Capturing lightning in solid-state materials

Dielectric breakdown is the process by which an insulating material becomes conductive when subjected to high enough voltages, and electric current flows through it. We have all observed dielectric breakdown in air- that is, lightning. A similar process, known as "electrical treeing", happens inside of optically transparent non-crystalline materials such as, e.g., poly(methyl methacrylate) (PMMA). This results in socalled "Lichtenberg figures" growing inside of the material. While this process has been observed in PMMA,direct time-resolved imaging of dielectric breakdown inside of industrially relevant opaque crystalline dielectrics has never been done. We believe that we will be able to perform this challenging experiment by using a newly developed methodology: Dark-Field X-ray Microscopy (DFXM) at X-ray Free-Electron Lasers (XFELs).