The divertor plate of next generation tokamak device such as the International Thermonuclear Experimental Reactor (ITER) is subjected to high heat and particle fluxes from the plasma. The armor material of the divertor plate will be damaged by plasma disruptions. Therefore the divertor components are required to be easily repaired or replaced. To realize the easy maintenance of divertor high heat flux components, the thermal bond layer (TBL) concept is the most promising. The TBL is a soft braze material which has a low melting temperature such as lead-based alloys. By using TBL for divertor high heat flux components, the damaged armor tiles are expected to be easily replaceable. Moreover, TBL plays a role of a compliant interlayer to reduce the interfacial thermal stress between the armor tile and the heat sink substrate. The authors have developed and tested Divertor Mock-UPS with lead-based TBL. This paper presents the results of the high heat flux experiments on the Divertor Mock-UPS with the TBL. The mock-up consists of replaceable armor blocks and a permanent substrate which is made of pure copper. The armor block consists of a bonded structure with armor tiles and a copper pivot. The armor blocks are brazed onto the substrate with pure lead. The permanent substrate has parallel cooling tubes which have twisted tape insert to enhance heat transfer. The high heat flux experiments on these mock-ups were carried out at JAERI Electron Beam Irradiation System (JEBIS). For the simulation of normal operation of ITER, the incident heat flux of 5 MW/m2 at a maximum pulse duration of 50 s was loaded; and for the simulation of transient period of ITER, the heat flux of up to 15 MW/m2 at a maximum pulse duration of 10 s was loaded. The thermal performance of the mock-ups was stably sustained against both thermal loads.
