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The Radiation Laboratory, commonly called the Rad Lab, was located at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts (US) and functioned from October 1940 until December 31, 1945. Alfred Lee Loomis, a millionaire and physicist who headed his own private laboratory, selected the location for the laboratory on the campus, named it the MIT Radiation Laboratory, and arranged funding for the Rad Lab until federal money was allocated. It was formed by, and initially operated under, the National Defense Research Committee (NDRC), a commission established by U.S. President Franklin D. Roosevelt with Vannevar Bush as its chairman. In 1941, the NDRC was enlarged to become the Office of Scientific Research and Development (OSRD), with Bush remaining as chairman. Lee A. DuBridge served as the Rad Lab director. This facility was responsible for developing most of the microwave radars used by the United States during World War II, including the H2X radar used for bomb-aiming and the subsequent improvements to the initial H2X radar's technology. The Rad Lab also developed Loran-A, the first worldwide radio navigation system, which originally was known as "LRN" for Loomis Radio Navigation, after Alfred Lee Loomis, who invented it and played a crucial role in military research and development during WWII. It remained the most widely used long-range navigation system until it was gradually replaced by Loran-C. Loran-A was discontinued by the United States in 1980. ==Formation== During the mid- and late-1930s, radio systems for the detection and location of distant targets had been developed under great secrecy in the United States and Great Britain, as well as in several other nations, notably Germany, the USSR, and Japan. These usually operated at Very High Frequency (VHF) wavelengths in the electromagnetic spectrum and carried several cover names, such as Ranging and Direction Finding (RDF) in Great Britain. In 1941, the U. S. Navy coined the acronym 'RADAR' (RAdio Detection And Ranging) for such systems; this soon led to the name 'radar' and spread to other countries. The potential advantages of operating such systems in the Ultra High Frequency (UHF or microwave) region were well known and vigorously pursued. One of these advantages was smaller antennas, a critical need for detection systems on aircraft. The primary technical barrier to developing UHF systems was the lack of a usable source for generating high-power microwaves. In February 1940, researchers John Randall and Harry Boot at Birmingham University in Great Britain built a resonant cavity magnetron to fill this need; it quickly was placed in the highest level of secrecy. Shortly after this breakthrough, Britain's Prime Minister Winston Churchill and President Roosevelt agreed that the two nations would pool their technical secrets and jointly develop many urgently needed warfare technologies. At the initiation of this exchange in the late summer of 1940, the Tizard Mission brought to America one of the first of the new magnetrons. On October 6, Edward George Bowen, a key developer of RDF at the Telecommunications Research Establishment (TRE) and a member of the mission, demonstrated this magnetron, producing some 15,000 watts (15 kW) of power at . (Microwave components usually are designated in wavelength, rather than frequency.) American researchers and officials were amazed at the magnetron, and the NDRC immediately started plans for manufacturing and incorporating these devices. Alfred Lee Loomis, who headed the NDRC Microwave Committee, led in establishing the Radiation Laboratory at MIT as a joint Anglo-American effort for microwave research and developing systems using the new magnetron. The name 'Radiation Laboratory', selected by Loomis when he selected the building for it on the MIT campus, intentionally was deceptive,〔"The MIT Radiation Laboratory - RLE's Microwave Heritage", RLE Currents, v.2 no. 4, Spring 1991 (in 18.4MB PDF )〕 albeit obliquely correct in that radar uses radiation in a portion of the electromagnetic spectrum. It was chosen to imply that the laboratory's mission was similar to that of the Ernest O. Lawrence's Radiation Laboratory at UC Berkeley; i.e., that it employed scientists to work on nuclear physics research. At the time, nuclear physics was regarded as relatively theoretical and inapplicable to military equipment, as this was before atomic bomb development had begun. Ernest Lawrence was an active participant in forming the Rad Lab and personally recruited many key members of the initial staff. Most of the senior staff were Ph.D. physicists who came from university positions. They usually had no more than an academic knowledge of microwaves, and almost no background involving electronic hardware development. Their capability, however, to attack complex problems of almost any type was outstanding. Later in life, nine members of the staff were recipients of the Nobel Prize for their other accomplishments. In June 1941, the NDRC became part of the new Office of Scientific Research and Development (OSRD), also administered by Vannevar Bush, who reported directly to President Roosevelt. The OSRD was given almost unlimited access to funding and resources, with the Rad Lab receiving a large share for radar research and development. Starting in 1942, the Manhattan Project absorbed a number of the Rad Lab physicists into Los Alamos and Lawrence's facility at Berkeley. This was made simpler by Lawrence and Loomis being involved in all of these projects. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Radiation Laboratory (MIT)」の詳細全文を読む スポンサード リンク
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