Size-Selective Sub-micromter-Particle Confinement Utilizing Ionic Entropy-Directed Trapping in Inscribed Nanovoid Patterns

ACS Nano ◽  
2021 ◽  
Author(s):  
Long Chen ◽  
Ashwin Panday ◽  
Jonggab Park ◽  
Mingyu Kim ◽  
Dong Kyo Oh ◽  
...  
Keyword(s):  
Particle Confinement

scholarly journals Drift kinetic theory of alpha transport by tokamak perturbations

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Elizabeth A. Tolman ◽  
Peter J. Catto
Keyword(s):  
Heat Flux ◽  
Kinetic Theory ◽  
Alpha Particle ◽  
Heat Fluxes ◽  
Alpha Particles ◽  
Alpha Power ◽  
Mode Amplitude ◽  
Effective Collision Frequency ◽  
Perturbation Frequency ◽  
Particle Confinement

Upcoming tokamak experiments fuelled with deuterium and tritium are expected to have large alpha particle populations. Such experiments motivate new attention to the theory of alpha particle confinement and transport. A key topic is the interaction of alpha particles with perturbations to the tokamak fields, including those from ripple and magnetohydrodynamic modes like Alfvén eigenmodes. These perturbations can transport alphas, leading to changed localization of alpha heating, loss of alpha power and damage to device walls. Alpha interaction with these perturbations is often studied with single-particle theory. In contrast, we derive a drift kinetic theory to calculate the alpha heat flux resulting from arbitrary perturbation frequency and periodicity (provided these can be studied drift kinetically). Novel features of the theory include the retention of a large effective collision frequency resulting from the resonant alpha collisional boundary layer, correlated interactions over many poloidal transits and finite orbit effects. Heat fluxes are considered for the example cases of ripple and the toroidal Alfvén eigenmode (TAE). The ripple heat flux is small. The TAE heat flux is significant and scales with the square of the perturbation amplitude, allowing the derivation of constraints on mode amplitude for avoidance of significant alpha depletion. A simple saturation condition suggests that TAEs in one upcoming experiment will not cause significant alpha transport via the mechanisms in this theory. However, saturation above the level suggested by the simple condition, but within numerical and experimental experience, which could be accompanied by the onset of stochasticity, could cause significant transport.

Effects of a Vertical Magnetic Field on Particle Confinement in a Magnetized Plasma Torus

2004 ◽  
Vol 93 (16) ◽  
Author(s):  
S. H. Müller ◽  
A. Fasoli ◽  
B. Labit ◽  
M. McGrath ◽  
M. Podestà ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetized Plasma ◽  
Vertical Magnetic Field ◽  
Plasma Torus ◽  
Particle Confinement

scholarly journals Particle-confinement criteria for axisymmetric field-reversed magnetic configurations

1984 ◽  
Vol 24 (8) ◽  
pp. 1029-1038 ◽  
Author(s):  
M.-Y. Hsiao ◽  
G.H. Miley
Keyword(s):  
Particle Confinement

Effects of edge biasing on blob dynamics and associated transport in the edge of the J-TEXT tokamak

2022 ◽  
Author(s):  
Wei Li ◽  
Yuhong Xu ◽  
Jun Cheng ◽  
Hai Liu ◽  
Zhipeng Chen ◽  
...  
Keyword(s):  
Electric Field ◽  
Large Scale ◽  
Turbulent Transport ◽  
Radial Electric Field ◽  
Plasma Confinement ◽  
Flow Shear ◽  
Theoretical Predictions ◽  
Outward Motion ◽  
Electrode Biasing ◽  
Particle Confinement

Abstract Effects of edge radial electric field Er and Er × B flow shear on edge turbulence and turbulent transport, in particular, on large-scale blobs and blobby transport have been investigated in the positive and negative biasing discharges in the J-TEXT tokamak. The results show that under certain conditions, the positive electrode biasing induces better plasma confinement than the negative biasing. Further studies reveal that in addition to flow shear effects on blob dynamics, the local radial electric field at the edge region plays a significant role in repulsion of the blobs and associated transport, leading to improvement of particle confinement when the outward motion of the blobs is blocked. The results are in accordance with theoretical predictions.

A Study of Particle Confinement Using Skin Radiative Approximation Method in JT-60 Tokamak

1990 ◽  
Vol 29 (Part 1, No. 2) ◽  
pp. 402-408 ◽  
Author(s):  
Shinji Koide ◽  
Katsuhiro Shimizu ◽  
Takashi Sugiyama ◽  
Takeo Nishitani
Keyword(s):  
Approximation Method ◽  
Particle Confinement
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