Zobrazeno 1 - 10
of 71
pro vyhledávání: '"Calvo, Ivan"'
Stellarator magnetic fields that are perfectly optimized for neoclassical transport (with levels of radial neoclassical transport comparable to tokamaks) are called omnigenous. Quasi-isodynamic magnetic fields are a subset of omnigenous magnetic fiel
Externí odkaz:
http://arxiv.org/abs/2410.17836
We present a new neoclassical transport model for large aspect ratio tokamaks where the gradient scale lengths are of the size of the poloidal gyroradius. Previous work on neoclassical transport across transport barriers assumed large density and pot
Externí odkaz:
http://arxiv.org/abs/2301.07080
New orbit averaged equations for low collisionality neoclassical fluxes in large aspect ratio stellarators with mirror ratios close to unity are derived. The equations retain finite orbit width effects by employing the second adiabatic invariant $J$
Externí odkaz:
http://arxiv.org/abs/2202.01318
Autor:
Fujita, Keiji, Satake, Shinsuke, Nunami, Masanori, García-Regaña, José Manuel, Velasco, José Luis, Calvo, Iván
Publikováno v:
Nucl. Fusion 61 086025 (2021)
An impurity hole observed in the Large Helical Device (LHD) is a hollow density profile of an impurity ion species formed in the core plasma where the negative (inward-pointing) ambipolar radial electric field ($E_r$) exists. Although local neoclassi
Externí odkaz:
http://arxiv.org/abs/2104.12995
Publikováno v:
Nucl. Fusion 60, 016035 (2020)
Main ions influence impurity dynamics through a variety of mechanisms; in particular, via impurity-ion collisions. To lowest order in an expansion in the main ion mass over the impurity mass, the impurity-ion collision operator only depends on the co
Externí odkaz:
http://arxiv.org/abs/1907.08482
Publikováno v:
J. Plasma Phys. 84, 905840407 (2018)
The component of the neoclassical electrostatic potential that is non-constant on the magnetic surface, that we denote by $\tilde\varphi$, can affect radial transport of highly charged impurities, and this has motivated its inclusion in some modern n
Externí odkaz:
http://arxiv.org/abs/1804.11104
Publikováno v:
Nucl. Fusion 58, 124005 (2018)
The control of impurity accumulation is one of the main challenges for future stellarator fusion reactors. The standard argument to explain this accumulation relies on the, in principle, large inward pinch in the neoclassical impurity flux caused by
Externí odkaz:
http://arxiv.org/abs/1803.05691
Autor:
Monreal, Pedro, Sánchez, Edilberto, Calvo, Iván, Bustos, Andrés, Parra, Félix I., Mishchenko, Alexey, Könies, Axel, Kleiber, Ralf
Due to their capability to reduce turbulent transport in magnetized plasmas, understanding the dynamics of zonal flows is an important problem in the fusion programme. Since the pioneering work by Rosenbluth and Hinton in axisymmetric tokamaks, it is
Externí odkaz:
http://arxiv.org/abs/1701.02722
Publikováno v:
Plasma Physics and Controlled Fusion 59, 055014 (2017)
In general, the orbit-averaged radial magnetic drift of trapped particles in stellarators is non-zero due to the three-dimensional nature of the magnetic field. Stellarators in which the orbit-averaged radial magnetic drift vanishes are called omnige
Externí odkaz:
http://arxiv.org/abs/1610.06016
Autor:
Calvo, Ivan, Parra, Felix I.
Publikováno v:
Plasma Physics and Controlled Fusion 57, 075006 (2015)
The radial flux of toroidal angular momentum is needed to determine tokamak intrinsic rotation profiles. Its computation requires knowledge of the gyrokinetic distribution functions and turbulent electrostatic potential to second-order in $\epsilon =
Externí odkaz:
http://arxiv.org/abs/1412.0959