ITER startup studies in the DIII-D tokamak

Journal Article · Tue Jan 01 00:00:00 EST 2008 · Nuclear Fusion

DOI:https://doi.org/10.1088/0029-5515/48/12/125002· OSTI ID:1016618

Jackson, G. L. ^[1]; Casper, T. A. ^[2]; Luce, T. C. ^[3]; Humphreys, D A ^[3]; Ferron, J. R. ^[3]; Hyatt, A. W. ^[3]; Lazarus, Edward Alan ^[4]; Moyer, R. A. ^[5]; Petrie, T W ^[3]; Rudakov, D. L. ^[5]; West, W. P. ^[3]

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1. General Atomics
2. Lawrence Livermore National Laboratory (LLNL)
3. General Atomics, San Diego
4. ORNL
5. University of California, San Diego

plasma initiation and current ramp up scenario envisioned for ITER has been simulated in DIII-D experiments. These discharges were limited on the low field side (LFS) during the initial current ramp up, as specified for the ITER baseline startup scenario. Initial experiments produced internal inductance (l(i)),higher than the design value for the ITER shaping coils, often leading to vertical instabilities. A modified startup with larger volume was developed to reduce l(i) in the current ramp up. This large-bore scenario, also limiting on the LFS, produced a lower l(i) and avoided the vertical instabilities. Feedback control of l(i), using the ohmic field coil power supply as the actuator, was successfully demonstrated. Such control may be useful in avoiding vertical instabilities and in providing access to sawtooth-free steady state and hybrid scenarios in ITER. Experiments at reduced inductive voltage and with electron cyclotron assist for breakdown and burnthrough have also been carried out. The Corsica equilibrium and transport code has modelled these data to provide validation of transport models used to simulate this phase of ITER discharges in order to yield more accurate extrapolation to ITER scenarios.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1016618
• Journal Information: Nuclear Fusion, Vol. 48, Issue 12; ISSN 0029--5515
• Country of Publication: United States
• Language: English