Relative yields of stable tin isotopes in neutron-induced fission

Laeter, J. R. De; Thode, H. G.

doi:10.1139/p69-181

Cited by 9 publications

(2 citation statements)

References 2 publications

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“…[11] have also predicted a dip at mass number III. Investigations by DE LATER and THODE [12] and ROSMAN eta/. [13] on Sn isotopes for the mass numbers 117,118,119,120,122,124 and 126 did not lead to any such fine structure or dip but it may be mentioned that these investigators did not include the fission yields for mass numbers 121,123 and 125.…”

Section: Uranium-233mentioning

confidence: 96%

Fission Yields in the Thermal Neutron Fission of ²³³U,²³⁵U,²³⁹Pu and ²⁴¹Pu

1987

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J3 3 -23 Sjj _ 23 9-2 4 n>" / Thermal neutron fission /Fission yields 2. Experimental AbstiactFission yields for 40 mass numbers in the thermal neutron fission of'"U, "'U, "'Puand '"Pu were determined under identical conditions of neutron irradiation and measurements using mass spectrometric, gamma spectrometric and radiochemical methods. The estimated uncertainties on the fission yield values determined using the mass spectrometric method are 1 -3%. Those determined using the gamma spectrometric and the radiochemical methods have an uncertainty of about 4% on the fission yield values in the asymmetric region (yields greater than 1%) and upto 12% on the fission yield values in the Symmetrie region. Fission yield values in the light mass peak of " 'Pu(nth, f) and '*'Pu(nth,0 aswell as in the Symmetrie region for '"U(n{i,,f) and '"Pu(nth,f) give import information about fine structure and the extent of Symmetrie and asymmetric fission in mass distribution.

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Section: Uranium-233mentioning

confidence: 96%

Fission Yields in the Thermal Neutron Fission of ²³³U,²³⁵U,²³⁹Pu and ²⁴¹Pu

1987

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“…Most elements are multi-isotopic, and hence a number of fission yields can be determined from a mass spectrometric analysis of the one element. In the case of Sn, the relative cumulative fission yields of six fission chains- 117,118,119,120,122, and 124 Sn can be determined from the mass spectrometric analysis of the one element, and valuable information on the mobility of Sn in the reactor zones from the long-lived radioactive precursor 126 Sn in the mass 126 fission chain can also be obtained (De Laeter & Thode, 1969).…”

Section: Fission Yields and The Nier Sector-field Mass Spectrometermentioning

confidence: 99%

The role of mass spectrometry to study the Oklo–Bangombé natural reactors

Laeter

Hidaka

2007

Mass Spectrometry Reviews

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The discovery of the existence of chain reactions at the Oklo natural reactors in Gabon, Central Africa in 1972 was a triumph for the accuracy of mass spectrometric measurements, in that a 0.5% anomaly in the (235)U/(238)U ratio of certain U ore samples indicated a depletion in (235)U. Mass spectrometric techniques thereafter played a dominant role in determining the nuclear parameters of the reactor zones themselves, and in deciphering the geochemical characteristics of various elements in the U-rich ore and in the surrounding rock strata. The variations in the isotopic composition of a large number of elements, caused by a combination of nuclear fission, neutron capture and radioactive decay, provide a powerful tool for investigating this unique geological environment. Mass spectrometry can be used to measure the present-day elemental and isotopic abundances of numerous elements, so as to decipher the past history of the reactors and examine the retentivity/mobility of these elements. Many of the fission products have a radioactive decay history that have been used to date the age and duration of the reactor zones, and to provide insight into their nuclear and geochemical behavior as a function of time. The Oklo fission reactors and their near neighbor at Bangombé, some 30 km to the south-east of Oklo, are unique in that not only did they become critical some 2 x 10(9) years ago, but also the deposits have been preserved over this period of geological time. The long-term geochemical behavior of actinides and fission products have been extensively studied by a variety of mass spectrometric techniques over the past 30 years to provide us with significant information on the mobility/retentivity of this material in a natural geological repository. The Oklo-Bangombé natural reactors are therefore geological analogs that can be evaluated in terms of possible radioactive waste containment sites. As more reactor zones were discovered, it was realized that they could be classified into two groups according to their burial depth in the Oklo mine-site. Reactor Zones 10, 13, and 16 were buried more deeply, and were therefore less weathered than the other zones. The less-weathered zones are of great importance in mobility/retentivity studies and therefore to the question of radioactive waste containment. Isotopic studies of these natural reactors are also of value in physics to examine possible variations in fundamental constants over the past 2 billion years.

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