Capturing atomic-scale stress

Scientists used the powerful X-ray laser at the US Department of Energy's SLAC National Accelerator Laboratory in Menlo Park, California, US, to create images detailing trillionths-of-a-second changes in the arrangement of copper atoms following an extreme shock. These molecular dynamics simulations play an important role in the design of stronger, more durable materials – such as shielding for satellites to withstand pelting by high-speed space debris – but they have previously been hard to test in the lab because of the tiny sample sizes and short timescales involved.

SLAC scientists at the Linac Coherent Light Source (LCLS) led the experiment. Published October 11 in Science, the research pinpointed the precise breaking point at which extreme pressures began to permanently deform the structure – meaning the copper was no longer able to bounce back to its original shape. Such experiments provide a direct test of complex computer simulations that model the behavior of many millions of atoms within tiny material samples.

- Amber Harmon