A proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and a mass less than that of a neutron. Protons and neutrons, each with masses of one atomic mass unit, are collectively referred to as "nucleons". One or more protons are present in the nucleus of every atom; the number of protons in the nucleus is the defining property of an element, is referred to as the atomic number. Since each element has a unique number of protons, each element has its own unique atomic number; the word proton is Greek for "first", this name was given to the hydrogen nucleus by Ernest Rutherford in 1920. In previous years, Rutherford had discovered that the hydrogen nucleus could be extracted from the nuclei of nitrogen by atomic collisions. Protons were therefore a candidate to be a fundamental particle, hence a building block of nitrogen and all other heavier atomic nuclei. In the modern Standard Model of particle physics, protons are hadrons, like neutrons, the other nucleon, are composed of three quarks.
Although protons were considered fundamental or elementary particles, they are now known to be composed of three valence quarks: two up quarks of charge +2/3e and one down quark of charge –1/3e. The rest masses of quarks contribute only about 1% of a proton's mass, however; the remainder of a proton's mass is due to quantum chromodynamics binding energy, which includes the kinetic energy of the quarks and the energy of the gluon fields that bind the quarks together. Because protons are not fundamental particles, they possess a physical size, though not a definite one. At sufficiently low temperatures, free protons will bind to electrons. However, the character of such bound protons does not change, they remain protons. A fast proton moving through matter will slow by interactions with electrons and nuclei, until it is captured by the electron cloud of an atom; the result is a protonated atom, a chemical compound of hydrogen. In vacuum, when free electrons are present, a sufficiently slow proton may pick up a single free electron, becoming a neutral hydrogen atom, chemically a free radical.
Such "free hydrogen atoms" tend to react chemically with many other types of atoms at sufficiently low energies. When free hydrogen atoms react with each other, they form neutral hydrogen molecules, which are the most common molecular component of molecular clouds in interstellar space. Protons are composed of three valence quarks, making them baryons; the two up quarks and one down quark of a proton are held together by the strong force, mediated by gluons. A modern perspective has a proton composed of the valence quarks, the gluons, transitory pairs of sea quarks. Protons have a positive charge distribution which decays exponentially, with a mean square radius of about 0.8 fm. Protons and neutrons are both nucleons, which may be bound together by the nuclear force to form atomic nuclei; the nucleus of the most common isotope of the hydrogen atom is a lone proton. The nuclei of the heavy hydrogen isotopes deuterium and tritium contain one proton bound to one and two neutrons, respectively. All other types of atomic nuclei are composed of two or more protons and various numbers of neutrons.
The concept of a hydrogen-like particle as a constituent of other atoms was developed over a long period. As early as 1815, William Prout proposed that all atoms are composed of hydrogen atoms, based on a simplistic interpretation of early values of atomic weights, disproved when more accurate values were measured. In 1886, Eugen Goldstein discovered canal rays and showed that they were positively charged particles produced from gases. However, since particles from different gases had different values of charge-to-mass ratio, they could not be identified with a single particle, unlike the negative electrons discovered by J. J. Thomson. Wilhelm Wien in 1898 identified the hydrogen ion as particle with highest charge-to-mass ratio in ionized gases. Following the discovery of the atomic nucleus by Ernest Rutherford in 1911, Antonius van den Broek proposed that the place of each element in the periodic table is equal to its nuclear charge; this was confirmed experimentally by Henry Moseley in 1913 using X-ray spectra.
In 1917, Rutherford proved that the hydrogen nucleus is present in other nuclei, a result described as the discovery of protons. Rutherford had earlier learned to produce hydrogen nuclei as a type of radiation produced as a product of the impact of alpha particles on nitrogen gas, recognize them by their unique penetration signature in air and their appearance in scintillation detectors; these experiments were begun when Rutherford had noticed that, when alpha particles were shot into air, his scintillation detectors showed the signatures of typical hydrogen nuclei as a product. After experimentation Rutherford traced the reaction to the nitrogen in air, found that when alphas were produced into pure nitrogen gas, the effect was larger. Rutherford determined that this hydrogen could have come only from the nitrogen, therefore nitrogen must contain hydrogen nuclei. One hydrogen nucleus was being knocked off by the impact of the alpha particle, producing oxygen-17 in the process; this was 14N + α → 17O + p.
(This reaction wo
Ernest Orlando Lawrence was a pioneering American nuclear scientist and winner of the Nobel Prize in Physics in 1939 for his invention of the cyclotron. He is known for his work on uranium-isotope separation for the Manhattan Project, as well as for founding the Lawrence Berkeley National Laboratory and the Lawrence Livermore National Laboratory. A graduate of the University of South Dakota and University of Minnesota, Lawrence obtained a PhD in physics at Yale in 1925. In 1928, he was hired as an associate professor of physics at the University of California, becoming the youngest full professor there two years later. In its library one evening, Lawrence was intrigued by a diagram of an accelerator that produced high-energy particles, he contemplated how it could be made compact, came up with an idea for a circular accelerating chamber between the poles of an electromagnet. The result was the first cyclotron. Lawrence went on to build a series of larger and more expensive cyclotrons, his Radiation Laboratory became an official department of the University of California in 1936, with Lawrence as its director.
In addition to the use of the cyclotron for physics, Lawrence supported its use in research into medical uses of radioisotopes. During World War II, Lawrence developed electromagnetic isotope separation at the Radiation Laboratory, it used devices known as calutrons, a hybrid of the standard laboratory mass spectrometer and cyclotron. A huge electromagnetic separation plant was built at Oak Ridge, which came to be called Y-12; the process was inefficient. After the war, Lawrence campaigned extensively for government sponsorship of large scientific programs, was a forceful advocate of "Big Science", with its requirements for big machines and big money. Lawrence backed Edward Teller's campaign for a second nuclear weapons laboratory, which Lawrence located in Livermore, California. After his death, the Regents of the University of California renamed the Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory after him. Chemical element number 103 was named lawrencium in his honor after its discovery at Berkeley in 1961.
Ernest Orlando Lawrence was born in Canton, South Dakota on August 8, 1901. His parents, Carl Gustavus and Gunda Lawrence, were both the offspring of Norwegian immigrants who had met while teaching at the high school in Canton, where his father was the superintendent of schools, he had a younger brother, John H. Lawrence, who would become a physician, was a pioneer in the field of nuclear medicine. Growing up, his best friend was Merle Tuve, who would go on to become a accomplished physicist. Lawrence attended the public schools of Canton and Pierre enrolled at St. Olaf College in Northfield, but transferred after a year to the University of South Dakota in Vermillion, he completed his bachelor's degree in chemistry in 1922, his Master of Arts degree in physics from the University of Minnesota in 1923 under the supervision of William Francis Gray Swann. For his master's thesis, Lawrence built an experimental apparatus that rotated an ellipsoid through a magnetic field. Lawrence followed Swann to the University of Chicago, to Yale University in New Haven, where Lawrence completed his Doctor of Philosophy degree in physics in 1925 as a Sloane Fellow, writing his doctoral thesis on the photoelectric effect in potassium vapor.
He was elected a member of Sigma Xi, and, on Swann's recommendation, received a National Research Council fellowship. Instead of using it to travel to Europe, as was customary at the time, he remained at Yale University with Swann as a researcher. With Jesse Beams from the University of Virginia, Lawrence continued to research the photoelectric effect, they showed that photoelectrons appeared within 2 x 10−9 seconds of the photons striking the photoelectric surface—close to the limit of measurement at the time. Reducing the emission time by switching the light source on and off made the spectrum of energy emitted broader, in conformance with Werner Heisenberg's uncertainty principle. In 1926 and 1927, Lawrence received offers of assistant professorships from the University of Washington in Seattle and the University of California at a salary of $3,500 per annum. Yale promptly matched the offer of the assistant professorship, but at a salary of $3,000. Lawrence chose to stay at the more prestigious Yale, but because he had never been an instructor, the appointment was resented by some of his fellow faculty, in the eyes of many it still did not compensate for his South Dakota immigrant background.
Lawrence was hired as an associate professor of physics at the University of California in 1928, two years became a full professor, becoming the university's youngest professor. Robert Gordon Sproul, who became university president the day after Lawrence became a professor, was a member of the Bohemian Club, he sponsored Lawrence's membership in 1932. Through this club, Lawrence met William Henry Crocker, Edwin Pauley, John Francis Neylan, they were influential men who helped him obtain money for his energetic nuclear particle investigations. There was great hope for medical uses to come from the development of particle physics, this led to much of the early funding for advances Lawrence was able to obtain. While at Yale, Lawrence met Mary Kimberly Blumer, the eldest of four daughters of George Blumer, the dean of the Yale School of Medicine, they first met in 1926 and became engaged in 1931, were married on May 14, 1932, at Trinity Church on the Green in New Haven, Connecticut. They had six children: Eric, Mary, Robert and Susan.
Lawrence named his son Robert after theoretical phys
The European Organization for Nuclear Research, known as CERN, is a European research organization that operates the largest particle physics laboratory in the world. Established in 1954, the organization is based in a northwest suburb of Geneva on the Franco–Swiss border and has 23 member states. Israel is the only non-European country granted full membership. CERN is an official United Nations Observer; the acronym CERN is used to refer to the laboratory, which in 2016 had 2,500 scientific and administrative staff members, hosted about 12,000 users. In the same year, CERN generated 49 petabytes of data. CERN's main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research – as a result, numerous experiments have been constructed at CERN through international collaborations; the main site at Meyrin hosts a large computing facility, used to store and analyse data from experiments, as well as simulate events. Researchers need remote access to these facilities, so the lab has been a major wide area network hub.
CERN is the birthplace of the World Wide Web. The convention establishing CERN was ratified on 29 September 1954 by 12 countries in Western Europe; the acronym CERN represented the French words for Conseil Européen pour la Recherche Nucléaire, a provisional council for building the laboratory, established by 12 European governments in 1952. The acronym was retained for the new laboratory after the provisional council was dissolved though the name changed to the current Organisation Européenne pour la Recherche Nucléaire in 1954. According to Lew Kowarski, a former director of CERN, when the name was changed, the abbreviation could have become the awkward OERN, Werner Heisenberg said that this could "still be CERN if the name is ". CERN's first president was Sir Benjamin Lockspeiser. Edoardo Amaldi was the general secretary of CERN at its early stages when operations were still provisional, while the first Director-General was Felix Bloch; the laboratory was devoted to the study of atomic nuclei, but was soon applied to higher-energy physics, concerned with the study of interactions between subatomic particles.
Therefore, the laboratory operated by CERN is referred to as the European laboratory for particle physics, which better describes the research being performed there. At the sixth session of the CERN Council, which took place in Paris from 29 June - 1 July 1953, the convention establishing the organization was signed, subject to ratification, by 12 states; the convention was ratified by the 12 founding Member States: Belgium, France, the Federal Republic of Germany, Italy, the Netherlands, Sweden, the United Kingdom, Yugoslavia. Several important achievements in particle physics have been made through experiments at CERN, they include: 1973: The discovery of neutral currents in the Gargamelle bubble chamber. In September 2011, CERN attracted media attention when the OPERA Collaboration reported the detection of faster-than-light neutrinos. Further tests showed that the results were flawed due to an incorrectly connected GPS synchronization cable; the 1984 Nobel Prize for Physics was awarded to Carlo Rubbia and Simon van der Meer for the developments that resulted in the discoveries of the W and Z bosons.
The 1992 Nobel Prize for Physics was awarded to CERN staff researcher Georges Charpak "for his invention and development of particle detectors, in particular the multiwire proportional chamber". The 2013 Nobel Prize for Physics was awarded to François Englert and Peter Higgs for the theoretical description of the Higgs mechanism in the year after the Higgs boson was found by CERN experiments; the World Wide Web began as a CERN project named ENQUIRE, initiated by Tim Berners-Lee in 1989 and Robert Cailliau in 1990. Berners-Lee and Cailliau were jointly honoured by the Association for Computing Machinery in 1995 for their contributions to the development of the World Wide Web. Based on the concept of hypertext, the project was intended to facilitate the sharing of information between researchers; the first website was activated in 1991. On 30 April 1993, CERN announced. A copy of the original first webpage, created by Berners-Lee, is still published on the World Wide Web Consortium's website as a historical document.
Prior to the Web's development, CERN had pioneered the introduction of Internet technology, beginning in the early 1980s. More CERN has become a facility for the development of grid computing, hosting projects including the Enabling Grids for E-sciencE and LHC Computing Grid, it hosts the CERN Internet Exchange Point, one of the two main internet exchange points in Switzerland. CERN operates a network of a decelerator; each machine in the chain increases the energy of particle beams before delivering them
The Netherlands is a country located in Northwestern Europe. The European portion of the Netherlands consists of twelve separate provinces that border Germany to the east, Belgium to the south, the North Sea to the northwest, with maritime borders in the North Sea with Belgium and the United Kingdom. Together with three island territories in the Caribbean Sea—Bonaire, Sint Eustatius and Saba— it forms a constituent country of the Kingdom of the Netherlands; the official language is Dutch, but a secondary official language in the province of Friesland is West Frisian. The six largest cities in the Netherlands are Amsterdam, The Hague, Utrecht and Tilburg. Amsterdam is the country's capital, while The Hague holds the seat of the States General and Supreme Court; the Port of Rotterdam is the largest port in Europe, the largest in any country outside Asia. The country is a founding member of the EU, Eurozone, G10, NATO, OECD and WTO, as well as a part of the Schengen Area and the trilateral Benelux Union.
It hosts several intergovernmental organisations and international courts, many of which are centered in The Hague, dubbed'the world's legal capital'. Netherlands means'lower countries' in reference to its low elevation and flat topography, with only about 50% of its land exceeding 1 metre above sea level, nearly 17% falling below sea level. Most of the areas below sea level, known as polders, are the result of land reclamation that began in the 16th century. With a population of 17.30 million people, all living within a total area of 41,500 square kilometres —of which the land area is 33,700 square kilometres —the Netherlands is one of the most densely populated countries in the world. It is the world's second-largest exporter of food and agricultural products, owing to its fertile soil, mild climate, intensive agriculture; the Netherlands was the third country in the world to have representative government, it has been a parliamentary constitutional monarchy with a unitary structure since 1848.
The country has a tradition of pillarisation and a long record of social tolerance, having legalised abortion and human euthanasia, along with maintaining a progressive drug policy. The Netherlands abolished the death penalty in 1870, allowed women's suffrage in 1917, became the world's first country to legalise same-sex marriage in 2001, its mixed-market advanced economy had the thirteenth-highest per capita income globally. The Netherlands ranks among the highest in international indexes of press freedom, economic freedom, human development, quality of life, as well as happiness; the Netherlands' turbulent history and shifts of power resulted in exceptionally many and varying names in different languages. There is diversity within languages; this holds for English, where Dutch is the adjective form and the misnomer Holland a synonym for the country "Netherlands". Dutch comes from Theodiscus and in the past centuries, the hub of Dutch culture is found in its most populous region, home to the capital city of Amsterdam.
Referring to the Netherlands as Holland in the English language is similar to calling the United Kingdom "Britain" by people outside the UK. The term is so pervasive among potential investors and tourists, that the Dutch government's international websites for tourism and trade are "holland.com" and "hollandtradeandinvest.com". The region of Holland consists of North and South Holland, two of the nation's twelve provinces a single province, earlier still, the County of Holland, a remnant of the dissolved Frisian Kingdom. Following the decline of the Duchy of Brabant and the County of Flanders, Holland became the most economically and politically important county in the Low Countries region; the emphasis on Holland during the formation of the Dutch Republic, the Eighty Years' War and the Anglo-Dutch Wars in the 16th, 17th and 18th century, made Holland serve as a pars pro toto for the entire country, now considered either incorrect, informal, or, depending on context, opprobrious. Nonetheless, Holland is used in reference to the Netherlands national football team.
The region called the Low Countries and the Country of the Netherlands. Place names with Neder, Nieder and Nedre and Bas or Inferior are in use in places all over Europe, they are sometimes used in a deictic relation to a higher ground that consecutively is indicated as Upper, Oben, Superior or Haut. In the case of the Low Countries / Netherlands the geographical location of the lower region has been more or less downstream and near the sea; the geographical location of the upper region, changed tremendously over time, depending on the location of the economic and military power governing the Low Countries area. The Romans made a distinction between the Roman provinces of downstream Germania Inferior and upstream Germania Superior; the designation'Low' to refer to the region returns again in the 10th century Duchy of Lower Lorraine, that covered much of the Low Countries. But this time the corresponding Upper region is Upper Lorraine, in nowadays Northern France; the Dukes of Burgundy, who ruled the Low Countries in the 15th century, used the term les pays de par deçà for the Low Countries as opposed to les pays de par delà for their original
Philips Natuurkundig Laboratorium
The Philips Natuurkundig Laboratorium or NatLab was the Dutch section of the Philips research department, which did research for the product divisions of that company. Located in the Strijp district of Eindhoven, the facility moved to Waalre in the early 1960s. A 1972 municipal rezoning brought the facility back into Eindhoven, followed some years by Eindhoven renaming the street the facility is on into the Prof. Holstlaan, after the first director. In 1975, the NatLab employed some 2000 people, including 600 researchers with university degrees. Research done at the NatLab has ranged from product-specific to fundamental research into electronics and chemistry, as well as computing science and information technology; the original NatLab facility was disbanded in 2001 and the facility has been transformed into the High Tech Campus Eindhoven, open to researchers from many different companies. Philips Research is still one of the largest campus tenants, although not with anything like the number of people employed in the NatLab days.
Philips Research has branches in Germany, the United Kingdom, United States and China. The history of the NatLab spans three periods: 1914-1946, 1946–1972 and 1972-2001; the NatLab was founded in 1914 after a direct decision of Anton Philips. At the time Philips was branching out into different areas of electronics and they felt the need to do in-house research to support product development, as well as create a company patent portfolio and reduce the company dependence on patents held by third parties, they hired physicist Gilles Holst who assembled a staff consisting of Ekko Oosterhuis and a small number of research assistants. Holst held the director's position until 1946 and spent his tenure creating and maintaining an academic atmosphere at the facility in which researchers were given a lot of leeway and access to external research and resources; the external access included colloquia by some of the great physicists of the day. This managerial philosophy made the NatLab different from all the other Philips facilities and laboratories.
Unlike the other Philips labs, NatLab was more like the AT&T Bell Laboratories in the United States. The research was not limited to industrial research. Van der Pol was hired in 1922 to start a research program into radio technology; this research program resulted in publishable results in the areas of propagation of radio waves, electrical circuit theory, harmonics and a number of related, mathematical problems. Van der Pol studied the effect of the curvature of the Earth on radio wave propagation. Van der Pol's senior assistant was Bernard Tellegen, he started working on triodes and invented the penthode in 1926. The penthode was the centerpiece of the famous Philips radio and it soon found its way into every radio and amplifier in the market. Tellegen did pioneering research in the area of electrical networks. In 1925 Van der Pol took on a junior student from Johan Numans. Numans designed and built a short wave crystal controlled telephony transmitter for his required period of practical work, with call sign PCJJ.
This transmitter made world headlines on March 11, 1927 when it transmitted undistorted music and voice across the entire globe. As a result of this, the Philips Omroep Holland-Indië was founded. In 1946 Holst was succeeded by a triumvirate: physicist Hendrik Casimir, chemist Evert Verwey and engineer Herre Rinia; the NatLab saw its heyday under this triumvirate. For the Philips company as a whole, the era of Frits Philips had made the company part of the world's electronics giants with 350.000 employees in 1970. NatLab became a world class research facility. By 1963 a new campus was designed with space for 3.000 employees. NatLab never grew to quite those numbers though, 2.400 was the record – and that included the foreign branches, added in the meantime. The NatLab became a superuniversity where the "best of the best" could do research in perfect circumstances. Kees Schouhamer Immink, digital pioneer and one of NatLab's top-scientists, formulated the atmosphere at that time: "We were able to conduct whatever research we found relevant, had no pre-determined tasks.
We went not knowing what we would do that day. This view -or rather ambiguous view- on how research should be conducted, led to amazing inventions as a result, it was an innovation heaven". The result was a slew of commercial and fundamental results, including the cassette tape in 1962, Plumbicon camera tube and the Video Long Play disc, the technological basis for the 1980 compact disc. Results were achieved in the area of integrated circuitry: Else Kooi invented the LOCOS technology and Kees Hart and Arie Slob developed the I²L in the early 1970s. Dick Raaijmakers and Tom Dissevelt did fundamental user experience research into the first synthesizers
W and Z bosons
The W and Z bosons are together known as the weak or more as the intermediate vector bosons. These elementary particles mediate the weak interaction; the W bosons have either a positive or negative electric charge of 1 elementary charge and are each other's antiparticles. The Z boson is its own antiparticle; the three particles have a spin of 1. The W bosons have a magnetic moment. All three of these particles are short-lived, with a half-life of about 3×10−25 s, their experimental discovery was a triumph for what is now known as the Standard Model of particle physics. The W bosons are named after the weak force; the physicist Steven Weinberg named the additional particle the "Z particle", gave the explanation that it was the last additional particle needed by the model. The W bosons had been named, the Z bosons have zero electric charge; the two W bosons are verified mediators of neutrino emission. During these processes, the W boson charge induces electron or positron emission or absorption, thus causing nuclear transmutation.
The Z boson is not involved in the emission of electrons and positrons. The Z boson mediates the transfer of momentum and energy when neutrinos scatter elastically from matter; such behavior is as common as inelastic neutrino interactions and may be observed in bubble chambers upon irradiation with neutrino beams. Whenever an electron is observed as a new free particle moving with kinetic energy, it is inferred to be a result of a neutrino interacting directly with the electron, since this behavior happens more when the neutrino beam is present. In this process, the neutrino strikes the electron and scatters away from it, transferring some of the neutrino's momentum to the electron; because neutrinos are neither affected by the strong force nor the electromagnetic force, because the gravitational force between subatomic particles is negligible, such an interaction can only happen via the weak force. Since such an electron is not created from a nucleon, is unchanged except for the new force impulse imparted by the neutrino, this weak force interaction between the neutrino and the electron must be mediated by an electromagnetically neutral, weak-force boson particle.
Thus, this interaction requires a Z boson. These bosons are among the heavyweights of the elementary particles. With masses of 80.4 GeV/c2 and 91.2 GeV/c2 the W and Z bosons are 80 times as massive as the proton – heavier than entire iron atoms. Their high masses limit the range of the weak interaction. By way of contrast, the photon is the force carrier of the electromagnetic force and has zero mass, consistent with the infinite range of electromagnetism. All three bosons have particle spin s = 1; the emission of a W+ or W− boson either raises or lowers the electric charge of the emitting particle by one unit, alters the spin by one unit. At the same time, the emission or absorption of a W boson can change the type of the particle – for example changing a strange quark into an up quark; the neutral Z boson cannot change the electric charge of any particle, nor can it change any other of the so-called "charges". The emission or absorption of a Z boson can only change the spin and energy of the other particle.
The W and Z bosons are carrier particles that mediate the weak nuclear force, much as the photon is the carrier particle for the electromagnetic force. The W bosons are best known for their role in nuclear decay. Consider, for example, the beta decay of cobalt-60. 6027Co → 6028Ni+ + e− + νeThis reaction does not involve the whole cobalt-60 nucleus, but affects only one of its 33 neutrons. The neutron is converted into a proton while emitting an electron and an electron antineutrino: n0 → p+ + e− + νeAgain, the neutron is not an elementary particle but a composite of an up quark and two down quarks, it is in fact one of the down quarks that interacts in beta decay, turning into an up quark to form a proton. At the most fundamental level the weak force changes the flavour of a single quark: d → u + W−which is followed by decay of the W− itself: W− → e− + νe The Z boson is its own antiparticle. Thus, all of its flavour quantum numbers and charges are zero; the exchange of a Z boson between particles, called a neutral current interaction, therefore leaves the interacting particles unaffected, except for a transfer of momentum.
Z boson interactions involving neutrinos have distinctive signatures: They provide the only known mechanism for elastic scattering of neutrinos in matter. The first prediction of Z bosons was made by Brazilian physicist José Leite Lopes in 1958, by devising an equation which showed the analogy of the weak nuclear interactions with electromagnetism. Steve Weinberg, Sheldon Glashow and Abdus Salam used these results to develop the electroweak unification, in 1973. Weak neutral currents via Z boson exchange were confirmed shortly thereafter, in a neutrino experiment in the Gargamelle bubble chamber at CERN. Following the spectacular success of quantum electrodynamics in the 1950s, attempts were undertaken to formulate a similar theory of the weak nuclear force; this culminated around 1968 in a
Super Proton Synchrotron
The Super Proton Synchrotron is a particle accelerator of the synchrotron type at CERN. It is housed in a circular tunnel, 6.9 kilometres in circumference, straddling the border of France and Switzerland near Geneva, Switzerland. The SPS was designed by a team led by John Adams, director-general of what was known as Laboratory II. Specified as a 300 GeV accelerator, the SPS was built to be capable of 400 GeV, an operating energy it achieved on the official commissioning date of 17 June 1976. However, by that time, this energy had been exceeded by Fermilab, which reached an energy of 500 GeV on 14 May of that year; the SPS has been used to accelerate protons and antiprotons and positrons, heavy ions. From 1981 to 1991, the SPS operated as a hadron collider, when its beams provided the data for the UA1 and UA2 experiments, which resulted in the discovery of the W and Z bosons; these discoveries and a new technique for cooling particles led to a Nobel Prize for Carlo Rubbia and Simon van der Meer in 1984.
From 2006 to 2012, the SPS was used by the CNGS experiment to produce a neutrino stream to be detected at the Gran Sasso laboratory in Italy, 730 km from CERN. The SPS is now used as the final injector for high-intensity proton beams for the Large Hadron Collider, which began preliminary operation on 10 September 2008, for which it accelerates protons from 26 GeV to 450 GeV; the LHC itself accelerates them to several teraelectronvolts. Operation as injector still allows continuation of the ongoing fixed-target research program, where the SPS is used to provide 400 GeV proton beams for a number of active fixed-target experiments, notably COMPASS, NA61/SHINE and NA62; the SPS has served, continues to be used as a test bench for new concepts in accelerator physics. In 1999 it served as an observatory for the electron cloud phenomenon. In 2003, SPS was the first machine where the Hamiltonian resonance driving terms were directly measured, and in 2004, experiments to cancel the detrimental effects of beam encounters were carried out.
Major scientific discoveries made by experiments that operated at the SPS include the following. 1983: The discovery of W and Z bosons in the UA1 and UA2 experiments. The 1984 Nobel Prize in physics was awarded to Carlo Rubbia and Simon van der Meer for the developments that led to this discovery. 1999: The discovery of direct CP violation by the NA48 experiment. The Large Hadron Collider will require an upgrade to increase its luminosity during the 2020s; this would require upgrades to the entire linac/pre-injector/injector chain, including the SPS. The SPS will need to be able to handle a much higher intensity beam. One improvement considered in the past was increasing the extraction energy to 1 TeV. However, the extraction energy will be kept at 450 GeV; the acceleration system will be modified to handle the higher voltages needed to accelerate a higher intensity beam. The beam dumping system will be upgraded so it can accept a higher intensity beam without sustaining significant damage