Fusion Plasma Research
AMTEX Program on JFT-2M
(Advanced Material Tokamak Experiment)
AMTEX is planned for the development of reactor material as well as toroidal field ripple reduction of ITER.
1. Ripple reduction test
Guideline for reduction of α particle loss in ITER
for negative shear,
Ripple loss 27% goal 10%
Ripple magnitude 2% 0.8%

Reduce the ripple by inserting ferritic steel

2. Plasma-material test
Reactor structural material
Low activation ferritic steel is promising. However, its magnetism is worried about because of the error field.

Replace material of the JFT-2M vacuum vessel with ferritic steel

    Issues of Ferritic Vacuum Vessel
      Plasma-wall interaction
      Disruption by mode lock due to error field
      Reduction of toroidal field ripple
      Compatibility with improved confinement, etc.