The Super-X divertor (SXD) is an alternative divertor configuration
leveraging total flux expansion at the outer strike point (OSP). Key features
for the attractiveness of the SXD are facilitated detachment access and
control, as predicted by the extended 2-point model (2PM). However, parallel
flows are not consistently included in the 2PM. In this work, the 2PM is
refined to overcome this limitation: the role of total flux expansion on the
pressure balance is made explicit, by including the effect of parallel flows.
In consequence, the effect of total flux expansion on detachment access and
control is weakened, compared to predictions of the 2PM. This new model
partially explains discrepancies between the 2PM and experiments performed on
TCV, in ohmic L-mode scenarios, where in core density ramps in lower
single-null (SN) configuration, the impact of the OSP major radius Rt on the
CIII emission front movement in the divertor outer leg - used as a proxy for
the plasma temperature - is substantially weaker than 2PM predictions; and in
OSP sweeps in lower and upper SN configurations, with a constant core density,
the peak parallel particle flux density at the OSP is almost independent of Rt,
while the 2PM predicts a linear dependence. Finally, analytical and numerical
modelling of parallel flows in the divertor is presented, to support the
argument. It is shown that an increase in total flux expansion can favour
supersonic flows at the OSP. Parallel flows are also shown to be relevant by
analysing SOLPS-ITER simulations of TCV