No abstract

No abstract

No abstract

No abstract

The tungsten surface structure was analyzed after the test in the QSPA-T under heat loads relevant to those expected in the ITER during disruptions. Repeated pulses lead to the melting and the recrystallization of the tungsten surface layer of ~50 μm thickness. The recrystallized layer has the same texture as the original structure with the orientation <100> which is normal to the surface, at the same time the grains' sizes in the recrystallized layer are much larger. There is an interface layer between the original structure and the recrystallized layer. The interface layer has a random grains' orientation and ~50 μm thickness. The texture of this layer differs considerably from the original tungsten structure. The cracks which are normal to the surface were observed in the recrystallyzed layer as well as the cracks which are parallel to the surface at the depth up to 300 μm. Such cracks can result in the brittle destruction which is a hazard for the full tungsten divertor of the ITER. The theoretical analysis of the crack formation reasons and a possible consequence for the ITER is given.

No abstract

No abstract

No abstract