CERN, home of the 27-kilometre Large Hadron Collider (LHC), is developing a new particle accelerator just two metres long. The miniature linear accelerator (mini-Linac) is designed for use in hospitals for imaging and the treatment of cancer. It will consist of four modules, each 50cm long, the first of which has already been constructed. “With this first module we have validated all of the stages of construction and the concept in general”, says Serge Mathot of the CERN engineering department.