layer Discretely Heated Chamber Partly Filled with Porous Medium

International Journal of Energy Research, Volume 2024, Issue 1, 2024.
The present research presents an innovative approach by integrating magnetohydrodynamic (MHD) flow with resistive heating, integrating a partly permeable layer and interior heat production to scrutinize natural convective flow within a square domain. It also examines both straight and wavy interfaces between the porous and fluid domains.
Nahid Hasan, Niloy Deb, Sumon Saha, Mohamed Zbair   +3 more
wiley   +1 more source

Intrinsic Turbulence Stabilization in a Stellarator

Physical Review X, 2016
The magnetic surfaces of modern stellarators are characterized by complex, carefully optimized shaping and exhibit locally compressed regions of strong turbulence drive.
P. Xanthopoulos, G. G. Plunk, A. Zocco, P. Helander   +3 more
doaj   +1 more source