Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rotation and Neoclassical Ripple Transport in ITER   Neoclassical transport in the presence of non-axisymmetric magnetic fields
causes a toroidal torque known as neoclassical toroidal viscosity (NTV). The
toroidal symmetry of ITER will be broken by the finite number of toroidal field
coils and by test blanket modules (TBMs). The addition of ferritic inserts
(FIs) will decrease the magnitude of the toroidal field ripple. 3D magnetic
equilibria with toroidal field ripple and ferromagnetic structures are
calculated for an ITER steady-state scenario using the Variational Moments
Equilibrium Code (VMEC). Neoclassical transport quantities in the presence of
these error fields are calculated using the Stellarator Fokker-Planck Iterative
Neoclassical Conservative Solver (SFINCS). These calculations fully account for
$E_r$, flux surface shaping, multiple species, magnitude of ripple, and
collisionality rather than applying approximate analytic NTV formulae. As NTV
is a complicated nonlinear function of $E_r$, we study its behavior over a
plausible range of $E_r$. We estimate the toroidal flow, and hence $E_r$, using
a semi-analytic turbulent intrinsic rotation model and NUBEAM calculations of
neutral beam torque. The NTV from the $\rvert n \rvert = 18$ ripple dominates
that from lower $n$ perturbations of the TBMs. With the inclusion of FIs, the
magnitude of NTV torque is reduced by about 75% near the edge. We present
comparisons of several models of tangential magnetic drifts, finding
appreciable differences only for superbanana-plateau transport at small $E_r$.
We find the scaling of calculated NTV torque with ripple magnitude to indicate
that ripple-trapping may be a significant mechanism for NTV in ITER. The
computed NTV torque without ferritic components is comparable in magnitude to
the NBI and intrinsic turbulent torques and will likely damp rotation, but the
NTV torque is significantly reduced by the planned ferritic inserts.

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The categories of this paper are: q-bio
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The categories of this paper are: econ
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: astro-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: nlin
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The categories of this paper are: quant-ph