Neutron diffraction stress determination in W-laminates for structural divertor applications

Abstract

Neutron diffraction measurements have been carried out to develop a non-destructive experimental tool for characterizing the crystallographic structure and the internal stress field in W foil laminates for structural divertor applications in future fusion reactors. The model sample selected for this study had been prepared by brazing, at 1085 °C, 13 W foils with 12 Cu foils. A complete strain distribution measurement through the brazed multilayered specimen and determination of the corresponding stresses has been obtained, assuming zero stress in the through-thickness direction. The average stress determined from the technique across the specimen (over both ‘phases’ of W and Cu) is close to zero at −17 ± 32 MPa, in accordance with the expectations.

Keywords

• Divertor
• Tungsten-copper joining
• Internal stresses
• Neutron diffraction