During the ICRF(Ion Cyclotron Range of Frequencies) heating on JET(Joint European Torus) the highly localised impurity influxes from the Faraday screens(FS) of RF antennas are observed. The influxes result from the acceleration of deuterium and impurity ions in the RF enhanced Bohm-Debye sheaths. The RF enhanced sheaths form when a magnetic field line, linking a large RF magnetic flux, connects two surfaces and closes a loop where the RF voltage is induced. The FS influxes depend on two intimately linked parameters, antenna voltage and the density at FS, as well as on the magnetic field angle, antenna phasing, FS geometry and material. The influx of Beryllium(Be) from the front face of the Be-gettered FS is ϕFSBe = 3 = 1x1019 atoms MW-1 s-1 in monopole (k|| = 0m-1) phasing when the torus had carbon( C) belt limiters. The contribution of the Be front face influx and the remaining Ni influx from the FS gaps to the ion dilution is δZeff/PRF < 0.015 MW-1. When the C-belt limiters were replaced by the Be-belt limiters, the influxes were reduced by more than a factor of 2. In the dipole phasing(k|| = 7m-1) the front fac influx is negligible.