betatron

betatron
/bay"teuh tron'/ or, esp. Brit., /bee"-/, n. Physics.
an accelerator in which electrons are accelerated to high energies by an electric field produced by a changing magnetic field.
[1940-45; BETA (see BETA PARTICLE) + -TRON]

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      a type of particle accelerator that uses the electric field induced by a varying magnetic field to accelerate (acceleration) electrons (electron) (beta particles (beta particle)) to high speeds in a circular orbit. The first successful betatron was completed in 1940 at the University of Illinois at Urbana-Champaign, under the direction of the American physicist Donald W. Kerst, who had deduced the detailed principles that govern the operation of such a device. Modern compact betatron designs are used to produce high-energy X-ray beams for a variety of applications.

      The betatron consists of an evacuated tube formed into a circular loop and embedded in an electromagnet in which the windings are parallel to the loop. An alternating electric current in these windings produces a varying magnetic field that periodically reverses in direction. During one quarter of the alternating current cycle, the direction and strength of the magnetic field, as well as the rate of change of the field inside the orbit, have values appropriate for accelerating electrons in one direction.

      Electron acceleration is controlled by two forces, one acting in the direction of the motion of the electrons and the other at right angles to that direction. The force in the direction of electron motion is exerted by the electric field produced via induction (Faraday's law of induction) by the strengthening of the magnetic field within the circle; this force accelerates the electrons. The second—perpendicular—force arises as the electrons move through the magnetic field, and it maintains the electrons in a circular orbit within the closed loop.

      At the beginning of the appropriate quarter-cycle, electrons are injected into the betatron, where they make hundreds of thousands of orbits, gaining energy all the while. At the end of the quarter-cycle, the electrons are deflected onto a target to produce X-rays or other high-energy phenomena. Large betatrons have produced electron beams (electron beam) with energies greater than 340 megaelectron volts (MeV) for use in particle-physics (physics) research. Weight considerations place severe limitations on the construction of high-energy betatrons; the electromagnet of a 340-MeV unit weighs about 330 tons.

      Lower-energy betatrons in the 7–20-MeV range, however, have been specially constructed to serve as sources of energetic “hard” X-rays for use in medical and industrial radiography (X-ray). Portable betatrons, operating at energy levels of approximately 7 MeV, have been designed for specialized applications in industrial radiography—for example, to examine concrete, steel, and cast-metal construction for structural integrity.

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Universalium. 2010.

Look at other dictionaries:

  • betatron — BETATRÓN, betatroane, s.n. (fiz.) Aparat de accelerare a electronilor. – Din fr. bêtatron. Trimis de paula, 02.06.2002. Sursa: DEX 98  betatrón s. n. (sil. tron), pl. betatroáne Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic … …   Dicționar Român

  • Betatrón — Saltar a navegación, búsqueda Un betatrón es un acelerador de partículas desarrollado por Donald Kerst en la Universidad de Illinois en 1940 para acelerar electrones. El betatrón es esencialmente un transformador con un gran tubo vacío como su… …   Wikipedia Español

  • bêtatron — [ bɛtatrɔ̃ ] n. m. • v. 1936; de 1. bêta et (cyclo)tron ♦ Sc. Cyclotron à électrons. ⇒ accélérateur (II, 4o). ● bêtatron nom masculin (de rayons bêta et électron) Synchrotron dans lequel l accélération des électrons produit des rayons X utilisés… …   Encyclopédie Universelle

  • betatrón — betatron betatron m. instrum. Acelerador de electrones mediante un campo magnético circular que permite obtener haces de electrones de alta energía u otro tipo de radiaciones (rayos X o gamma). Se utiliza en medicina para combatir procesos… …   Diccionario médico

  • betatron — e ta*tron n. a type of particle accelerator which accelerates a continuous beam of electrons to high speeds by means of the electric field produced by changing magnetic flux. Syn: induction accelerator. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • bétatron — s. m. [Física] Aparelho acelerador de partículas que serve para produzir elétrons animados de uma grande energia. • [Brasil] Plural: betátrones ou bétatrons.   ♦ Grafia em Portugal: betatrão …   Dicionário da Língua Portuguesa

  • betatron — bȅtatrōn m DEFINICIJA fiz. kružni akcelerator za proizvodnju visoko energetskih elektrona (do 340 MeV), uključujući proizvodnju visoko energetskih X zraka, elektroni se ubrzavaju pomoću magnetske indukcije ETIMOLOGIJA v. beta + v. ciklotron …   Hrvatski jezični portal

  • betatrón — m. Fís. Máquina aceleradora de electrones, con aplicaciones en radioterapia …   Diccionario de la lengua española

  • betatron — ☆ betatron [bāt′ə trän΄ ] n. [< BETA RAY + (ELEC)TRON] an electron accelerator which uses a rapidly changing magnetic field to accelerate the particles and maintain them in a focused circular path …   English World dictionary

  • Betatron — A betatron is a cyclotron developed by Donald Kerst at the University of Illinois in 1940 to accelerate electrons. The betatron is essentially a transformer with a torus shaped vacuum tube as its secondary coil. An alternating current in the… …   Wikipedia

  • Betatron — Historisches Betatron (6MeV, Konstruktionsbeginn 1942) Das Betatron (auch anschaulich „Elektronenschleuder“ genannt) ist ein für leichte geladene Teilchen (wie Elektronen oder Positronen) geeigneter Kreisbeschleuniger. Das Betatron ähnelt dem… …   Deutsch Wikipedia

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