Material damage and thermal response of LHD divertor mock-ups by high heat flux

Abstract

Mockups for tests were fabricated and thermal response and thermal fatigue lifetime tests using electron beam facilities were carried out to examine material damage and thermal response of carbon carbon fiber composite (CFC) brazed the oxygen free high conductivity (OFHC) for a local island divertor (LID) plate. Model calculation for thermal response was also carried out to explain the phenomena of experimental results. Thermal response tests of an MFC-1 mockup were performed at the condition that the water flow velocity, pressure and temperature were 1.6–10 m/s, 1.0–4.0 MPa and 20°C, 150°C respectively. The MFC-1 mockup showed good heat removal performance. In the case of a CX-2002U mockup with 10 mm armor thickness, surface temperature is near 1000°C at 10 MW/m 2. Therefore, use of CX-2002U as armor material is allowable concerning the maximum surface temperature due to heat flux. A thermal fatigue test of the MFC-1 mockup was also performed. Temperatures increase due to degradation was not observed up to 1000 cycles. Calculation for thermal response was performed using a finite element analysis code. The comparison measured with calculated data presented information of critical heat flux and detachment of the tile.