X-ray flash imaging of laser-induced bubbles and shockwaves in water

An infrared laser pulse (shown as a dark red oscillating wave) has been tightly focused into pure water where a plasma (green cloud) is formed; a shock wave and a bubble (hemispheres) are then created. An acoustic signal recorded with a microphone is used to determine the deposited energy, a diverging X-ray beam (purple cone) is used to image a hologram captured by a detector. Photo: Markus Osterhoff Holographic 'movie' of bubbles and high-pressure shockwave created by research team led by Göttingen University Everyone is familiar with tiny gas bubbles gently rising up in sparkling water. But the bubbles that were created by intense focused lasers in this experiment were ten times smaller and contained water vapour at a pressure around a hundred thousand times higher. Under these conditions, the bubble expands at supersonic speed and pushes a shockwave, consisting of a spherical shell of highly compressed water, ahead of itself. Now the research team led by the University of Göttingen, together with the Deutsches Elektronen-Synchroton (DESY) and the European X-Ray Free-Electron Laser (European XFEL), has created such an event and then, with an innovative technique that they developed using holographic flash imaging and nanofocused X-ray laser pulses, captured data and images. The research was published .