Full hamiltonian description of the interaction of particles with magnetic islands in Tokamak

AbstractMagnetic islands (MIs), resulting from a magnetic field reconnection, are ubiquitous structures in magnetized plasmas. In tokamak plasmas, recent researches suggested that the interaction between an MI and ambient turbulence can be important for the nonlinear MI evolution, but a lack of detailed experimental observations and analyses has prevented further understanding. Here, we provide comprehensive observations such as turbulence spreading into an MI and turbulence enhancement at the reconnection site, elucidating intricate effects of plasma turbulence on the nonlinear MI evolution.

Download Full-text

Simulation of the loss of passing fast ions induced by magnetic islands in EAST tokamak plasmas

AIP Advances ◽

10.1063/5.0032049 ◽

2021 ◽

Vol 11 (2) ◽

pp. 025020

Author(s):

Limin Yu ◽

Erbing Xue ◽

Debing Zhang ◽

Shuyu Zheng ◽

Xianmei Zhang ◽

...

Keyword(s):

Tokamak Plasmas ◽

Magnetic Islands ◽

Fast Ions

Download Full-text

Hamiltonian description of barotropic Rossby waves on a sphere and in a paraboloid

Physics Letters A ◽

10.1016/s0375-9601(96)00691-3 ◽

1996 ◽

Vol 223 (1-2) ◽

pp. 96-104

Author(s):

A.A. Kurkin ◽

Yu.A. Stepanyants

Keyword(s):

Rossby Waves ◽

Hamiltonian Description

Download Full-text

GAUGE INVARIANCE AND CONSTRAINTS: OPEN GAUGE ALGEBRAS

International Journal of Modern Physics A ◽

10.1142/s0217751x92002519 ◽

1992 ◽

Vol 07 (22) ◽

pp. 5549-5561 ◽

Cited By ~ 1

Author(s):

KH. S. NIROV ◽

P.N. PYATOV ◽

A.V. RAZUMOV

Keyword(s):

Wide Class ◽

Gauge Invariance ◽

Poisson Brackets ◽

Hamiltonian Description ◽

Gauge Invariant

For a wide class of gauge-invariant systems with open gauge algebras the Hamiltonian description is constructed and the Poisson brackets of the constraints are calculated. It is shown that in the case under consideration there arise only first class constraints.

Download Full-text

Resistless Patterning of Magnetic Storage Media Using Ion Projection Structuring

MRS Proceedings ◽

10.1557/proc-705-y3.4 ◽

2001 ◽

Vol 705 ◽

Cited By ~ 2

Author(s):

A. Dietzel ◽

R. Berger ◽

H. Grimm ◽

C. Schug ◽

W. H. Bruenger ◽

...

Keyword(s):

Process Development ◽

Ion Beam ◽

Silicon On Insulator ◽

Magnetic Storage ◽

Magnetic Islands ◽

Superlattice Structure ◽

Head Positioning ◽

Out Of Plane ◽

Set Up ◽

The Impact

AbstractCo/Pt thin film multilayers with strong perpendicular anisotropy and out-of-plane coercivities of 5-11 kOe were magnetically altered in areas of local ion beam interaction. The ion irradiations were performed by ion projection through silicon stencil masks fabricated by silicon on insulator (SOI) membrane technology. The ion projector at the Fraunhofer Institute for Silicon Technology (ISiT) was operated at 73 keV ion energy and with a 8.7- fold demagnification. After exposure to 3 × 1014Ar+/ cm2 magnetic islands smaller than 100 nm in diameter were resolved in the Co/Pt multilayersby means of magnetic force microscopy. The impact of different ion species (He+, Ar+ and Xe+) and ion energies (10 – 200 keV) on the multilayer structure was evaluated using Monte Carlo simulations. The ballistic interface intermixing was used to predict magnetic coercivity changes for various irradiation conditions. The simulations revealed that with 73 keV Ar+ and Xe+ ions the irradiation dose could be reduced by a factor of 100 and 400 respectively in comparison to 73 keV He+which was verified in the experiments. X-ray reflectivity measurements confirmed that the Co/Pt superlattice structure is slightly weakened during the irradiation and that the surface smoothness of the media is preserved. Using the Ion Projection Process Development Tool (PDT) at IMS-Vienna concentric data tracks including head positioning servo informations were patterned onto a 1” IBM microdrive™ glass disk which was coated with Co/Pt multilayers. In a single exposure step several tracks within an exposure field of 17 mm in diameter were structured by 2 × 1015He+/ cm2 at 45 keV using a 4- fold demagnification set-up.

Download Full-text