Current hole plasmas in JET are those in which the current density within r/a < 0.3 is close to zero. Tritium ions injected quasi-tangentially into
such plasmas can fulfil a stagnation condition whereby their vertical drift is cancelled by the poloidal component of their parallel velocity. These ions remain trapped at approximately 0.2mfrom the plasma axis and can be detected by a distortion in the neutron emission profile. Numerical modelling of the steady-state distribution reproduces the experimental results while the decay of neutron emission after the cessation of injection is found to be sensitive to small changes in the q-profile.