![]() ![]() It is also used on brushes for removing dust from photographic films. however, beta sources are both more commonly used and less dangerous. The element has been used in devices for eliminating static charges in textile mills, etc. Polonium can be mixed or alloyed with beryllium to provide a source of neutrons. Usesīecause almost all alpha radiation is stopped within the solid source and its container, giving up its energy, polonium has attracted attention for uses as a lightweight heat source for thermoelectric power in space satellites. Polonium slats of organic acids char rapidly halide amines are reduced to the metal. Polonium is readily dissolved in dilute acids, but is only slightly soluble in alkali. A few curies (1 curie = 3.7 x 10 10Bq) of polonium exhibit a blue glow, caused by excitation of the surrounding gas. The capsule also presents a contact gamma-ray dose rate of 0.012 Gy/h. The energy released by its decay is so large (140W/g) that a capsule containing about half a gram reaches a temperature above 500C. A milligram emits as many alpha particles as 5 g of radium. It is an alpha emitter with a half-life of 138.39 days. Polonium-210 is a low-melting, fairly volatile metal, 50% of which is vaporized in air in 45 hours at 55C. Polonium is available commercially on special order from the Oak Ridge National Laboratory. Milligram amounts of polonium may now be prepared this way, by using the high neutron fluxes of nuclear reactors. In 1934, scientists discovered that when they bombarded natural bismuth (209Bi) with neutrons, 210Bi, the parent of polonium, was obtained. ![]() Its abundance is only about 0.2% of that of radium. Uranium ores contain only about 100 micrograms of the element per ton. The electroscope showed it separating with bismuth. Curie in 1898 while seeking the cause of radioactivity of pitchblend from Joachimsthal, Bohemia. Curie) Polonium, also called Radium F, was the first element discovered by Mme. #RADIUM AND POLONIUM WINDOWS#"In England by Queen Alexandra, and in Russia by her sister, the Czarina, they both investigating the system while visiting their father, the King of Denmark." There is even a claim that Finsen was able to spare smallpox victims from scarring by keeping them in a room with red glass windows while the disease went through certain stages.(Poland, native country of Mme. to-day the world rings with his praises." It is claimed that by 1903, Finsen's work was approved of. time Finsen's work received little credence. The book concludes with nine pages concerning the work of Niels R Finsen of Copenhagen who was treating various diseases with light. Ruhmer is also credited with using a seleniun cell to turn off the lights of maritime navigation buoys during daylight hours, thus conserving the gas they burned. It recorded sound rather in the manner of a phonograph, but the sound waves were used, via a selenium cell, to vary the brightness of a beam falling on a moving strip of photographic film. The variation in the light falling on the sensor translated to a varying electrical signal which could be transmitted, then turned back into vibrations in the air.) The photographophone of Ernest Ruhmer is described. A beam of light bounced off the mirror onto a selenium object. (Bell used the sound waves to be transmitted to vibrate a mirror. Use of selenium in a "radiophone" devised by Alexander Graham Bell around 1883 is described. A quantitative measurement of an eclipse of the sun, by means of a selenium based sensor, is reported. There are 21 pages devoted to "The properties and applications of selenium", including the use of its changing electrical resistance in different light levels. Alpha, Beta, Gamma, X-rays, including radiographs of mice made by the latter, and experiments into the lethal effects both of X-rays and of radioactive sources.The work of Pierre and Marie Curie, Dewar, Roentgen, Henri Becquerel, Rutherford, J.In addition to the matters implied by the title of the lecture, ( radium, polonium, actinium, thorium) Hammer discusses such things as: ![]()
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