A Radiochemical Study for the α-Decay of ^<229m>Th(II. Radiochemistry)

概要

論文の詳細を見る
The decay of low energy isomeric state of ^<229>Th was explored applying a novel radiochemical technique to the (γ, xn) reaction products on ^<230>Th target. The decaying α-emitter was observed between 4.687 MeV α-peak of ^<230>Th and the α-peaks of the (γ, 2n) product ^<228>Th. The energy of the decaying component is consistent with the expected energy for the α-particles from ^<229m>Th. The half-life of the decaying component was determined to be 13.9±3 hours. It seems that the present determination of the half-life is the longest value for ^<229m>Th, because fluoride has no valence electrons that undergo electronic bridge interaction with the thorium nucleus.
東北大学の論文