Recent Upgrades to the Residual Stress Diffractometer at the High Flux Isotope Reactor (HIDRA)

The residual stress scanning diffractometer at the High Flux Isotope Reactor (HFIR) located at Oak Ridge National Laboratory (ORNL) recently underwent a major upgrade. The upgraded instrument is now called the High Intensity Diffractometer for Residual stress Analysis (HIDRA). This paper describes the hardware and software upgrades, operation, and performance of the HIDRA instrument. The new instrument has a single 3He multiwire 2D 30cm x 30cm position sensitive detector, yielding a field of view of 17° 2θ. The increase in field of view (from 4° 2θ) from the previous model instrument has contributed the tremendous improvement in the out of plane solid angle such that 3D count rate could be obtained easily. Accordingly, the hardware, software, Data Acquisition System (DAS), etc. have also been updated. Details of the new data acquisition system and user consideration for access to neutron diffraction are detailed. Finally, all these enhanced features of HIDRA have been ably demonstrated by conducting multi directional diffraction measurements in quenched 750-T74 aluminum and the evolved and improved strain/stress mappings are presented.