A medium-energy electron-ion collider for Jefferson Lab

One of the main goals of the 12 GeV program is to map out the spin and flavor structure of the nucleon.in the valence region. After this, the next step in the evolution of our understanding, and of the Jefferson Lab program, is to explore the sea (quarks and gluons). This can be realized through a high-luminosity, medium-energy collider, which will provide both answers to key questions, and a broad range of opportunities for the JLab user community.