Evidence for Primordial Superheavy Elements

Gentry, Robert V.; Cahill, Thomas A.; Fletcher, N.R.; Kaufmann, Henry C.; Medsker, Larry R.; Nelson, J.W.; Flocchini, Robert G.

doi:10.1103/physrevlett.37.11

Cited by 152 publications

(32 citation statements)

References 12 publications

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“…Recent proton-induced x-ray studies by Gentry et al [1] on some monazite inclusions showing "giant" halo formation in biotite mica have caused quite an excitement amidst the scientific community. As suggested by Gentry [2], the large halos with radii up to 100 ~tm, occasionally observed around monazite inclusions in biotite, may be due to the radiation damage caused by long-range alpha particles with energies up to 14 MeV.…”

Section: Introductionmentioning

confidence: 99%

On the possible existence of superheavy elements in monazite

et al. 1977

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Proton-induced x-ray studies of monazite grains from different occurrences show no evidence for primordial superheavy elements. It is demonstrated that the recently reported evidence for superheavy elements in monazite inclusions of biotite mica showing giant halo formation is not significant: the observed differences in the x-ray spectra of normal and giant halo inclusions are due to different backgrounds in the respective spectra. Moreover, it is shown that the 27.2 keV line tentatively interpreted as theL~l x-ray of element Z = 126 can be entirely attributed to the reaction 14~ ny)14~

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Section: Introductionmentioning

confidence: 99%

On the possible existence of superheavy elements in monazite

et al. 1977

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“…Although the details of the final purification steps would need to be developed, it seems probable that washing, extracting back into the aqueous phase, following an appropriate reduction, elution from an ion exchange column and a final extraction and back extraction from an organic phase as used in the isolation of 244pu from nature [7] would prove to be successful. In view of the reported observation of hundreds of picograms of element 126 in microscopic inclusions in mica [1], it would appear probable that the half life of element 126~5 x l0 s years. Furthermore, the shell energies I-2] calculated for element 126 suggest that its initial terrestrial abundance should have exceeded the abundances of nearby elements.…”

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confidence: 99%

“…The recently [1] reported observation of naturally occurring super heavy elements in microscopic monazite inclusions in certain micas showing giant halo formation, if correct, has far-reaching consequences. It implies the existence in nature of a new island of stability in the region around proton number 126 and most probably [2] neutron number 228.…”

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confidence: 99%

A suggested source of element 126

Sheline¹

1976

Z Physik A

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“…The possible evidence [1] of the elements Z=l16 or 127, 124 and 126 is based on proton-induced X-ray spectroscopy considering the 2p3/2 level as final state. There are numerous transitions in several elements which can account for the measured energies but which can be ruled out either by too low a transition rate or the absence of other dominant transitions in the same energy range [2].…”

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confidence: 99%

“…In the following we give a short review of the formalism and finally we discuss the numerical results. In first order time-dependent perturbation theory the transition probability per unit time of bound electrons is given by Fermi's golden rule 12 ,o(Ef) (1) where N means averaging over initial states and summation over final states. In this chapter we use natural units (h=me=c=l) throughout.…”

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confidence: 99%

Transition rates of electrons in superheavy elements

Soff

Müller

1977

Z Physik A

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Transition rates for electrons in the superheavy elements Z = 114, 126, 134, 145, 164 and 173 are calculated. K, L and M-shells are considered as final states. The 2s-1 s transition of multipolarity M 1 is dominant for Z = 173 with a transition time of 10-18 s. The radical expectation values (r) and (r2) ~/2 are given.The precise knowledge of electronic transition rates is necessary for the experimental identification of superheavy elements by their characteristic X-rays. The possible evidence [1] of the elements Z=l16 or 127, 124 and 126 is based on proton-induced X-ray spectroscopy considering the 2p3/2 level as final state. There are numerous transitions in several elements which can account for the measured energies but which can be ruled out either by too low a transition rate or the absence of other dominant transitions in the same energy range [2]. The quasimolecular spectroscopy in heavy ion collisions even allows the investigation of systems with a total nuclear charge of Z=184 (U+ U). MO-X rays for systems up to Z=145 (I+ U) have been observed by several groups [3-73 . The identification of the measured lines results from a good agreement with relativistic Hartree-Fock-Slater (HFS) calculations [8,9]. For a theoretical explanation of quasimolecular spectra in strong electromagnetic fields (Z e > 1) an evaluation of electronic transition rates is necessary in order to include all dominant modes into the calculation. Because of the experimental accuracy concerning electronic transition rates in high Z elements the difference between a multiconfiguration HF [10] and a HFS [11,12] calculation can be neglected. Therefore using the relativistic HFS model and following the lines of Scofield [13] we evaluated electronic transition rates for the superheavy elements Z=l14 and 164 (the possible islands of nuclear stability [14, 153) Increasing the nuclear charge the Is-electron would dive into the Dirac sea, which opens the possibility of spontaneous positron creation [16,17]. The dived electron has no pure bound state character and includes a continuum part which cannot be handled within the used computer code [11,12]. As initial state we take into account all electrons up to the 4f7/2 level. In the following we give a short review of the formalism and finally we discuss the numerical results. In first order time-dependent perturbation theory the transition probability per unit time of bound electrons is given by Fermi's golden rule with j = -e e, ~ are the usual Dirac matrices. We expand the A-field in electric and magnetic multipoles [13,18]. It follows

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Evidence for Primordial Superheavy Elements

Cited by 152 publications

References 12 publications

On the possible existence of superheavy elements in monazite

On the possible existence of superheavy elements in monazite

A suggested source of element 126

Transition rates of electrons in superheavy elements

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