A Clearer View of the Atomic World

Ultracompact bunches of electrons are an essential tool for deducing the atomic structure of a material and for capturing the rapid motion of the material’s atoms. But when millions of electrons are crammed together into a bunch, they repel one another. This repulsion increases the width of the electron bunch, reducing the spatial and temporal resolutions with which the tool can operate. Now researchers have found a way to capitalize on electron repulsion, using the repulsion between electrons in one bunch to compress those in another. Their approach could create electron beams with shorter electron bunches, enabling researchers to study molecular processes that occur on time scales currently too fast to capture, such as proton transfer or the oscillations of molecules made of lightweight atoms.