Current Status of RESA: Diffractometer for Neutron Residual Stress Measurements at JRR-3

 RESA (Diffractometer for REsidual Stress Analysis) is an angle-dispersive neutron diffractometer installed at the T2-1 beam port of the JRR-3 research reactor in Tokai, Japan. The instrument is dedicated to nondestructive residual stress measurements in engineering materials and structural components. Internal strain and stress are evaluated from shifts in diffraction peaks, enabling residual stress distributions introduced by manufacturing processes such as welding and plastic deformation to be investigated. These measurements provide important information for structural integrity assessment and lifetime evaluation of engineering components. An upgrade of RESA is currently being planned to improve the efficiency of residual stress measurements through increased neutron intensity and improved detection efficiency. As a preliminary step toward this upgrade, the present performance of RESA was quantitatively evaluated, and the performance requirements for the detector were investigated. This presentation reports the results of these preliminary investigations for the planned upgrade of RESA.