## Abstract

The total radiated fraction is examined in high density H-mode plasmas (Greenwald fraction of about 85 %) in JET by the variation of the auxiliary heating power of P_{heat} = 14 MW-29 MW. An achieved radiation fraction of about 75 % at most has been observed in JET-ILW, which is less than the highest achievable (≈90 %) fraction in JET-C during the high radiative power scenarios with N_{2} seeding. It is shown that the maximal achievable total radiation fraction averaged over ELM cycles has a strong dependence on the radiation efficiency of the ELM energy, θ_{rad}: [Formula presented] About 50 % and 16 % of the ELM induced diamagnetic energy drop (ΔW_{ELM}) radiates during the ELM in JET-C and JET-ILW, respectively, which corresponds to the maximum total radiated powers of γ_{rad,JET-C}^{max}=0.87 and γ_{rad,JET-ILW}^{max}=0.77. These values of the maximum of the radiative power fractions are in good agreement with γ_{rad}^{max} experimentally observed in JET-C (90 %) and JET-ILW (75 %).

Original language | English |
---|---|

Article number | 101299 |

Journal | Nuclear Materials and Energy |

Volume | 33 |

DOIs | |

Publication status | Published - Oct 2022 |

## Keywords

- High radiation plasma scenarios
- Impurity
- Impurity seeding
- JET-ILW