Crane type: radial capacity (tons) 30 overhead span (ft) 77 Concrete shielding: 15 ft thick on sides, 4 ft on top _History_ Design started: January 1940. Construction started: August 1940. First operation for deuterons and alpha particles: November 1946. for protons: December 1948. Rebuilt: 1955-1957. [Illustration: Synchrocyclotron Building] [Transcriber's Note: The following changes have been made to the printed text: Page 15, added closing quote (are called "caves" because) Page 19, "iostopes" corrected to "isotopes" ] End of Project Gutenberg's LRL Accelerators, by Lawrence Radiation Laboratory