The JLab free-electron laser uses an energy recovery LINAC. Electrons are injected into a linear accelerator. The fast-moving electrons then pass through a wiggler which produces a bright laser light beam. The electrons are then captured and steered back to the injection end of the LINAC where they transfer most of their energy to a new batch of electrons to repeat the process. By reusing the electrons and most of their energy, the free-electron laser requires less electricity to operate. The JLab is the first energy recovery LINAC to produce ultravoliet light. Cornell University is now trying to build one to produce X-rays.