  Numerical simulations explore the possibility to test the tightly baffled,
long-legged divertor (TBLLD) concept in a future upgrade of the Tokamak \`a
configuration variable (TCV). The SOLPS-ITER code package is used to compare
the exhaust performance of several TBLLD configurations with existing unbaffled
and baffled TCV configurations. The TBLLDs feature a range of radial gaps
between the separatrix and the outer leg side walls. All considered TBLLDs are
predicted to lead to a denser and colder plasma in front of the targets and
improve the power handling by factors of 2-3 compared to the present, baffled
divertor and by up to a factor of 12 compared to the original, unbaffled
configuration. The improved TBLLD performance is mainly due to a better neutral
confinement with improved plasma-neutral interactions in the divertor region.
Both power handling capability and neutral confinement increases when reducing
the radial gap. The core compatibility of TBLLDs with nitrogen seeding is also
evaluated and the detachment window with acceptable core pollution for the
proposed TBLLDs is explored, showing a reduction of required upstream impurity
concentration up to 18% to achieve the detachment with thinner radial gap.
