In the period 1998—2001 the JET tokamak was operated with the MkII Gas Box divertor. On two occasions
during that period a number of limiter and divertor tiles were retrieved from the torus and then examined ex situ
with surface sensitive techniques. Erosion and deposition patterns were determined in order to assess the material
erosion, material migration and fuel inventory on plasma facing components. Tracer techniques, e.g. injection of
13C labelled methane and tiles coated with a low-Z and high-Z marker layer, were used to enhance the volume of
information on the material transport. The results show significant asymmetry in the distribution of fuel and plasma
impurity species between the inner (net deposition area) and the outer (net erosion) divertor channels. No significant
formation of highly hydrogenated carbon films has been found in the Gas Box structure. The important processes
for material migration, and the influence of operation scenarios on the morphology of the deposits are discussed.
Comparison is also made with results obtained following previous divertor campaigns.