Speaker
Description
The HIPPO neutron time-of-flight diffractometer [1] at LANSCE has been upgraded with an event-mode, energy-resolved neutron imaging camera [2], enabling simultaneous diffraction for microstructural characterization and energy-resolved neutron imaging. This multimodal approach reduces beam time requirements and leverages HIPPO's extensive detector coverage and sample environment capabilities for combined diffraction and imaging investigations.
The imaging system features a 20x20 mm field-of-view viewing HIPPO's 10 mm diameter beam spot (14 mm base-to-base), utilizing a 450 μm 6LiF-ZnO:Zn scintillator intensified and coupled to a TimePix3 sensor. Energy discrimination provides Bragg edge contrast for grain mapping and resonance absorption for isotopic density or sensor-less temperature measurements from Doppler broadening [3]. White beam imaging add information e.g. observing decomposition in hydride experiments [4]. Event-mode readout enables high rates, neutron/gamma discrimination, and center-of-gravity positioning algorithms for quantitative imaging of irregular samples.
By integrating diffraction and imaging, HIPPO enables unique multimodal experiments e.g. combining texture analysis from diffraction with spatial grain mapping for characterization of large-grained samples. We report on the calibration and show example applications of the new capabilities such a wire silver specimen from New Mexico, a large-grained steel sample from a reactor pressure vessel, and Bragg-edge imaging on depleted uranium.
| Abstract Topic | Development of experimental techniques and new principles |
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