ELM Size Analysis in JET Hybrid Plasmas.
Experimental results are presented in this paper, characterizing the behaviour of type I ELMs for a JET data base of standard ELMy H-mode and hybrid plasmas. Whereas the collisionality scaling published has been reproduced for the new baseline discharges, no clear correlation can be established from the analysis of hybrid scenarios. The ELM losses normalized to the pedestal stored energy for high triangularity hybrid plasmas seem to be signi cantly larger than the energies for baseline plasmas at similar values of collisionality. For low triangularity hybrid plasmas, the ELM losses are of the same order as those obtained in baseline scenarios. The important scatter of the results seem to be due to the sensitivity of hybrid plasmas to gas-fuelling. Analysis of the ITER-like wall compatibility of hybrid discharges is also reported.