The particle accelerator DESY (acronym for ''Deutsches Elektronen-Synchrotron'' or German

Electron The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

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 ...

) was the first

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 ...

of the

DESY DESY, short for Deutsches Elektronen-Synchrotron (English: ''German Electron Synchrotron''), is a national research centre for fundamental science located in Hamburg and Zeuthen near Berlin in Germany. It operates particle accelerators used to ...

research centre in

Hamburg Hamburg (, ; ), officially the Free and Hanseatic City of Hamburg,. is the List of cities in Germany by population, second-largest city in Germany after Berlin and List of cities in the European Union by population within city limits, 7th-lar ...

and the one that gave the research centre its name. The DESY synchrotron was used for research in

particle physics Particle physics or high-energy physics is the study of Elementary particle, fundamental particles and fundamental interaction, forces that constitute matter and radiation. The field also studies combinations of elementary particles up to the s ...

from 1964 to 1978 and served as a pre-accelerator for other accelerator facilities at

. Construction of the

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 ...

started in 1960. With a circumference of 300 m, it was the world's largest facility of its kind and accelerated

electron The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

s to 7.4

GeV 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 through an electric potential difference of one volt in vacuum. When us ...

. The first electrons circulated in acceleration on 25 February 1964, and research activities into elementary particles at the DESY synchrotron started in May 1964. In the experiments carried out at DESY, the electron beams were directed at fixed targets.

Research at the DESY particle accelerator

DESY first attracted international attention in 1966 with its confirmation of the theory of

quantum electrodynamics In particle physics, quantum electrodynamics (QED) is the Theory of relativity, relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quant ...

. A world-first, production of

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 ...

–

antiproton The antiproton, , (pronounced ''p-bar'') is the antiparticle of the proton. Antiprotons are stable, but they are typically short-lived, since any collision with a proton will cause both particles to be annihilated in a burst of energy. The exis ...

pairs using high-energy radiation, was also achieved at the DESY accelerator in 1966. Additionally, protons were very accurately scanned, showing that they do not have a solid nucleus. In the following decade, DESY established itself as a skills centre for developing and operating particle accelerator facilities. Before 1964 no continuous soft-x-ray radiation sources existed. In that year, research began using the

synchrotron radiation Synchrotron radiation (also known as magnetobremsstrahlung) is the electromagnetic radiation emitted when relativistic charged particles are subject to an acceleration perpendicular to their velocity (). It is produced artificially in some types ...

that occurs as a side effect of electron acceleration in the DESY ring. Synchrotron radiation was first used for

absorption spectroscopy Absorption spectroscopy is spectroscopy that involves techniques that measure the absorption of electromagnetic radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons ...

at the synchrotron in 1967. The European Molecular Biology Laboratory (EMBL) made use of this new technology's potential and 1972 established a permanent branch at DESY with the aim of analyzing the structure of biological molecules through synchrotron radiation.

Pre-accelerator and test beam facility

The particle physics experiments at the original DESY synchrotron ran until 1978. After that, it was rebuilt and upgraded several times, serving as a pre-accelerator for DESY's larger accelerator facilities starting in 1973 for the storage ring DORIS, and from 1978 mainly for

PETRA Petra (; "Rock"), originally known to its inhabitants as Raqmu (Nabataean Aramaic, Nabataean: or , *''Raqēmō''), is an ancient city and archaeological site in southern Jordan. Famous for its rock-cut architecture and water conduit systems, P ...

. After a fundamental modification to become the proton synchrotron DESY III, the facility went back into operation in 1987 together with the newly built electron synchrotron DESY II as a pre-accelerator for

HERA In ancient Greek religion, Hera (; ; in Ionic Greek, Ionic and Homeric Greek) is the goddess of marriage, women, and family, and the protector of women during childbirth. In Greek mythology, she is queen of the twelve Olympians and Mount Oly ...

. With the shutdown of HERA in 2007, the proton synchrotron DESY III was also decommissioned after 43 years of operation. Today, the DESY II electron synchrotron still serves as a pre-accelerator for

PETRA III Petra (; "Rock"), originally known to its inhabitants as Raqmu (Nabataean: or , *''Raqēmō''), is an ancient city and archaeological site in southern Jordan. Famous for its rock-cut architecture and water conduit systems, Petra is also called ...

and as a test beam facility with three beamlines used by research groups worldwide to test detector components.

References

External links

DESY
{{coord, 53, 34, 33, N, 9, 52, 46, E, region:DE-HH_type:landmark, display=title Particle accelerators Particle physics facilities Synchrotron radiation facilities Buildings and structures in Altona, Hamburg