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An overview of JET experimental results in DT plasmas directly relevant to ITER modes of operation are presented. Experiments in D:T mixtures varying from 100:0 to 10:90 and those carried out in hydrogen plasmas, show that the H-mode threshold power has approximately an inverse isotopic mass dependence. Matching some of the key dimensionless parameters to the ITER values, the ITER-similarity experiments with ITER shape and safety factor (q) show that the global the energy confinement time is practically independent of isotopic mass (~A0.03±0.08) where A is the atomic mass of the hydrogenic species. Subtracting the edge pedestal energy (which scales as ~A0.57±0.2) from the total stored energy leads to a ~A-0.17±0.1 dependence of confinement in the plasma cord, very similar to that expected from the gyro-Bohm transport (~A-0.2) model. The observed scaling of the edge pedestal energy is consistent with a model in which the edge pressure gradient saturates at the ballooning limit over a region of width that scales oa the ion poloidal Larmor radius governed by the average energy of the fast-ions in the edge.The steady state total stored energy for a given input power in both ion cyclotron resonance heated (ICRH) and NBI discharges is the same despite the lower edge pedestal in the ICRH case which is compensated by a more peaked power deposition profiles in ICRH.ELM frequency is smaller with NBI; it decreases with isotopic mass both in NBI and ICRH discharges. A steady-state, type I ELMy H-mode discharge with ITER shape and q at 3.8 T/3.8 MA with an input power of 22 MW, produced a Q~0.18 for 3.5 s and extrapolates well to ignition with ITER parameters. Here,Q is the ratio of fusion output power to input power. The thermal ELMy H-mode confinement bothin deuterium and tritium gas fueled plasmas decreases significantly when the plasma density exeeds 0.75 of the Greenwald (ngw) limit and the maximum density achieved is 0.85ngw. In L-mode, the density limit decreases with in

Additional information

Bibliographic Reference: Article: Overview of ITER Physics Deuterium-Tritium Experiments in JET, (31)1998, 1-26
Record Number: 199910296 / Last updated on: 1999-03-12
Original language: en
Available languages: en
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