Plutonium synthesis

Kilogram amounts of neptunium ( Np) have been isolated as a by-product of the large-scale synthesis of plutonium in nuclear reactors that utilise 235u and 238u as fuel. The following transmutations occur ... 

One of the major advances of science in the first half of this century was the synthesis of ten elements beyond uranium. Glenn T. Seaborg participated in the discovery oj most of these, a sufficient tribute to his outstanding ability as a scientist. For the first such discoveries, those of neptunium and plutonium, he shared with Professor Edwin M. McMillan the Nobel Prize in Chemistry for 1951. 

Hydrazine, bis(allylthiocarbamido)-in gravimetry, 1, 534 liquid-liquid extraction, 1,546 Hydrazines, 2, 101 macrocyclic synthesis, 2,904 metal complexes, 2, 30 in plutonium extraction, 6, 948 Hydrazoic acid... 

The chemistry of a single element is rarely the focal point of a symposium, but the occasion of the 40th anniversary of the first synthesis and weighing of pure compounds of plutonium suggested to us that such a symposium would be both timely and productive. The interest, enthusiasm, and stimulating interaction that the symposium generated showed that this supposition was indeed correct. 

Although much of the preceding discussion involved the synthesis of new molecules by organic and inorganic chemists, there is another area of chemistry in which such creation is important—the synthesis of new atoms. The periodic table lists elements that have been discovered and isolated from nature, but a few have been created by human activity. Collision of atomic particles with the nuclei of existing atoms is the normal source of radioactive isotopes and of some of the very heavy elements at the bottom of the periodic table. Indeed nuclear chemists and physicists have created some of the most important elements that are used for nuclear energy and nuclear weapons, plutonium in particular. 

Curium can be synthesized in a nuclear reactor by several methods. The first synthesis involved alpha particle bombardment of plutonium-239 ... 

Nohehum may he synthesized by several methods involving irradiation of isotopes of curium, plutonium, and fermium in the form of thin targets with heavy ions of boron, carbon, and oxygen using double-recod technique. The nuclear reaction in the synthesis of No-254 carried out by Ghiorso and his group is as foUows ... 

Plutonium is produced from natural uranium which is a mixture of nonfis-sionable uranium-238 (99.3%) and fissionable uranium-235(0.7%). The first synthesis of this element was in a cyclotron generating plutonium in microgram quantities. The isotope Pu-239 can be produced in much larger quantities in a nuclear reactor, either a conventional thermal reactor or a breeder type reactor by neutron bombardment of uranium- 238. The nuclear reactions are shown below. 

Synthesis of plutonium in significant quantities requires a sufficiently long reactor fuel irradiation period. Uranium, plutonium, and the fission products obtained after neutron irradiation are removed from the reactor and stored under water for several weeks. During such cooling periods most neptunium-239 initially formed from uranium and present in the mixture transforms to plutonium-239. Also, the highly radioactive fission products, such as xenon-133 and iodine-131 continue to decay during this period. 

The complexity of the reactions involved in the bombardment of plutonium and the production of higher transuranium elements can be seen from the following scheme which indicates the method of synthesis of einsteinium and fermium ... 

Other nuclear transmutations can lead to the synthesis of entirely new elements never before seen on Earth. In fact, all the transuranium elements—those elements with atomic numbers greater than 92—have been produced by bombardment reactions. Plutonium, for example, can be made by bombarding uranium-238 with a particles ... 

Recently, three more elements have been detected. Synthesis of element 114 was reported 1999 at Dubna by Oganessian et al. who irradiated plutonium with Ca. Formation of 114 was inferred from the following decay chain ... 

Plutonium complex H[Pu02(0x)3] is described in the work [138]. Another attempt to synthesize solid Pu compounds with Ox was made in the work [65], but authors found that Pu(VI) is reduced in conditions suitable for synthesis. Work [103] describes structure of Np complex with bis(salicylidene)-ethylenediamine [Np02(0H4C6HC=NCH2CH2N=CHC6H40)(CH30H)] (26). 

Seaborg s contributions illustrate how certain areas of science can be highly influenced by a particular institution or even a national tradition over time. His discovery of plutonium at the University of California at Berkeley followed the 1940 synthesis of neptunium at the same site by Edwin... 

It is is the third most toxic substance known after plutonium and botulism it is a protein toxin that is extracted from the castor bean (Ricinus communis). The USA Centers for Disease Control (CDC) considers 500 pg to be the lethal dose of ricin in humans if exposure is from injection or inhalation. Ricin is poisonous if inhaled, injected, or ingested, acting by the inhibition of protein synthesis. While there is no known antidote, the US military has developed a vaccine. 

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