  Core turbulent particle transport with multiple isotopes can display
observable differences in behaviour between the electron and ion particle
channels. Experimental observations at JET with mixed H-D plasmas and varying
NBI and gas-puff sources [M. Maslov et al., Nucl. Fusion 7 076022 (2018)]
inferred source dominated electron peaking, but transport dominated isotope
peaking. In this work, we apply the QuaLiKiz quasilinear gyrokinetic transport
model within JINTRAC flux-driven integrated modelling, for core transport
validation in this multiple-isotope regime. The experiments are successfully
reproduced, predicting self consistently $ j $, $ n_{e} $, $ n_{Be} $, $ T_{e}
$, $ T_{i} $, $\omega_{tor}$ and the isotope composition. As seen in the
experiments, both H and D profiles are predicted to be peaked regardless of the
core isotope source. An extensive sensitivity study confirmed that this result
does not depend on the specific choices made for the boundary conditions and
physics settings. While kinetic profiles and electron density peaking did vary
depending on the simulation parameters, the isotope ratio remained nearly
invariant, and tied to the electron density profile. These findings have
positive ramifications for multiple-isotope fuelling, burn control, and helium
ash removal.
