Betatron Radiation Emittance Experiment (image) DOE/Lawrence Berkeley National Laboratory Caption The LOASIS team measured the emittance of the electron beam by recording the spectrum of the x-ray pulse it emitted as the electrons accelerated, a phenomenon known as betatron radiation. The electron pulse itself (multiple pulses are shown here for clarity) is first diverted by the strong magnets of an electron spectrometer. The drive laser beam (red) is then deflected by a mirror of foils, through which the x-ray pulse (green) passes unhindered. The camera is positioned 4.7 meters away behind a window inside a vacuum chamber, surrounded by lead and plastic shielding with additional shielding from a concrete wall. Credit Lawrence Berkeley National Laboratory Usage Restrictions Credit required 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.