Americium and Curium

perhaps, the only occasion in the history of transuranium elements that an element with a higher number (Z = == 96) was identified earlier than its predecessor Z = 95). In July 1944 the cyclotron of the University of California, 

After absorption of neutrons plutonium converted into element 95 via beta decay and this element absorbed a neutron and converted into element 96. 

This final product was similar to that which the scientists had assumed to be the isotope of element 96 with a mass number of 242. The newly discovered element was named curium after the Curies. Another factor prompted this name. In the Mendeleev table element 96 was regarded as an analogue of gadolinium belonging to the rare-earth series the history of which had been started by J. Gadolin in their turn, the Curies were the pioneers of the study of radioactivity whose development produced such amazing results. 

In January 1945 element 95 was extracted from plutonium bombarded with neutrons. The element was named americium in honour of America (and owing to its similarity to europium from the rare-earth series). 

Though the researchers had accumulated considerable experience in syntheses the difficulties involved in producing americium and curium proved unusually great. It took a long time to distinguish definitely between americium-241 and curium-242. Both isotopes proved to be not the longest- 

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In general, the absorption bands of the actinide ions are some ten times more intense than those of the lanthanide ions. Fluorescence, for example, is observed in the trichlorides of uranium, neptunium, americium, and curium, diluted with lanthanum chloride (15). 

Holden NE (1989) Total and spontaneous fission half-lives for uranium, plutonium, americium and curium nuclides. Pure Appl Chem 61(8) 1483-1504... 

Dacheux N, Aupiais J (1997) Determination of uranium, thorium, plutonium, americium, and curium ultratraces by photon electron rejecting alpha liquid scintillation. Anal Chem 69 2275-2282 Duan YX, Chamberlin EP, Olivares JA (1997) Development of a new high-efficiency thermal ionization source for mass spectrometry. Inti JMass Spectrom IonProcessesl61 27-39 Edwards RL, Chen JH, Wasserburg GJ (1987) systematics and the precise... 

Bulman RA. 1978. The movement of plutonium, americium, and curium through the food chain. 

Cooper JR, Gowing HS. 1981. The binding of americium and curium to human serum proteins. IntJ Radiat Biol 40(5) 569-572. 

Dacheux N, Aupiais J. 1997. Determination of uranium, thorium, plutonium, americium, and curium ultratraces by photon electron rejection a liquid scintillation. Anal Chem 69 2275-2282. 

Dacheux N, Aupiais J. 1998. Determination of low concentrations of americium and curium by photon/electron rejecting alpha liquid scintillation. Anal Chim Acta 363 279-294. 

Directorate of Fisheries Research. 1990. Determination of alpha-emitting nuclides of plutonium, americium and curium in environmental materials Pt. 1. Seawater. Lowestoft, England Directorate of Fisheries Research. NTIS/DE92614732. 

Ham GJ, Stradling GN, Breadmore SE. 1977. Determination of americium and curium in biological samples of extraction and liquid scintillation. Anal Chem 49 1268-1270. 

Harrison JD, David AJ, Stather JW. 1980. The wound clearance and distribution of plutonium, americium and curium in rodents. Int J Radiat Biol 37(5) 505-512. 

National Radiological Protection Board. 1982. Gut uptake factors for plutonium, americium and curium. Hartwell, England National Radiological Protection Board. DE83702055. 

Paatero J, Jaakkola T. 1998. Transfer of plutonium, americium and curium from fallout into reindeer after the Chernobyl accident. Boreal Environment Research 3 181-189. 

Poupard D, Jouniaux B. 1990. Determination of picogram quantities of americium and curium by thermal ionization mass spectrometry (TIMS). Radiochim Acta 41(l) 25-28. 

Stradling GN, Popplewell DS, Ham GJ. 1976. The chemical form of americium and curium in urine. Health Phys 31 517-519. 

Tumer GA, Taylor DM. 1968. The transport of plutonium, americium and curium in the blood of rats. Phys Med Biol 13(4) 535-546. 

Some Compounds of Americium and Curium. Report UCRL-846 (1. Aug. 1950). 

A Review of Americium and Curium Chemistry. Report A/Conf. 8/P/838. 

Street, K., and G. T. Seaborg Separation of Americium and Curium from... 

Since there is now considerable concern in the technologically advanced countries concerning the contamination of the environment by actinides, such as plutonium, americium and curium, this review attempts to present an understanding of how the actinides could concentrate and/or become transported through the biosphere to man. 

Since plutonium is the actinide generating most concern at the moment this review will be concerned primarily with this element. However, in the event of the fast breeder reactors being introduced the behaviour of americium and curium will be emphasised. As neptunium is of no major concern in comparison to plutonium there has been little research conducted on its behaviour in the biosphere. This review will not discuss the behaviour of berkelium, californium, einsteinium, fermium, mendelevium, nobelium and lawrencium which are of no concern in the nuclear power programme although some of these actinides may be used in nuclear powered pacemakers. Occasionally other actinides, and some lanthanides, are referred to but merely to illustrate a particular fact of the actinides with greater clarity. 

The behaviour of americium and curium in soil has been the subject of very few investigations. Hajek (42) observed that water and sodium nitrate (1 m) extracted americium from the soil to the extent of 7.5 % and 33% respectively. As noted earlier Knoll (40) extracted 100% of the americium in soil. 

In comparison to plutonium both americium and curium are taken up by plants quite readily. The concentration factors for both americium and curium are 10-4 to 10-2 (127). While plutonium has been the subject of considerable research into its environmental impact there have been few investigations into americium and curium. Bondi-etti et al (94) have concluded that plutonium hydroxide polymers would be resistant... 

Y. Shiokawa, S. Suzuki, in Americium and Curium Chemistry and Technology, (Eds. ... 

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