Richter (Richter), Burton( The American physicist, Nobel Prize in Physics, 1976)
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Biography Richter (Richter), Burton
genus. March 22, 1931
American physicist Burton Richter was born in New York and was the only son and eldest of the children in the family textile workers Abraham Richter and Fanny (nee Pollack) Richter. Interest in natural sciences in the P. manifested early. In the basement of his home, he creates a chemical laboratory and read a lot on physics. Prior to 1948. to enter the Massachusetts Institute of Technology (MIT), he learns to Farrokeveyskoy school in Queens (New York) and Mersersbergskoy Academy (Pennsylvania). Initially, he hesitated in the choice of a profiling object, not knowing what to prefer - physics or chemistry, but one of the professors, Francis Friedman, revealed to him, as was later said to R. 'eyes to the beauty of physics'.
In the second year P. operates under the guidance of Francis Bitter in the laboratory of magnetism at MIT, researching the physical system consisting of an electron and a positron (antiparticle of the electron). Work for which P. 25 years later won the Nobel Prize, was based on experiments with the same two particles. His thesis at MIT, written under the guidance of Bitter, was devoted to the study of strong magnetic fields on the energy levels of hydrogen atom.
Received in 1952. BA, P. remained in the laboratory Bitter already as graduate. His first assignment was to get korotkodvizhuschego isotope of mercury with the bombing of gold atoms with high-energy nuclei of deuterium (heavy hydrogen). The source of high-energy nuclei served cyclotron accelerator in which charged particles are accelerated, unwinding of the helix. AND R. soon became interested in the principles of the cyclotron and laid down therein opportunities for research in the fields of nuclear physics and elementary particle physics to a much greater extent than the problems of obtaining isotope of mercury.
At this time, P. met with physicist David Frisch, who organized an invitation to him for six months at Brookhaven National Laboratory on Long Island in New York. There he had the opportunity to work on cosmotron one of the most powerful of the then accelerators. Upon returning to MIT P. conducting experiments at the college synchrotron accelerator, similar cosmotron in design, but are much smaller than that size. In the synchrotron accelerated particles move in circular orbits, but not in a spiral.
In 1959, Mr.. R. completing a doctoral dissertation using a synchrotron to produce some unstable particles. After defending it becomes a research assistant at the Physics Department at Stanford University. By that time, his interests focus entirely on quantum electrodynamics - the theory of electromagnetic forces acting on charged particles. R. proposed to test this theory by observing the collision between moving and quiescent electrons. His colleague Wolfgang Panofsky and Sidney Drell suggested a better approach - to study a pair of electrons and positrons produced by gamma radiation (the most high-energy components of the electromagnetic radiation). Obtained R. Results showed that quantum electrodynamics correctly describes the electromagnetic forces at distances up to one centimeter desyatitrillionnoy.
. In conventional accelerators, a beam of particles accelerated to high energy is directed to a stationary target atoms
. Much higher energies can be achieved by the collision of two particles moving towards each other. In 1957. Gerard K. O'Neill of Princeton University proposed for obtaining such collisions accumulate colliding accelerated particles moving in circular orbits in a toroidal vacuum chamber. In the following year, R., . O'Neill and several other physicists have begun construction of two storage rings at Stanford Accelerator Laboratory for High Energy Physics at the University had to feed the two rings electrons, . overclocked to an energy of 700 million,
. electron volts. Took several years to overcome various technical difficulties, before storage rings started to function normally. On its first results - confirmation of quantum electrodynamics with confirmation about 10 times more accurate than the earlier experiment R., - group reported in 1965
Meanwhile, in 1960. R. is an associate professor in the Laboratory for High Energy Physics. Three years later he moved to work at the Stanford Linear Accelerator Center (SLAC), located near the university and representing a two-mile electron accelerator. In 1967, while working at SLAC, P. becomes full (real) professor at Stanford University.
Having such a source of high-energy electrons, as SLAC physicists were able to build a new type of storage rings. The designers of previous storage rings had two rings in the form of Eight: the electrons circulating in separate rings encountered in the general segment joining the ring. SLAC allowed to receive both electrons and positrons, which could accumulate in a single ring. The same electromagnetic fields that cause the electrons to circulate in the ring clockwise, forcing positrons circulate counterclockwise. In this case beams of particles and antiparticles may face twice at every turn.
Richter led the group that in 1980. began construction of electron-positron storage ring at SLAC. This installation, called Stanford-positron accelerator ring Rain sensor, allows up to collision energies of 8 billion. electron volts. A year after the installation commissioned scientific world learned of the opening. Experiments using the new installation, which began in 1973. were opposed to experiments conducted by P. at Stanford. If those experiments, electrons and positrons are born of the high-energy electromagnetic radiation, . that in each collision, . what was happening in the new installation, . electron and positron annihilate, . generating electromagnetic 'fayrboll' ( 'fireball'), . from which in turn give birth to new particles.,
. In the summer of 1974
. Group F. involved in measuring the dependence of the rate hadron production (class of particles which determine the strong nuclear interaction between protons and neutrons) of the collision energy. Cumulative ring is taken out each time on a certain collision energy, and counting the number of formed hadrons. Then the energy slightly increases and repeated measurement. As the researchers expected, the birth rate increased smoothly and gradually. But at a certain energy, corresponding to approximately threefold mass of the proton in the rate of hadron production revealed a high narrow peak. This kind of 'resonance' is often a telling sign of the emergence of a new particle with a mass corresponding to the collision energy at which the peak is observed.
P. and his team spent several months on the repetition of the experiment, . excluding possible sources of technical errors, and measuring the dependence of the hadron production of energy collisions with smaller steps to increase energy in order to avoid 'false alarms',
. By November, all potential sources of error have been eliminated, and the group announced the discovery of the particle. A day after that Samuel Ting of MIT independently and (almost) simultaneously identified the same particle, using a different experimental technique. R. a new particle called the Greek letter о┬ (psi), because 'this was the only Greek letter, which was not yet used to denote an atomic particle'. Ting chose for the new particles 'name' J (DJ). Subsequently, the two symbols were combined into one (J / psi).
The opening of another new subatomic particle is not in itself would cause a special recovery among those who engage in high-energy physics: from 50-ies. opened more than 10 of hadrons, and there were good reasons to expect that their number will increase even more. But at least all the massive hadrons were extremely short-lived. They represent the excited states of less massive hadrons, similar to the excited states of atoms, which quickly decay, giving rise to their less massive cousins, such as the proton and neutron. Unusually in the DJ / psi particle was the time of her life, about 10 thousand. time exceeds the size of which would be expected for a particle mass. Such unexpected longevity to induce the belief that the DJ / psi has some property of matter, which do not have other light particles. The need to somehow get rid of this new property, reset it and leads to delay its dissolution, as no lightest particle of this property does not possess.
Opening of Tingo and P. J / psi particle was experimental confirmation of the availability of certain properties of the fundamental particles called charmed. Even in 1963. physicists Murray Gell-Mann and George Zweig conjectured, . according to which all hadrons are composed of several fundamental particles, . that Gell-Mann called quarks Initially there were three types of quarks: the upper, . bottom and strange, . and they allow to describe all hadrons, . which were known before the opening of DJ / psi particle,
. But in 1964. Sheldon L. Glashow and James D. Bjorken argued in favor of the existence of a fourth quark, called a charmed quark, which could explain some of the features in the interactions of known particles. Opening DJ / psi particles confirmed the hypothesis Glashow Bjorken, since the particle was composed of a charmed quark associated with the charm antiquark. Since then, dozens of others were open charmed particles. Many of them were first discovered by a group R.
P. and Tingv 1976. were awarded the Nobel Prize in Physics "for pioneering work on the discovery of a heavy elementary particle of a new type '. In his Nobel lecture P. described his scientific career as a 'long history of love ... electron. Like most such stories, she knew during combustion and cooling, but as for me, the joy has always outweighed the disappointments'. Award of the Nobel Prize for discoveries made only two years ago - an event extremely rare for the Royal Swedish Academy of Sciences. However, as noted R., 'my work, and Ting gave essentially instantaneous confirmation of the correctness of our search. "
Since 1979, Mr.. R. has served as a professor at Stanford, combining his duties with work on the accelerator SLAC. He is also a consultant to U.S. Department of Energy.
In 1960, Mr.. R. married to assistant administrator at Stanford University Lauroze Becker. They have a son and daughter's colleagues speak of P. as a sensitive man with a truly inexhaustible sense of humor. In his spare time he likes walks, ski, play squash and do the work in its own garden.
In addition to the Nobel Prize, P. awarded the memory of Ernest Orlando Lawrence Agency for Research and Development of Energy in the U.S. (1975). He is a member of the U.S. National Academy of Sciences, the American Association of Basic Sciences and the American Physical Society.