Massachusetts Institute of Technology. Radiation Laboratory

• Division 1: Business
• Division 2: Buildings and Maintenance
• Division 3: Personnel and Shops
• Division 4: Research
• Division 5: Transmitter Components
• Division 6: Receiver Components
• Division 7: Beacons
• Division 8: Fire Control and Army Ground Forces
• Division 9: Airborne Systems
• Division 10: Ground and Ship
• Division 11: Navigation
• Division 12: Field Service

Radar, an acronym for radio detection and ranging, was patented by British scientist Sir Robert Watson Watt for meteorological applications in 1935. Since practical applications for airborne microwave radar had not been developed before World War II, the government of Great Britain requested assistance from the United States to develop this capability. Britain's secret Tizard mission was dispatched to Washington, DC, in September 1940 to introduce the 10 centimeter cavity magnetron. Beginning in late 1940 and continuing through World War II, large-scale research at the Radiation Laboratory, which operated as part of Division 14, Radar, of the National Defense Research Committee (NDRC) and was sited at the Massachusetts Institute of Technology, was devoted to the rapid development of microwave radar.

The "Rad Lab" designed almost half of the radar deployed in World War II, created over 100 different radar systems, and constructed radar systems on several continents. Physicist Lee DuBridge directed the Radiation Laboratory. From a staff of 30 physicists the lab grew to comprise almost 3,900 research and support staff by late 1945. The Radiation Laboratory was officially terminated on December 31, 1945, but the NDRC set aside funds for a Basic Research Division to continue from January 1 to June 30, 1946, under the direction of MIT professor Julius A. Stratton, and it was known as the NDRC Research Laboratory of Electronics. Beginning July 1, 1946, the laboratory continued operations as the MIT Research Laboratory of Electronics.

From the guide to the Collection of Papers and Records of the Radiation Laboratory at the Massachusetts Institute of Technology, 1941-1991, (Massachusetts Institute of Technology. Institute Archives and Special Collections)