Transfermium Working Group

Wetherill GW (1975) diometiic chronology of the early solar system. Ann Rev Nud Sci 25 283 Wilczynski J, Volkov W, Decowski P (1967) Some features of the mechanism of many-neutron-transfer reactions. Sov J Nud Phys 5 672 Yad Fiz 5 942 Wilkins BD, Steinberg EP, Chasman RR (1976) Scission-point model of nuclear fission based on deformed-shell effects. Phys Rev G 14 1832 Wilkinson DH, Wapstra AH, Ulehla I et al (1993) Discovery of the transfermium dements, Report of the Transfermium Working Group of lUPAC and lUPAP II, Introduction to discovery profiles. III, Discovery profiles of the transfermium elements. Pure Appl Chem 65 1757, 1764 Willard JE (1953) Chemical effects of nuclear transformations. Ann Rev Nud Sci 3 193... 

The discovery of elements 93 to 103 is summarized in Table 18.1. The names and symbols from element 101 through 103 were approved in 1992 by lUPAC (International Union of Pure and Applied Chemistry) based on the report of the Transfermium Working Group (TWG) (Barber et al. 1992), which consisted of scientists appointed by both lUPAP (International Union of Pure and Applied Physics) and lUPAC. 

The decision on the priority of the discovery of a new chemical element is the responsibility of the lUPAC. The detailed definition of the criteria for the discovery of a new element was prepared by the Transfermium Working Group (Barber et aL 1992). O Table 19.2 displays the elements for which the priority of discovery has been assigned. The lUPAC accepted the following names and symbols for the transactinides (Sargeson 1997). The laboratories associated with their discovery as accepted by lUPAC are given in parentheses (Barber et al. 1992, 2009 Karol et al. 2001, 2003). 

The general problem is however, that superheavy nuclei are the very definition of terra incognita being as they are at the frontiers of the chart of nucKdes with unknown properties. Therefore, all such evidence is of limited value for the identification of a new element and while necessary, it is not sufficient to make a conclusive determination according to the rules of lUPAC as elaborated by the transfermium working group (Barber et al. 1992). 

Allred Nobel was immediately accepted by the lUPAC. However, experiments at Berkeley and the Kurchatov Institute in Moscow showed that the original Swedish claim to have prepared element 102 was in error. Attempts to synthesize and identify isotopes of element 102 in heavy ion bombardments of actinide targets dragged on for many years at the laboratories in Berkeley and EHibna, Russia. Thus, scientists from Berkeley suggested that the credit for the discovery should be shared. But, in 1993 the lUPAC-lUPAP Transfermium Working Group concluded that the Dubna laboratory finally achieved an undisputed synthesis. 

The early history of experiments on the synthesis of the light transactinides is complicated by the report of results that could not be reproduced in subsequent experiments. The international union of pure and applied chemistry (lUPAC) and the international union of pure and applied physics (lUPAP) established a working group to answer questions of priority in the discoveries of the transfermium elements the report generated by the group [136] provides a reasonable analysis (though not without flaws) of the pertinent literature and underlies the following discussion. 

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