File:U.S. Department of Energy - Science - 278 001 007 (16517741531).jpg

THE CONCAVE INNER SURFACE OF ONE HEMISPHERE OF THE PLASTIC BALL.

THE PLASTIC BALL IS A PARTICLE DETECTOR CAPABLE OF ELECTRONICALLY RECORDING ALL THE CHARGED PARTICLES SIMULTANEOUSLY EMITTED FROM A NUCLEAR REACTION. THE PLASTIC BALL IS COMPRISED OF A SPHERE WITH AN OUTSIDE DIAMETER OF FOUR FEET, AND COVERING 96 PERCENT OF THE SPACE AROUND A TARGET PLACED IN ITS HOLLOW CENTER. THE SPHERE IS CONSTRUCTED OF 815 TAPERED TRIANGULAR BARS MADE OF TWO TYPES OF SCINTILLATORS THAT EMIT LIGHT AT DIFFERENT SPEEDS WHEN STRUCK BY THE REACTION PRODUCTS. ON THE OUTER SURFACE OF THE SPHERE, PHOTOMULTIPLIER TUBES CONVERT THE LIGHT FROM THE TWO KINDS OF SCINTILLATORS INTO ELECTRICAL PULSES WHICH ARE DIGITIZED BY COMPACT ELECTRONICS, PRODUCING A MAGNETIC TAPE CONTAINING NUMBERS. THE NUMBERS HAVE PARTICLE-IDENTIFYING POWERS. THE PLASTIC BALL WILL FURTHER SCIENTISTS' UNDERSTANDING OF HOW NUCLEAR FORCES ACT TO PRODUCE PARTICULAR REACTION PARTICLES.