Edwin Mattison McMillan (September 18, 1907 – September 7, 1991) was an American physicist and Nobel laureate credited with being the first-ever to produce a transuranium element, neptunium. For this, he shared the Nobel Prize in Chemistry with Glenn Seaborg in 1951.
A graduate of California Institute of Technology, he earned his doctorate from Princeton University in 1933, and joined the Berkeley Radiation Laboratory, where he discovered oxygen-15 and beryllium-10. During World War II, he worked on microwave radar at the MIT Radiation Laboratory, and on sonar at the Navy Radio and Sound Laboratory. In 1942 he joined the Manhattan Project, the wartime effort to create atomic bombs, and helped establish the project's Los Alamos Laboratory where the bombs were designed. He led teams working on the gun-type nuclear weapon design, and also participated in the development of the implosion-type nuclear weapon.
McMillan co-invented the synchrotron with Vladimir Veksler. He returned to the Radiation Laboratory after the war, and built them. In 1954 he was appointed associate director of the Radiation Laboratory, being promoted to deputy director in 1958. On the death of Lawrence that year, he became director, and he stayed in that position until his retirement in 1973.
Edwin Mattison McMillan
September 18, 1907
|Died||September 7, 1991 (aged 83)|
El Cerrito, California, U.S.
|Alma mater||California Institute of Technology|
|Known for||Discovery of neptunium, the first transuranium element|
|Awards||Nobel Prize in Chemistry (1951)|
Atoms for Peace Award (1963)
National Medal of Science (1990)
|Institutions||University of California, Berkeley|
Berkeley Radiation Laboratory
|Thesis||Deflection of a Beam of HCI Molecules in a Non-Homogeneous Electric Field (1933)|
|Doctoral advisor||Edward Condon|
McMillan was born in Redondo Beach, California, on September 18, 1907, the son of Edwin Harbaugh McMillan and his wife Anna Marie McMillan née Mattison. He had a younger sister, Catherine Helen. His father was a physician, as was his father's twin brother, and three of his mother's brothers. On October 18, 1908, the family moved to Pasadena, California, where he attended McKinley Elementary School from 1913 to 1918, Grant School from 1918 to 1920, and then Pasadena High School, from which he graduated in 1924.
California Institute of Technology (Caltech) was only a mile from his home, and he attended some of the public lectures there. He entered Caltech in 1924. He did a research project with Linus Pauling as an undergraduate and received his Bachelor of Science degree in 1928 and his Master of Science degree in 1929, writing an unpublished thesis on "An improved method for the determination of the radium content of rocks". He then took his Doctor of Philosophy from Princeton University in 1933, writing his thesis on the "Deflection of a Beam of HCI Molecules in a Non-Homogeneous Electric Field" under the supervision of Edward Condon.
In 1932, McMillan was awarded a National Research Council fellowship, allowing him to attend a university of his choice for postdoctoral study. With his PhD complete, although it was not formally accepted until January 12, 1933, he accepted an offer from Ernest Lawrence at the University of California, Berkeley, to join the Berkeley Radiation Laboratory, which Lawrence had founded the year before. McMillan's initial work there involved attempting to measure the magnetic moment of the proton, but Otto Stern and Immanuel Estermann were able to carry out these measurements first.
The main focus of the Radiation laboratory at this time was the development of the cyclotron, and McMillan, who was appointed to the faculty at Berkeley as an instructor in 1935, soon became involved in the effort. His skill with instrumentation came to the fore, and he contributed improvements to the cyclotron. In particular, he helped develop the process of "shimming", adjusting the cyclotron to produce a homogeneous magnetic field. Working with M. Stanley Livingston, he discovered oxygen-15, an isotope of oxygen that emits positrons. To produce it, they bombarded nitrogen gas with deuterons. This was mixed with hydrogen and oxygen to produce water, which was then collected with hygroscopic calcium chloride. Radioactivity was found concentrated in it, proving that it was in the oxygen. This was followed by an investigation of the absorption of gamma rays produced by bombarding fluorine with protons.
In 1935, McMillan, Lawrence and Robert Thornton carried out cyclotron experiments with deuteron beams that produced a series of unexpected results. Deuterons fused with a target nuclei, transmuting the target to a heavier isotope while ejecting a proton. Their experiments indicated a nuclear interaction at lower energies than would be expected from a simple calculation of the Coulomb barrier between a deuteron and a target nucleus. Berkeley theoretical physicist Robert Oppenheimer and his graduate student Melba Phillips developed the Oppenheimer–Phillips process to explain the phenomenon. McMillan became an assistant professor in 1936, and an associate professor in 1941. With Samuel Ruben, he also discovered the isotope beryllium-10 in 1940. This was both interesting and difficult to isolate due to its extraordinarily long half-life, about 1.39 million years.
Following the discovery of nuclear fission in uranium by Otto Hahn and Fritz Strassmann in 1939, McMillan began experimenting with uranium. He bombarded it with neutrons produced in the Radiation Laboratory's 37-inch (94 cm) cyclotron through bombarding beryllium with deuterons. In addition to the nuclear fission products reported by Hahn and Strassmann, they detected two unusual radioactive isotopes, one with a half-life of about 2.3 days, and the other with one of around 23 minutes. McMillan identified the short-lived isotope as uranium-239, which had been reported by Hahn and Strassmann. McMillan suspected that the other was an isotope of a new, undiscovered element, with an atomic number of 93.
At the time it was believed that element 93 would have similar chemistry to rhenium, so he began working with Emilio Segrè, an expert on that element from his discovery of its homolog technetium. Both scientists began their work using the prevailing theory, but Segrè rapidly determined that McMillan's sample was not at all similar to rhenium. Instead, when he reacted it with hydrogen fluoride (HF) with a strong oxidizing agent present, it behaved like members of the rare-earth elements. Since these comprise a large percentage of fission products, Segrè and McMillan decided that the half-life must have been simply another fission product, titling the article "An Unsuccessful Search for Transuranium Elements".
McMillan realized that his 1939 work with Segrè had failed to test the chemical reactions of the radioactive source with sufficient rigor. In a new experiment, McMillan tried subjecting the unknown substance to HF in the presence of a reducing agent, something he had not done before. This reaction resulted in the sample precipitating with the HF, an action that definitively ruled out the possibility that the unknown substance was a rare earth. In May 1940, Philip Abelson from the Carnegie Institute in Washington, DC, who had independently also attempted to separate the isotope with the 2.3-day half-life, visited Berkeley for a short vacation, and they began to collaborate. Abelson observed that the isotope with the 2.3-day half-life did not have chemistry like any known element, but was more similar to uranium than a rare earth. This allowed the source to be isolated and later, in 1945, led to the classification of the actinide series. As a final step, McMillan and Abelson prepared a much larger sample of bombarded uranium that had a prominent 23-minute half-life from 239U and demonstrated conclusively that the unknown 2.3-day half-life increased in strength in concert with a decrease in the 23-minute activity through the following reaction:
This proved that the unknown radioactive source originated from the decay of uranium and, coupled with the previous observation that the source was different chemically from all known elements, proved beyond all doubt that a new element had been discovered. McMillan and Abelson published their results in an article entitled Radioactive Element 93 in the Physical Review on May 27, 1940. They did not propose a name for the element in the article, but they soon decided on "neptunium", since uranium had been named after the planet Uranus, and Neptune is the next planet beyond in our solar system. McMillan suddenly departed at this point, leaving Glenn Seaborg to pursue this line of research, which led to the second transuranium element, plutonium. In 1951, McMillan shared the Nobel Prize in Chemistry with Seaborg "for their discoveries in the chemistry of the transuranium elements".
McMillan's abrupt departure was caused by the outbreak of World War II in Europe. In November 1940, he began working at the MIT Radiation Laboratory in Cambridge, Massachusetts, where he participated in the development and testing of airborne microwave radar during World War II. He conducted tests in April 1941 with the radar operating from an old Douglas B-18 Bolo medium bomber. Flying over the Naval Submarine Base New London with Luis Walter Alvarez and Air Chief Marshal Hugh Dowding, they showed that the radar was able to detect the conning tower of a partly submerged submarine. McMillan married Elsie Walford Blumer in New Haven, Connecticut, on June 7, 1941. Her father was George Blumer, Dean Emeritus of the Yale Medical School. Her sister Mary was Lawrence's wife. The McMillans had three children: Ann Bradford, David Mattison and Stephen Walker.
McMillan joined the Navy Radio and Sound Laboratory near San Diego in August 1941. There he worked on a device called a polyscope. The idea, which came from Lawrence, was to use sonar to build up a visual image of the surrounding water. This proved to be far more difficult that doing so with radar, because of objects in the water and variations in water temperature that caused variations in the speed of sound. The polyscope proved to be impractical, and was abandoned. He also, however, developed a sonar training device for submariners, for which he received a patent.
Oppenheimer recruited McMillan to join the Manhattan Project, the wartime effort to create atomic bombs, in September 1942. Initially, he commuted back and forth between San Diego, where his family was, and Berkeley. In November he accompanied Oppenheimer on a trip to New Mexico on which the Los Alamos Ranch School was selected as the site of the project's weapons research laboratory, which became the Los Alamos Laboratory. With Oppenheimer and John H. Manley, he drew up the specifications for the new laboratory's technical buildings. He recruited personnel for the laboratory, including Richard Feynman and Robert R. Wilson, established the test area known as the Anchor Ranch, and scoured the country for technical equipment from machine tools to a cyclotron.
As the laboratory took shape, McMillan became deputy head of the gun-type nuclear weapon effort under Navy Captain William S. Parsons, an ordnance expert. The plutonium gun, codenamed Thin Man, needed a muzzle velocity of at least 3,000 feet (910 m) per second, which they hoped to achieve with a modified Navy 3-inch antiaircraft gun. The alternative was to build an implosion-type nuclear weapon. McMillan took an early interest in this, watching tests of this concept conducted by Seth Neddermeyer. The results were not encouraging. Simple explosions resulted in distorted shapes. John von Neumann looked at the implosion program in September 1943, and proposed a radical solution involving explosive lenses. This would require expertise in explosives, and McMillan urged Oppenheimer to bring in George Kistiakowsky. Kistiakowsky joined the laboratory on February 16, 1944, and Parsons's E (Explosives) Division was divided in two, with McMillan as deputy for the gun and Kistiakowsky as deputy for implosion. 
McMillan heard disturbing news in April 1944, and drove out to Pajarito Canyon to confer with Segrè. Segrè's group had tested samples of plutonium bred in the Manhattan Project's nuclear reactors and found that it contained quantities of plutonium-240, an isotope that caused spontaneous fission, making Thin Man impractical. In July 1944, Oppenheimer reorganised the laboratory to make an all-out effort on implosion. McMillan remained in charge of the gun-type weapon, which would now be used only with uranium-235. This being the case, Thin Man was replaced by a new, scaled-back design called Little Boy. McMillan was also involved with the implosion as the head of the G-3 Group within the G (Gadget) Division, which was responsible for obtaining measurements and timings on implosion, and served as the laboratory's liaison with Project Camel, the aerial test program being carried out by Caltech. On July 16, 1945, he was present at the Trinity nuclear test, when the first implosion bomb was successfully detonated.
In June 1945, McMillan's thoughts began to return to cyclotrons. Over time they had gotten larger and larger. A 184-inch cyclotron was under construction at the Radiation Laboratory, but he realised that a more efficient use could be made of the energy used to accelerate particles. By varying the magnetic field used, the particles could be made to move in stable orbits, and higher energies achieved with the same energy input. He dubbed this the "phase stability principle", and the new design a "synchrotron". Unknown to McMillan, the synchrotron principle had already been invented by Vladimir Veksler, who had published his proposal in 1944. McMillan became aware of Veksler's paper in October 1945. The two began corresponding, and eventually became friends. In 1963 they shared the Atoms for Peace Award for the invention of the synchrotron.
The phase stability principle was tested with the old 37-inch cyclotron at Berkeley after McMillan returned to the Radiation Laboratory in September 1945. When it was found to work, the 184-inch cyclotron was similarly modified. He became a full professor in 1946. In 1954 he was appointed associate director of the Radiation Laboratory. He was promoted to deputy director in 1958. On the death of Lawrence that year, he became director, and he stayed in that position until his retirement in 1973. The laboratory was renamed the Lawrence Radiation Laboratory in 1958. In 1970, it split into the Lawrence Berkeley Laboratory and the Lawrence Livermore Laboratory, and McMillan became director of the former.
McMillan was elected to the National Academy of Sciences in 1947, serving as its chairman from 1968 to 1971. He served on the influential General Advisory Committee (GAC) of the Atomic Energy Commission from 1954 to 1958, and the Commission on High Energy Physics of the International Union of Pure and Applied Physics from 1960 to 1967. After his retirement from the faculty at Berkeley in 1974, he spent 1974–75 at CERN, where he worked on the g minus 2 experiment to measure the magnetic moment of the muon. He was awarded the National Medal of Science in 1990.
McMillan suffered the first of a series of strokes in 1984. He died at his home in El Cerrito, California, from complications from diabetes on September 7, 1991. He was survived by his wife and three children. His gold Nobel Prize medal is in the National Museum of American History, a division of The Smithsonian, in Washington DC.
The year 1940 in science and technology involved some significant events, listed below.Bevatron
The Bevatron was a particle accelerator — specifically, a weak-focusing proton synchrotron — at Lawrence Berkeley National Laboratory, U.S., which began operating in 1954. The antiproton was discovered there in 1955, resulting in the 1959 Nobel Prize in physics for Emilio Segrè and Owen Chamberlain. It accelerated protons into a fixed target, and was named for its ability to impart energies of billions of eV. (Billions of eV Synchrotron.)Ernest Lawrence
Ernest Orlando Lawrence (August 8, 1901 – August 27, 1958) 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, Berkeley, 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, and 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 ever 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 also 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, Tennessee, which came to be called Y-12. The process was inefficient, but it worked.
After the war, Lawrence campaigned extensively for government sponsorship of large scientific programs, and was a forceful advocate of "Big Science", with its requirements for big machines and big money. Lawrence strongly 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.Glenn T. Seaborg
Glenn Theodore Seaborg (; April 19, 1912 – February 25, 1999) was an American chemist whose involvement in the synthesis, discovery and investigation of ten transuranium elements earned him a share of the 1951 Nobel Prize in Chemistry. His work in this area also led to his development of the actinide concept and the arrangement of the actinide series in the periodic table of the elements.
Seaborg spent most of his career as an educator and research scientist at the University of California, Berkeley, serving as a professor, and, between 1958 and 1961, as the university's second chancellor. He advised ten US Presidents – from Harry S. Truman to Bill Clinton – on nuclear policy and was Chairman of the United States Atomic Energy Commission from 1961 to 1971, where he pushed for commercial nuclear energy and the peaceful applications of nuclear science. Throughout his career, Seaborg worked for arms control. He was a signatory to the Franck Report and contributed to the Limited Test Ban Treaty, the Nuclear Non-Proliferation Treaty and the Comprehensive Test Ban Treaty. He was a well-known advocate of science education and federal funding for pure research. Toward the end of the Eisenhower administration, he was the principal author of the Seaborg Report on academic science, and, as a member of President Ronald Reagan's National Commission on Excellence in Education, he was a key contributor to its 1983 report "A Nation at Risk".
Seaborg was the principal or co-discoverer of ten elements: plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium and element 106, which, while he was still living, was named seaborgium in his honor. He also discovered more than 100 atomic isotopes and is credited with important contributions to the chemistry of plutonium, originally as part of the Manhattan Project where he developed the extraction process used to isolate the plutonium fuel for the second atomic bomb. Early in his career, he was a pioneer in nuclear medicine and discovered isotopes of elements with important applications in the diagnosis and treatment of diseases, including iodine-131, which is used in the treatment of thyroid disease. In addition to his theoretical work in the development of the actinide concept, which placed the actinide series beneath the lanthanide series on the periodic table, he postulated the existence of super-heavy elements in the transactinide and superactinide series.
After sharing the 1951 Nobel Prize in Chemistry with Edwin McMillan, he received approximately 50 honorary doctorates and numerous other awards and honors. The list of things named after Seaborg ranges from the chemical element Seaborgium to the asteroid 4856 Seaborg. He was a prolific author, penning numerous books and 500 journal articles, often in collaboration with others. He was once listed in the Guinness Book of World Records as the person with the longest entry in Who's Who in America.John Reginald Richardson
John Reginald Richardson (1912 in Edmonton, Alberta, Canada – 25 November 1997 in Fremont, California) was a Canadian-American physicist and one of the dominant figures in cyclotron development. His many achievements include participation in the first demonstration of phase stability, the development of the first synchrocyclotron and the first sector-focused cyclotron.Richardson grew up in Vancouver until his family emigrated to the US in 1922. He studied physics at UCLA and was a doctoral student in nuclear physics of Ernest Orlando Lawrence at the University of California, Berkeley, receiving his PhD in 1937. After a year at the University of Michigan, he became Assistant Professor at the University of Illinois. From 1942 he worked on electromagnetic isotope separation for the Manhattan Project in Berkeley and Oak Ridge (calutron). In 1946, after the discovery of the phase stability and the synchrotron principle by Weksler and Edwin McMillan, he collaborated with a group of physicists consisting of Ed Lofgren, Ken MacKenzie, Bernard Peters, Fred Schmidt and Byron Wright in converting the fixed-frequency 37-inch cyclotron at Berkeley to the first synchrocyclotron. This success not only provided the first demonstration of the phase-stability principle but also confirmed the feasibility of converting the large Berkeley 184-inch cyclotron from a classical cyclotron to a synchrocyclotron.An even bigger sector cyclotron with energies up to 520 MeV was built by Richardson's line at TRIUMF in Vancouver. From 1971 to 1976, Richardson was the director of the laboratory, where he oversaw the construction of the cyclotron.
In 1991 he received the Robert R. Wilson Prize.Joseph O. Hirschfelder
Joseph Oakland Hirschfelder (May 27, 1911 – March 30, 1990) was an American physicist who participated in the Manhattan Project and in the creation of the nuclear bomb. Robert Oppenheimer assembled a team at the Los Alamos Laboratory to work on plutonium gun design Thin Man, that included senior engineer Edwin McMillan and senior physicists Charles Critchfield and Joseph Hirschfelder. Hirschfelder had been working on internal ballistics. Oppenheimer led the design effort himself until June 1943, when Navy Captain William Sterling Parsons arrived took over the Ordnance and Engineering Division and direct management of the "Thin Man" project.
Hirschfelder was a member of the National Academy of Sciences, a group leader in theoretical physics and ordnance at the Los Alamos Atomic Bomb Laboratory, chief phenomenologist at the nuclear bomb tests at Bikini, the founder of the Theoretical Chemistry Institute and the Homer Adkins professor emeritus of chemistry at the University of Wisconsin.
Hirschfelder was also a fellow of the American Academy of Arts and Sciences. He was awarded the National Medal of Science from President Gerald Ford “for his fundamental contributions to atomic and molecular quantum mechanics, the theory of the rates of chemical reactions, and the structure and properties of gases and liquids.”The National Academies Press called him "one of the leading figures in theoretical chemistry during the period 1935-90"."
In 1991 an award was established in his name by the University of Wisconsin's Theoretical Chemistry Institute - the annual Joseph O. Hirschfelder Prize in Theoretical Chemistry. He was an elected member of the International Academy of Quantum Molecular Science. His book Molecular theory of gases and liquids is an authoritative text on the kinetic theories of gases and liquids.Joseph W. Kennedy
Joseph William Kennedy (May 30, 1916 – May 5, 1957) was an American chemist who was a co-discoverer of plutonium, along with Glenn T. Seaborg, Edwin McMillan and Arthur Wahl. During World War II he was head of the CM (Chemistry and Metallurgy) Division at the Manhattan Project's Los Alamos laboratory, where he oversaw research onto the chemistry and metallurgy of uranium and plutonium. After the war, he was recruited as a professor at Washington University in St. Louis, where he is credited with transforming a university primarily concerned with undergraduate teaching into one that also boasts strong graduate and research programs. He died of cancer of the stomach at the age of 40.Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory (LBNL), commonly referred to as Berkeley Lab, is a United States national laboratory that conducts scientific research on behalf of the United States Department of Energy (DOE). It is located in the Berkeley Hills near Berkeley, California, overlooking the main campus of the University of California, Berkeley. It is managed and operated by the University of California.Neptunium
Neptunium is a chemical element with symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. Its position in the periodic table just after uranium, named after the planet Uranus, led to it being named after Neptune, the next planet beyond Uranus. A neptunium atom has 93 protons and 93 electrons, of which seven are valence electrons. Neptunium metal is silvery and tarnishes when exposed to air. The element occurs in three allotropic forms and it normally exhibits five oxidation states, ranging from +3 to +7. It is radioactive, poisonous, pyrophoric, and can accumulate in bones, which makes the handling of neptunium dangerous.
Although many false claims of its discovery were made over the years, the element was first synthesized by Edwin McMillan and Philip H. Abelson at the Berkeley Radiation Laboratory in 1940. Since then, most neptunium has been and still is produced by neutron irradiation of uranium in nuclear reactors. The vast majority is generated as a by-product in conventional nuclear power reactors. While neptunium itself has no commercial uses at present, it is used as a precursor for the formation of plutonium-238, used in radioisotope thermal generators to provide electricity for spacecraft. Neptunium has also been used in detectors of high-energy neutrons.
The most stable isotope of neptunium, neptunium-237, is a by-product of nuclear reactors and plutonium production. It, and the isotope neptunium-239, are also found in trace amounts in uranium ores due to neutron capture reactions and beta decay.Pasadena High School (California)
Pasadena High School (PHS) is a public high school in Pasadena, California. It is one of four high schools in the Pasadena Unified School District.Philip Abelson
Philip Hauge Abelson (April 27, 1913 – August 1, 2004) was an American physicist, a scientific editor, and a science writer.Richard P. Brent
Richard Peirce Brent (born 20 April 1946, Melbourne) is an Australian mathematician and computer scientist. He is an emeritus professor at the Australian National University and a conjoint professor at the University of Newcastle (Australia). From March 2005 to March 2010 he was a Federation Fellow at the Australian National University. His research interests include number theory (in particular factorisation), random number generators, computer architecture, and analysis of algorithms.
In 1973, he published a root-finding algorithm (an algorithm for solving equations numerically) which is now known as Brent's method.
In 1975 he and Eugene Salamin independently conceived the Salamin–Brent algorithm, used in high-precision calculation of . At the same time, he showed that all the elementary functions (such as log(x), sin(x) etc.) can be evaluated to high precision in the same time as (apart from a small constant factor) using the arithmetic-geometric mean of Carl Friedrich Gauss.
In 1979 he showed that the first 75 million complex zeros of the Riemann zeta function lie on the critical line, providing some experimental evidence for the Riemann hypothesis.
In 1980 he and Nobel laureate Edwin McMillan found a new algorithm for high-precision computation of the Euler–Mascheroni constant using Bessel functions, and showed that can not have a simple rational form p/q (where p and q are integers) unless q is extremely large (greater than 1015000).
In 1980 he and John Pollard factored the eighth Fermat number using a variant of the Pollard rho algorithm. He later factored the tenth and eleventh Fermat numbers using Lenstra's elliptic curve factorisation algorithm.
In 2002, Brent, Samuli Larvala and Paul Zimmermann discovered a very large primitive trinomial over GF(2):
The degree 6972593 is the exponent of a Mersenne prime.
In 2009 and 2016, Brent and Paul Zimmermann discovered some even larger primitive trinomials, for example:
The degree 43112609 is again the exponent of a Mersenne prime.
In 2011, Brent and Paul Zimmermann published Modern Computer Arithmetic (Cambridge University Press), a book about algorithms for performing arithmetic, and their implementation on modern computers.
Brent is a Fellow of the Association for Computing Machinery, the IEEE, SIAM and the Australian Academy of Science. In 2005, he was awarded the Hannan Medal by the Australian Academy of Science. In 2014, he was awarded the Moyal Medal by Macquarie University.Synchrocyclotron
A synchrocyclotron is a special type of cyclotron, patented by Edwin McMillan, in which the frequency of the driving RF electric field is varied to compensate for relativistic effects as the particles' velocity begins to approach the speed of light. This is in contrast to the classical cyclotron, where this frequency is constant.There are two major differences between the synchrocyclotron and the classical cyclotron. In the synchrocyclotron, only one dee (hollow "D"-shaped sheet metal electrode) retains its classical shape, while the other pole is open (see patent sketch). Furthermore, the frequency of oscillating electric field in a synchrocyclotron is decreasing continuously instead of kept constant so as to maintain cyclotron resonance for relativistic velocities. One terminal of the oscillating electric potential varying periodically is applied to the dee and the other terminal is on ground potential. The protons or deuterons to be accelerated are made to move in circles of increasing radius. The acceleration of particles takes place as they enter or leave the dee. At the outer edge, the ion beam can be removed with the aid of electrostatic deflector. The first synchrocyclotron produced 195 MeV deuterons and 390 MeV α-particles.Synchrophasotron
The Synchrophasotron was a synchrotron-based particle accelerator for protons at the Joint Institute for Nuclear Research in Dubna that was operational from 1957 to 2003. It was designed and constructed under supervision of Vladimir Veksler, who had invented the synchrotron independently from Edwin McMillan.
Its final energy for protons, and later deuterium nuclei, was 10 GeV.Synchrotron
A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The magnetic field which bends the particle beam into its closed path increases with time during the accelerating process, being synchronized to the increasing kinetic energy of the particles (see image). The synchrotron is one of the first accelerator concepts to enable the construction of large-scale facilities, since bending, beam focusing and acceleration can be separated into different components. The most powerful modern particle accelerators use versions of the synchrotron design. The largest synchrotron-type accelerator, also the largest particle accelerator in the world, is the 27-kilometre-circumference (17 mi) Large Hadron Collider (LHC) near Geneva, Switzerland, built in 2008 by the European Organization for Nuclear Research (CERN). It can accelerate beams of protons to an energy of 6.5 teraelectronvolts (TeV).
The synchrotron principle was invented by Vladimir Veksler in 1944. Edwin McMillan constructed the first electron synchrotron in 1945, arriving at the idea independently, having missed Veksler's publication (which was only available in a Soviet journal, although in English). The first proton synchrotron was designed by Sir Marcus Oliphant and built in 1952.Timeline of particle physics technology
Timeline of particle physics technology
1896 - Charles Wilson discovers that energetic particles produce droplet tracks in supersaturated gases
1897-1901 - Discovery of the Townsend discharge by John Sealy Townsend
1908 - Hans Geiger and Ernest Rutherford use the Townsend discharge principle to detect alpha particles.
1911 - Charles Wilson finishes a sophisticated cloud chamber
1928 - Hans Geiger and Walther Muller invent the Geiger Muller tube, which is based upon the gas ionisation principle used by Geiger in 1908, but is a practical device that can also detect beta and gamma radiation. This is implicitly also the invention of the Geiger Muller counter.
1934 - Ernest Lawrence and Stan Livingston invent the cyclotron
1945 - Edwin McMillan devises a synchrotron
1952 - Donald Glaser develops the bubble chamber
1968 - Georges Charpak and Roger Bouclier build the first multiwire proportional mode particle detection chamberTransuranium element
The transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, which is the atomic number of uranium. All of these elements are unstable and decay radioactively into other elements.Vladimir Veksler
Vladimir Iosifovich Veksler (Ukrainian: Володимир Йосипович Векслер; March 4, 1907 in Zhytomyr, Zhytomyr Oblast, Ukraine) – September 22, 1966 in Moscow, USSR) was a prominent Russian experimental physicist.
Veksler's family moved from Zhitomir to Moscow in 1915. In 1931 he graduated from the Moscow Power Engineering Institute. He began working at the Lebedev Physical Institute in 1936, and became involved in particle detector development and the study of cosmic rays. He participated in a number of expeditions to the Pamir Mountains and to Mount Elbrus, which were devoted to the study of cosmic ray composition. In 1944, he began working in the field of accelerator physics, where he became famous for the invention of the microtron, and the development of the synchrotron in independence to Edwin McMillan, pursuing the development of modern particle accelerators.
In 1956 he established and became the first director of the Laboratory of High Energy at the Joint Institute for Nuclear Research in Dubna, where the Synchrophasotron, that, along with Protvino, incorporated the largest circular proton accelerators in the world at their time, was constructed under his leadership.From 1946-1957, he was a corresponding member of the Soviet Academy of Sciences. Veksler became a full member of the Academy in 1958. In 1963 he was appointed head of the Nuclear Physics Department of the Academy. In 1965, Veksler established the journal Nuclear Physics (Yadernaya Fizika) and became its first editor-in-chief.He received numerous honours, including the Stalin Prize in 1951, the American Atoms for Peace Award in 1963 and the Lenin Prize in 1959.
Streets in Dubna, Odessa, Zhytomyr and CERN are named in his honour.