A Positron Trap (IMAGE) Technical University of Munich (TUM) Caption Dr. Eve Stenson uses spare parts to demonstrate the structure of the positron trap: in the center is the permanent magnet. The wire on the left represents a probe that can be inserted into the trap. It allows researchers to determine the quantity of injected particles successfully captured inside the magnetic field. Credit Axel Griesch / IPP 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.