neutron wall

This is one of the two neutron walls. The flat-sided glass tubes contain liquid scintillator, which emits a pulse of light when a neutron interacts with the material. The small curved plastic tubes projecting from each tube connect to individual overflow containers, which are out of sight behind the panel of electronic connections in this photo. The cylinders at the end of each scintillator are photomultiplier tubes, which detect the emitted light and send an electronic signal to the computer-controlled data-acquisition system.