The Antiproton Collector (AC) was part of the antiparticle factory at

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designed to decelerate and store

antimatter In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding subatomic particle, particles in "ordinary" matter, and can be thought of as matter with reversed charge and parity, or go ...

, to study the properties of antimatter and to create atoms of

antihydrogen Antihydrogen () is the antimatter counterpart of hydrogen. Whereas the common hydrogen atom is composed of an electron and proton, the antihydrogen atom is made up of a positron and antiproton. Scientists hope that studying antihydrogen may sh ...

. It was built in 1986 around the existing Antiproton Accumulator (AA) to improve the antiproton production by a factor of 10. Together, the Antiproton Collector and the Antiproton Accumulator formed the so-called Antiproton Accumulator Complex (AAC). Low energy antiproton research continues at CERN using the

Antiproton Decelerator The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory near Geneva. It was built from the Antiproton Collector (AC) to be a successor to the Low Energy Antiproton Ring (LEAR) and started operation in the year 2000. Antiprotons ...

. It was built as a successor to LEAR and started operation in 2000.

History

After the Antiproton Accumulator (AA) had been operational since 1980, the update program ACOL (Antiproton COLlector) was proposed in 1983."CERN Scientific Committee: ''Design Study of an Antiproton Collector for the Antiproton Accumulator (ACOL)''" (1983)
Retrieved 3 August 2018 The update comprised improvement work on the antiproton source, the construction of the Antiproton Collector (AC), as well as reconstructions of the injection and ejection systems of the Antiproton Accumulator (AA) and its stochastic cooling system. The estimated budget of the upgrade program was 40.2 million CHF. The changes were implemented during 1986 and 1987, with the AC getting constructed tightly around the existing AA ring."E. Jones: ''Progress on ACOL''" (1985)
Retrieved 3 August 2018 The Antiproton Accumulator Complex (AAC) served its last particles to the Proton-Antiproton Collider SpS in 1991. After the (SpS) was shut down, AAC continued to produce antiprotons for LEAR. Operation stopped in 1997, when the AA was dismantled and the AC was converted into the

(AD)."B. Autin et al.: ''The antiproton decelerator (AD), a simplified antiproton source (feasibility study)''" (1995)
Retrieved 3 August 2018

Operation

Sketch of hydraulic analogon of the Antiproton Accumulator Complex

The main scope of the Antiproton Collector (AC) was to increase the antiproton

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in CERN's accelerator complex. Upgrading to the AC increased the number of available antiprotons tenfold to around antiprotons per second. The reason for this was the much larger acceptance of the AC compared to the Antiproton Accumulator (AA) alone. Additionally, several methods to compress the antiproton beams'

phase space The phase space of a physical system is the set of all possible physical states of the system when described by a given parameterization. Each possible state corresponds uniquely to a point in the phase space. For mechanical systems, the p ...

volume were applied, e.g. stochastic cooling."B. Autin: ''The CERN Antiproton Collector''" (1985)
Retrieved 3 August 2018 The antiprotons were produced by accelerating protons onto a target. The resulting antiprotons emitted by the target material had a large

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, which called for special devices to focus them. Instead of

quadrupole magnet Quadrupole magnets, abbreviated as Q-magnets, consist of groups of four magnets laid out so that in the planar multipole expansion of the field, the dipole terms cancel and where the lowest significant terms in the field equations are quadrupole. ...

s, which are conventionally used to focus particle beams, rods of solid

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with an applied high gradient magnetic field were implemented. The functionality of the Antiproton Accumulator Complex can be well understood through the analogon of a hydraulic system, which is depicted in the included picture. The tap represents the target systems that produce antiprotons. These are collected in the collector ring with a large acceptance (the funnel). The accumulator ring can be compared to a reservoir, where the antiprotons are accumulated and eventually released as even, well defined bunches.

References

External links

The History of Antimatter
*Record fo
Antiproton Collector
experiment on

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{{CERN Particle experiments CERN accelerators Particle physics facilities CERN facilities

History

Operation

See also

References

External links