DESY

The German Electron Synchrotron DESY, the Helmholtz Association is a research center for basic scientific research based in Hamburg and Zeuthen.

DESY has three main research areas:

• Development, construction and operation of particle accelerators
• Particle Physics
• Research with Photons

The research center DESY is a Foundation under civil law and is financed from public funds. Founded as the foundation "German Electron Synchrotron DESY " in Hamburg by an international treaty, the Siegfried Balke, the then Federal Minister of Nuclear Energy and Water, and the mayor of Hamburg Max Brauer signed on 18 December 1959. The DESY Foundation is a member of the Helmholtz Association of German Research Centres.

• 6.1 DESY
• 6.2 DORIS
• 6.3 PETRA 6.3.1 PETRA III

• 7.1 HERA 7.1.1 H1
• 7.1.2 ZEUS
• 7.1.3 HERMES
• 7.1.4 HERA -B

• 8.1 ILC
• 8.2 XFEL
• 8.3 CFEL
• 8.4 TESLA technology

Tasks

The task of DESY is the basic scientific research. Here, the research focuses on three main areas:

• Development, construction and operation of particle accelerators;
• Investigation of the fundamental properties of matter and forces in the context of particle physics or high energy physics;
• Research with Photons, ie synchrotron and free electron laser in ( inter alia ) physics, chemistry, biology, geology and medicine.

DESY, the science large accelerator facilities are available, which are used nationally and internationally by various institutes and universities. Particularly in the area of research with photons, the wide range of interdisciplinary research DESY is clear.

Locations

DESY has two locations. The larger site is located in Hamburg- Bahr field near the Altona public parks. On 1 January 1992 DESY was a second site in Zeuthen, southeast of Berlin, expanded. Previously there was the Institute for High Energy Physics ( IfH ), the Laboratory for High Energy Physics of the former GDR.

Budget and Finance

The research center has an annual budget of approximately € 192 million. Of this amount, approximately € 173 million for the Hamburg site, the remaining approximately € 19 million for the Zeuthen. The financing takes over 90% of the Federal Ministry of Education and Research and to 10 %, the City of Hamburg and the State of Brandenburg.

Employees and Training

Overall, DESY employs approximately 2,000 people. Approximately 1,800 people are employed in the Hamburg office and about 200 in Zeuthen. Included in these figures are over 100 apprentices in commercial and technical fields and over 100 graduate students, more than 350 graduate students and 300 young researchers who are supported by DESY.

International cooperation

DESY is firmly embedded in the national and international research community. All research projects show a high degree of internationality. More than 3,000 scientists from more than 45 nations use the DESY facilities.

" HERA model"

The construction of the collider HERA by the DESY was groundbreaking for international cooperation. HERA was the first internationally funded project in the particle physics. Prior to the construction of accelerators always be 100 % funded by the host states where there were the plants. The by leading national and international institutions involved solely in the experiments they use. The desire for the HERA accelerator facility, however, was so great that many international institutions willing declared also to build the collider contribute significantly. In total, twelve participating countries with more than 45 institutions in the construction of the plant (about 22 % of the HERA - construction costs of approximately € 700 million were acquired by foreign institutions).

Following the example of HERA many large-scale scientific projects have been jointly supported by several States in the following years. Meanwhile, the model is established and the international cooperation with the construction of the plant is very common nowadays.

Particle accelerators and equipment

The DESY accelerators emerged one after the other with the requirement of particle physicists for ever higher particle energies for improved investigation of the particle. Through the establishment of newer accelerators older accelerators were converted to pre-accelerators and dedicated synchrotron radiation sources. Dedicated sources are accelerator facilities that are optimized and used exclusively for the production of synchrotron radiation.

The development of the different systems is shown in chronological order below:

DESY

The construction of the first particle accelerator DESY ( Deutsches Elektronen -Synchrotron ), who gave his name to the research center, began in 1960. The ring accelerator at the time was the world's largest facility of its kind and could accelerate electrons to 7.4 GeV. On January 1, 1964 electrons were first accelerated in the synchrotron and included the research on elementary particles. Between 1965 and 1976 the system of particle physics research served.

Attracted international attention DESY for the first time in 1966 with his contribution to the examination of quantum electrodynamics. Results confirmed this theory. In the following decade, DESY as a competence center for the development and operation of particle accelerators.

The Photon Science began at the Research in 1964, as occurring as a side effect of accelerating electrons in the DESY synchrotron accelerator was used for measurements.

The DESY II and the proton synchrotron DESY III in 1987 and 1988 respectively taken as pre-accelerator for HERA running.

Today, DESY is used as a pre-accelerator for the synchrotron radiation source PETRA III and as a test beam for detector development.

DORIS

DORIS (double - ring memory ), built 1969-1974, was the second ring accelerator and the first storage ring at DESY. The scope of DORIS is just under 300 meters. Originally developed as an electron-positron storage ring collider experiments between electrons and their antiparticles could be carried out at energies of 3.5 GeV per particle beam in DORIS first time. In 1978, the energy of the jets was raised to 5 GeV. DORIS was used until 1992 for particle physics research.

By the proof of the " excited charmonium states" made ​​DORIS 1975 an important contribution for the detection of heavy quarks. The ARGUS detector 1987 (originally "A Russian - German - United States - Swedish Collaboration" ) of the DORIS storage ring for the first time the conversion of a B meson into its antiparticle, an anti -B meson, observed. From this it was concluded that the second- heaviest quark - the bottom- quark - can convert, under certain conditions into another quark. Furthermore followed from the observation that not yet found sixth quark - the top quark - had to have a very large mass. The top quark was finally demonstrated in 1995 for the first time in the U.S. at Fermilab.

With the establishment of the Hamburg Synchrotron Radiation Laboratory HASYLAB in 1980, originally produced by synchrotron DORIS as a by-product was also used for research. Focus was initially only a third of the operating time of DORIS for research with synchrotron radiation available, the storage ring was used from 1993 under the name DORIS III solely as a radiation source for HASYLAB and was operated up to 4.5 GeV. To get a more intense and more controllable synchrotron radiation, DORIS was equipped from 1984 with wigglers and undulators. A special magnet arrangement, the accelerated electrons could now be brought to a slalom course. Characterized the intensity of the synchrotron radiation emitted increased by many orders of magnitude compared to conventional storage ring systems. Over two decades DORIS was one of the five strongest sources in the world and was also the strongest X-ray source in Europe. On October 22, 2012 HASYLAB was separated from DORIS III. Until 2 January 2013 was still running the experiment OLYMPUS before then DORIS was shut down after nearly 40 years of operation.

PETRA

PETRA (Positron - Electron Tandem Ring Accelerator ) was built from 1975 to 1978. The accelerator was at the time of its commissioning with 2,304 meters in length the largest storage ring of its kind and is today the second largest after the HERA ring accelerator at DESY. PETRA was originally the study of elementary particles. Positrons and electrons were accelerated to 19 GeV. As one of the biggest successes is the demonstration of the gluon, the carrier particle of the strong force, at Petra in 1979.

Research at Petra led to a more intensive use of international DESY facilities. Scientists from China, England, France, Israel, Japan, the Netherlands, Norway and the USA participated in addition to numerous German colleagues at the first examinations at Petra.

In 1990, the plant was put under the name of PETRA II as a pre- protons and electrons / positrons for the new HERA particle accelerator in operation. Electrons or positrons are accelerated to 12 GeV case, protons to 40 GeV.

In March 1995, Petra II was equipped with an undulator to generate synchrotron radiation using an intensive X-ray content. Since then, PETRA II and HASYLAB served as a source of high-energy synchrotron radiation with two test measuring stations.

PETRA III

On 2 July 2007, the use of PETRA II ended as a pre-accelerator for HERA, because HERA was shut down. After the conversion of the PETRA II at PETRA III, a most brilliant light source began. For this purpose, about 300 meters were built completely new from the 2.3 miles of the ring and equipped with 14 undulators. On 16 November 2009 PETRA III was taken with 14 new beamlines in operation in the field of X-ray radiation, the plant is one of the best sources in the world. In order to increase the number of measuring stations and thus make the radiation of this light source to more accessible to users, currently building measures to expand the Halls North and East will take place. Due to the renovation work of the storage ring is opened so that the PETRA III synchrotron radiation source is not as available at the time.

HERA

HERA ( Hadron Electron Ring Accelerator ) is having a circumference of 6336 meters, the largest circular accelerator, DESY has built. The construction of the underground facility began in 1984, on 8 November 1990 the accelerator was put into operation. On 19 October 1991, the first proton -electron collision succeeded in HERA. Thus, the first experiments in 1992 could start their measurement mode. HERA was in operation until the end of June 2007.

The HERA accelerator was built in international cooperation (see " HERA model"). For construction of HERA new technologies have been developed. HERA was the first particle, wherein the superconducting magnets are installed on a large scale.

The tunnel of HERA is 10 to 25 meters below the surface and has an inner diameter of 5.2 meters. For the construction of the tunnel was the same technique used, which is otherwise used for the construction of underground tunnels. In the tunnel run two annular particle accelerator. One accelerates electrons to an energy of 27.5 GeV, and the other protons to an energy of 920 GeV. Both particle beams by flying in the opposite direction nearly the speed of light its accelerator rings about 47,000 times in one second.

In two places of the ring of the electron and the proton beam could be made ​​to collide. Either electrons or positrons on the blocks of the proton, the quarks were scattered. The products of this particle reactions, on the one hand, the scattered lepton and the other arising from the fragmentation of the proton hadrons were detected in large detectors. In addition, there are in the HERA ring two more interaction zones, in which the particles could collide with stationary targets. All four zones are housed in large underground halls, each about 1.5 km apart ( see research at HERA ).

FLASH

The free-electron laser FLASH (Free-Electron Laser in Hamburg ) is a superconducting linear accelerator with a free-electron laser radiation in the soft X-ray range. FLASH works on the SASE principle (self amplified spontaneous emission ) and is based on a 1997 built test facility for the TESLA project, which was expanded in 2003 by about 100 meters in length to approximately 260 meters. By April 2006, the facility was first called VUV -FEL (Vacuum Ultra Violet - free-electron laser). FLASH also continues to serve as a test facility for possible future superconducting linear accelerator, in particular the European XFEL and the International Linear Collider ILC. At FLASH, the technology can be continuously developed and tested.

Besides FLASH is currently (2013 ) built on FLASH II, which will use the same accelerator, but a new undulator and to offer additional measuring stations.

Further accelerators

In addition to the large plants, there are several small particle accelerator at DESY, which act mostly as a pre-accelerator for PETRA and HERA. These include the linear accelerator LINAC I ( 1964-1991 for electrons), LINAC II ( since 1969 for positrons) and LINAC III (since 1988 as a pre-accelerator for protons for HERA ).

Research

HERA

HERA was used to investigate the structure of protons from quarks and gluons and the properties of heavy quarks. HERA storage ring was the only world, could be brought into the protons and electrons and their antiparticles, positrons collide (see also Colliding Beam Experiment). At HERA the structure of protons could be examined at a much higher precision than before HERA was possible. In the years following the opening of many discoveries about the composition of protons from quarks and gluons were made.

The HERA accelerator runs large underground halls where detection devices were housed for particle collisions by four. In three of the four halls each worked an international experimental group. These independent groups developed, built and operated in many years of common work -house high complex instruments and evaluate today millions of data from particle collisions from. The fourth hall was used from 1999 to 2003 by a group of international scientists.

The following experiments were housed in the subterranean halls HERA: H1, ZEUS, HERMES and HERA -B.

H1

H1 is a universal detector for the collision of electrons and protons and is located in the HERA hall "North". He was in operation since 1992, is 12 m × 10 m × 15 m tall and weighs about 2,800 tons.

The tasks of H1 are deciphering the internal structure of the proton, the study of the strong interaction and the search for new forms of matter and for unexpected phenomena in particle physics.

H1 was able to show that two fundamental forces of nature, the electromagnetic force and the weak force, unite at high energies. At low energies, the weak force is much weaker than the electromagnetic force, which is why it is not noticeable in everyday life. At the collision energies of the particles in HERA, however, both forces are equally strong. This helped with the evidence that both forces have a common origin, the electroweak force. It was a major step towards a unification of all fundamental forces.

The particle collisions, which were measured in H1, provide information on the strength of the strong force. This could be measured for the first time in a single experiment over a large energy away the strength of the strong force. The change in strength was proven: The closer quarks are to each other, the lower is the strong force between the particles. The greater the distance between the quarks will reinforce the strong force that holds together the quarks.

ZEUS

ZEUS is similar to H1 is a universal detector for the collision of electrons and protons, and was in the HERA hall "South". He was in operation since 1992, 12 m × 11 m × 20 m tall and weighs about 3,600 tons.

The tasks of ZEUS are similar to those of the H1 detector. ZEUS and H1 complement and verify each other in their studies. All these research results of H1 must be credited to the same extent ZEUS. By the measurements of the ZEUS and H1 understanding could be considerably extended and improved the structure of the proton. The particle collisions in HERA provide at the same time according to a state that existed shortly after the Big Bang the universe. Research at the HERA accelerator, therefore, the understanding of the first moments could be expanded after the Big Bang.

HERMES

HERMES is an experiment in the HERA hall "East" and was commissioned in 1995. The longitudinally polarized electron beam at HERA has been used here to study the spin structure of nucleons. For this, the electrons are scattered at an energy of 27.5 GeV on an internal gas - target. This target and the particle detector are specifically designed in terms of spin-polarized physics. The detector is 3.50 m × 8 m × 5 m tall and weighs about 400 tons.

HERMES examined how the total spin of a proton is produced. The total spin of a proton can only explain one third of the spins of the three main constituents of the proton, the three valence quarks. HERMES was able to show that the spins of the gluons contribute a significant portion to the total spin of the proton. The spin of the many sea quarks in the proton, however, further contributes only a small part of the total spin.

HERA -B

HERA -B was an experiment in the HERA hall "West" and collected between 1999 and February 2003 data. The dimensions of the particle were 8 m × 20 m × 9 m, its weight about 1,000 tons. In HERA -B the proton beam collided in the detector with solid aluminum wires and thus generated particles, which consist of heavy quarks, including B- mesons.

B mesons are used, inter alia, to investigate the symmetry in physics. With B- mesons can examine the question of why the universe today consists almost entirely of matter, although originated in the Big Bang, both matter and antimatter in equal amounts. Later, the physicist at HERA -B focused on specific questions regarding the strong force, arising for example from heavy quarks as elementary particles in matter and how these particles react with the matter.

Meanwhile, the particle HERA -B is decommissioned. Data analysis on the physics of heavy quarks is still running. HERA -B delivered both new scientific findings as well as important results for the modern detector construction and the analysis of large amounts of data in particle physics. The findings from HERA -B were included in many other projects and help today scientists around the world.

HASYLAB

The Hamburg Synchrotron Radiation Laboratory HASYLAB at DESY was opened in 1980 and serves the research with radiation from the accelerator facilities. Two types of radiation sources are used by HASYLAB, storage rings, which produce synchrotron radiation in the operation, and linear free-electron lasers producing laser-like radiation. Here, the research spectrum of experiments ranging in, inter alia, physics, chemistry, biology, biochemistry, molecular biology, medicine, geology and material science to application-oriented research and industrial collaborations.

The first experiments with synchrotron radiation began in 1964 at the DESY accelerator ring after devices for observation of the electron beam in the accelerator with the help of synchrotron radiation had been built before. Immediately, showed the outstanding features of this new radiation source which focused very strong, intense and brief flashes of radiation delivered over a wide range. It was formed a rapidly growing group of scientists to this new radiation source. Later, the synchrotron radiation was used by the scientists from the storage ring DORIS ( since 1974) and PETRA ( since 1995).

Early 1980s had HASYLAB 15 measuring stations at the storage ring DORIS. The installation of wigglers and undulators from 1984, the radiation intensity at the measuring stations could be increased considerably. Since 1993 to the severance October 2012 the storage ring DORIS was operated solely for the production of synchrotron radiation and other experimental stations were established.

The synchrotron PETRA has been used since 1995 by HASYLAB, when Petra was not needed for HERA as a pre. Since 2009 serves PETRA III, after a two- year renovation, solely for the production of synchrotron radiation. This is one of the world's most brilliant X-ray sources for the research.

Since 2004, the free-electron laser FLASH in Hamburg as a radiation source in operation. Researchers can use the laser-like X-ray radiation from FLASH to five measuring stations for scientific experiments.

Applications of radiation at HASYLAB affect many areas of natural science. Some examples are listed below.

In 1975, the first tests of the X-ray lithography were held at DESY, later the procedure for deep X-ray lithography was developed.

In 1984, the first obtained by synchrotron Mössbauer spectrum was recorded at HASYLAB.

1985 could be elucidated by further developing the X-ray technique, the detailed structure of the cold virus.

The following year in 1986 for the first time succeeded in the attempt, with synchrotron single lattice vibrations to stimulate ( phonons) in solids. Due to the inelastic X-ray scattering ( IXS ) studies of the properties of materials could be carried out, which were previously only in nuclear reactors by neutron scattering ( INS ) is possible.

In the recent past the company OSRAM used the facilities of HASYLAB to let her examine the filaments lamps using synchrotron radiation. With the newfound knowledge of the annealing process, the durability of lamps in certain application areas could be better controlled.

At HASYLAB smallest impurities in silicon are analyzed for computer chips, the mode of action of catalysts investigated, examined the microscopic properties of materials and by illuminated protein molecules with the X-rays of synchrotron radiation.

AMANDA and IceCube

DESY, represented in particular by the Zeuthen, is involved in two research projects in astroparticle physics, the Antarctic Muon And Neutrino telescope Neutrino Detector Array ( AMANDA ) and based on it IceCube.

In international cooperation DESY scientists from Zeuthen operate the neutrino telescope AMANDA. At the South Pole Located registered AMANDA neutrino, which left its trace in the ice. Since the neutrinos react only very rarely with other particles, they can even fly through the earth. Neutrinos therefore provide information even from those areas of the universe that otherwise would be inaccessible to astronomers, such as from the interior of the sun or of stellar explosions.

Scientists from Zeuthen were instrumental in the development of the neutrino telescope AMANDA. Meanwhile, the AMANDA project IceCube was expanded. Also in this project DESY plays an important role in the production of the detector modules and data analysis.

Theory

The development of physics requires a continuous and close cooperation between theoretical physics and experimental physics. Thus, this close cooperation is possible at DESY, there are at DESY scientists who are concerned with the theoretical physics behind the experiments.

The theory department at DESY is divided into several groups, which have different issues. Special emphasis is placed in elementary particle physics and cosmology. In Zeuthen, DESY operates in the " Center for Parallel Computing " massively parallel high-performance computers that are used inter alia for calculations in theoretical particle physics.

Further projects with DESY participation

ILC

The next big project in high energy physics is the International Linear Collider ( ILC). ILC is a global project with participation of DESY for a 30 to 40 kilometer-long linear accelerator, crashing up to 1 TeV in the electron with its antiparticle, the positron, at energies. The aim of the project is to investigate central questions in particle physics and astrophysics, the nature of matter, energy, space and time, including the dark matter, dark energy and the existence of extra dimensions. Early on, all interested researchers have agreed that there should be only one plant of this size worldwide.

In August 2004, the " International Technology Recommendation Panel ITRP " has given the recommendation to build the linear accelerator based on superconducting accelerator technology, the DESY and its international partners have jointly developed as TESLA technology and successfully tested in a pilot plant in Hamburg.

XFEL

2009 started in European and international cooperation, the construction of the XFEL (X -ray Free- Electron Laser ), which is rich in a three- kilometer tunnel from the DESY site in Hamburg to Schenefeld. Particles are accelerated in the tunnel and at the end produce X-ray bursts of very high intensity and of very short duration (about 10-100 fs). In order for the XFEL is one of the most powerful sources of X-rays on the earth, many orders of magnitude stronger than X-rays from today's storage rings. He will open up completely new possibilities for research and application areas, for example, it is chemical reactions of single atoms can reproduce three-dimensional. The commissioning of the XFEL is planned for 2014.

CFEL

On 1 January 2008, the Center for Free - Electron Laser Science CFEL began its work. CFEL is a cooperation between DESY and University of Hamburg and the Max Planck Society Max Planck Society.

TESLA technology

TESLA ( TeV -Energy Superconducting Linear Accelerator ) is a project proposal in 2000, a particle accelerator such as the next generation might look like. This linear accelerator should be built in a 33 km long, lying just below the surface relative tunnel of Hamburg in the north - northwest. The superconducting TESLA technology and other insights from this project are included in both the European XFEL as well as in the International Linear Collider ( ILC).

DESY Directors

• Willibald Jentschke, founding director of DESY, Chairman of the Board 1959-1970
• Wolfgang Paul (1971-1972)
• Herwig Schopper (1973-1980)
• Volker Soergel, German physicist, 1974-1979 Chairman of the Council of the German Electron Synchrotron DESY in the Helmholtz Association, 1981-1993 Chair of the DESY Directorate, co-ordinator from 1981 to 1993 for the construction of the electron-proton storage ring HERA
• Bjørn Wiik, Norwegian physicist, 1993-1999 Chairman of the DESY Board of Directors
• Albrecht Wagner, Chairman of the DESY Board of Directors from 1999 to early 2009
• Since 2 March 2009, Helmut Dosch, formerly at the Max Planck Institute for Metals Research, Stuttgart, Chairman of the DESY Board of Directors.