EXISTENCE OF LONG-LIVED ISOTOPES OF A SUPERHEAVY ELEMENT IN NATURAL Au

Abstract

Evidence for the existence of long-lived isotopes with atomic mass numbers 261 and 265 and abundance of (1-10)x10 −10 relative to Au has been found in a study of natural Au using an inductively coupled plasma -sector field mass spectrometer. The measured masses fit the predictions made for the masses of 261 Rg and 265 Rg (Z=111) and for some isotopes of nearby elements. The possibility that these isotopes belong to the recently discovered class of long-lived high spin superand hyperdeformed isomeric states is discussed.

Icp-SFMS Search for Long-Lived Naturally-Occurring Heavy, Superheavy and Superactinide Nuclei Compared to Ams Experiments

“…We argue that it may not be surprising that results obtained from small random samplings of inhomogeneous natural minerals would contrast with concentrations found in homogeneous materials extracted from large quantities of ore. We also point out that it is possible that the groups of counts at masses 296 and 294 seen by Dellinger et al could be, within experimental uncertainties, due to Another comment we would like to make is related to the conclusion of Dellinger et al that based on their results, there are no naturally-occurring SHEs. In addition to what was mentioned above [4][5][6][7] and also in [9], it seems to us that even their results could indicate the contrary. We refer in particular to Fig.…”

“…(However see below.) As for ThO 2 , we do not think, that based on a single measurement using a very complicated system, one can conclude that all our measurements [4][5][6][7] done with the relatively straightforward ICP-SFMS system are artifacts. It would be more convincing to point out a weakness in our measurements, which neither we nor Dellinger et al [1][2][3] have been able to find.…”

“…An important difference between our works [4][5][6][7] and those of Dellinger et al [1][2][3] is that we used processed Au and Th starting materials, and Dellinger et al, except for a few cases, used raw minerals. It may not be surprising that results obtained with random samplings of a few mg would contrast with concentrations found in processed homogeneous starting materials which probe a large amount of natural ore.…”

“…−11 relative to 232 Th) [4], in the superheavy nuclei 261,265 Rg (abundance of (1-10)x10 −10 relative to Au) [5,6] 1 , and in the superactinide nucleus 292 eka-Th (abundance of (1-10)x10…”

Accelerator mass spectrometry – from DNA to astrophysics

“…However, the group of A. Marinov et al from Jerusalem recently reported positive evidence from highresolution inductively coupled plasma -sector field mass spectrometry (ICP-SF-MS) for long-lived neutrondeficient Th isotopes [29], neutron deficient Rg isotopes in gold [30], and a SHE nuclide with A = 292 and Z ~ 122 in thorium [31]. This triggered extensive AMS experiments at the 14-MV tandem accelerator in Munich [32,33], and at the 3-MV VERA facility in Vienna [34][35][36].…”