On June 6, 2013, researchers at Jefferson Lab completed the construction of the Forward Calorimeter in Hall D. The calorimeter was built to measure the energy of particles as they are created inside the target area and strike against lead glass blocks that make up the calorimeter. Upon striking the calorimeter, the particles will create a shower of light, which will then be digitized and used to measure energy of particles. In this photo, John Leckey, a postdoctoral researcher from Indiana University, is assembling the Forward Calorimeter in Jefferson Lab's newest experimental area, Hall D. Leckey helped assemble the calorimeter along with Manuel Lara and Daniel Bennett, postgraduate students from Indiana University. The calorimeter contains 2,800 lead glass blocks. | Photo courtesy of Jefferson National Laboratory.