1,679 research outputs found
Investigation of conventional and Super-X divertor configurations of MAST Upgrade using SOLPS
One of the first studies of MAST Upgrade divertor configurations with
SOLPS5.0 are presented. We focus on understanding main prospects associated
with the novel geometry of the Super-X divertor (SXD). This includes a
discussion of the effect of magnetic flux expansion and volumetric power losses
on the reduction of target power loads, the effect of divertor geometry on the
divertor closure and distribution of neutral species and radiation in the
divertor, the role of the connection length in broadening the target wetted
area. A comparison in conditions typical for MAST inter-ELM H-mode plasmas
confirms improved performance of the Super-X topology resulting in
significantly better divertor closure with respect to neutrals (the atomic flux
from the target increased by a factor of 6, but the atomic flux from the
divertor to the upper SOL reduced by a factor of 2), increased radiation volume
and increased total power loss (a factor of 2) and a reduction of target power
loads through both magnetic flux expansion and larger volumetric power loss in
the divertor (a factor of 5-10 in attached plasmas). The reduction of the
target power load by SXD further increases with collisionality (high density or
detached regimes) thanks to larger importance of volumetric power losses. It is
found that a cold divertor plasma leads to stronger parallel temperature
gradients in the SOL which drive more parallel heat flux, meaning that the
effectiveness of perpendicular transport in spreading the power at the target
can be reduced, and this needs to be taken into account in any optimisation.Comment: 32 pages, 23 figures. This is an author-created, un-copyedited
version of an article accepted for publication in PPCF. IOP Publishing Ltd
and IAEA are not responsible for any errors or omissions in this version of
the manuscript or any version derived from i
Benchmarking of a 1D Scrape-off layer code SOLF1D with SOLPS and its use in modelling long-legged divertors
A 1D code modelling SOL transport parallel to the magnetic field (SOLF1D) is
benchmarked with 2D simulations of MAST-U SOL performed via the SOLPS code for
two different collisionalities. Based on this comparison, SOLF1D is then used
to model the effects of divertor leg stretching in 1D, in support of the
planned Super-X divertor on MAST. The aim is to separate magnetic flux
expansion from volumetric power losses due to recycling neutrals by stretching
the divertor leg either vertically or radially.Comment: 31 pages, 17 figures. This is an author-created, un-copyedited
version of an article accepted for publication in Plasma Physics and
Controlled Fusion. IOP Publishing Ltd is not responsible for any errors or
omissions in this version of the manuscript or any version derived from i
SOLPS-ITER modeling of ASDEX Upgrade L-mode detachment states
SOLPS-ITER is used to model ASDEX Upgrade L-mode detachment states including the onset of detachment, the fluctuating detachment, and the complete detachment states, considering drifts and mimicking filamentary convective transport with a radial outward velocity in the low field side. The effect of drifts, perpendicular outward convection and core boundary conditions on the numerical solution is presented. The modeling results are validated against experimental data. We find a good agreement of particle flux at the inner target between modeling results and experimental data. On the opposite, at the outer target computations underestimate measured particle flux by a factor of about 2 ∼ 3 in the onset of detachment and the fluctuating detachment states
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