38 citations · 65 across the 13 of their papers we have counts for
13 papers · 1 filter
Combination of quasi-isodynamic and piecewise omnigenous magnetic fields
J. L. Velasco, I. Calvo, V. Fernández-Pacheco +5
Due to their simultaneous optimization for radial and parallel neoclassical transport, quasi-isodynamic fields have been the main choice of stellarator magnetic configuration for m…
Role of the radial electric field in the confinement of energetic ions in the Wendelstein 7-X stellarator
M. Arranz, J. L. Velasco, I. Calvo +1
Good fast-ion confinement is an essential requirement for a fusion reactor. The magnetic configuration of the Wendelstein 7-X (W7-X) stellarator is partially optimized in this rega…
The Geometry of Flux Surfaces with Quasi-Poloidal Symmetry
Rishin Madan, Wrick Sengupta, Elizabeth J. Paul +4
Quasi-poloidal (QP) magnetic fields have desirable properties for confining plasma: no radial drift of guiding centres (with positive implications for neoclassical transport), zero…
CIEMAT-QI4X: a reactor-relevant quasi-isodynamic stellarator configuration compatible with an island divertor
E. Sánchez, J. L. Velasco, I. Calvo +3
A four-field-period quasi-isodynamic stellarator configuration is presented that exhibits small neoclassical and electrostatic turbulent transport, good fast-ion confinement over a…
Energetic-particle orbits near rational flux surfaces in stellarators: I. Passing particles
Thomas E. Foster, Felix I. Parra, Roscoe B. White +3
Recent simulations have shown that, even when the magnetic field of a stellarator possesses nested toroidal flux surfaces, the orbits of passing energetic particles can exhibit isl…
Piecewise omnigenous stellarators with zero bootstrap current
Ivan Calvo, Jose Luis Velasco, Per Helander +1
Until now, quasi-isodynamic magnetic fields have been the only known stellarator configurations that, at low collisionality, give small radial neoclassical transport and zero boots…
Optimizing stellarators with hidden symmetry
Hengqian Liu, Guodong Yu, Caoxiang Zhu +8
Stellarators confine fusion plasmas using three-dimensional magnetic fields composed of nested toroidal magnetic surfaces. In generic stellarators, trapped particles can drift acro…
Exploration of the parameter space of piecewise omnigenous stellarator magnetic fields
J. L. Velasco, E. Sánchez, I. Calvo
Piecewise omnigenous fields are stellarator magnetic fields that are optimized with respect to radial neoclassical transport thanks to a second adiabatic invariant that is piecewis…
Evaluation of neoclassical transport in nearly quasi-isodynamic stellarator magnetic fields using MONKES
Francisco Javier Escoto, José Luis Velasco, Iván Calvo +1
Stellarator magnetic fields that are perfectly optimized for neoclassical transport (with levels of radial neoclassical transport comparable to tokamaks) are called omnigenous. Qua…
Piecewise omnigenous stellarators
J. L. Velasco, I. Calvo, F. J. Escoto +3
In omnigeneous magnetic fields, charged particles are perfectly confined in the absence of collisions and turbulence. For this reason, the magnetic configuration is optimized to be…
Reduced turbulent transport in the quasi-isodynamic stellarator configuration CIEMAT-QI4
J. M. García-Regaña, I. Calvo, E. Sánchez +3
CIEMAT-QI4 is a quasi-isodynamic stellarator configuration that simultaneously features very good fast-ion confinement in a broad range of values, low neoclassical transport an…
KNOSOS: a fast orbit-averaging neoclassical code for stellarator geometry
J. L. Velasco, I. Calvo, F. I. Parra +1
KNOSOS (KiNetic Orbit-averaging SOlver for Stellarators) is a freely available, open-source code (\href{https://github.com/joseluisvelasco/KNOSOS}{https://github.com/joseluisvelasc…
Electrostatic potential variations on stellarator magnetic surfaces in low collisionality regimes
Ivan Calvo, J. L. Velasco, Felix I. Parra +2
The component of the neoclassical electrostatic potential that is non-constant on the magnetic surface, that we denote by , can affect radial transport of highly charged i…