Experiments to develop divertor

Example of divertor mock-ups developed in JAEA

Schematic drawing of a monoblock divertor

1. Heating tests in high heat flux test facilities

( Electron beam test facility, Ion beam test facility )

- Thermal fatigue experiment : Several thousands of cyclic heat flux are loaded on divertor mock-ups to clarify their thermal fatigue behavior. Lifetime of the divertor in terms of thermal fatigue is obtained from the experiments.

- Critical heat flux (CHF) experiment : High heat flux which exceeds the design heat flux of the divertor is loaded on the divertor cooling tubes to clarify their ultimate heat removal capability. Safety factor of the cooling tubes to the design heat flux is obtained from the experiments.

- Disruption simulation experiment : Extremely high heat flux simulating plasma disruptions is loaded on the armor materials of the divertor, mainly CFCs and tungsten, to clarify their durability against plasma disruptions. Erosion lifetime of the divertor in terms of plasma disruptions is obtained from the experiments.

2. Erosion tests in ion irradiation facility

(Super Low Energy Ion Irradiation System : SLEIS)

- Sputtering experiment : Low energy ion simulating particle flux from the plasma is loaded on the armor materials of the divertor, mainly CFCs and tungsten, to clarify their erosion characteristics. Erosion lifetime of the divertor in terms of particle flux from the plasma is obtained from the experiments.