| Popis: |
Samples of monazite from Australia; Malaysia; South Africa; Georgia, U.S.A.; and Madagascar were examined by using a multiplicity counter capable of detecting coincident neutrons from binary or ternary spontaneous fission decay of any element. Corrections were made for empty counter background, uranium spontaneous fission, muon reactions with rare earth and thorium, and neutron absorption by Sm and Gd. The corrected counts showed no evidence of spontaneous fission decay of superheavy elements. Derived limits indicate that if superheavy elements were present, their spontaneous fission half-lives must be extremely long or their concentrations extremely small. |
