The Cosmotron was a

particle accelerator A particle accelerator is a machine that uses electromagnetic fields to propel electric charge, charged particles to very high speeds and energies to contain them in well-defined particle beam, beams. Small accelerators are used for fundamental ...

, specifically a

proton A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...

synchrotron A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The strength of the magnetic field which bends the particle beam i ...

, at

Brookhaven National Laboratory Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratories, United States Department of Energy national laboratory located in Upton, New York, a hamlet of the Brookhaven, New York, Town of Brookhaven. It w ...

. Its construction was approved by the U.S. Atomic Energy Commission in 1948, reaching its full energy in 1953, and continuing to run until 1966. It was dismantled in 1969. It was the first particle accelerator to impart

kinetic energy In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Rober ...

in the range of GeV to a single particle, accelerating protons to 3.3 GeV. It was also the first accelerator to allow the extraction of the

particle beam A particle beam is a stream of charged particle, charged or neutral particles other than photons. In Particle accelerator, particle accelerators, these particles can move with a velocity close to the speed of light. There is a difference between ...

for experiments located physically outside the accelerator. It was used to observe a number of

meson In particle physics, a meson () is a type of hadronic subatomic particle composed of an equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticles, the ...

s previously seen only in

cosmic ray Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the ...

s, and to make the first discoveries of heavy, unstable particles (called V particles at the time) leading to the experimental confirmation of the theory of associated production of strange particles. It was the first accelerator that was able to produce all positive and negative mesons known to exist in cosmic rays. Its discoveries include the first vector meson. The name chosen for the

was Cosmitron (representing an ambition to produce cosmic rays) but was changed to Cosmotron to sound like the

cyclotron A cyclotron is a type of particle accelerator invented by Ernest 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: Januar ...

. The beam size of 64 × 15 cm and an energy goal of about 3 GeV determined the machine parameters. The synchrotron had a 75-foot/22.9-meter diameter. It consisted of 288 magnets each weighing 6 tons and providing up to 1.5 T, forming four curved sections. The range of field change was kept within limits by first accelerating particles to an intermediate energy in another accelerator and then injected into the Cosmotron. The straight sections without

magnets A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, ...

were worrisome because there was no focusing and the betatron oscillations would change suddenly and might swing wildly. But, all these major problems were overcome.

Gallery

File:HD.6B.430 (11969919804).jpg, HD.6B.430 - Injection system for the Cosmotron at the Brookhaven National Laboratory. c. 1952 File:HD.6B.438 (11969997484).jpg, HD.6B.438 - General view of the Cosmotron from the main control console. Equipment in the center of the ring is mainly vacuum gear. (Personnel - E. Maher). c. 1952 File:HD.6B.448 (11970235563).jpg, HD.6B.448 - No description provided. File:HD.6B.427 (11969917824).jpg, HD.6B.427 - Injection equipment connected to Brookhaven cosmotron. c. 1958 File:HD.6B.437 (11969996344).jpg, HD.6B.437 - A view of the inside of the Cosmotron ring showing engineer working or high level power amplifier. The orderly assembly of tubes and hoses to the left is a portion of the waterflow interlock system. File:HD.6B.434 (11969994334).jpg, HD.6B.434 - Picture of Sodium Iodide Mosaic used to view 3 Billion Electron Volt External Proton Beam from Cosmotron appears on TV screen at remote monitoring station. c. 1957 File:HD.6B.431 (11969919854).jpg, HD.6B.431 - Front view of the strong focusing magnet used to narrow down external beams of charged nuclear particles which emerge from the Cosmotron (not shown) at Brookhaven National Laboratory. c. 1957 File:HD.6B.433 (11969994274).jpg, HD.6B.433 The 3 BEV Cosmotron at the Brookhaven National Laboratory. c. 1961

References

External links

BNL-Cosmotron
experiment record on

INSPIRE-HEP INSPIRE-HEP is an open access digital library for the field of high energy physics (HEP). It is the successor of the Stanford Physics Information Retrieval System (SPIRES) database, the main literature database for high energy physics since the 1 ...

Cosomtron Magnet Lamina
at the Smithsonian Museum of Natural History
History from BNL website

BNL website on BNL's 60th anniversary
Brookhaven National Laboratory Particle physics facilities Particle experiments {{accelerator-stub