Laue diffraction setup optimized for microstructural studies at high pressure will be available for users at 16BMD beamline of the Advanced Photon Source in 2025.

In the transmission geometry, the limited opening of the diamond cells is overcome especially when using incident beam energies up to ~90 keV which assures sufficient number of reflections to be observed. With a typical beam size of ~2x2 um² and the use of rapid 2D positional scanning, both spatial and time resolved measurements can be performed in a matter of seconds. Nano-focusing KB mirrors from JTec will provide x-ray beam focused down ~250nm².

Due to fast data collection, microstructure of mulitgrain samples will be studied in situ and in real time.

• Twinning
• Lattice rotation
• Redistribution of dislocations and other crystal lattice defects
• Parent/product interface propagation
• Product variants

Some examples of research areas using the new Laue setup include: elastic and plastic deformation under hydrostatic or non-hydrostatic stress, pressure induced phase transitions, and melting and crystallization under high pressure.

In-house developed software:

• polyLaue: Python code to process high pressure Laue diffraction data developed by D. Popov, HPCAT beamline scientist, and Patrick Avery of Kitware, Inc.  Although still being developed, PolyLaue is already somewhat usable. The latest version is available from a publicly open GitHub repository: GitHub - PolyLaue/PolyLaue: A tool for visualizing and analyzing scans of Laue x-ray diffraction patterns.
• indexLaue: Evgenii Vasilev transferred modules for indexation from polyLaue to MATLAB code, combined with suitable GUI to visualize and map Laue reflections. This program is available for download from GitHub: https://github.com/avellko/IndexLaue

For a summary of Laue fundamentals, see: https://www.sciencedirect.com/book/9780120574506/the-laue-method 
or send request to dpopov@anl.gov  

HPCAT publications using Laue technique:

1. Daniel Yin, Bibhu Sahu, Phillip Tsurkan, Dmitry Popov, Avinash M. Dongare, Nenad Velisavljevic, Amit Misra.  (2024)
   High-Pressure Phase Transitions in a Laser Directed Energy Deposited Fe-33Cu Alloy
   Acta Materialia, 268, 119797 
2. Evgenii Vasilev, Dmitry Popov, Maddury Somayazulu, Nenad Velisavljevic, Marko Knezevic  (2023)
   White Laue and powder diffraction studies to reveal mechanisms of HCP-to-BCC phase transformation in single crystals of Mg under high pressure
   Sci. Rep. 13, 2173
3. Arya Chatterjee, Dmitry Popov, Nenad Velisavljevic, and Amit Misra.  (2022)
   Phase Transitions of Cu and Fe at Multiscales in an Additively Manufactured Cu–Fe Alloy under High-Pressure
   Nanomater. 12 (9), 1514
4. Hao Chen, Valery I. Levitas, Dmitry Popov, and Nenad Velisavljevic.  (2022) 
   Nontrivial nanostructure, stress relaxation mechanisms, and crystallography for pressure-induced Si-I→Si-II phase transformation
   Nature Communications 13, 982
5. Popov, Dmitry; Nenad Velisavljevic, and Maddury Somayazulu. (2019)
   Mechanisms of Pressure-Induced Phase Transitions by Real-Time Laue Diffraction
   Crystals 9, 12: 672
6. Popov, D., N. Velisavljevic, Wenjun Liu, R. Hrubiak, Changyong Park, and G. Shen. (2019)  Real time study of grain enlargement in zirconium under room-temperature compression across the [alpha] to [omega] phase transition 
   Sci. Rep. 9, 15712-1-15712-7
7. Popov D. et al. (2019)
   New Laue Micro-diffraction Setup for Real-Time In Situ Microstructural Characterization of Materials Under External Stress
   In: Nakano J. et al. (eds) Advanced Real Time Imaging II. The Minerals, Metals & Materials Series. Springer, Cham
8. Popov, D., C. Park, C. Kenney-Benson, and G. Shen.  (2015)
   High pressure Laue diffraction and its application to study microstructural changes during the α→β phase transition in Si
   Rev. Sci. Instrum. 86, 072204
9. R. Barabash, O. Barabash, D. Popov, G. Shen, C. Park and W. Yang.  (2015)
   Multiscale twin hierarchy in NiMnGa shape memory alloys with Fe and Cu.
   Acta Materialia, 2015, 87, 344-349