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133-503: The Large Hadron Collider ( LHC ) is the world's largest and highest-energy particle accelerator . It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundreds of universities and laboratories across more than 100 countries. It lies in a tunnel 27 kilometres (17 mi) in circumference and as deep as 175 metres (574 ft) beneath

266-425: A failsafe power abort of the electrical systems powering the superconducting magnets, but had also caused an electric arc (or discharge) which damaged the integrity of the supercooled helium's enclosure and vacuum insulation, causing the coolant's temperature and pressure to rapidly rise beyond the ability of the safety systems to contain it, and leading to a temperature rise of about 100 degrees Celsius in some of

399-411: A klystron and a complex bending magnet arrangement which produces a beam of energy 6–30  MeV . The electrons can be used directly or they can be collided with a target to produce a beam of X-rays . The reliability, flexibility and accuracy of the radiation beam produced has largely supplanted the older use of cobalt-60 therapy as a treatment tool. In the circular accelerator, particles move in

532-788: A sub-alpine mountain range a short distance north of the Western Alps and mainly demarcate a long part of the French–Swiss border . While the Jura range proper (" folded Jura", Faltenjura ) is located in France and Switzerland, the range continues northeastwards through northern Switzerland and Germany as the Table Jura ("not folded Jura", Tafeljura ), which is crossed by the High Rhine . The mountain range gives its name to

665-677: A worldwide network across more than 40 countries. The LHC first went operational on 10 September 2008, but initial testing was delayed for 14 months from 19 September 2008 to 20 November 2009, following a magnet quench incident that caused extensive damage to over 50 superconducting magnets , their mountings, and the vacuum pipe . During its first run (2010–2013), the LHC collided two opposing particle beams of either protons at up to 4  teraelectronvolts (4 TeV or 0.64 microjoules ) , or lead nuclei (574 TeV per nucleus, or 2.76 TeV per nucleon ). Its first run discoveries included

798-423: A 3 km long waveguide, buried in a tunnel and powered by hundreds of large klystrons . It is still the largest linear accelerator in existence, and has been upgraded with the addition of storage rings and an electron-positron collider facility. It is also an X-ray and UV synchrotron photon source. Jura Mountains The Jura Mountains ( / ˈ dʒ ʊər ə , ˈ ʒ ʊər ə / JOOR -ə, ZHOOR -ə ) are

931-489: A Celtic word for mountains, with similar putative etymologies (e.g. * juris , "mountainous forest") still appearing in more recent non-academic publications. However, since there are no clear cognates in the surviving corpus of the Celtic languages, modern studies of Proto-Celtic and Gaulish etymology tend not to list any lemmata connected to Jura, and the name must be considered fundamentally unclear. The Jura Mountains are

1064-410: A beam, which travel in opposite directions around the ring. The beams intersect at four points around the ring, which is where the particle collisions take place. Some 1,232 dipole magnets keep the beams on their circular path (see image), while an additional 392 quadrupole magnets are used to keep the beams focused, with stronger quadrupole magnets close to the intersection points in order to maximize

1197-402: A circle until they reach enough energy. The particle track is typically bent into a circle using electromagnets . The advantage of circular accelerators over linear accelerators ( linacs ) is that the ring topology allows continuous acceleration, as the particle can transit indefinitely. Another advantage is that a circular accelerator is smaller than a linear accelerator of comparable power (i.e.

1330-536: A combined energy of 13 TeV. On 3 June 2015, the LHC started delivering physics data after almost two years offline. In the following months, it was used for proton–proton collisions, while in November, the machine switched to collisions of lead ions and in December, the usual winter shutdown started. In 2016, the machine operators focused on increasing the luminosity for proton–proton collisions. The design value

1463-553: A constant frequency by a RF accelerating power source, as the beam spirals outwards continuously. The particles are injected in the center of the magnet and are extracted at the outer edge at their maximum energy. Cyclotrons reach an energy limit because of relativistic effects whereby the particles effectively become more massive, so that their cyclotron frequency drops out of sync with the accelerating RF. Therefore, simple cyclotrons can accelerate protons only to an energy of around 15 million electron volts (15 MeV, corresponding to

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1596-431: A day, as the protons are accelerated from 450  GeV to 6.5  TeV , the field of the superconducting dipole magnets is increased from 0.54 to 7.7 teslas (T) . The protons each have an energy of 6.5 TeV, giving a total collision energy of 13 TeV. At this energy, the protons have a Lorentz factor of about 6,930 and move at about 0.999 999 990   c , or about 3.1 m/s (11 km/h) slower than

1729-679: A far province of the larger Central European uplands . The Jura range proper lies in France and Switzerland. In France, the Jura covers most of the Franche-Comté region, stretching south into the Rhône-Alpes region and north into the Grand Est region. The range reaches its highest point at the Crêt de la Neige (1,720 m (5,640 ft)), in department of Ain , 5 km west from

1862-696: A hole in the plate, the polarity is switched so that the plate now repels them and they are now accelerated by it towards the next plate. Normally a stream of "bunches" of particles are accelerated, so a carefully controlled AC voltage is applied to each plate to continuously repeat this process for each bunch. As the particles approach the speed of light the switching rate of the electric fields becomes so high that they operate at radio frequencies , and so microwave cavities are used in higher energy machines instead of simple plates. Linear accelerators are also widely used in medicine , for radiotherapy and radiosurgery . Medical grade linacs accelerate electrons using

1995-427: A linac would have to be extremely long to have the equivalent power of a circular accelerator). Depending on the energy and the particle being accelerated, circular accelerators suffer a disadvantage in that the particles emit synchrotron radiation . When any charged particle is accelerated, it emits electromagnetic radiation and secondary emissions . As a particle traveling in a circle is always accelerating towards

2128-433: A magnet quench and liquid helium escape (inaugural testing, 2008). Because electricity costs are lower during the summer, the LHC normally does not operate over the winter months, although exceptions over the 2009/10 and 2012/2013 winters were made to make up for the 2008 start-up delays and to improve precision of measurements of the new particle discovered in 2012, respectively. With the 2022 Russian invasion of Ukraine ,

2261-514: A magnetic field which is fixed in time, but with a radial variation to achieve strong focusing , allows the beam to be accelerated with a high repetition rate but in a much smaller radial spread than in the cyclotron case. Isochronous FFAs, like isochronous cyclotrons, achieve continuous beam operation, but without the need for a huge dipole bending magnet covering the entire radius of the orbits. Some new developments in FFAs are covered in. A Rhodotron

2394-434: A major centre of the watchmaking industry. The area has several cities at very high altitudes, such as La Chaux-de-Fonds , Le Locle and Sainte-Croix (renowned for its musical boxes ); however, it generally has had a marked decline in population since 1960. Both Le Locle and its geographical twin town La Chaux-de-Fonds are recognised as an UNESCO World Heritage Site for their horological and related cultural past. In

2527-519: A particle and an atomic nucleus. Beams of high-energy particles are useful for fundamental and applied research in the sciences and also in many technical and industrial fields unrelated to fundamental research. There are approximately 30,000 accelerators worldwide; of these, only about 1% are research machines with energies above 1 GeV , while about 44% are for radiotherapy , 41% for ion implantation , 9% for industrial processing and research, and 4% for biomedical and other low-energy research. For

2660-432: A reactor to produce tritium . An example of this type of machine is LANSCE at Los Alamos National Laboratory . Electrons propagating through a magnetic field emit very bright and coherent photon beams via synchrotron radiation . It has numerous uses in the study of atomic structure, chemistry, condensed matter physics, biology, and technology. A large number of synchrotron light sources exist worldwide. Examples in

2793-562: A reduction in CERN's budget, pushed the completion date from 2005 to April 2007. The superconducting magnets were responsible for SFr 180M of the cost increase. There were also further costs and delays owing to engineering difficulties encountered while building the cavern for the Compact Muon Solenoid , and also due to magnet supports which were insufficiently strongly designed and failed their initial testing (2007) and damage from

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2926-426: A shorter distance in each orbit than they would in a classical cyclotron, thus remaining in phase with the accelerating field. The advantage of the isochronous cyclotron is that it can deliver continuous beams of higher average intensity, which is useful for some applications. The main disadvantages are the size and cost of the large magnet needed, and the difficulty in achieving the high magnetic field values required at

3059-904: A special class of light sources based on synchrotron radiation that provides shorter pulses with higher temporal coherence . A specially designed FEL is the most brilliant source of x-rays in the observable universe. The most prominent examples are the LCLS in the U.S. and European XFEL in Germany. More attention is being drawn towards soft x-ray lasers, which together with pulse shortening opens up new methods for attosecond science . Apart from x-rays, FELs are used to emit terahertz light , e.g. FELIX in Nijmegen, Netherlands, TELBE in Dresden, Germany and NovoFEL in Novosibirsk, Russia. Thus there

3192-474: A speed of roughly 10% of c ), because the protons get out of phase with the driving electric field. If accelerated further, the beam would continue to spiral outward to a larger radius but the particles would no longer gain enough speed to complete the larger circle in step with the accelerating RF. To accommodate relativistic effects the magnetic field needs to be increased to higher radii as is done in isochronous cyclotrons . An example of an isochronous cyclotron

3325-649: A straight line, or circular , using magnetic fields to bend particles in a roughly circular orbit. Magnetic induction accelerators accelerate particles by induction from an increasing magnetic field, as if the particles were the secondary winding in a transformer. The increasing magnetic field creates a circulating electric field which can be configured to accelerate the particles. Induction accelerators can be either linear or circular. Linear induction accelerators utilize ferrite-loaded, non-resonant induction cavities. Each cavity can be thought of as two large washer-shaped disks connected by an outer cylindrical tube. Between

3458-452: A target or an external beam in beam "spills" typically every few seconds. Since high energy synchrotrons do most of their work on particles that are already traveling at nearly the speed of light c , the time to complete one orbit of the ring is nearly constant, as is the frequency of the RF cavity resonators used to drive the acceleration. In modern synchrotrons, the beam aperture is small and

3591-402: Is 3 km (1.9 mi) long. SLAC was originally an electron – positron collider but is now a X-ray Free-electron laser . Linear high-energy accelerators use a linear array of plates (or drift tubes) to which an alternating high-energy field is applied. As the particles approach a plate they are accelerated towards it by an opposite polarity charge applied to the plate. As they pass through

3724-405: Is a circular magnetic induction accelerator, invented by Donald Kerst in 1940 for accelerating electrons . The concept originates ultimately from Norwegian-German scientist Rolf Widerøe . These machines, like synchrotrons, use a donut-shaped ring magnet (see below) with a cyclically increasing B field, but accelerate the particles by induction from the increasing magnetic field, as if they were

3857-413: Is a great demand for electron accelerators of moderate ( GeV ) energy, high intensity and high beam quality to drive light sources. Everyday examples of particle accelerators are cathode ray tubes found in television sets and X-ray generators. These low-energy accelerators use a single pair of electrodes with a DC voltage of a few thousand volts between them. In an X-ray generator, the target itself

3990-509: Is an industrial electron accelerator first proposed in 1987 by J. Pottier of the French Atomic Energy Agency (CEA) , manufactured by Belgian company Ion Beam Applications . It accelerates electrons by recirculating them across the diameter of a cylinder-shaped radiofrequency cavity. A Rhodotron has an electron gun, which emits an electron beam that is attracted to a pillar in the center of the cavity. The pillar has holes

4123-504: Is because massive superconducting magnets require considerable magnet training to handle the high currents involved without losing their superconducting ability , and the high currents are necessary to allow a high proton energy. The "training" process involves repeatedly running the magnets with lower currents to provoke any quenches or minute movements that may result. It also takes time to cool down magnets to their operating temperature of around 1.9 K (close to absolute zero ). Over time

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4256-422: Is commonly used for sterilization. Electron beams are an on-off technology that provide a much higher dose rate than gamma or X-rays emitted by radioisotopes like cobalt-60 ( Co) or caesium-137 ( Cs). Due to the higher dose rate, less exposure time is required and polymer degradation is reduced. Because electrons carry a charge, electron beams are less penetrating than both gamma and X-rays. Historically,

4389-497: Is contained in a circular tunnel, with a circumference of 26.7 kilometres (16.6 mi), at a depth ranging from 50 to 175 metres (164 to 574 ft) underground. The variation in depth was deliberate, to reduce the amount of tunnel that lies under the Jura Mountains to avoid having to excavate a vertical access shaft there. A tunnel was chosen to avoid having to purchase expensive land on the surface and to take advantage of

4522-404: Is determined by the accelerating voltage , which is limited by electrical breakdown . Electrodynamic or electromagnetic accelerators, on the other hand, use changing electromagnetic fields (either magnetic induction or oscillating radio frequency fields) to accelerate particles. Since in these types the particles can pass through the same accelerating field multiple times, the output energy

4655-655: Is expected to continue until 2026. In addition to a higher energy the LHC is expected to reach a higher luminosity, which is expected to increase even further with the upgrade to the HL-LHC after Run 3. An initial focus of research was to investigate the possible existence of the Higgs boson , a key part of the Standard Model of physics which was predicted by theory, but had not yet been observed before due to its high mass and elusive nature. CERN scientists estimated that, if

4788-474: Is mainly based on proton–proton collisions. However, during shorter running periods, typically one month per year, heavy-ion collisions are included in the programme. While lighter ions are considered as well, the baseline scheme deals with lead ions (see A Large Ion Collider Experiment ). The lead ions are first accelerated by the linear accelerator LINAC 3 , and the Low Energy Ion Ring (LEIR)

4921-560: Is more often used for accelerators that employ oscillating rather than static electric fields. Due to the high voltage ceiling imposed by electrical discharge, in order to accelerate particles to higher energies, techniques involving dynamic fields rather than static fields are used. Electrodynamic acceleration can arise from either of two mechanisms: non-resonant magnetic induction , or resonant circuits or cavities excited by oscillating radio frequency (RF) fields. Electrodynamic accelerators can be linear , with particles accelerating in

5054-399: Is not limited by the strength of the accelerating field. This class, which was first developed in the 1920s, is the basis for most modern large-scale accelerators. Rolf Widerøe , Gustav Ising , Leó Szilárd , Max Steenbeck , and Ernest Lawrence are considered pioneers of this field, having conceived and built the first operational linear particle accelerator , the betatron , as well as

5187-571: Is one of the electrodes. A low-energy particle accelerator called an ion implanter is used in the manufacture of integrated circuits . At lower energies, beams of accelerated nuclei are also used in medicine as particle therapy , for the treatment of cancer. DC accelerator types capable of accelerating particles to speeds sufficient to cause nuclear reactions are Cockcroft–Walton generators or voltage multipliers , which convert AC to high voltage DC, or Van de Graaff generators that use static electricity carried by belts. Electron beam processing

5320-402: Is still extremely popular today, with the electrostatic accelerators greatly out-numbering any other type, they are more suited to lower energy studies owing to the practical voltage limit of about 1 MV for air insulated machines, or 30 MV when the accelerator is operated in a tank of pressurized gas with high dielectric strength , such as sulfur hexafluoride . In a tandem accelerator

5453-468: Is that the curvature of the particle trajectory is proportional to the particle charge and to the magnetic field, but inversely proportional to the (typically relativistic ) momentum . The earliest operational circular accelerators were cyclotrons , invented in 1929 by Ernest Lawrence at the University of California, Berkeley . Cyclotrons have a single pair of hollow D-shaped plates to accelerate

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5586-633: Is that the magnetic field need only be present over the actual region of the particle orbits, which is much narrower than that of the ring. (The largest cyclotron built in the US had a 184-inch-diameter (4.7 m) magnet pole, whereas the diameter of synchrotrons such as the LEP and LHC is nearly 10 km. The aperture of the two beams of the LHC is of the order of a centimeter.) The LHC contains 16 RF cavities, 1232 superconducting dipole magnets for beam steering, and 24 quadrupoles for beam focusing. Even at this size,

5719-745: Is the Lägern , situated east of the river Aare. Much of the Swiss Jura region has no historical association with Early Modern Switzerland and was incorporated as part of the Swiss Confederacy only in the 19th century. In the 20th century, a movement for Jura separatism developed which resulted in the creation of the Canton of Jura in 1979. The east of the Jura range proper separates the Rhine and Rhône basins . The northern and eastern part of

5852-604: Is the PSI Ring cyclotron in Switzerland, which provides protons at the energy of 590 MeV which corresponds to roughly 80% of the speed of light. The advantage of such a cyclotron is the maximum achievable extracted proton current which is currently 2.2 mA. The energy and current correspond to 1.3 MW beam power which is the highest of any accelerator currently existing. A classic cyclotron can be modified to increase its energy limit. The historically first approach

5985-501: Is the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory . Particle accelerators can also produce proton beams, which can produce proton-rich medical or research isotopes as opposed to the neutron-rich ones made in fission reactors ; however, recent work has shown how to make Mo , usually made in reactors, by accelerating isotopes of hydrogen, although this method still requires

6118-551: Is the linear particle accelerator Linac4 generating 160 MeV negative hydrogen ions (H ions), which feeds the Proton Synchrotron Booster (PSB). There, both electrons are stripped from the hydrogen ions leaving only the nucleus containing one proton. Protons are then accelerated to 2 GeV and injected into the Proton Synchrotron (PS), where they are accelerated to 26 GeV. Finally,

6251-405: Is to allow physicists to test the predictions of different theories of particle physics , including measuring the properties of the Higgs boson , searching for the large family of new particles predicted by supersymmetric theories , and studying other unresolved questions in particle physics . The term hadron refers to subatomic composite particles composed of quarks held together by

6384-519: Is used as an ion storage and cooler unit. The ions are then further accelerated by the PS and SPS before being injected into LHC ring, where they reach an energy of 2.3 TeV per nucleon (or 522 TeV per ion), higher than the energies reached by the Relativistic Heavy Ion Collider . The aim of the heavy-ion programme is to investigate quark–gluon plasma , which existed in the early universe . Nine detectors have been built in large caverns excavated at

6517-946: The Diamond Light Source which has been built at the Rutherford Appleton Laboratory in England or the Advanced Photon Source at Argonne National Laboratory in Illinois , USA. High-energy X-rays are useful for X-ray spectroscopy of proteins or X-ray absorption fine structure (XAFS), for example. Synchrotron radiation is more powerfully emitted by lighter particles, so these accelerators are invariably electron accelerators. Synchrotron radiation allows for better imaging as researched and developed at SLAC's SPEAR . Fixed-Field Alternating Gradient accelerators (FFA)s , in which

6650-483: The France–Switzerland border near Geneva . The first collisions were achieved in 2010 at an energy of 3.5  tera electronvolts (TeV) per beam, about four times the previous world record. The discovery of the Higgs boson at the LHC was announced in 2012. Between 2013 and 2015, the LHC was shut down and upgraded; after those upgrades it reached 6.5 TeV per beam (13.0 TeV total collision energy). At

6783-793: The French department of Jura , the Swiss canton of Jura , the Jurassic period of the geologic timescale, and the Montes Jura of the Moon . It is first attested as mons Iura in book one of Julius Caesar 's Commentarii de Bello Gallico . Strabo uses a Greek masculine form ὁ Ἰόρας ("through the Jura mountains", διὰ τοῦ Ἰόρα ὄρους ) in his Geographica (4.6.11). Based on suggestions by Ferdinand de Saussure , early celticists such as Georges Dottin tried to establish an etymon "iura-, iuri" as

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6916-635: The Jura ridgeway , a 310 km (190 mi) hiking route. Several peaks feature observation towers (e.g. Faux d'Enson , Hage ). Tourist attractions in the Swiss Jura include natural features such as the Creux du Van , lookout peaks such as the Chasseral , caves such as the Grottes de Vallorbe , as well as gorges such as Taubenloch . The Swiss Jura has been industrialized since the 18th century and became

7049-565: The Relativistic Heavy Ion Collider at Brookhaven National Laboratory in New York and the largest accelerator, the Large Hadron Collider near Geneva, Switzerland, operated by CERN . It is a collider accelerator, which can accelerate two beams of protons to an energy of 6.5  TeV and cause them to collide head-on, creating center-of-mass energies of 13 TeV. There are more than 30,000 accelerators in operation around

7182-463: The Standard Model and Higgsless model required high-energy particle experiment data to validate their predictions and allow further theoretical development. The Standard Model was completed by detection of the Higgs boson by the LHC in 2012. LHC collisions have explored other questions, including: Other open questions that may be explored using high-energy particle collisions include: The collider

7315-492: The Super Proton Synchrotron (SPS) is used to increase their energy further to 450 GeV before they are at last injected (over a period of several minutes) into the main ring. Here, the proton bunches are accumulated, accelerated (over a period of 20 minutes ) to their peak energy, and finally circulated for 5 to 24 hours while collisions occur at the four intersection points. The LHC physics programme

7448-481: The Tevatron 's previous record of 0.98 TeV per beam held for eight years. The early part of 2010 saw the continued ramp-up of beam in energies and early physics experiments towards 3.5 TeV per beam and on 30 March 2010, LHC set a new record for high-energy collisions by colliding proton beams at a combined energy level of 7 TeV. The attempt was the third that day, after two unsuccessful attempts in which

7581-435: The cyclotron . Because the target of the particle beams of early accelerators was usually the atoms of a piece of matter, with the goal being to create collisions with their nuclei in order to investigate nuclear structure, accelerators were commonly referred to as atom smashers in the 20th century. The term persists despite the fact that many modern accelerators create collisions between two subatomic particles , rather than

7714-445: The long-sought Higgs boson, several composite particles ( hadrons ) like the χ b (3P) bottomonium state, the first creation of a quark–gluon plasma, and the first observations of the very rare decay of the B s meson into two muons (B s → μμ), which challenged the validity of existing models of supersymmetry . The size of the LHC constitutes an exceptional engineering challenge with unique operational issues on account of

7847-505: The speed of light ( c ). It takes less than 90 microseconds (μs) for a proton to travel 26.7 km around the main ring. This results in 11,245 revolutions per second for protons whether the particles are at low or high energy in the main ring, since the speed difference between these energies is beyond the fifth decimal. Rather than having continuous beams, the protons are bunched together, into up to 2,808 bunches , with 115 billion protons in each bunch so that interactions between

7980-459: The strong force (analogous to the way that atoms and molecules are held together by the electromagnetic force ). The best-known hadrons are the baryons such as protons and neutrons ; hadrons also include mesons such as the pion and kaon , which were discovered during cosmic ray experiments in the late 1940s and early 1950s. A collider is a type of a particle accelerator that brings two opposing particle beams together such that

8113-522: The French Jura, the 11th-century Fort de Joux , famously remodeled and strengthened by Vauban in 1690 and subsequently by other military engineers, is situated on a natural rock outcropping in the middle of the range not far from Pontarlier . Part of the A40 autoroute crosses through a portion of the southern Jura between Bourg-en-Bresse and Bellegarde-sur-Valserine , which is known as the "Highway of

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8246-507: The Jura consists of a sequence of geologic folds, the formation of which is facilitated by an evaporitic decollement layer. The box folds are still relatively young, which is evident by the general shape of the landscape showing that they have not existed long enough to experience erosion , thus revealing recent mountain building. The Jura range offer a variety of tourist activities including hiking, cycling, downhill skiing and cross-country skiing. There are many signposted trails including

8379-484: The LHC is limited by its ability to steer the particles without them going adrift. This limit is theorized to occur at 14 TeV. However, since the particle momentum increases during acceleration, it is necessary to turn up the magnetic field B in proportion to maintain constant curvature of the orbit. In consequence, synchrotrons cannot accelerate particles continuously, as cyclotrons can, but must operate cyclically, supplying particles in bunches, which are delivered to

8512-580: The LHC the largest cryogenic facility in the world at liquid helium temperature. LHC uses 470 tonnes of Nb–Ti superconductor. During LHC operations, the CERN site draws roughly 200  MW of electrical power from the French electrical grid , which, for comparison, is about one-third the energy consumption of the city of Geneva; the LHC accelerator and detectors draw about 120 MW thereof. Each day of its operation generates 140 terabytes of data. When running an energy of 6.5 TeV per proton, once or twice

8645-574: The LHC to discover. The first physics results from the LHC, involving 284 collisions which took place in the ALICE detector, were reported on 15 December 2009. The results of the first proton–proton collisions at energies higher than Fermilab's Tevatron proton–antiproton collisions were published by the CMS collaboration in early February 2010, yielding greater-than-predicted charged-hadron production. Particle accelerator Large accelerators include

8778-555: The LHC would run through to the end of 2012, with a short break at the end of 2011 to allow for an increase in beam energy from 3.5 to 4 TeV per beam. At the end of 2012, the LHC was planned to be temporarily shut down until around 2015 to allow upgrade to a planned beam energy of 7 TeV per beam. In late 2012, in light of the July 2012 discovery of the Higgs boson, the shutdown was postponed for some weeks into early 2013, to allow additional data to be obtained before shutdown. The LHC

8911-462: The LHC's intersection points. Two of them, the ATLAS experiment and the Compact Muon Solenoid (CMS), are large general-purpose particle detectors . ALICE and LHCb have more specialized roles, while the other five— TOTEM , MoEDAL , LHCf , SND and FASER —are much smaller and are for very specialized research. The ATLAS and CMS experiments discovered the Higgs boson, which is strong evidence that

9044-504: The Large Hadron Collider will help answer some of the fundamental open questions in physics, which concern the basic laws governing the interactions and forces among elementary particles and the deep structure of space and time, particularly the interrelation between quantum mechanics and general relativity . These high-energy particle experiments can provide data to support different scientific models. For example,

9177-558: The Proton Synchrotron Booster starting on 2 June 2014, the final interconnection between magnets completing and the Proton Synchrotron circulating particles on 18 June 2014, and the first section of the main LHC supermagnet system reaching operating temperature of 1.9 K (−271.25 °C), a few days later. Due to the slow progress with "training" the superconducting magnets, it was decided to start

9310-746: The Saône ca. 140 km (87 mi) north of the French city of Lyon . In Lyon, the Saône joins the Rhône. While the Rhine flows into the North Sea , the Rhône flows into the Mediterranean Sea . Northeast, the Jura range proper (known as "folded Jura", Faltenjura ) is continued as the Table Jura ( Tafeljura ). The Table Jura ranges (from southwest to northeast) across the Swiss cantons of Basel-Landschaft , Aargau , and Schaffhausen ( Randen ), and

9443-608: The Standard Model has the correct mechanism of giving mass to elementary particles. Data produced by LHC, as well as LHC-related simulation, were estimated at 200 petabytes per year. The LHC Computing Grid was constructed as part of the LHC design, to handle the massive amounts of data expected for its collisions. It is an international collaborative project that consists of a grid-based computer network infrastructure initially connecting 140 computing centres in 35 countries (over 170 in more than 40 countries as of 2012). It

9576-469: The Standard Model was correct, the LHC would produce several Higgs bosons every minute, allowing physicists to finally confirm or disprove the Higgs boson's existence. In addition, the LHC allowed the search for supersymmetric particles and other hypothetical particles as possible unknown areas of physics. Some extensions of the Standard Model predict additional particles, such as the heavy W' and Z' gauge bosons , which are also estimated to be within reach of

9709-526: The Swiss border of the canton of Geneva , and finds its southern terminus in the northwestern part of the department of Savoie . The north end of the Jura extends into the southern tip of Alsace ( Sundgau ). Roughly 1,600 km (600 sq mi) of the mountain range in France is protected by the Jura Mountains Regional Natural Park . The Swiss Jura is one of the three distinct geographical regions of Switzerland,

9842-609: The Tevatron, LEP , and LHC may deliver the particle bunches into storage rings of magnets with a constant magnetic field, where they can continue to orbit for long periods for experimentation or further acceleration. The highest-energy machines such as the Tevatron and LHC are actually accelerator complexes, with a cascade of specialized elements in series, including linear accelerators for initial beam creation, one or more low energy synchrotrons to reach intermediate energy, storage rings where beams can be accumulated or "cooled" (reducing

9975-687: The U.S. are SSRL at SLAC National Accelerator Laboratory , APS at Argonne National Laboratory, ALS at Lawrence Berkeley National Laboratory , and NSLS-II at Brookhaven National Laboratory . In Europe, there are MAX IV in Lund, Sweden, BESSY in Berlin, Germany, Diamond in Oxfordshire, UK, ESRF in Grenoble , France, the latter has been used to extract detailed 3-dimensional images of insects trapped in amber. Free-electron lasers (FELs) are

10108-543: The Ukrainian contribution to CERN for 2022 to the amount already remitted to the Organization, thereby waiving the second installment of the contribution. In both of its runs (2010 to 2012 and 2015), the LHC was initially run at energies below its planned operating energy, and ramped up to just 2 x 4 TeV energy on its first run and 2 x 6.5 TeV on its second run, below the design energy of 2 x 7 TeV. This

10241-401: The accelerator and 1.16bn (SFr) (about $ 1.1bn, €0.8bn, or £0.7bn as of January 2010) for the CERN contribution to the experiments. The construction of LHC was approved in 1995 with a budget of SFr 2.6bn, with another SFr 210M toward the experiments. However, cost overruns, estimated in a major review in 2001 at around SFr 480M for the accelerator, and SFr 50M for the experiments, along with

10374-426: The affected magnets. Energy stored in the superconducting magnets and electrical noise induced in other quench detectors also played a role in the rapid heating. Around two tonnes of liquid helium escaped explosively before detectors triggered an emergency stop, and a further four tonnes leaked at lower pressure in the aftermath. A total of 53 magnets were damaged in the incident and were repaired or replaced during

10507-571: The amount of energy stored in the magnets and the beams. While operating, the total energy stored in the magnets is 10 GJ (2,400 kilograms of TNT) and the total energy carried by the two beams reaches 724 MJ (173 kilograms of TNT). Loss of only one ten-millionth part (10) of the beam is sufficient to quench a superconducting magnet, while each of the two beam dumps must absorb 362 MJ (87 kilograms of TNT). These energies are carried by very little matter: under nominal operating conditions (2,808 bunches per beam, 1.15×10 protons per bunch),

10640-494: The beam is handled independently by specialized quadrupole magnets , while the acceleration itself is accomplished in separate RF sections, rather similar to short linear accelerators. Also, there is no necessity that cyclic machines be circular, but rather the beam pipe may have straight sections between magnets where beams may collide, be cooled, etc. This has developed into an entire separate subject, called "beam physics" or "beam optics". More complex modern synchrotrons such as

10773-466: The beam pipes contain 1.0×10 gram of hydrogen, which, in standard conditions for temperature and pressure , would fill the volume of one grain of fine sand. With a budget of €7.5 billion (about $ 9bn or £6.19bn as of June 2010), the LHC is one of the most expensive scientific instruments ever built. The total cost of the project is expected to be of the order of 4.6bn Swiss francs (SFr) (about $ 4.4bn, €3.1bn, or £2.8bn as of January 2010) for

10906-404: The bending magnets were upgraded to safely handle the current required for 7 TeV per beam (14 TeV collision energy). However, the bending magnets were only trained to handle up to 6.5 TeV per beam (13 TeV collision energy), which became the operating energy for 2015 to 2018. The energy was first reached on 10 April 2015. The upgrades culminated in colliding protons together with

11039-460: The center of the circle, it continuously radiates towards the tangent of the circle. This radiation is called synchrotron light and depends highly on the mass of the accelerating particle. For this reason, many high energy electron accelerators are linacs. Certain accelerators ( synchrotrons ) are however built specially for producing synchrotron light ( X-rays ). Since the special theory of relativity requires that matter always travels slower than

11172-461: The chances of interaction where the two beams cross. Magnets of higher multipole orders are used to correct smaller imperfections in the field geometry. In total, about 10,000 superconducting magnets are installed, with the dipole magnets having a mass of over 27 tonnes. About 96 tonnes of superfluid helium-4 is needed to keep the magnets, made of copper-clad niobium-titanium , at their operating temperature of 1.9 K (−271.25 °C), making

11305-410: The damage caused by the quench incident, along with two further vacuum leaks identified in July 2009; this pushed the start of operations to November of that year. On 20 November 2009, low-energy beams circulated in the tunnel for the first time since the incident, and shortly after, on 30 November, the LHC achieved 1.18 TeV per beam to become the world's highest-energy particle accelerator, beating

11438-613: The disks is a ferrite toroid. A voltage pulse applied between the two disks causes an increasing magnetic field which inductively couples power into the charged particle beam. The linear induction accelerator was invented by Christofilos in the 1960s. Linear induction accelerators are capable of accelerating very high beam currents (>1000 A) in a single short pulse. They have been used to generate X-rays for flash radiography (e.g. DARHT at LANL ), and have been considered as particle injectors for magnetic confinement fusion and as drivers for free electron lasers . The Betatron

11571-435: The electrons can pass through. The electron beam passes through the pillar via one of these holes and then travels through a hole in the wall of the cavity, and meets a bending magnet, the beam is then bent and sent back into the cavity, to another hole in the pillar, the electrons then again go across the pillar and pass though another part of the wall of the cavity and into another bending magnet, and so on, gradually increasing

11704-499: The electrons moving at nearly the speed of light in a relatively small radius orbit. In a linear particle accelerator (linac), particles are accelerated in a straight line with a target of interest at one end. They are often used to provide an initial low-energy kick to particles before they are injected into circular accelerators. The longest linac in the world is the Stanford Linear Accelerator , SLAC, which

11837-403: The end of 2008. However, owing to the delay caused by the incident, the collider was not operational until November 2009. Despite the delay, LHC was officially inaugurated on 21 October 2008, in the presence of political leaders, science ministers from CERN's 20 Member States, CERN officials, and members of the worldwide scientific community. Most of 2009 was spent on repairs and reviews from

11970-529: The end of 2018, it was shut down for maintenance and further upgrades, reopened over three years later in April 2022. The collider has four crossing points where the accelerated particles collide. Nine detectors , each designed to detect different phenomena, are positioned around the crossing points. The LHC primarily collides proton beams, but it can also accelerate beams of heavy ions , such as in lead –lead collisions and proton –lead collisions. The LHC's goal

12103-461: The energy of the beam until it is allowed to exit the cavity for use. The cylinder and pillar may be lined with copper on the inside. Ernest Lawrence's first cyclotron was a mere 4 inches (100 mm) in diameter. Later, in 1939, he built a machine with a 60-inch diameter pole face, and planned one with a 184-inch diameter in 1942, which was, however, taken over for World War II -related work connected with uranium isotope separation ; after

12236-409: The first accelerators used simple technology of a single static high voltage to accelerate charged particles. The charged particle was accelerated through an evacuated tube with an electrode at either end, with the static potential across it. Since the particle passed only once through the potential difference, the output energy was limited to the accelerating voltage of the machine. While this method

12369-401: The luminosity by a factor of 10. LS2 ended in April 2022. The Long Shutdown 3 (LS3) in the 2020s will take place before the HL-LHC project is done. LHC became operational again on 22 April 2022 with a new maximum beam energy of 6.8 TeV (13.6 TeV collision energy), which was first achieved on 25 April. It officially commenced its run 3 physics season on 5 July 2022. This round

12502-468: The magnet "beds in" and ceases to quench at these lesser currents and can handle the full design current without quenching; CERN media describe the magnets as "shaking out" the unavoidable tiny manufacturing imperfections in their crystals and positions that had initially impaired their ability to handle their planned currents. The magnets, over time and with training, gradually become able to handle their full planned currents without quenching. The first beam

12635-411: The magnet aperture required and permitting tighter focusing; see beam cooling ), and a last large ring for final acceleration and experimentation. Circular electron accelerators fell somewhat out of favor for particle physics around the time that SLAC 's linear particle accelerator was constructed, because their synchrotron losses were considered economically prohibitive and because their beam intensity

12768-412: The magnetic field does not cover the entire area of the particle orbit as it does for a cyclotron, so several necessary functions can be separated. Instead of one huge magnet, one has a line of hundreds of bending magnets, enclosing (or enclosed by) vacuum connecting pipes. The design of synchrotrons was revolutionized in the early 1950s with the discovery of the strong focusing concept. The focusing of

12901-481: The most basic inquiries into the dynamics and structure of matter, space, and time, physicists seek the simplest kinds of interactions at the highest possible energies. These typically entail particle energies of many GeV , and interactions of the simplest kinds of particles: leptons (e.g. electrons and positrons ) and quarks for the matter, or photons and gluons for the field quanta . Since isolated quarks are experimentally unavailable due to color confinement ,

13034-450: The most stable "orbit" of the beams in the ring. In August 2011, a second application (Test4Theory) went live which performs simulations against which to compare actual test data, to determine confidence levels of the results. By 2012, data from over 6 quadrillion ( 6 × 10 ) LHC proton–proton collisions had been analysed. The LHC Computing Grid had become the world's largest computing grid in 2012, comprising over 170 computing facilities in

13167-517: The need for a huge magnet of large radius and constant field over the larger orbit demanded by high energy. The second approach to the problem of accelerating relativistic particles is the isochronous cyclotron . In such a structure, the accelerating field's frequency (and the cyclotron resonance frequency) is kept constant for all energies by shaping the magnet poles so to increase magnetic field with radius. Thus, all particles get accelerated in isochronous time intervals. Higher energy particles travel

13300-576: The others being the Swiss plateau and the Swiss Alps . Most of the range covers the western border with France. In Switzerland, the Jura Mountains extend over an area covering (from northeast to southwest) the cantons of Zurich , Aargau , Basel-Landschaft , Solothurn , Jura , Bern (i.e., Bernese Jura ), Neuchâtel , Vaud , and Geneva . The easternmost mountain of the Jura range proper

13433-455: The outer edge of the structure. Synchrocyclotrons have not been built since the isochronous cyclotron was developed. To reach still higher energies, with relativistic mass approaching or exceeding the rest mass of the particles (for protons, billions of electron volts or GeV ), it is necessary to use a synchrotron . This is an accelerator in which the particles are accelerated in a ring of constant radius. An immediate advantage over cyclotrons

13566-559: The participation of Russians with CERN was called into question. About 8% of the workforce are of Russian nationality. In June 2022, CERN said the governing council "intends to terminate" CERN's cooperation agreements with Belarus and Russia when they expire, respectively in June and December 2024. CERN said it would monitor developments in Ukraine and remains prepared to take additional steps as warranted. CERN further said that it would reduce

13699-412: The particles and a single large dipole magnet to bend their path into a circular orbit. It is a characteristic property of charged particles in a uniform and constant magnetic field B that they orbit with a constant period, at a frequency called the cyclotron frequency , so long as their speed is small compared to the speed of light c . This means that the accelerating D's of a cyclotron can be driven at

13832-576: The particles collide. In particle physics , colliders, though harder to construct, are a powerful research tool because they reach a much higher center of mass energy than fixed target setups. Analysis of the byproducts of these collisions gives scientists good evidence of the structure of the subatomic world and the laws of nature governing it. Many of these byproducts are produced only by high-energy collisions, and they decay after very short periods of time. Thus many of them are hard or nearly impossible to study in other ways. Many physicists hope that

13965-449: The potential is used twice to accelerate the particles, by reversing the charge of the particles while they are inside the terminal. This is possible with the acceleration of atomic nuclei by using anions (negatively charged ions ), and then passing the beam through a thin foil to strip electrons off the anions inside the high voltage terminal, converting them to cations (positively charged ions), which are accelerated again as they leave

14098-472: The protons had to be "dumped" from the collider and new beams had to be injected. This also marked the start of the main research programme. The first proton run ended on 4 November 2010. A run with lead ions started on 8 November 2010, and ended on 6 December 2010, allowing the ALICE experiment to study matter under extreme conditions similar to those shortly after the Big Bang. CERN originally planned that

14231-565: The protons travelled the full length of the collider. It took less than one hour to guide the stream of particles around its inaugural circuit. CERN next successfully sent a beam of protons in an anticlockwise direction, taking slightly longer at one and a half hours owing to a problem with the cryogenics , with the full circuit being completed at 14:59. On 19 September 2008, a magnet quench occurred in about 100 bending magnets in sectors 3 and 4, where an electrical fault vented about six tonnes of liquid helium (the magnets' cryogenic coolant) into

14364-486: The range drains towards the Rhine river and its tributaries Aare and Ill , whereas the western and southern parts drain towards the Rhône river and its (sub)tributaries Doubs , Saône , and Ain . Initially the river Doubs (a subtributary of the Rhône) flows about 100 km (62 mi) northeast, briefly venturing into Switzerland, then changing direction and flowing about 170 km (110 mi) southwest before joining

14497-457: The second run with a lower energy of 6.5 TeV per beam, corresponding to a current in the magnet of 11,000 amperes . The first of the main LHC magnets were reported to have been successfully trained by 9 December 2014, while training the other magnet sectors was finished in March 2015. On 5 April 2015, the LHC restarted after a two-year break, during which the electrical connectors between

14630-434: The secondary winding in a transformer, due to the changing magnetic flux through the orbit. Achieving constant orbital radius while supplying the proper accelerating electric field requires that the magnetic flux linking the orbit be somewhat independent of the magnetic field on the orbit, bending the particles into a constant radius curve. These machines have in practice been limited by the large radiative losses suffered by

14763-697: The shielding against background radiation that the Earth's crust provides. The 3.8-metre (12 ft) wide concrete-lined tunnel, constructed between 1983 and 1988, was formerly used to house the Large Electron–Positron Collider . The tunnel crosses the border between Switzerland and France at four points, with most of it in France. Surface buildings hold ancillary equipment such as compressors, ventilation equipment, control electronics and refrigeration plants. The collider tunnel contains two adjacent parallel beamlines (or beam pipes ) each containing

14896-571: The simplest available experiments involve the interactions of, first, leptons with each other, and second, of leptons with nucleons , which are composed of quarks and gluons. To study the collisions of quarks with each other, scientists resort to collisions of nucleons, which at high energy may be usefully considered as essentially 2-body interactions of the quarks and gluons of which they are composed. This elementary particle physicists tend to use machines creating beams of electrons, positrons, protons, and antiprotons , interacting with each other or with

15029-405: The simplest nuclei (e.g., hydrogen or deuterium ) at the highest possible energies, generally hundreds of GeV or more. The largest and highest-energy particle accelerator used for elementary particle physics is the Large Hadron Collider (LHC) at CERN , operating since 2009. Nuclear physicists and cosmologists may use beams of bare atomic nuclei , stripped of electrons, to investigate

15162-538: The southern German states of Baden-Württemberg and Bavaria (as Klettgau Jura, Baar Jura , and the Swabian and Franconian plateaus). The range is built up vertically while decreasing in size laterally (along a rough northwest–southeast line). This deformation accommodates the compression from alpine folding as the main Alpine orogenic front moves roughly northwards. The deformation becomes less pervasive away from

15295-426: The speed of light in vacuum , in high-energy accelerators, as the energy increases the particle speed approaches the speed of light as a limit, but never attains it. Therefore, particle physicists do not generally think in terms of speed, but rather in terms of a particle's energy or momentum , usually measured in electron volts (eV). An important principle for circular accelerators, and particle beams in general,

15428-471: The structure, interactions, and properties of the nuclei themselves, and of condensed matter at extremely high temperatures and densities, such as might have occurred in the first moments of the Big Bang . These investigations often involve collisions of heavy nuclei – of atoms like iron or gold  – at energies of several GeV per nucleon . The largest such particle accelerator

15561-507: The terminal. The two main types of electrostatic accelerator are the Cockcroft–Walton accelerator , which uses a diode-capacitor voltage multiplier to produce high voltage, and the Van de Graaff accelerator , which uses a moving fabric belt to carry charge to the high voltage electrode. Although electrostatic accelerators accelerate particles along a straight line, the term linear accelerator

15694-437: The time needed to warm up the affected sectors and then cool them back down to operating temperature. CERN released an interim technical report and preliminary analysis of the incident on 15 and 16 October 2008 respectively, and a more detailed report on 5 December 2008. The analysis of the incident by CERN confirmed that an electrical fault had indeed been the cause. The faulty electrical connection had led (correctly) to

15827-400: The tunnel. The escaping vapour expanded with explosive force, damaging 53 superconducting magnets and their mountings, and contaminating the vacuum pipe, which also lost vacuum conditions. Shortly after the incident, CERN reported that the most likely cause of the problem was a faulty electrical connection between two magnets. It estimated that repairs would take at least two months, owing to

15960-472: The two beams take place at discrete intervals, mainly 25 nanoseconds (ns) apart, providing a bunch collision rate of 40 MHz. It was operated with fewer bunches in the first years. The design luminosity of the LHC is 10 cms, which was first reached in June 2016. By 2017, twice this value was achieved. Before being injected into the main accelerator, the particles are prepared by a series of systems that successively increase their energy. The first system

16093-573: The war it continued in service for research and medicine over many years. The first large proton synchrotron was the Cosmotron at Brookhaven National Laboratory , which accelerated protons to about 3  GeV (1953–1968). The Bevatron at Berkeley, completed in 1954, was specifically designed to accelerate protons to enough energy to create antiprotons , and verify the particle–antiparticle symmetry of nature, then only theorized. The Alternating Gradient Synchrotron (AGS) at Brookhaven (1960–)

16226-425: The winter shutdown. This accident was thoroughly discussed in a 22 February 2010 Superconductor Science and Technology article by CERN physicist Lucio Rossi . In the original schedule for LHC commissioning, the first "modest" high-energy collisions at a centre-of-mass energy of 900 GeV were expected to take place before the end of September 2008, and the LHC was expected to be operating at 10 TeV by

16359-476: The world. There are two basic classes of accelerators: electrostatic and electrodynamic (or electromagnetic) accelerators. Electrostatic particle accelerators use static electric fields to accelerate particles. The most common types are the Cockcroft–Walton generator and the Van de Graaff generator . A small-scale example of this class is the cathode-ray tube in an ordinary old television set. The achievable kinetic energy for particles in these devices

16492-663: The younger, more active Alpine mountain building. The geologic folds comprise three major bands ( lithological units) of building that date from three epochs : the Lias ( Early Jurassic ), the Dogger ( Middle Jurassic ) and the Malm ( Late Jurassic ) geologic periods . Each era of folding reveals effects of previously shallow marine environments as evidenced by beds with carbonate sequences, containing abundant bioclasts and oolitic divisions between layers (called horizons). Structurally,

16625-423: Was circulated through the collider on the morning of 10 September 2008. CERN successfully fired the protons around the tunnel in stages, three kilometres at a time. The particles were fired in a clockwise direction into the accelerator and successfully steered around it at 10:28 local time. The LHC successfully completed its major test: after a series of trial runs, two white dots flashed on a computer screen showing

16758-482: Was designed by CERN to handle the significant volume of data produced by LHC experiments, incorporating both private fibre optic cable links and existing high-speed portions of the public Internet to enable data transfer from CERN to academic institutions around the world. The LHC Computing Grid consists of global federations across Europe, Asia Pacific and the Americas. The distributed computing project LHC@home

16891-413: Was first reached 29 June, and further improvements increased the collision rate to 40% above the design value. The total number of collisions in 2016 exceeded the number from Run 1 – at a higher energy per collision. The proton–proton run was followed by four weeks of proton–lead collisions. In 2017, the luminosity was increased further and reached twice the design value. The total number of collisions

17024-501: Was higher than in 2016 as well. The 2018 physics run began on 17 April and stopped on 3 December, including four weeks of lead–lead collisions. Long Shutdown 2 (LS2) started on 10 December 2018. The LHC and the whole CERN accelerator complex was maintained and upgraded. The goal of the upgrades was to implement the High Luminosity Large Hadron Collider (HL-LHC) project that will increase

17157-648: Was lower than for the unpulsed linear machines. The Cornell Electron Synchrotron , built at low cost in the late 1970s, was the first in a series of high-energy circular electron accelerators built for fundamental particle physics, the last being LEP , built at CERN, which was used from 1989 until 2000. A large number of electron synchrotrons have been built in the past two decades, as part of synchrotron light sources that emit ultraviolet light and X rays; see below. Some circular accelerators have been built to deliberately generate radiation (called synchrotron light ) as X-rays also called synchrotron radiation, for example

17290-544: Was shut down on 13 February 2013 for its two-year upgrade called Long Shutdown 1 (LS1), which was to touch on many aspects of the LHC: enabling collisions at 14 TeV, enhancing its detectors and pre-accelerators (the Proton Synchrotron and Super Proton Synchrotron), as well as replacing its ventilation system and 100 km (62 mi) of cabling impaired by high-energy collisions from its first run. The upgraded collider began its long start-up and testing process in June 2014, with

17423-454: Was started to support the construction and calibration of the LHC. The project uses the BOINC platform, enabling anybody with an Internet connection and a computer running Mac OS X , Windows or Linux to use their computer's idle time to simulate how particles will travel in the beam pipes. With this information, the scientists are able to determine how the magnets should be calibrated to gain

17556-414: Was the synchrocyclotron , which accelerates the particles in bunches. It uses a constant magnetic field B {\displaystyle B} , but reduces the accelerating field's frequency so as to keep the particles in step as they spiral outward, matching their mass-dependent cyclotron resonance frequency. This approach suffers from low average beam intensity due to the bunching, and again from

17689-502: Was the first large synchrotron with alternating gradient, " strong focusing " magnets, which greatly reduced the required aperture of the beam, and correspondingly the size and cost of the bending magnets. The Proton Synchrotron , built at CERN (1959–), was the first major European particle accelerator and generally similar to the AGS. The Stanford Linear Accelerator , SLAC, became operational in 1966, accelerating electrons to 30 GeV in

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