Beam particles (IMAGE) DOE/Fermi National Accelerator Laboratory Caption The beam particles each emit ultrafast light pulses as they pass through a special magnet called a pickup undulator (bottom right). Information about each particle’s energy or trajectory error is encoded in its light pulse. The light pulses are captured, focused and tuned by various light optics. The particles then interact with their own pulses inside an identical kicker undulator (center). The interaction can be used to cool the particles or even control them, depending on the configuration of the system. Credit Jonathan Jarvis, Fermilab Usage Restrictions None License Original 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.