Trace tritium transport in JET

Trace amounts of tritium (1-5% of the deuterium content) have been introduced in short puffs (∼40 ms) into the low-field mid plane edge of steady-state deuterium plasmas in JET. The transport properties of the edge and core plasma, and the time evolution of the fraction of tritium in recycling flux, determine the evolution in space and time of the 14 MeV neutron emission following these puffs. Earlier work on TFTR has been in transient, high performance plasmas. The JET experiments offered a unique opportunity to perform measurements of fuel ion transport in an ITER relevant regime. The main objective of these trace tritium transport experiments was to apply the dimensionless parameter approach, used in the study of energy confinement, to particle transport and to connect particle and energy transport in the same data set. (author)