Figure 1 (IMAGE) Moscow Institute of Physics and Technology Caption X-ray free-electron laser. A source (1) emits free electrons (2) moving merely tens of times slower than the speed of light through the undulator (4), a tunnel lined with many magnets. The magnetic field causes an electron traveling through the tunnel to oscillate and therefore emit X-rays. The movement of the electrons in the undulator is synchronized to generate tight, high-frequency X-ray pulses of remarkable intensity (3). Credit Elena Khavina/MIPT Press Office Usage Restrictions None License Licensed content 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.