A 2-Headed Instrument (image) American Institute of Physics Caption A view inside the photoemission chamber, "Hydra," shows the entry point for one time-of-flight electron spectrometer (on the left, opposite the larger open round hole), as well as a second time-of-flight electron spectrometer (on the left front side looking toward the sample, which is a round silver crystal covered by an ultrathin layer of nickel oxide). Credit M.Huth/Max Planck Usage Restrictions This image may be used only with appropriate caption and credit. 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.