Cylinder (image) Johannes Gutenberg Universitaet Mainz Share Print E-Mail Caption This metal cylinder is the outermost layer of a four-layer magnetic shield. At its center is a paraffin-coated rubidium gas chamber that acts as a magnetic sensor. Credit photo/©: Arne Wickenbrock, JGU Usage Restrictions This image may only be used in connection with the press release "Experimental physicist Dmitry Budker receives an ERC Advanced Grant", issued by Johannes Gutenberg University Mainz on May 12, 2016. Share Print E-Mail 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.