Eyeglasses for an Electron Beam
Just as we use lenses to focus and reshape visible light, magnets are used to focus and reshape electron beams. The red devices shown in the picture are called quadrupoles. Each has four powerful magnets that keep the beam in line as it travels down the path. There are almost 70 of these focusing magnets along the football-field-length track of the beam. Precise alignment is key to getting the prettiest, strongest laser possible.
Image: Jefferson Laboratory