Large Hadron Collider (LHC)

Large Hadron Collider (LHC)

The Large Hadron Collider (LHC) is the world's largest and most powerful particle collider and the world's largest machine. This was done by the European Organization in collaboration with more than 10,000 scientists and hundreds of universities and labs, along with more than 100 countries between 1998 and 2008 for nuclear research (CERN). It is located 27 kilometers (17 miles) in a tunnel and is deeper than 175 meters (574 feet) below Geneva's France-Switzerland border. Its first data-taking period was on the energy of 3.5 to 4 terenetronovolts (TeV) per beam (7 to 8 TeV total) from March 2010 to early 2013, which is about four times the previous world record for a collider and accelerator was. Later, the accelerator was taken offline and upgraded during two years. This was resumed for its second research run in early 2015, which reached 6.5 teV per beam (13 TeV total, current world record). At the end of 2018, it entered the second two year shutdown period.

The purpose of LHC is to allow physicists to test the predictions of particle physics, in which measuring the properties of Higgs boson and discovering a large family of new particles, which have been predicted by supersymmetric principles, as well as physics There are also other unresolved questions. .

The collider has four crossing points, around which seven detectors are deployed, each of which is designed for some kind of research. LHC primarily collides with proton beam, but it can also use beams of heavy ions. The lead-lead collision occurred in 2010, 2011, 2013, 2015 and 2018, proton-lead conflicts for short periods in 2013 and 2016, and a small part of the Zenon-Xenon collisions in 2017.

LHC's computing grid is a world record holder. To analyze the infrastructure of grid-based computer networks connecting 170 computing centers in 42 countries, collision data was produced at an unprecedented rate for the first collision (tens of patabytes per year). The LHC Computing Grid was the world's largest distributed computing grid by 2017 - 2012, in which 36 networked network comprised more than 170 computing features in 36 countries.

Background of Large Hadron Collider (LHC)

The word Hadron is from particles made of quarks placed together by strong particles (as atoms and molecules are simultaneously assembled by electromagnetic force). The most famous are the Baryons such as the Hadron protons and neutrons; Hadron also includes meson like lion and cawn, which were discovered during cosmic ray experiments in the late 1940s and early 1950s.

A collider is a type of particle accelerator in which the particles have two guided beams. In particle physics, the collider is used as a research tool: They accelerate the particles in relatively high kinetic energy and affect other particles. Analysis of the by-products of these conflicts gives scientists good evidence of the structure of the sub-atomic world and the rules of nature that govern it. Many of these subproducts are produced only by high-energy conflicts, and they become decay after a very short period of time. In this way, many of them are difficult or almost impossible to study in other ways.

Purpose of Large Hadron Collider (LHC)

Physicists hope that the Large Hadron Collider will help in answering some fundamental open questions in physics, interacting between the interaction between the primary objects, space and time, and especially the relationship between Quantity Mechanics and the controllers of forces Regarding basic laws general relativity.

Data from high-energy particle experiments is also required so that it can be suggested that which version of the current scientific model is more likely to be correct - specifically selecting between the standard model and the Higgs model and its predictions valid To allow and to further theoretical development. Many theorists expect new physics beyond the standard model, which emerges at the level of TEV energy, because the standard model appears to be unsatisfactory. The issues covered in LHC collisions include:

Is the Higgs system being made by breaking the electrochemical symmetry of the electric particles? It was expected that the collider experiment would display or rule the existence of the elusive Higgs boson, allowing physicists to consider whether the standard model or its Higgs options option is more likely to be correct.

Supersymmetry is the extension of standard model and poincor symmetry, which is realized in nature, which means that all known particles have supercimetric partners?

Are there additional principles, as predicted by different models, which are based on string theory, and can we detect them?

What is the nature of the dark matter visible for 27% of the mass-energy of the universe?

Other open questions that can be searched using high-energy particle collision:

It is already known that electromagnetism and weak nuclear force are different manifestations of the same force called electrocake force. LHC can clarify whether electrocoche force and strong nuclear force are equally different expressions of a universal integrated force, as predicted by various Grand Unification theories.

Why is the fourth fundamental force (gravity) so vulnerable to the magnitude more than the other three fundamental forces? See also Hierarchy Problems

Are there additional sources of quark taste mix already present within the standard model?

Why are there a clear violation of symmetry between matter and antimatter? See also CP violation

What is the nature and properties of quark-glueon plasma, it is thought that it is present in the early universe and some compact and strange astronomical objects? It will be investigated primarily by ALICE, but by heavy ion collisions in CMS, ATLAS and LHCb. First seen in 2010, the results published in 2012 confirmed the occurrence of jet mitigation in heavy ion collisions.

Design of Large Hadron Collider (LHC)

LHC is the world's largest and highest energy particle accelerator. Depending on the depth of 50 to 175 meters (164 to 574 ft), the underground of 26.7 kilometers (16.6 miles) underground is included in a circular tunnel, underground. 3.8-meter wide (12 ft) wide concrete-line tunnel, built between 1983 and 1988, was previously used in the house for the large electron-positron collider. It crosses the border between Switzerland and France at four points, most of which is in France. The ground floor buildings have auxiliary equipment such as compressors, ventilation equipment, control electronics, and refrigeration

The collider tunnel has two adjacent parallel beamline (or beam pipes), each of which has a beam, which travels in opposite directions around the ring. Beam around the ring intersects at four points, which is where the particle collision occurs. Some 1,232 bipolar magnet beams are placed on their circular path, while the extra 392 quadrangular magnet is used to keep the beam concentrated, in which the intersection has a strong quadruple magnet to maximize the possibility of reciprocal connectivity, where Two beams are crossed. Magnetization of high multiplication orders is used to fix small flaws in field geometry. Altogether, there are about 10,000 superconducting magnets installed, in which the bipolar magnets have a mass of more than 27 tons. About 96 tonnes of superfluid helium-4 is necessary to keep the magnets, which are made of copper-clad nebium-titanium, their operating temperature is at 1.9 K (1271.25 ° C), making LHC the largest cryogenic facility in the world. Helium temperature. During LHC operations, the CERN site draws about 200 MW of electric power from the French electrical grid, which for comparison, Geneva has about one-third of the city's energy consumption; The LHC accelerator and detector is about 120 MW.n plants.

Prior to injecting into the main accelerator, the particles are prepared by a series of systems which gradually increase their energy. The first system is the linear particle accelerator LINAC 2, which produces 50-MeV proton, which feeds proton synchrotron booster (PSB). There protons are accelerated to 1.4 GeV and injected into proton synchrotron (PS), where they are accelerated to 26 GeV. Ultimately, Super Proton Synchrotron (SPS) is used to increase their energy upto 450 gigas, before they are in the final ring (more than several minutes) in the main ring. Here the clusters of the protons are accumulated, accelerated (more than 20 minutes) in their extreme energy, and finally circulated for 5 to 24 hours, while the collision occurs on four intersections.

The LHC physics program is primarily based on proton-proton collisions. However, the low-running period, usually one month per year, is included in the program with heavy-ion collisions. While lighter ions are considered as well, the basic plan relates to lead ions (see a large ion collider experiment). Lead ions are accelerated by the first linear accelerator LINAC 3, and the low energy ion ring (LEIR) is used as ion storage and cooler unit. Prior to injection into LHC ring, ions are made faster by PS and SPS, where they reach the energy of 2.3 TUVs per nucleon (or 522 teas per ion), the relativist is more than the energy reached by heavy ion collider . The purpose of the heavy-ion program is to investigate the quark-glueon plasma, which was present in the early universe.

When the current energy record of 6.5 teV per day is running on a daily basis, because protons are accelerated from 450 GeV to 6.5 teV, the area of the superconducting dipole magnets will be increased from 0.54 to 7.7 teslas (T). Each of the protons has an energy of 6.5 teV, which gives the total energy of 13 TeV. On this energy the proton has a Lorentz factor of approximately 6,930 and is approximately 0.999999990 c or about 3.1 m / s (11 km / h) slow compared to the speed of light. Traveling around 26.7 km around the main ring takes less than 90 microseconds (μs) for a proton. This results in 11,245 revolutions per second for protons whether the particles are in low or high energy in the main ring, because the speed difference between these energies is beyond the fifth decimal.

Instead of continuous beam, protons are bundled together up to 2,808 clusters in flakes, each flux has 115 billion protons, so that at interconnected discrete intervals between two beams, mainly 25 nanoseconds (ns) varies There is a bunch of conflicts, from which a bunch is collision. The rate of 40 MHz. It was operated with low bunch in the first years. LHC's design brightness is 1034 cm - 2 s which is 1, which first arrived in June 2016. By 2017 this price was acquired twice.

Detectors

Seven detectors have been built in LHC, which are located in big caves excavated at the intersection points of LHC. Two of them, Atlas Experiment and Compact Moon Solenoid (CMS), are large general-purpose particle detectors. Alice and LHCB have more specific roles and the last three, TOTEM, MoEDAL and LHCf are very small and are for very specific research. Atlas and CMS experiments have discovered Higgs boson, which is a strong proof that standard models have the right mechanism to give primary particles mass.

The BBC's summary of the main detectors is:

Detector	Description
ATLAS	One of two general-purpose detectors. ATLAS studies the Higgs boson and looks for signs of new physics, including the origins of mass and extra dimensions.
CMS	The other general-purpose detector, like ATLAS, studies the Higgs boson and look for clues of new physics.
ALICE	ALICE is studying a "fluid" form of matter called quark–gluon plasma that existed shortly after the Big Bang.
LHCb	Equal amounts of matter and antimatter were created in the Big Bang. LHCb investigates what happened to the "missing" antimatter.

Computing and analysis facilities

Data created by LHC, as well as LHC-related simulations, was estimated approximately 15 petabits per year (maximum throughput not specified) - a big challenge in itself at that time.

The LHC computing grid was constructed as part of the LHC design, so that it could handle the large amount of data required for its collisions. It is an international collaborative project, initially involving a grid-based computer network infrastructure connecting 140 computing centers in 35 countries (more than 170 in 36 countries according to 2012). It was designed by CERN to handle significant amount of data produced by LHC experiments, including private fiber optic cable links and existing high-speed parts of the public Internet, from CERN to data transfer in educational institutions around the world Exist to enable The Open Science Grid is used as the primary infrastructure in the United States, and is also used as part of an interconnection federation with the LHC Computing Grid.

The distributed computing project LHC @ Home was started to support the construction and calibration of LHC. The project uses the BOINC platform, which enables anyone to enable Internet connection and computers running Mac OS X, Windows or Linux, to use the idle time of their computer to simulate how the beam pipes The particles will travel. With this information, scientists are able to determine how the magnets should be calibrated to achieve the most stable "orbit" of the beam in the ring. [51] In August 2011, another application went live (Test 4 theory), which simulates to compare actual test data to determine the level of confidence of the results.

By 2012, data of 6 quadrillion (6 x 1015) LHC proton-proton collisions was analyzed, data of LHC collision was being produced at around 25 petabits per year, and LHC Computing Grid 2012 was the world's largest computing The grid was made. More than 170 computing features in 36 countries worldwide network.

Cost for making Large Hadron Collider (LHC)

With a budget of € 7.5 billion (approximately $ 9bn or £ 6.19bn of June 2010), the LHC is one of the most expensive scientific instruments ever. The total cost of the project for Accelerator and 1.163b (SFr) is 4.6bn Swiss Franc (SFr) (approximately $ 1.1bn, € 0.8bn, or £ 0.7bn till January 2010 for CERN contributions for approximately $.

Construction of LHC was approved in 1995 with the budget of SFr 2.6bn, another SFr 210M for experiments was made. However, for cost overrun, accelerator, SFR 480M was estimated in a major review in 2001, and SFR 50M for experiments, with a reduction in CERN's budget, on completion date from 2005 to April 2007. pushed off.  Superconducting magnets were responsible for increasing the cost of SFR 180M. There were also further costs and delays to cope with the difficulties of engineering while building an underground cave for compact moon solenoid, and due to the magnet support which was insufficiently designed and their initial test (2007) And a magnet was extinguished and damaged by liquid. Helium Escape (inaugural trial, 2008) (see: Construction accidents and delays). Because the cost of electricity during summer is low, LHC usually does not work in the winter months, although the exceptions in the winter of 2009/10 and 2012/2013 are to delay the beginning of 2008 and to improve the accuracy of the measurement Were made for. New particles discovered in 2012, respectively.