Single Hit Energy-resolved Laue Diffraction

TL;DR

This paper extends in-situ Laue diffraction by recording photon energy of diffraction peaks, enabling in-situ measurement of volumetric and strain states during rapid compression, demonstrated on silicon with preliminary elastic results.

Contribution

It introduces an energy-resolved Laue diffraction technique to measure volumetric and strain states during dynamic compression, enhancing the capabilities of traditional white light Laue.

Findings

Successful measurement of volumetric compression during rapid compression.

Observation of elastic strain in silicon during experiments.

Support for the hypothesis of disorder or large-scale rotation in material downstream of the second wave.

Abstract

In-situ white light Laue diffraction has been successfully used to interrogate the structure of single crystal materials undergoing rapid (nanosecond) dynamic compression up to megabar pressures. However, information on strain state accessible via this technique is limited, reducing its applicability for a range of applications. We present an extension to the existing Laue diffraction platform in which we record the photon energy of a subset of diffraction peaks. This allows for a measurement of the longitudinal and transverse strains in-situ during compression. Consequently, we demonstrate measurement of volumetric compression of the unit cell, in addition to the limited aspect ratio information accessible in conventional white light Laue. We present preliminary results for silicon, where only an elastic strain is observed. VISAR measurements show the presence of a two wave structure and measurements show that material downstream of the second wave does not contribute to the observed diffraction peaks, supporting the idea that this material may be highly disordered, or has undergone large scale rotation.