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W. W. Hansen
William Webster Hansen (May 27, 1909 – May 23, 1949) was an American physicist and professor. He was one of the founders of the technology of microwave electronics. Biography Hansen's father William G Hansen, who was a son of immigrants from Denmark, was a hardware store owner in Fresno, California. He encouraged his son's early talent in mathematics and enthusiasm for electronics. He entered Stanford University at the age of 16, earning his B.A. in 1929 and his Ph.D. in 1933.Süsskind (1981) Hansen went on to become interested in the problem of accelerating electrons for X-ray experiments, using oscillating fields, rather than large static voltages. At the University of California, Berkeley, Ernest Lawrence and his assistant David H. Sloan, had worked on an accelerator driven by a resonant coil. Hansen proposed replacing the coil with a cavity resonator. In 1937, brothers Russel H. Varian and Sigurd F. Varian came to Stanford to work on the foundations of what was to become ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresno, California
Fresno () is a major city in the San Joaquin Valley of California, United States. It is the county seat of Fresno County and the largest city in the greater Central Valley region. It covers about and had a population of 542,107 in 2020, making it the fifth-most populous city in California, the most populous inland city in California, and the 34th-most populous city in the nation. The Metro population of Fresno is 1,008,654 as of 2022. Named for the abundant ash trees lining the San Joaquin River, Fresno was founded in 1872 as a railway station of the Central Pacific Railroad before it was incorporated in 1885. It has since become an economic hub of Fresno County and the San Joaquin Valley, with much of the surrounding areas in the Metropolitan Fresno region predominantly tied to large-scale agricultural production. Fresno is near the geographic center of California, approximately north of Los Angeles, south of the state capital, Sacramento, and southeast of San Franc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavity Resonator
A resonator is a device or system that exhibits resonance or resonant behavior. That is, it naturally oscillates with greater amplitude at some frequencies, called resonant frequencies, than at other frequencies. The oscillations in a resonator can be either electromagnetic or mechanical (including acoustic). Resonators are used to either generate waves of specific frequencies or to select specific frequencies from a signal. Musical instruments use acoustic resonators that produce sound waves of specific tones. Another example is quartz crystals used in electronic devices such as radio transmitters and quartz watches to produce oscillations of very precise frequency. A cavity resonator is one in which waves exist in a hollow space inside the device. In electronics and radio, microwave cavities consisting of hollow metal boxes are used in microwave transmitters, receivers and test equipment to control frequency, in place of the tuned circuits which are used at lower freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perley Ason Ross
Perley Ason Ross (6 April 1883 – 13 March 1939) was a U.S. experimental physicist who worked, carefully and without seeking publicity, at some essential problems in the behaviour of X-rays. Born in Panacea, Missouri he was awarded his PhD from Stanford University in 1911, becoming a full professor there in 1927, after a year at Cornell University. Some of his principal studies included: *Scattering of X-rays by matter; *Development of the Ross differential filter for X-ray spectroscopy; *X-ray polarization; *Compton scattering; and *Radiative Auger effect Radiative Auger effect is a decay channel of an inner-shell atomic vacancy state, in which an x-ray photon is emitted accompanying simultaneous promotion of an electron into either a bound or a continuum state. Thus the transition energy is shared b .... His daughter, Betsy, married fellow Stanford physicist William Webster Hansen.Süsskind, C. (1981) "Hansen, William Webster" in References 1883 births 1938 deaths ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hansen Experimental Physics Laboratory
The Hansen Experimental Physics Laboratory (HEPL) was founded in 1947 and is a facility at Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ..., California, United States, aiming to promote interdisciplinary enterprises across different branches of science. External linksOfficial webpage of HEPL Stanford University places {{California-university-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beryllium
Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form minerals. Notable gemstones high in beryllium include beryl ( aquamarine, emerald) and chrysoberyl. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. Within the cores of stars, beryllium is depleted as it is fused into heavier elements. Beryllium constitutes about 0.0004 percent by mass of Earth's crust. The world's annual beryllium production of 220 tons is usually manufactured by extraction from the mineral beryl, a difficult process because beryllium bonds strongly to oxygen. In structural applications, the combination of high flexural rigidity, thermal stability, thermal conductivity and low density (1.85 times that of water) ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berylliosis
Berylliosis, or chronic beryllium disease (CBD), is a chronic allergic-type lung response and chronic lung disease caused by exposure to beryllium and its compounds, a form of beryllium poisoning. It is distinct from acute beryllium poisoning, which became rare following occupational exposure limits established around 1950. Berylliosis is an occupational lung disease. While there is no cure, symptoms can be treated. Signs and symptoms With single or prolonged exposure by inhalation the lungs may become sensitized to beryllium. Berylliosis has a slow onset and progression. Some people who are sensitized to beryllium may not have symptoms.OSHBeryllium Health EffectsPage accessed March 29, 2016 Continued exposure causes the development of small inflammatory nodules, called granulomas. Of note, the authors of a 2006 study suggested that beryllium inhalation was not the only form of exposure and perhaps skin exposure was also a cause, as they found that a reduction in beryllium inhalat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varian Associates
Varian Associates was one of the first high-tech companies in Silicon Valley. It was founded in 1948 by Russell H. and Sigurd F. Varian, William Webster Hansen, and Edward Ginzton to sell the klystron, the first vacuum tube which could amplify electromagnetic waves at microwave frequencies, and other electromagnetic equipment. Varian Associates split into three companies in 1999: Varian Medical Systems, Varian, Inc. and Varian Semiconductor. Incorporation and leadership On April 20, 1948, the Articles of Incorporation were filed, signed by nine directors: Edward Ginzton, who had worked with the Varian brothers since his days as a doctoral student; William Webster Hansen, Richard M. Leonard, an attorney; Leonard I. Schiff, then head of the physics department at Stanford University; H. Myrl Stearns, Russell H. Varian, his wife, Dorothy Varian, Sigurd F. Varian and Paul B. Hunter. The company began with six full-time employees: the Varian brothers, Dorothy, Myrl Stearns, Fred Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Ginzton
Edward Leonard Ginzton (December 27, 1915 – August 13, 1998) was a Ukrainian-American engineer. Education Ginzton completed his B.S. (1936) and M.S. (1937) in Electrical Engineering at the University of California, Berkeley, and his Ph.D. in Electrical Engineering from Stanford University in 1941. Career As a student at Stanford University, Ginzton worked with William Hansen and brothers Russell and Sigurd Varian. In 1941 he became a member of the Varian–Hansen group at the Sperry Gyroscope Company. Ginzton was appointed Assistant Professor in Physics at Stanford University in 1945 and remained on the faculty until 1961. In 1949, Ginzton and Marvin Chodorow developed the 1 BeV 220-foot accelerator at Stanford University. After completion of the 1 BeV accelerator, Ginzton became director of the Microwave Laboratory, which was later renamed thGinzton Laboratory Ginzton, along with Russell and Sigurd Varian, was one of the original board members of Varian Associates, fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Particle Accelerator
A linear particle accelerator (often shortened to linac) is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear beamline. The principles for such machines were proposed by Gustav Ising in 1924, while the first machine that worked was constructed by Rolf Widerøe in 1928 at the RWTH Aachen University. Linacs have many applications: they generate X-rays and high energy electrons for medicinal purposes in radiation therapy, serve as particle injectors for higher-energy accelerators, and are used directly to achieve the highest kinetic energy for light particles (electrons and positrons) for particle physics. The design of a linac depends on the type of particle that is being accelerated: electrons, protons or ions. Linacs range in size from a cathode ray tube (which is a type of linac) to the linac at the SLAC National Accelerator Laboratory in Menlo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sperry Corporation
Sperry Corporation was a major American equipment and electronics company whose existence spanned more than seven decades of the 20th century. Sperry ceased to exist in 1986 following a prolonged hostile takeover bid engineered by Burroughs Corporation, which merged the combined operation under the new name Unisys. Some of Sperry's former divisions became part of Honeywell, Lockheed Martin, Raytheon Technologies, and Northrop Grumman. The company is best known as the developer of the artificial horizon and a wide variety of other gyroscope-based aviation instruments like autopilots, bombsights, analog ballistics computers and gyro gunsights. In the post-WWII era the company branched out into electronics, both aviation related, and later, computers. History Early history The company was founded in 1910 by Elmer Ambrose Sperry, as the Sperry Gyroscope Company, to manufacture navigation equipment—chiefly his own inventions the marine gyrostabilizer and the gyrocompass—at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John R
John R. (born John Richbourg, August 20, 1910 - February 15, 1986) was an American radio disc jockey who attained fame in the 1950s and 1960s for playing rhythm and blues music on Nashville radio station WLAC. He was also a notable record producer and artist manager. Richbourg was arguably the most popular and charismatic of the four announcers at WLAC who showcased popular African-American music in nightly programs from the late 1940s to the early 1970s. (The other three were Gene Nobles, Herman Grizzard, and Bill "Hoss" Allen.) Later rock music disc jockeys, such as Alan Freed and Wolfman Jack, mimicked Richbourg's practice of using speech that simulated African-American street language of the mid-twentieth century. Richbourg's highly stylized approach to on-air presentation of both music and advertising earned him popularity, but it also created identity confusion. Because Richbourg and fellow disc jockey Allen used African-American speech patterns, many listeners thought that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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