The Westinghouse Atom Smasher was a 5 million volt Van de Graaff

electrostatic nuclear accelerator An electrostatic particle accelerator is a particle accelerator in which charged particles are accelerated to a high energy by a static high voltage potential. This contrasts with the other major category of particle accelerator, oscillating fie ...

operated by the

Westinghouse Electric Corporation The Westinghouse Electric Corporation was an American manufacturing company founded in 1886 by George Westinghouse. It was originally named "Westinghouse Electric & Manufacturing Company" and was renamed "Westinghouse Electric Corporation" in ...

at their Research Laboratories in

Forest Hills, Pennsylvania Forest Hills is a borough in Allegheny County, Pennsylvania, United States. The population was 6,518 at the 2010 census, as compared to 6,831 in 2000, and 7,335 in 1990. The borough was named after Forest Hills, Queens. Geography Forest Hills ...

. It was instrumental in the development in practical applications of nuclear science for energy production. In particular, it was used in 1940 to discover the

photofission Photofission is a process in which a nucleus, after absorbing a gamma ray, undergoes nuclear fission and splits into two or more fragments. The reaction was discovered in 1940 by a small team of engineers and scientists operating the Westingho ...

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

and

thorium Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high me ...

, and was most cited for certain nuclear physics measurements. It was the first industrial

Van de Graaff generator A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage direct ...

in the world, and marked the beginning of nuclear research for civilian applications. Built in 1937, it was a

pear Pears are fruits produced and consumed around the world, growing on a tree and harvested in the Northern Hemisphere in late summer into October. The pear tree and shrub are a species of genus ''Pyrus'' , in the family Rosaceae, bearing the p ...

-shaped tower. It went dormant in 1958. In 1985, it was named an Electrical Engineering Milestone by the

Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...

How it worked

Westinghouse Van de Graaff atom smasher - cutaway

In a

, invented in 1929 by

Robert J. Van de Graaff Robert Jemison Van de Graaff (December 20, 1901 – January 16, 1967) was an American physicist, noted for his design and construction of high-voltage Van de Graaff generators. The bulk of his career was spent in the Massachusetts Institute of T ...

, an endless rubber or fabric belt carries

electric charge Electric charge is the physical property of matter that causes charged matter to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative'' (commonly carried by protons and electrons respe ...

s from a roller at the base of the device and deposits them inside a hollow metal electrode at the top. This causes a

high voltage High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, ''high voltage'' refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant spec ...

to develop between electrodes at the top and bottom of the apparatus. In the Westinghouse machine, two high-speed belts traveled up a 47-foot shaft to a mushroom-shaped electrode near the top of the bulb-shaped enclosure, where

s were accumulated ''(see cutaway schematic)''. Various ions, like those generated from hydrogen gas (

protons A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

) or helium gas (

alpha particles Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be prod ...

), were injected into the upper part of an accelerator tube. The high

electrostatic potential Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber ...

between the top and bottom of the tube then caused these

subatomic particle In physical sciences, a subatomic particle is a particle that composes an atom. According to the Standard Model of particle physics, a subatomic particle can be either a composite particle, which is composed of other particles (for example, a pr ...

s to accelerate to extremely high velocities as they traveled down a 17-inch-diameter evacuated cylinder 40 feet in height, which was a sealed stack of many individual glass segments that collectively composed the largest

vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. The type kn ...

in the world at the time of construction. The accelerator tube ran between and parallel to the whirling belts to the base of the machine, where the accelerated particles bombarded experimental

target Target may refer to: Physical items * Shooting target, used in marksmanship training and various shooting sports ** Bullseye (target), the goal one for which one aims in many of these sports ** Aiming point, in field artillery, fi ...

s placed inside the tube, inducing various

nuclear reaction In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two atomic nucleus, nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a t ...

s. The energy of the particles was measured through the

gamma ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

s that the

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

produced when its particles hit a

fluorine Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists at standard conditions as a highly toxic, pale yellow diatomic gas. As the most electronegative reactive element, it is extremely reacti ...

target, which was directly related to the voltage

potential Potential generally refers to a currently unrealized ability. The term is used in a wide variety of fields, from physics to the social sciences to indicate things that are in a state where they are able to change in ways ranging from the simple re ...

between the machine's electrodes. The maximum voltage that a Van de Graaff generator can produce is limited by leakage of the charge off the upper electrode due to

corona discharge A corona discharge is an electrical discharge caused by the ionization of a fluid such as air surrounding a conductor carrying a high voltage. It represents a local region where the air (or other fluid) has undergone electrical breakdown ...

and

arcing An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The electric current, current through a normally Electrical conductance, nonconductive medium such as air produces a plasma (p ...

. At atmospheric pressure, a Van de Graaff machine is generally limited to around 1 megavolt. Thus this instrument was installed inside a pear-shaped 65-foot tall, 30-foot diameter air tank which was pressurized during operation to 120 pounds per square inch. High pressure improved the insulating qualities of the air and reduced

charge Charge or charged may refer to: Arts, entertainment, and media Films * ''Charge, Zero Emissions/Maximum Speed'', a 2011 documentary Music * ''Charge'' (David Ford album) * ''Charge'' (Machel Montano album) * ''Charge!!'', an album by The Aqua ...

leakage, allowing the machine to achieve a voltage potential of 5 megavolts. This allowed a beam energy of 5

MeV In physics, an electronvolt (symbol eV, also written electron-volt and electron volt) is the measure of an amount of kinetic energy gained by a single electron accelerating from rest through an Voltage, electric potential difference of one volt i ...

, although it was originally hoped to reach 10

Preservation efforts

In 2012, the property surrounding the atom smasher was purchased by P&L Investments, LLC. The company was run by Gary Silversmith, a developer who intended to build apartments and expressed an interest in saving the smasher. In 2013, the Young Preservationists Association of Pittsburgh named it as one of the city’s top 10 preservation opportunities. During 2013, plans had been discussed of the

Woodland Hills School District Woodland Hills School District is a public school district located in Allegheny County, Pennsylvania, serving twelve municipalities in the Pittsburgh area; Braddock, Braddock Hills, Chalfant, Churchill, East Pittsburgh, Edgewood, Forest Hil ...

establishing a

STEM Stem or STEM may refer to: Plant structures * Plant stem, a plant's aboveground axis, made of vascular tissue, off which leaves and flowers hang * Stipe (botany), a stalk to support some other structure * Stipe (mycology), the stem of a mushro ...

educational facility with the atom smasher as the centerpiece, but the $4 to $5 million cost was prohibitive and the project never moved forward. By 2015, the structure was in significant disrepair and was dislodged from its supports, due to vandalism and age. On January 20, 2015, Silversmith had the atom smasher removed from its supports and laid on its side. Workers laid bricks to brace the fall, and tipped it over. In an email to the ''

Pittsburgh Post-Gazette The ''Pittsburgh Post-Gazette'', also known simply as the PG, is the largest newspaper serving metropolitan Pittsburgh, Pennsylvania. Descended from the ''Pittsburgh Gazette'', established in 1786 as the first newspaper published west of the All ...

'', Silversmith pronounced his continuing commitment to refurbishing and restoring the atom smasher, saying "The iconic Atom Smasher bulb survives."

References

External links

* {{Pittsburgh Industrial buildings completed in 1937 Nuclear power plants in Pennsylvania Decommissioned nuclear power stations in the United States Buildings and structures demolished in 2015 Buildings and structures in Allegheny County, Pennsylvania 1958 disestablishments in Pennsylvania

How it worked

Preservation efforts

See also

References

External links