Townes (Townes), Charles H.( The American physicist, Nobel Prize in Physics, 1964)
Comments for Townes (Townes), Charles H.
Biography Townes (Townes), Charles H.
genus. July 28, 1915
American physicist Charles Hard Townes was born in Greenville (South Carolina), he was the fourth of six children of Henry Keith Townes, a lawyer, Sumter, and Ellen (nee Hardy) Townes. Growing up on a farm of twenty acres in the vicinity of Greenville, the boy began to show early interest in nature. Finding a brilliant school and skipping the seventh grade, he enrolled in Furmanska University in Greenville at the age of 16. He graduated in 1935. with double honors, he became a Bachelor of Science in Physics and Bachelor of Arts in Modern Languages. Although he chose physics of their main occupation, attracted by its logic and elegance of its structure, it is a life well read in French, German, Spanish, Italian and Russian languages. After one year of postgraduate study at Duke University T. received a master's degree in physics in 1936, and then a doctorate in 1939. the California Institute of Technology. His doctoral thesis was called 'isotope separation and determination of the nuclear spin carbon-13' ( 'The Separation of Isotopes and the Determination of the Spin of the Nucleus of Carbon 13').
The first job of T. held in the laboratories of the telephone companies 'Bell', where he stayed from 1939 to 1947, engaged primarily and very successfully tasks of military-applied nature, such as the development of aviation radar for precision bombing. It is noteworthy that once was his success in predicting failure. During the war, used in radar wavelength of 3 cm (corresponding frequency 10000 MHz). After the war leadership of the Air Force asked the company 'Bell' to develop radar that would work at a wavelength of 1.25 cm (24 000 MHz). A high-Radar was not only to ensure greater accuracy, but also had to have less weight and take up less space in the plane. T. predicted that the new system would be ineffective, because water vapor in the atmosphere absorb the energy of this particular frequency. Not convinced of this, the Air Force built the radar, and their unlucky. However, this case aroused the T. interest in the interaction of high-frequency radio waves (microwaves) with molecules.
In 1948, Mr.. T. was appointed associate professor of physics at Columbia University. He became executive director of the University Radiation Laboratory in 1950, headed the Physics Department from 1952 to 1955. and remained at the university full professor until 1961,. During this period he also studied music and vocal music classes in evening schools Zhuyyara. Carrying out research at Columbia University, T. realized that the absorption of microwaves can be the basis for new technology - microwave spectroscopy, which allows to determine the structure of molecules.
During the T. in the company 'Bell' radar waves generated by electrons oscillating inside a metal resonators, whose dimensions were determined with high accuracy. These dimensions are determined by the wavelength and the shortest attainable wavelength was about 1 mm (300 000 MHz). T. conceived as opposed to the use of the natural properties of the molecules to overcome these limitations.
In the late XIX - early XX century. Physics found that molecules and atoms of energy takes discrete values and the smallest of the energy states, or levels, is called the ground state. The set of 'acceptable' levels individually for each atom or molecule. The energy associated with configuration and movement of electrons around the nucleus of an atom. Similarly, the electromagnetic radiation in the form of, for example, heat, radio waves or light consists of discrete bundles of energy (photons), whose magnitude is proportional to the frequency of waves. Atom or molecule can absorb photons, whose energy is equal to the difference between the two levels, and rise as a result of a higher energy level. In this case we say that the atom is in an excited state. Excited atoms or molecules possess eledovatelno, excess energy. Shortly after the excitation, they move to a lower energy levels spontaneously, highlighting energy as a photon, equal to the difference between the two levels. In 1917, Mr.. Albert Einstein discovered the induced radiation, the third process in the interaction of radiation with matter, in addition to the absorption and spontaneous emission. In this process, the excited atoms or molecules, . radiation-exposed, . photon energy which corresponds to the difference between excited and ground levels, . immediately returned to the ground state, . emitting photons, . indistinguishable from those, . which stimulated this return.,
. realized that the stimulated emission provides a way to release excess energy of excited molecules by increasing the radiation, causing a release. In order to do it, it was necessary to obtain a large number of excited molecules, comparable to the number of molecules in the ground state. T. found a practical way to implement this plan with the help of positive feedback in a resonant circuit, similar in essence with the oscillators that generate radio waves in the transmitter.
. Nikolai Basov and Aleksandr Prokhorov (USSR) came to similar conclusions independently
. T. with graduate students at Columbia University has built a working device in December 1953. and called it 'maser' - an abbreviation of the English expression microwave amplification by stimulated emission of radiation: microwave enhancement using induced (stimulated) radiation. In the first maser molecule of ammonia passed through the electric field of special configuration, which repelled molecules in the ground state, and focusing the excited molecules in a resonant cavity. When the cavity had accumulated a sufficient concentration of excited molecules, it becomes possible oscillation. A small amount of radiation desired frequency (with photon energy, . equal to the difference between the ground and excited states of a molecule of ammonia) can cause an avalanche-like growth stimulated emission, . excitation of even larger numbers of molecules, . in the ground state, . and an even greater increase of the radiation,
. The result is a powerful amplifier radiation. Energy difference in the ground and excited states in the ammonia molecule determines the photon energy is released and, consequently, the frequency, which in this case lies in the microwave range.
. It soon became clear that the masers have such a stable frequency, which can serve as a high-precision clock
. With the help of two masers T. and his colleagues have tested and confirmed the special theory of relativity, where the check was later called the most accurate physical experiment in history.
During his sabbatical in Paris in 1956. T. with colleagues at the University of Paris showed that maser action can be accomplished through a process of three levels in some solid crystals containing impurities. Radiation of a suitable frequency can excite the atoms of impurities to the highest of three levels. Then these atoms, losing part of its energy, are 'caught' relatively stable intermediate energy state. Then to maser action and the allocation of excess energy in the form of radiation is added to the jump from intermediate to ground state, accompanied by increased input radiation at the same frequency. In such a system to the physical carrier maser should have put more energy frequency (with a shorter wavelength) than the increases, because the atoms have to bring to a higher, third, the level. Soon maser was to serve as a highly sensitive amplifier with low noise for the reception of microwaves in many different systems. For example, in astronomy, he has allowed to identify radio sources at great distances from Earth.
In 1958, Mr.. T. and his brother-Arthur L. Schawlow state requirements that must be done to build a maser operating in a high-frequency region corresponding to the infrared, visible and ultraviolet light. Two years later, American physicist Theodore Maiman built such a device, . emitting red light, . in which a resonant cavity used a rod of synthetic ruby with mirrored ends, . and the atoms were excited chromium atoms, . embedded in ruby,
. This device called a laser from the English expression of light amplification by stimulated emission of radiation - light increased with the induced (stimulated) radiation. Further development of the laser was of an avalanche process, leading to the formation of a new field, called quantum electronics. Today, lasers are used in communications, engineering, medicine, tools and measuring devices, in art and in military fields
T: Section 1964. Nobel Prize in physics with Nikolai Basov and Aleksandr Prokhorov "for fundamental work in quantum electronics, which led to the creation of oscillators and amplifiers based on the maser-laser principle."
From 1959 to 1961. T. was Vice President and Director of Research Institute of Defense Studies, dealing with defense, strategy and weapons systems. In 1961. he was appointed vice-rector and professor of physics at MIT and in 1966. was appointed university professor of physics at the University of California at Berkeley, where he works in that capacity today.
During the service at the Institute for Defense Studies T. continued to participate actively in the development of science policy in the work of numerous local and government committees. University of California at T. and his colleagues in the field of infrared and microwave astronomy opened the first polyatomic molecules in interstellar space, namely, the molecule of ammonia and water. He also introduced a new modern methods of infrared detection using laser oscillators, in astronomical spectroscopy and interferometry. This work led to the creation in 1987. sliding infrared telescopes, which, according to TV, will distinguish up to 100 times more detail than the usual radio telescope.
T. was a member of the Board Solkovskogo Institute for Biological Studies from 1963 to 1968. and companies 'Rand Corporation' in 1965 ... 1970. He was a member of the Scientific Advisory Group United States Air Force from 1958 to 1961. and head of the Scientific and Technological Consultative Committee on manned space flight at NASA from 1964 to 1969. In 1969. he is a member of the Presidential Panel on national science policy, in 1971 ... 1973. - Scientific Advisor to the company 'General Motors'.
In 1941, Mr.. T. married Francis Brown. They have four daughters. Amateur naturalist, T. fond of music, languages, scuba diving and traveling.
In addition to the Nobel Prize, T. Comstock won the U.S. National Academy of Sciences (1959); medal Stuart Ballantyne Franklinovskogo Institute (1959, . 1962); Prize Electronics, David Sarnoff of American Electric Institute (1961), John Carty medal of the U.S. National Academy of Sciences (1962), an honorary medal for public activity, . awarded by NASA (1969), an international gold medal of Niels Bohr, the Danish Society of Mechanical Engineers - Builders, . electricians and mechanics (1979) and the National Medal 'For his scientific achievements' of the National Science Foundation (1982),
. He is a member of the U.S. National Academy of Sciences, Institute of Electrical and Electronics Engineers, the American Academy of Arts and Sciences, the American Philosophical Society and the American Astronomical Society. Is a foreign member of the Royal Society of London. He received honorary degrees from more than twenty colleges and universities and is a member of the editorial boards of the journals 'Review of sayentifik Tool' ( 'Review of Scientific Instruments'), . 'Fizikal Review' ( 'Physical Review'), . 'Journal of molecular spectroscopy' ( 'Journal of Molecular Spectroscopy').,