Results 51 to 60 of about 2,079 (226)

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

Finite-β turbulence in Wendelstein 7-X enhanced by sub-threshold kinetic ballooning modes

Nuclear Fusion
Magnetic fluctuations affecting turbulence and transport, which are manifest at finite normalized plasma pressure β , pose a significant challenge to magnetic confinement fusion devices aiming to achieve high performance.
P. Mulholland, M.J. Pueschel, J.H.E. Proll, K. Aleynikova, B.J. Faber, P.W. Terry, C.C. Hegna, C. Nührenberg   +7 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

Physics of Compact Advanced Stellarators [PDF]

, 2001
Compact optimized stellarators offer novel solutions for confining high-beta plasmas and developing magnetic confinement fusion. The 3-D plasma shape can be designed to enhance the MHD stability without feedback or nearby conducting structures and ...
Lewandowski, J., Sanchez, R., Strickler, D., Mynick, H., Lyon, J., Spong, D., White, R. B., Nuehrenberg, C., Hudson, S., Zarnstorff, M. C., Merkel, P., Fu, G. Y., Neilson, G. H., Mikkelsen, D., Nelson, B. E., Rutherford, P., Hirshman, S., Hatcher, R., Cooper, W. A., Brooks, A., Isaev, M., Reiersen, W., Boozer, A., Pomphrey, N., Lazarus, E., Monticello, D., Reiman, A., Berry, L. A., Kessel, C., Fredrickson, E., Ku, L. P., Goldston, R., Redi, M., Schmidt, J.   +33 more
core   +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

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

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

Recent Progress in MHD Stability Calculations of Compact Stellarators [PDF]

, 2000
A key issue for compact stellarators is the stability of beta-limiting MHD modes, such as external kink modes driven by bootstrap current and pressure gradient.
Fu, G. Y., Ware, A., Monticello, D. A., Reiman, A., Spong, D. A., Cooper, W. A., Nuehrenberg, C., Kessel, C., Redi, M. H., Ku, L. P., Sanchez, R., Hirshman, S. P.   +11 more
core  

Reduced electrostatic turbulence in the quasi-isodynamic stellarator configuration CIEMAT-QI4

Nuclear Fusion
CIEMAT-QI4 is a quasi-isodynamic stellarator configuration that simultaneously features very good fast-ion confinement in a broad range of β values, low neoclassical transport and bootstrap current, and ideal magnetohydrodynamic stability up to $\beta ...
J.M. García-Regaña, I. Calvo, E. Sánchez, H. Thienpondt, J.L. Velasco, J.A. Capitán   +5 more
doaj   +1 more source