EFDA-JET-CP(03)01/28

Study of Edge Properties and Power Deposition Profiles in JET ELMy H-Mode Discharges using Divertor Target Langmuir Probes

ELMy H-mode is the foreseen operational scenario for ITER. However the good confinement properties and high densities in this scenario are accompanied by the appearance of Type I ELMs which could possibly severly impact the lifetime of divertor and first wall components. Although Edge Localised Modes (ELMs) are a well-known phenomenon since the discovery of the H-mode, further improvements in diagnosis and modelling are still needed for a better understanding of ELM effects on wall elements in a tokamak. Langmuir probes embedded in the divertor are ideal for resolving local effects of ELMs on the divertor tiles. Using various techniques, such as triple probe operation, strike point sweeps and coherent averaging, spatial and temporal information can be obtained. Various tokamak scenarios will be discussed in this paper. Different methods for the mitigation of the impact of Type I ELMs are currently investigated in fusion research. In this paper we will summarize the effect of seeded impurities on the divertor power load and we will present a first analysis of space resolved ELM-measurements obtained from strike point sweeps.
Name Size  
EFDC030128 1.20 Mb