MEC Instrument (IMAGE) DOE/SLAC National Accelerator Laboratory Caption At the Matter in Extreme Conditions (MEC) instrument at SLAC’s Linac Coherent Light Source, researchers recreated the extreme conditions found on Neptune and Uranus and observed the formation of diamond rain. Credit Olivier Bonin/SLAC National Accelerator Laboratory Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.