IRIS Instrument (image) University of Copenhagen - Niels Bohr Institute Caption The IRIS instrument is viewed from above. The cement sample is lowered about 120 cm into a cryostat so that it is hit by the neutron beam. The cryostat is emptied of air to avoid signal noise from air. Credit Johan Jacobsen, Niels Bohr Institute Usage Restrictions Johan Jacobsen, Niels Bohr Institute 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.