Vacuum tube
In electronics, a vacuum tube, an electron tube, or valve or, colloquially, a tube, is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as a thermionic tube or thermionic valve uses the phenomenon of thermionic emission of electrons from a heated cathode and is used for a number of fundamental electronic functions such as signal amplification and current rectification. Non-thermionic types, such as a vacuum phototube however, achieve electron emission through the photoelectric effect, are used for such as the detection of light levels. In both types, the electrons are accelerated from the cathode to the anode by the electric field in the tube; the simplest vacuum tube, the diode invented in 1904 by John Ambrose Fleming, contains only a heated electron-emitting cathode and an anode. Current can only flow in one direction through the device—from the cathode to the anode. Adding one or more control grids within the tube allows the current between the cathode and anode to be controlled by the voltage on the grid or grids.
These devices became a key component of electronic circuits for the first half of the twentieth century. They were crucial to the development of radio, radar, sound recording and reproduction, long distance telephone networks, analogue and early digital computers. Although some applications had used earlier technologies such as the spark gap transmitter for radio or mechanical computers for computing, it was the invention of the thermionic vacuum tube that made these technologies widespread and practical, created the discipline of electronics. In the 1940s the invention of semiconductor devices made it possible to produce solid-state devices, which are smaller, more efficient and durable, cheaper than thermionic tubes. From the mid-1960s, thermionic tubes were being replaced with the transistor. However, the cathode-ray tube remained the basis for television monitors and oscilloscopes until the early 21st century. Thermionic tubes still have some applications, such as the magnetron used in microwave ovens, certain high-frequency amplifiers, amplifiers that audio enthusiasts prefer for their tube sound.
Not all electronic circuit valves/electron tubes are vacuum tubes. Gas-filled tubes are similar devices, but containing a gas at low pressure, which exploit phenomena related to electric discharge in gases without a heater. One classification of thermionic vacuum tubes is by the number of active electrodes. A device with two active elements is a diode used for rectification. Devices with three elements are triodes used for switching. Additional electrodes create tetrodes, so forth, which have multiple additional functions made possible by the additional controllable electrodes. Other classifications are: by frequency range by power rating by cathode/filament type and Warm-up time by characteristic curves design by application specialized parameters specialized functions tubes used to display information Tubes have different functions, such as cathode ray tubes which create a beam of electrons for display purposes in addition to more specialized functions such as electron microscopy and electron beam lithography.
X-ray tubes are vacuum tubes. Phototubes and photomultipliers rely on electron flow through a vacuum, though in those cases electron emission from the cathode depends on energy from photons rather than thermionic emission. Since these sorts of "vacuum tubes" have functions other than electronic amplification and rectification they are described in their own articles. A vacuum tube consists of two or more electrodes in a vacuum inside an airtight envelope. Most tubes have glass envelopes with a glass-to-metal seal based on kovar sealable borosilicate glasses, though ceramic and metal envelopes have been used; the electrodes are attached to leads. Most vacuum tubes have a limited lifetime, due to the filament or heater burning out or other failure modes, so they are made as replaceable units. Tubes were a frequent cause of failure in electronic equipment, consumers were expected to be able to replace tubes themselves. In addition to the base terminals, some tubes had an electrode terminating at a top cap.
The principal reason for doing this was to avoid leakage resistance through the tube base for the high impedance grid input. The bases were made with phenolic insulation which performs poorly as an insulator in humid conditions. Other reasons for using a top cap include improving stability by reducing grid-to-anode capacitance, improved high-frequency performance, keeping a high plate voltage away from lower voltages, accommodating one more electrode than allowed by the base. There was an occasional design that had two top cap connections; the earliest vacuum tubes evolved from incandescent light bulbs, containing a filament sealed in an evacuated glass envelope. When hot, the filament releases electrons into the vacuum, a process called thermio
Survey meter
Survey meters in radiation protection are hand-held ionising radiation measurement instruments used to check such as personnel and the environment for radioactive contamination and ambient radiation. The hand-held survey meter is the most familiar radiation measuring device owing to its wide and visible use; the most used hand-held survey meters are the scintillation counter, used in the measurement of alpha and neutron particles. The instruments are designed to be hand-held, are battery powered and of low mass to allow easy manipulation. Other features include an readable display, in counts or radiation dose, an audible indication of the count rate; this is the “click” associated with the Geiger type instrument, can be an alarm warning sound when a rate of radiation counts or dose has been exceeded. For dual channel detectors such as the scintillation detector it is normal to generate different sounds for alpha and beta; this gives the operator rapid feedback on both the level of radiation and the type of particle being detected.
These features allow the user to concentrate on manipulation of the meter whilst having auditory feedback of the rate of radiation detected. Meters can be integrated with probe and processing electronics in one housing to allow single-handed use, or have separate detector probe and electronics housings, joined by a signal cable; this latter is preferred for checking of convoluted surfaces for radioactive contamination due to the ease of manipulating the probe. The readout for alpha and beta radiation is in counts, whilst that for gamma and X-ray is in a reading of radiation dose; the SI unit for this latter is the sievert. There is no simple universal conversion from count rate to dose rate, as it depends on the particle type, its energy, the characteristic of the sensor. Count rate therefore tends to be used as a value, calculated for a particular application for use as a comparator or against an absolute alarm threshold. A dose instrument may be subsequently used. To help with this some instruments have both count rate displays.
Battery operated meters have a battery level check. Survey meters can be ratemeters or scalers In Radiation Protection, an instrument which reads a rate of detected events is known as a ratemeter, first developed by N. S. Gingrich et al. in 1936. This provided a real-time dynamic indication of the radiation rate, the principle has found widespread use in Health Physics and as radiation Survey meter. An instrument which totalises the events detected over a time period is known as a scaler; this colloquial name stems from the early days of automatic counting, when a scaling circuit was required to divide down a high count rate to a speed which mechanical counters could register. This technique was developed by C E Wynn-Williams at The Cavendish Laboratory and first published in 1932; the original counters used today known as a flip flop. This was before the era of electronic indicators, which started with the introduction of the Dekatron tube in the 1950s; the user must have an awareness of the types of radiation to be encountered so that the correct instrument is used.
A further complication is the possible presence of "mixed radiation fields" where more than one form of radiation is present. Many instruments are sensitive to more than one type of radiation; the necessary skills in using a hand-held instrument are not only to manipulate the instrument, but to interpret results of the rate of radiation exposure and the type of radiation being detected. For instance, a Geiger end-window instrument cannot discriminate between alpha and beta, but moving the detector away from the source of radiation will reveal a drop off in alpha as the detector tube must be within 10mm of the alpha source to obtain a reasonable counting efficiency; the operator can now deduce that both beta is present. For a beta/gamma geiger instrument, the beta may have an effect at a range in the order of metres, depending on the energy of the beta, which may give rise to the false assumption that only gamma is being detected, but if a sliding shield type detector is used, the beta can be shielded out manually, leaving only the gamma reading.
For this reason, an instrument such as the dual phosphor scintillation probe, which will discriminate between alpha and beta, is used where routine checking will come across alpha and beta emitters simultaneously. This type of counter is known as "dual channel" and can discriminate between radiation types and give separate readouts for each. However, scintillation probes can be affected by high gamma background levels, which must therefore be checked by the skilled operator to allow the instrument to compensate. A common technique is to remove the counter from any proximity to alpha and beta emitters and allow a "background" count of gamma; the instrument can subtract this in subsequent readings. In dose survey work Geiger counters are just used to locate sources of radiation, an ion chamber instrument is used to obtain a more accurate measurement owing to their better accuracy and capability of counting higher dose rates. In summary, there are a variety of instrument features and techniques to help the operator to work but the use by a skilled operator is necessary to ensure reliable results.
The UK Health and Safety Executive has issued a guidance note on selecting the correct instr
Electronvolt
In physics, the electronvolt is a unit of energy equal to 1.6×10−19 joules in SI units. The electronvolt was devised as a standard unit of measure through its usefulness in electrostatic particle accelerator sciences, because a particle with electric charge q has an energy E = qV after passing through the potential V. Like the elementary charge on which it is based, it is not an independent quantity but is equal to 1 J/C √2hα / μ0c0, it is a common unit of energy within physics used in solid state, atomic and particle physics. It is used with the metric prefixes milli-, kilo-, mega-, giga-, tera-, peta- or exa-. In some older documents, in the name Bevatron, the symbol BeV is used, which stands for billion electronvolts. An electronvolt is the amount of kinetic energy gained or lost by a single electron accelerating from rest through an electric potential difference of one volt in vacuum. Hence, it has a value of one volt, 1 J/C, multiplied by the electron's elementary charge e, 1.6021766208×10−19 C.
Therefore, one electronvolt is equal to 1.6021766208×10−19 J. The electronvolt, as opposed to volt, is not an SI unit, its derivation is empirical, which means its value in SI units must be obtained by experiment and is therefore not known unlike the litre, the light-year and such other non-SI units. Electronvolt is a unit of energy; the SI unit for energy is joule. 1 eV is equal to 1.6021766208×10−19 J. By mass–energy equivalence, the electronvolt is a unit of mass, it is common in particle physics, where units of mass and energy are interchanged, to express mass in units of eV/c2, where c is the speed of light in vacuum. It is common to express mass in terms of "eV" as a unit of mass using a system of natural units with c set to 1; the mass equivalent of 1 eV/c2 is 1 eV / c 2 = ⋅ 1 V 2 = 1.783 × 10 − 36 kg. For example, an electron and a positron, each with a mass of 0.511 MeV/c2, can annihilate to yield 1.022 MeV of energy. The proton has a mass of 0.938 GeV/c2. In general, the masses of all hadrons are of the order of 1 GeV/c2, which makes the GeV a convenient unit of mass for particle physics: 1 GeV/c2 = 1.783×10−27 kg.
The unified atomic mass unit, 1 gram divided by Avogadro's number, is the mass of a hydrogen atom, the mass of the proton. To convert to megaelectronvolts, use the formula: 1 u = 931.4941 MeV/c2 = 0.9314941 GeV/c2. In high-energy physics, the electronvolt is used as a unit of momentum. A potential difference of 1 volt causes an electron to gain an amount of energy; this gives rise to usage of eV as units of momentum, for the energy supplied results in acceleration of the particle. The dimensions of momentum units are LMT−1; the dimensions of energy units are L2MT−2. Dividing the units of energy by a fundamental constant that has units of velocity, facilitates the required conversion of using energy units to describe momentum. In the field of high-energy particle physics, the fundamental velocity unit is the speed of light in vacuum c. By dividing energy in eV by the speed of light, one can describe the momentum of an electron in units of eV/c; the fundamental velocity constant c is dropped from the units of momentum by way of defining units of length such that the value of c is unity.
For example, if the momentum p of an electron is said to be 1 GeV the conversion to MKS can be achieved by: p = 1 GeV / c = ⋅ ⋅ = 5.344286 × 10 − 19 kg ⋅ m / s. In particle physics, a system of "natural units" in which the speed of light in vacuum c and the reduced Planck constant ħ are dimensionless and equal to unity is used: c = ħ = 1. In these units, both distances and times are expressed in inverse energy units (while energy and mass are expressed in the same units, see mas
Beta particle
A beta particle called beta ray or beta radiation, is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay. There are two forms of beta decay, β− decay and β+ decay, which produce electrons and positrons respectively. Beta particles with an energy of 0.5 MeV have a range of about one metre in air. Beta particles are a type of ionizing radiation and for radiation protection purposes are regarded as being less ionising than alpha particles, but more ionising than gamma rays; the higher the ionising effect, the greater the damage to living tissue. An unstable atomic nucleus with an excess of neutrons may undergo β− decay, where a neutron is converted into a proton, an electron, an electron antineutrino: n → p + e− + νeThis process is mediated by the weak interaction; the neutron turns into a proton through the emission of a virtual W− boson. At the quark level, W− emission turns a down quark into an up quark, turning a neutron into a proton.
The virtual W− boson decays into an electron and an antineutrino. Β− decay occurs among the neutron-rich fission byproducts produced in nuclear reactors. Free neutrons decay via this process. Both of these processes contribute to the copious quantities of beta rays and electron antineutrinos produced by fission-reactor fuel rods. Unstable atomic nuclei with an excess of protons may undergo β+ decay called positron decay, where a proton is converted into a neutron, a positron, an electron neutrino: p → n + e+ + νeBeta-plus decay can only happen inside nuclei when the absolute value of the binding energy of the daughter nucleus is greater than that of the parent nucleus, i.e. the daughter nucleus is a lower-energy state. The accompanying decay scheme diagram shows the beta decay of Cs-137. Cs-137 is noted for a characteristic gamma peak at 661 KeV, but this is emitted by the daughter radionuclide Ba-137m; the diagram shows the type and energy of the emitted radiation, its relative abundance, the daughter nuclides after decay.
Phosphorus-32 is a beta emitter used in medicine and has a short half-life of 14.29 days and decays into sulfur-32 by beta decay as shown in this nuclear equation: 1.709 MeV of energy is released during the decay. The kinetic energy of the electron varies with an average of 0.5 MeV and the remainder of the energy is carried by the nearly undetectable electron antineutrino. In comparison to other beta radiation-emitting nuclides the electron is moderately energetic, it is blocked by 5 mm of acrylic glass. Of the three common types of radiation given off by radioactive materials, alpha and gamma, beta has the medium penetrating power and the medium ionising power. Although the beta particles given off by different radioactive materials vary in energy, most beta particles can be stopped by a few millimeters of aluminium. However, this does not mean that beta-emitting isotopes can be shielded by such thin shields: as they decelerate in matter, beta electrons emit secondary gamma rays, which are more penetrating than betas per se.
Shielding composed of materials with lower atomic weight generates gammas with lower energy, making such shields somewhat more effective per unit mass than ones made of high-Z materials such as lead. Being composed of charged particles, beta radiation is more ionizing than gamma radiation; when passing through matter, a beta particle is decelerated by electromagnetic interactions and may give off bremsstrahlung x-rays. In water, beta radiation from many nuclear fission products exceeds the speed of light in that material, thus generates blue Cherenkov radiation when it passes through water; the intense beta radiation from the fuel rods of pool-type reactors can thus be visualized through the transparent water that covers and shields the reactor. The ionizing or excitation effects of beta particles on matter are the fundamental processes by which radiometric detection instruments detect and measure beta radiation; the ionization of gas is used in ion chambers and Geiger-Müller counters, the excitation of scintillators is used in scintillation counters.
The following table shows radiation quantities in SI and non-SI units: The gray, is the SI unit of absorbed dose, the amount of radiation energy deposited in the irradiated material. For beta radiation this is numerically equal to the equivalent dose measured by the sievert, which indicates the stochastic biological effect of low levels of radiation on human tissue; the radiation weighting conversion factor from absorbed dose to equivalent dose is 1 for beta, whereas alpha particles have a factor of 20, reflecting their greater ionising effect on tissue. The rad is the deprecated CGS unit for absorbed dose and the rem is the deprecated CGS unit of equivalent dose, used in the USA. Beta particles can be used to treat health conditions such as eye and bone cancer and are used as tracers. Strontium-90 is the material most used to produce beta particles. Beta particles are used in quality control to test the thickness of an item, such as paper, coming through a system of rollers; some of the beta radiation is absorbed while passing through the product.
If the product is made too thick or thin, a correspondingly different amount of radiation will be absorbed. A computer program monitoring the quality of the manufactured paper will move the rollers to change the thickness of the final product. An illumination device called a betalight contains a phosphor; as tritium dec
Ernest Rutherford
Ernest Rutherford, 1st Baron Rutherford of Nelson, HFRSE LLD, was a New Zealand-born British physicist who came to be known as the father of nuclear physics. Encyclopædia Britannica considers him to be the greatest experimentalist since Michael Faraday. In early work, Rutherford discovered the concept of radioactive half-life, the radioactive element radon, differentiated and named alpha and beta radiation; this work was performed at McGill University in Canada. It is the basis for the Nobel Prize in Chemistry he was awarded in 1908 "for his investigations into the disintegration of the elements, the chemistry of radioactive substances", for which he was the first Canadian and Oceanian Nobel laureate. Rutherford moved in 1907 to the Victoria University of Manchester in the UK, where he and Thomas Royds proved that alpha radiation is helium nuclei. Rutherford performed his most famous work. In 1911, although he could not prove that it was positive or negative, he theorized that atoms have their charge concentrated in a small nucleus, thereby pioneered the Rutherford model of the atom, through his discovery and interpretation of Rutherford scattering by the gold foil experiment of Hans Geiger and Ernest Marsden.
He conducted research that led to the first "splitting" of the atom in 1917 in a nuclear reaction between nitrogen and alpha particles, in which he discovered the proton. Rutherford became Director of the Cavendish Laboratory at the University of Cambridge in 1919. Under his leadership the neutron was discovered by James Chadwick in 1932 and in the same year the first experiment to split the nucleus in a controlled manner was performed by students working under his direction, John Cockcroft and Ernest Walton. After his death in 1937, he was honoured by being interred with the greatest scientists of the United Kingdom, near Sir Isaac Newton's tomb in Westminster Abbey; the chemical element rutherfordium was named after him in 1997. Ernest Rutherford was the son of James Rutherford, a farmer, his wife Martha Thompson from Hornchurch, England. James had emigrated to New Zealand from Perth, Scotland, "to raise a little flax and a lot of children". Ernest was born near Nelson, New Zealand, his first name was mistakenly spelled ` Earnest'.
Rutherford's mother Martha Thompson was a schoolteacher. He studied at Havelock School and Nelson College and won a scholarship to study at Canterbury College, University of New Zealand, where he participated in the debating society and played rugby. After gaining his BA, MA and BSc, doing two years of research during which he invented a new form of radio receiver, in 1895 Rutherford was awarded an 1851 Research Fellowship from the Royal Commission for the Exhibition of 1851, to travel to England for postgraduate study at the Cavendish Laboratory, University of Cambridge, he was among the first of the'aliens' allowed to do research at the university, under the inspiring leadership of J. J. Thomson, which aroused jealousies from the more conservative members of the Cavendish fraternity. With Thomson's encouragement, he managed to detect radio waves at half a mile and held the world record for the distance over which electromagnetic waves could be detected, though when he presented his results at the British Association meeting in 1896, he discovered he had been outdone by another lecturer, by the name of Marconi.
In 1898, Thomson recommended Rutherford for a position at McGill University in Canada. He was to replace Hugh Longbourne Callendar who held the chair of Macdonald Professor of physics and was coming to Cambridge. Rutherford was accepted, which meant that in 1900 he could marry Mary Georgina Newton to whom he had become engaged before leaving New Zealand. In 1901, he gained a DSc from the University of New Zealand. In 1907, Rutherford returned to Britain to take the chair of physics at the Victoria University of Manchester, he was knighted in 1914. During World War I, he worked on a top secret project to solve the practical problems of submarine detection by sonar. In 1916, he was awarded the Hector Memorial Medal. In 1919, he returned to the Cavendish succeeding J. J. Thomson as the Cavendish professor and Director. Under him, Nobel Prizes were awarded to James Chadwick for discovering the neutron, John Cockcroft and Ernest Walton for an experiment, to be known as splitting the atom using a particle accelerator, Edward Appleton for demonstrating the existence of the ionosphere.
In 1925, Rutherford pushed calls to the Government of New Zealand to support education and research, which led to the formation of the Department of Scientific and Industrial Research in the following year. Between 1925 and 1930, he served as President of the Royal Society, as president of the Academic Assistance Council which helped 1,000 university refugees from Germany, he was appointed to the Order of Merit in the 1925 New Year Honours and raised to the peerage as Baron Rutherford of Nelson, of Cambridge in the County of Cambridge in 1931, a title that became extinct upon his unexpected death in 1937. In 1933, Rutherford was one of the two inaugural recipients of the T. K. Sidey Medal, set up by the Royal Society of New Zealand as an award for outstanding scientific research. For some time before his death, Rutherford had a small hernia, which he had neglected to have fixed, it became strangulated, causing him to be violently ill. Despite an emergency operation in Lon
Gamma ray
A gamma ray or gamma radiation, is a penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves and so imparts the highest photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation gamma rays based on their strong penetration of matter. Gamma rays from radioactive decay are in the energy range from a few keV to ~8 MeV, corresponding to the typical energy levels in nuclei with reasonably long lifetimes; the energy spectrum of gamma rays can be used to identify the decaying radionuclides using gamma spectroscopy. Very-high-energy gamma rays in the 100–1000 TeV range have been observed from sources such as the Cygnus X-3 microquasar. Natural sources of gamma rays originating on Earth are as a result of radioactive decay and secondary radiation from atmospheric interactions with cosmic ray particles.
However there are other rare natural sources, such as terrestrial gamma-ray flashes, that produce gamma rays from electron action upon the nucleus. Notable artificial sources of gamma rays include fission, such as occurs in nuclear reactors, as well as high energy physics experiments, such as neutral pion decay and nuclear fusion. Gamma rays and X-rays are both electromagnetic radiation and they overlap in the electromagnetic spectrum, the terminology varies between scientific disciplines. In some fields of physics, they are distinguished by their origin: Gamma rays are created by nuclear decay, while in the case of X-rays, the origin is outside the nucleus. In astrophysics, gamma rays are conventionally defined as having photon energies above 100 keV and are the subject of gamma ray astronomy, while radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy; this convention stems from the early man-made X-rays, which had energies only up to 100 keV, whereas many gamma rays could go to higher energies.
A large fraction of astronomical gamma rays are screened by Earth's atmosphere. Gamma rays are thus biologically hazardous. Due to their high penetration power, they can damage internal organs. Unlike alpha and beta rays, they pass through the body and thus pose a formidable radiation protection challenge, requiring shielding made from dense materials such as lead or concrete; the first gamma ray source to be discovered was the radioactive decay process called gamma decay. In this type of decay, an excited nucleus emits a gamma ray immediately upon formation. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900, while studying radiation emitted from radium. Villard knew that his described radiation was more powerful than described types of rays from radium, which included beta rays, first noted as "radioactivity" by Henri Becquerel in 1896, alpha rays, discovered as a less penetrating form of radiation by Rutherford, in 1899. However, Villard did not consider naming them as a different fundamental type.
In 1903, Villard's radiation was recognized as being of a type fundamentally different from named rays by Ernest Rutherford, who named Villard's rays "gamma rays" by analogy with the beta and alpha rays that Rutherford had differentiated in 1899. The "rays" emitted by radioactive elements were named in order of their power to penetrate various materials, using the first three letters of the Greek alphabet: alpha rays as the least penetrating, followed by beta rays, followed by gamma rays as the most penetrating. Rutherford noted that gamma rays were not deflected by a magnetic field, another property making them unlike alpha and beta rays. Gamma rays were first thought to be particles like alpha and beta rays. Rutherford believed that they might be fast beta particles, but their failure to be deflected by a magnetic field indicated that they had no charge. In 1914, gamma rays were observed to be reflected from crystal surfaces, proving that they were electromagnetic radiation. Rutherford and his co-worker Edward Andrade measured the wavelengths of gamma rays from radium, found that they were similar to X-rays, but with shorter wavelengths and higher frequency.
This was recognized as giving them more energy per photon, as soon as the latter term became accepted. A gamma decay was understood to emit a gamma photon. Natural sources of gamma rays on Earth include gamma decay from occurring radioisotopes such as potassium-40, as a secondary radiation from various atmospheric interactions with cosmic ray particles; some rare terrestrial natural sources that produce gamma rays that are not of a nuclear origin, are lightning strikes and terrestrial gamma-ray flashes, which produce high energy emissions from natural high-energy voltages. Gamma rays are produced by a number of astronomical processes in which high-energy electrons are produced; such electrons produce secondary gamma rays by the mechanisms of bremsstrahlung, inverse Compton scattering and synchrotron radiation. A large fraction of such astronomical gamma rays are screened by Earth's atmosphere. Notable artificial sources of gamma rays include fission, such as occurs in nuclear reactors, as well as high energy physics experiments, such as neutral pion decay and nuclear fusion.
A sample of gamma ray-emitting material, used for irradiating or imaging is known as a gamma source. It is called a radioactive sou
University of Manchester
The University of Manchester is a public research university in Manchester, formed in 2004 by the merger of the University of Manchester Institute of Science and Technology and the Victoria University of Manchester. The University of Manchester is a red brick university, a product of the civic university movement of the late 19th century; the main campus is south of Manchester city centre on Oxford Road. In 2016/17, the university had 40,490 students and 10,400 staff, making it the second largest university in the UK, the largest single-site university; the university had a consolidated income of £1 billion in 2017–18, of which £298.7 million was from research grants and contracts. It has the fourth-largest endowment of any university in the UK, after the universities of Cambridge and Edinburgh, it is a member of the worldwide Universities Research Association, the Russell Group of British research universities and the N8 Group. For 2018–19, the University of Manchester was ranked 29th in the world and 6th in the UK by QS World University Rankings.
In 2017 it was ranked 38th in the world and 6th in the UK by Academic Ranking of World Universities, 55th in the world and 8th in the UK by Times Higher Education World University Rankings and 59th in the world by U. S. News and World Report. Manchester was ranked 15th in the UK amongst multi-faculty institutions for the quality of its research and 5th for its Research Power in the 2014 Research Excellence Framework; the university owns and operates major cultural assets such as the Manchester Museum, Whitworth Art Gallery, John Rylands Library and Jodrell Bank Observatory and its Grade I listed Lovell Telescope. The University of Manchester has 25 Nobel laureates among its past and present students and staff, the fourth-highest number of any single university in the United Kingdom. Four Nobel laureates are among its staff – more than any other British university; the University of Manchester traces its roots to the formation of the Mechanics' Institute in 1824, its heritage is linked to Manchester's pride in being the world's first industrial city.
The English chemist John Dalton, together with Manchester businessmen and industrialists, established the Mechanics' Institute to ensure that workers could learn the basic principles of science. John Owens, a textile merchant, left a bequest of £96,942 in 1846 to found a college to educate men on non-sectarian lines, his trustees established Owens College in 1851 in a house on the corner of Quay Street and Byrom Street, the home of the philanthropist Richard Cobden, subsequently housed Manchester County Court. The locomotive designer, Charles Beyer became a governor of the college and was the largest single donor to the college extension fund, which raised the money to move to a new site and construct the main building now known as the John Owens building, he campaigned and helped fund the engineering chair, the first applied science department in the north of England. He left the college the equivalent of £10 million in his will in 1876, at a time when it was in great financial difficulty.
Beyer funded the total cost of construction of the Beyer building to house the biology and geology departments. His will funded Engineering chairs and the Beyer Professor of Applied mathematics; the university has a rich German heritage. The Owens College Extension Movement based their plans after a tour of German universities and polytechnics. Manchester mill owner, Thomas Ashton, chairman of the extension movement had studied at Heidelberg University. Sir Henry Roscoe studied at Heidelberg under Robert Bunsen and they collaborated for many years on research projects. Roscoe promoted the German style of research led teaching that became the role model for the redbrick universities. Charles Beyer studied at Dresden Academy Polytechnic. There were many Germans on the staff, including Carl Schorlemmer, Britain's first chair in organic chemistry, Arthur Schuster, professor of Physics. There was a German chapel on the campus. In 1873 the college moved to new premises on Oxford Road, Chorlton-on-Medlock and from 1880 it was a constituent college of the federal Victoria University.
The university was established and granted a Royal Charter in 1880 becoming England's first civic university. By 1905, the institutions were active forces; the Municipal College of Technology, forerunner of UMIST, was the Victoria University of Manchester's Faculty of Technology while continuing in parallel as a technical college offering advanced courses of study. Although UMIST achieved independent university status in 1955, the universities continued to work together. However, in the late-20th century, formal connections between the university and UMIST diminished and in 1994 most of the remaining institutional ties were severed as new legislation allowed UMIST to become an autonomous university with powers to award its own degrees. A decade the development was reversed; the Victoria University of Manchester and the University of Manchester Institute of Science and Technology agreed to merge into a single institution in March 2003. Before the merger, Victoria University of Manchester and UMIST counted 23 Nobel Prize winners amongst their former staff and students, with two further Nobel laureates being subsequently added.
Manchester has traditionally been strong in the sciences. Notable scientists as
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