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Related papers: Development of a Simple Stellarator using Tilted C…

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A direct construction of equilibrium magnetic fields with toroidal topology at arbitrary order in the distance from the magnetic axis is carried out, yielding an analytical framework able to explore the landscape of possible magnetic flux…

Plasma Physics · Physics 2020-01-29 R. Jorge , W. Sengupta , M. Landreman

Magnetic fields have been observed in massive Ap/Bp stars and presumably are also present in the radiative zone of solar-like stars. Yet, to date there is no clear understanding of the dynamics of the magnetic field in stably stratified…

Solar and Stellar Astrophysics · Physics 2023-03-27 G. Monteiro , G. Guerrero , F. Del Sordo , A. Bonanno , P. K. Smolarkiewicz

We present a novel method for numerically finding quasi-isodynamic stellarator magnetic fields with excellent fast-particle confinement and extremely small neoclassical transport. The method works particularly well in configurations with…

We present 3D MHD simulations of purely toroidal and mixed poloidal-toroidal magnetic field configurations to study the behavior of the Tayler instability. For the first time the simultaneous action of rotation and magnetic diffusion are…

Solar and Stellar Astrophysics · Physics 2015-05-27 Juan C. Ibañez-Mejia , Jonathan Braithwaite

Access to the plasma chamber in a stellarator reactor is essential for maintenance and diagnostics. However, the complex geometry of stellarator coils, often characterized by their strong twisting, can severely limit the space available for…

Plasma Physics · Physics 2025-02-19 A. Baillod , E. J. Paul , T. Elder , J. M. Halpern

A new method for reconstruction of coronal magnetic fields as force-free fields (FFFs) is presented. Our method employs poloidal and toroidal functions to describe divergence-free magnetic fields. This magnetic field representation…

Solar and Stellar Astrophysics · Physics 2022-10-04 Sibaek Yi , G. S. Choe , Kyung-Suk Cho , Sami K. Solanki , Jörg Büchner

The mathematical foundation is laid for a relatively new type of magnets generating uniform transverse field - tilted coil magnets. These consist of concentric nested solenoidal coils with elliptical turns tilted at a certain angle to the…

Accelerator Physics · Physics 2007-05-23 A. M. Akhmeteli , A. V. Gavrilin

We investigate the effects of the purely toroidal magnetic field on the equilibrium structures of the relativistic stars. The master equations for obtaining equilibrium solutions of relativistic rotating stars containing purely toroidal…

Astrophysics · Physics 2008-11-26 Kenta Kiuchi , Shijun Yoshida

It is found that the X-Divertor (XD) configuration [1-3] can be made with the conventional PF coil set on ITER[4], where all PF coils are outside the TF coils. Desirable configurations are possible where the PF currents are below the…

Plasma Physics · Physics 2015-06-18 Brent Covele , Prashant Valanju , Mike Kotschenreuther , Swadesh Mahajan

Turbulence simulation codes can exploit the flute-like nature of plasma turbulence to reduce the effective number of degrees of freedom necessary to represent fluctuations. This can be achieved by employing magnetic coordinates of which one…

Plasma Physics · Physics 2015-05-18 M. A. Ottaviani

We investigate the electromagnetic fields in the vacuum exterior of a rotating relativistic star endowed with a magnetic dipole moment, and with the stellar surface behaving as a perfect conductor. While the stellar rotation is treated in…

Astrophysics · Physics 2009-11-10 Yasufumi Kojima , Norihito Matsunaga , Taishi Okita

Several fast methods for computing stellarator coil shapes are compared, including the classical NESCOIL procedure [Merkel, Nucl. Fusion 27, 867 (1987)], its generalization using truncated singular value decomposition, and a Tikhonov…

Plasma Physics · Physics 2017-02-10 Matt Landreman

Optimized stellarator configurations and their analytical properties are obtained using a near-axis expansion approach. Such configurations are associated with good confinement as the guiding center particle trajectories and neoclassical…

Plasma Physics · Physics 2020-08-26 R. Jorge , W. Sengupta , M. Landreman

In fusion devices, the geometry of the confining magnetic field has a significant impact on the instabilities that drive turbulent heat loss. This is especially true of stellarators, where the "trapped electron mode" (TEM) is stabilised if…

We present numerical simulations of a self-sustaining magnetic field in a differentially rotating non-convective stellar interior. A weak initial field is wound up by the differential rotation; the resulting azimuthal field becomes unstable…

Astrophysics · Physics 2009-11-11 J. Braithwaite , H. C. Spruit

We present the verification, validation, and results of an approximate, analytic model for the radial profile of the stress, strain, and displacement within the toroidal field (TF) coil of a Tokamak at the inner midplane, where stress…

We present a combined model for magnetic field generation and transport in cool stars with outer convection zones. The mean toroidal magnetic field, which is generated by a cyclic thin-layer alpha-omega dynamo at the bottom of the…

Solar and Stellar Astrophysics · Physics 2011-11-11 Emre Işık , Dieter Schmitt , Manfred Schüssler

A new code for computing fully general relativistic solutions of strongly magnetized rapidly rotating compact stars is developed as a part of the COCAL (Compact Object CALculator) code. The full set of Einstein's equations, Maxwell's…

General Relativity and Quantum Cosmology · Physics 2019-12-25 Koji Uryu , Shijun Yoshida , Eric Gourgoulhon , Charalampos Markakis , Kotaro Fujisawa , Antonios Tsokaros , Keisuke Taniguchi , Yoshiharu Eriguchi

The questions of how strong magnetic fields can be stored in rotating stellar radiative zones without being subjected to pinch-type instabilities and how much radial mixing is produced if the fields are unstable are addressed. Linear…

Astrophysics · Physics 2009-11-13 L. L. Kitchatinov , G. Ruediger

We study the time evolution of non-axisymmetric linear perturbations of a rotating magnetised neutron star, whose magnetic field is multipolar and purely poloidal. The background stellar configurations are generated self-consistently,…

Solar and Stellar Astrophysics · Physics 2015-05-20 S. K. Lander , D. I. Jones