|
Cyclotron With Glowing Beam
A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. Lawrence, Ernest O. ''Method and apparatus for the acceleration of ions'', filed: January 26, 1932, granted: February 20, 1934 A cyclotron accelerates charged particles outwards from the center of a flat cylindrical vacuum chamber along a spiral path. The particles are held to a spiral trajectory by a static magnetic field and accelerated by a rapidly varying electric field. Lawrence was awarded the 1939 Nobel Prize in Physics for this invention. The cyclotron was the first "cyclical" accelerator. The primary accelerators before the development of the cyclotron were electrostatic accelerators, such as the Cockcroft–Walton accelerator and Van de Graaff generator. In these accelerators, particles would cross an accelerating electric field only once. Thus, the energy gained by the particles was limited by the maximum elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclotron With Glowing Beam
A cyclotron is a type of particle accelerator invented by Ernest O. Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. Lawrence, Ernest O. ''Method and apparatus for the acceleration of ions'', filed: January 26, 1932, granted: February 20, 1934 A cyclotron accelerates charged particles outwards from the center of a flat cylindrical vacuum chamber along a spiral path. The particles are held to a spiral trajectory by a static magnetic field and accelerated by a rapidly varying electric field. Lawrence was awarded the 1939 Nobel Prize in Physics for this invention. The cyclotron was the first "cyclical" accelerator. The primary accelerators before the development of the cyclotron were electrostatic accelerators, such as the Cockcroft–Walton accelerator and Van de Graaff generator. In these accelerators, particles would cross an accelerating electric field only once. Thus, the energy gained by the particles was limited by the maximum elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Therapy
Particle therapy is a form of external beam radiotherapy using beams of energetic neutrons, protons, or other heavier positive ions for cancer treatment. The most common type of particle therapy as of August 2021 is proton therapy. In contrast to X-rays (photon beams) used in older radiotherapy, particle beams exhibit a Bragg peak in energy loss through the body, delivering their maximum radiation dose at or near the tumor and minimizing damage to surrounding normal tissues. Particle therapy is also referred to more technically as hadron therapy, excluding photon and electron therapy. Neutron capture therapy, which depends on a secondary nuclear reaction, is also not considered here. Muon therapy, a rare type of particle therapy not within the categories above, has also been attempted however, muons are still most commonly used for imaging, rather than therapy. Method Particle therapy works by aiming energetic ionizing particles at the target tumor. These particles damage t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Telegraph Company
The Federal Telegraph Company was a United States manufacturing and communications company that played a pivotal role in the 20th century in the development of radio communications. Founded in Palo Alto, California in 1909 by Cyril Frank Elwell, the company would eventually merge in August 1927 with the Mackay Companies. In 1911-13, Lee De Forest and two assistants worked at FTC on the first vacuum tube amplifier and oscillator, which De Forest called the "Oscillaton" after his earlier Audion. The company remained a separate entity within the Mackay Companies, however, and when International Telephone and Telegraph (ITT) purchased the Mackay Companies in 1928 Federal remained a component of the Mackay structure as a manufacturing entity. In 1931, Dr. Ernest O. Lawrence, inventor of the cyclotron, convinced Federal Telegraph to donate an 80-ton magnet they had developed for a canceled project in China to his first cyclotron project on the campus of the University of Californi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arc Converter
The arc converter, sometimes called the arc transmitter, or Poulsen arc after Danish engineer Valdemar Poulsen who invented it in 1903, was a variety of spark transmitter used in early wireless telegraphy. The arc converter used an electric arc to convert direct current electricity into radio frequency alternating current. It was used as a radio transmitter from 1903 until the 1920s when it was replaced by vacuum tube transmitters. One of the first transmitters that could generate continuous sinusoidal waves, it was one of the first technologies used to transmit sound (amplitude modulation) by radio. It is on the list of IEEE Milestones as a historic achievement in electrical engineering. History Elihu Thomson discovered that a carbon arc shunted with a series tuned circuit would "sing". This "singing arc" was probably limited to audio frequencies. Bureau of Standards credits William Duddell with the shunt resonant circuit around 1900. The English engineer William Duddell discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Addison Wesley
Addison-Wesley is an American publisher of textbooks and computer literature. It is an imprint of Pearson PLC, a global publishing and education company. In addition to publishing books, Addison-Wesley also distributes its technical titles through the O'Reilly Online Learning e-reference service. Addison-Wesley's majority of sales derive from the United States (55%) and Europe (22%). The Addison-Wesley Professional Imprint produces content including books, eBooks, and video for the professional IT worker including developers, programmers, managers, system administrators. Classic titles include ''The Art of Computer Programming'', ''The C++ Programming Language'', ''The Mythical Man-Month'', and ''Design Patterns''. History Lew Addison Cummings and Melbourne Wesley Cummings founded Addison-Wesley in 1942, with the first book published by Addison-Wesley being Massachusetts Institute of Technology professor Francis Weston Sears' ''Mechanics''. Its first computer book was ''Progra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (journal)
''Science'', also widely referred to as ''Science Magazine'', is the peer-reviewed academic journal of the American Association for the Advancement of Science (AAAS) and one of the world's top academic journals. It was first published in 1880, is currently circulated weekly and has a subscriber base of around 130,000. Because institutional subscriptions and online access serve a larger audience, its estimated readership is over 400,000 people. ''Science'' is based in Washington, D.C., United States, with a second office in Cambridge, UK. Contents The major focus of the journal is publishing important original scientific research and research reviews, but ''Science'' also publishes science-related news, opinions on science policy and other matters of interest to scientists and others who are concerned with the wide implications of science and technology. Unlike most scientific journals, which focus on a specific field, ''Science'' and its rival ''Nature (journal), Nature'' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UC Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public university, public land-grant university, land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant university and the founding campus of the University of California system. Its fourteen colleges and schools offer over 350 degree programs and enroll some 31,800 undergraduate and 13,200 graduate students. Berkeley ranks among the world's top universities. A founding member of the Association of American Universities, Berkeley hosts many leading research institutes dedicated to science, engineering, and mathematics. The university founded and maintains close relationships with three United States Department of Energy National Laboratories, national laboratories at Lawrence Berkeley National Laboratory, Berkeley, Lawrence Livermore National Laboratory, Livermore and Los Alamos National Laboratory, Los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bancroft Library
The Bancroft Library in the center of the campus of the University of California, Berkeley, is the university's primary special-collections library. It was acquired from its founder, Hubert Howe Bancroft, in 1905, with the proviso that it retain the name Bancroft Library in perpetuity. The collection at that time consisted of 50,000 volumes of materials on the history of California and the North American West. It is now the largest such collection in the world. The building the library is located in, the Doe Annex, was completed in 1950. Inception The Bancroft Library's inception dates back to 1859, when William H. Knight, who was then in Bancroft's service as editor of statistical works relative to the Pacific coast, was requested to clear the shelves around Bancroft's desk to receive every book in the store having reference to this country. Looking through his stock he was agreeably surprised to find some 50 or 75 volumes. There was no fixed purpose at this time to collect a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archiv Für Elektronik Und Übertragungstechnik
Archiv Produktion is a classical music record label of German origin. It originated in 1949 as a classical label for the Deutsche Grammophon Gesellschaft (DGG), and in 1958 Archiv was established as a subsidiary of DGG, specialising in recordings of Early and Baroque music. It has since developed a particular focus on " historically informed performance" and the work of artists of the Early music revival movement of the 20th and 21st centuries. The first head of Archiv Produktion, serving in the position from 1948 to 1957, was Fred Hamel, a musicologist who set out the early Archiv Produktion releases according to 12 research periods, from Gregorian Chant to Mannheim and Vienna. Hamel's successor 1958-1968 Hans Hickmann was a professor at the University of Hamburg who focused on Bach and Handel. The next director was Andreas Holschneider (1931–2019) from 1970-1991. In December 1991 Holschneider gave an interview to ''Gramophone'' where he defended the entry of Archiv Produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolf Widerøe
Rolf Widerøe (11 July 1902 – 11 October 1996) was a Norwegian accelerator physicist who was the originator of many particle acceleration concepts, including the ''resonance accelerator'' and the betatron accelerator. Early life Widerøe was born in Kristiania (now Oslo) in 1902 as a son of the mercantile agent Theodor Widerøe (1868–1947) and Carla Johanne Launer (1875–1971). He was a brother of the aviator and entrepreneur Viggo Widerøe who became the founder of the Norwegian airline Widerøe. After his A-level exams (Examen artium) in the summer of 1920 at the Halling School in Oslo, Widerøe left for Karlsruhe, Germany, to study electrical engineering. Betatron accelerator concept There he conceived the concept of electromagnetic induction to accelerate electrons, which became the basis of what would be known as betatron. This idea was to use a vortex field surrounding a magnetic field to accelerate electrons in a tube. Return to Germany In 1924, he returned to Norw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betatron
A betatron is a type of cyclic particle accelerator. It is essentially a transformer with a torus-shaped vacuum tube as its secondary coil. An alternating current in the primary coils accelerates electrons in the vacuum around a circular path. The betatron was the first machine capable of producing electron beams at energies higher than could be achieved with a simple electron gun, and the first circular accelerator in which particles orbited at a constant radius. The concept of the betatron had been proposed as early as 1922 by Joseph Slepian. Through the 1920s and 30s a number of theoretical problems related to the device were considered by scientists including Rolf Wideroe, Ernest Walton, and Max Steenbeck. The first working betatron was constructed by Donald Kerst at the University of Illinois Urbana-Champaign in 1940. History After the discovery in the 1800s of Faraday's law of induction, which showed that an electromotive force could be generated by a changing magneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear 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 Park ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
