Thermal fatigue experiment of screw cooling tube under one-sided heating condition

Comparison of Cooling Schemes for High Heat Flux Components Cooling in Fusion Reactors

“…It was assumed that the screw would act as a crack initiator, but experiments carried out at JAERI found that this is not what happens. However, further investigation under cyclic loading is needed [37].…”

High heat flux testing of plasma facing materials and components – Status and perspectives for ITER related activities

“…In particular for water cooled divertor targets in next step fusion reactors the heat removal limitations due to critical heat fluxes (CHF) have to be thoroughly determined to avoid unanticipated material damage. This phenomenon has been investigated carefully for a number of different coolant channel geometries such as the circular cross-sections with swirl tube inserts, the hypervapotron with coolant fins perpendicular to the coolant flow [10], and a screw-type coolant channel [11]. At high flow rates CTF values of 40 MW m À2 and beyond have been achieved; these data provide satisfactory safety margins against burn-out failure.…”

Overview on materials R&D activities in Japan towards ITER construction and operation

“…Reduced-cost options for tungsten armor and copper cooling tube of the divertor Two reduced cost options have been explored for application to the tungsten armor and copper cooling tube of the divertor: a bundle of tungsten rods hotpressed onto a heat sink as an armor configuration ('rod-shaped tungsten armor' [1]); and a copper cooling tube with internal fins machined by simple mechanical threading ('screw tube' [2]). Both options have simple fabrication routes with reduced fabrication cost, and their performance has been examined under ITER heat load conditions.…”