Biographical Memoirs Volume 45 (1974) / Chapter Skim
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Irving Langmuir
Irving Langmuir
Pages 227-261
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They continued to increase steadily as efficiency improved. Further improvements in incandescent lamps were to be made in various laboratories, but Coolidge's tungsten filament and Langmuir's gas filling remain today two basic elements of incandescent lamps.
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The Electron Emission from Thoriated Tungsten Filaments (1921) Atomic Hydrogen Arc Welding (1926~.
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He received the Nobel Prize in 1932. Later he devoted his time more to "science out-of-doors." SCIENTIFIC WORK Irving Langmuir's scientific career covered fifty years, starting in 1904 with his doctoral dissertation at Gottingen, "Ueber partielle Wiedervereinigung dissociierter Gase im Verlauf einer Abkuhlung," and ending in 1955 with an unpublished report on "Widespread Control of Weather by Silver Iodide Seeding." In order to convey a feeling for the diversity of his work, Langmuir's published scientific work has been grouped into seven categories below, this grouping following rather closely that used by Lan'~muir himself in the Introduction to Phenomena, Atoms, and Molecules, a reprints of some twenty of his papers selected by him in 1950.
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From page 231... ...
This method of studying equilibria looked extremely attractive because of the simplicity of the apparatus involved, compared with the complexity of the equipment more generally used in such studies. This simple hypothesis proved not to be applicable to the interaction of nitrogen and oxygen in the vicinity of a glowing Nernst filament, and the thesis effort was shifted to studying other gaseous equilibria, such as the dissociation of carbon dioxide brought about by a glowing platinum filament, where the hypothesis was found to be valid.
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From page 232... ...
At that time, all incandescent lamps were vacuum lamps, and the general feeling was that, if the vacuum could be made better, the life of the lamp would be improved. Langmuir, on the other hand, had been impressed with how much better lamp-factory vacuum was than what had been available to him at the university, and, not knowing how to improve on this, he resolved to see what effects the opposite approach of adding various gases would have on the life of tungsten lamps.
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From page 233... ...
THERMAL EFFECTS IN GASES Lan,~muir had established that, apart from a special chain reaction with water vapor, the life of a tungsten vacuum lamp was insensitive to the residual gases usually present and was determined entirely by the evaporation of tungsten. This encouraged him to experiment with lamps containing much higher pressures of inert gases and to study heat losses from filaments under these conditions.
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From page 234... ...
This led Langmuir to the invention of the atomic hydrogen welding torch, in which large amounts of atomic hydrogen are produced by an arc between tungsten electrodes in hydrogen, and the atoms are allowed to recombine on the metal to be heated. ATO M I C STRU CTURE Some of Lan~muir's most productive thinking was guided by consideration of the differences between what he called "physical forces" and "chemical forces." This thinking led to his concept of the adsorption process and also to his rather brief sortie into the field of atomic structure during 1919-1921.
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From page 235... ...
Because of this he apparently made a decision not to develop a working knowledge of these new tools for himself, but to continue his work where more classical methods were still fruitful. THERMIONIC EMISSION AND SURFACES IN VACUUM As a natural outgrowth of his earlier work on tungsten lamps, Langmuir entered the field of thermionic emission in 1913 to answer the specific question of why relatively large electron currents did not appear as shunt currents from the negative leg to the positive leg of a tungsten lamp with a hairpin filament.
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From page 236... ...
The 3/2 power law became an important issue in a hard-fought patent suit concerning electron discharges in very high vacuum, a major result of which, perhaps, was to illustrate the difficulty of patenting something that came so close to being a law of nature. Thorium oxide is added to tungsten lamp filaments to improve their mechanical behavior at high temperatures, and it had been observed sporadically that abnormally high thermionic emission was obtained from some lamp filaments.
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striking a tungsten filament are robbed of an electron by the filament (work function 4.5 volts) and come off as positive ions that may be collected at a negative electrode.
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Langmuir made an early application of his ideas on surface films to the study of films on water surfaces, an area of science to which his attention had been drawn by the beautifully simple experimental techniques developed over the years by Miss
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He was impressed with the opportunities for electron tubes capable of controlling high power and endeavored to apply the newly understood phenomena of vacuum electron amplifier tubes to the much larger currents of gas tubes. Ernst F
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Langmuir's activity in the gas-discharge field developed rather slowly, but in 1923 he was analyzing the current-voltage characteristics of currents to probe electrodes placed in a mercury arc. He found that the current to a negatively charged plane collector was independent of voltage over a wide range and showed by "ridding tests that the current was due to the arrival of positive ions rather than the emission of photoelectrons.
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From page 241... ...
Langmuir and Tonks also made a study of electrical oscillations in an ionized gas. Langmuir was so impressed with the implication of organization and structure in the ionized gas, evidenced by the capability of oscillation, that he adopted the word "plasma" to indicate the fundamental nature of a volume of ionized gas essentially free of space charge.
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From page 242... ...
offered an excellent opportunity for the study of chemical reactions at high temperatures and low pressures; his attack on the random, anomalously high electron emission observed from tungsten filaments containing thoria; his appreciation of the possibilities of the surface tension trough for the study of surface film phenomena, coupled with the insight that his ideas on localized "chemical forces" gave him into the fundamentals of the problem; and his realization of the power of the probe-characteristic technique for studying the mechanism of electric discharge in gases. Langmuir's brilliant insight into fruitful directions for applying his effort was coupled with the characteristic of being a tremendous worker.
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From page 243... ...
Some of these were of great practical importance, such as the gas-filled incandescent lamp, high-vacuum electron tube principles, the condensation pump, the thoriated tungsten filament, atomic hydrogen welding, the grid-controlled arc, and the military smoke generator. Much of Langmuir's scientific work lay in areas in which there was little opportunity for patent protection, but whenever the opportunity existed, Langmuir was .
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From page 244... ...
At one time, when the electron emission studies were very active, Langmuir's notebook gave a list of some eighty-two experiments that he was interested in having Sweetser do. With such a backlog of work it would seem that the direct experimental staff might have been expanded, but apparently Langmuir preferred not to do this.
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He died August 16, 1957. HONORS Among scientific honors that were bestowed on Langmuir, the Nichols Medal, awarded by the New York Section of the American Chemical Society, was twice given to him, once in
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In the same year, Popular Science Monthly magazine awarded him its annual medal and honorarium of $ 10,000 for "an American who has done notable scientific work." The Franklin Medal of the Franklin Institute and the Holly Medal of the American Society of Mechanical Engineers were given him in 1934, and the city of Philadelphia presented him the John Scott Award in 1937. In 1940 he received a plaque as a "Modern Pioneer of Industry" from the National Association of Manufacturers, and in 1943 he became an honorary member of the British Institute of Metals.
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An honorary member of several societies, including the Chemical Society of London, Langmuir held honorary degrees from the following colleges and universities: Northwestern, Union, Edinburgh (Scotland) , Columbia, Kenyon, Princeton, Lehigh, Harvard, Oxford, Johns Hopkins, Rutgers, Queens (Canada)
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Electrochem. Zeitschrift ffir Electrochemie 1906 Ueber partielle Wiedervereinigung dissociierter Gase im Verlauf einer Abkuhlung.
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Soc., 24:53. Chemical reactions at very low pressures.
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Rev., 6: 138. Chemical reactions at low pressures.
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Rev., 12:368. 1919 Chemical reactions at low pressures.
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(A) The electron emission from thoriated tungsten filaments.
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Rev., 22:347. The electron emission from thoriated tungsten filaments.
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Zeitschrift fur Physik, 46:271. 1928 Electric discharges in gases at low pressures.
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Sci., 1 ~ :218. The interaction of electron and positive ion space charges in cathode sheaths.
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7. Electric discharges in gases at low pressures.
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Rev., 38:324. Electric discharges in vacuum and in gases at low pressures.
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IRVING LANGMUIR 245 With V
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Studies of the effects produced by dry ice seeding of stratus clouds. Research Laboratory Report No.
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A gamma pattern seeding of stratus clouds, Flight 52, and a race track pattern seeding of stratus clouds, Flight 53. Research Laboratory Report No.
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