The UNCtau 'Bottle' Trap (IMAGE) Indiana University Caption The UNCtau 'bottle' trap. A combination of magnetic fields and gravity prevent neutrons from escaping the container. Credit Los Alamos National Laboratory Usage Restrictions None License Licensed 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.