(EX/1-3) Improved Performance in Long-pulse ELMy H-mode Plasmas with Internal Transport Barrier in JT-60U
1) Japan Atomic Energy Agency, Naka, Japan
Abstract. The performance of long-pulse ELMy H-mode plasma was improved after the installation of ferritic steel tile on JT-60U in terms of the sustained duration for both high normalized beta and high thermal confinement factor (H98). High normalized beta larger than 2.3 simultaneously with
H98∼1 was sustained for 23.1 s (∼12 times resistive diffusion time) at
q95∼3.2, which provide high normalized beta times
H98 > 2.2 exceeding ITER reference scenario of ∼1.8. A sustainable high normalized beta times
H98 for maximum duration of 28.6 s was 2.0. Improved confinement is characterized by the larger thermal components at given density maintained by smaller heating power than previous experiments. A peaked pressure profile indicating better confinement was obtained at the same shape of the heating power deposition profile in the core region (r/a < 0.6) as that in the previous experiments before the installation of ferritic steel tile.
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