Nuclear Data Sheets for A = 224

Abstract

The experimental nuclear spectroscopic data for ten experimentally known nuclides of mass number 224 (Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa, U) have been evaluated and presented together with the Adopted properties for levels and γ rays. For 224Bi, 224Po, 224At, 224Rn, 224Fr, 224Pa and 224U nuclei, only the ground–state information is known. Half–lives of ground states of 224Bi and 224Po have not yet been measured. The decay of 224Rn to 224Fr has been studied, but no decay scheme has been proposed. The decay of 224Ac to 224Ra is reported only in an abstract style conference proceedings. For a definite Jπ assignment for ground state of 224Ac, a detailed study of this decay may be helpful. In the decay of 228Pa to 224Ac, authors of 1994Ah03 state that the lowest state observed in their work may not be the ground state. Thus an extensive study of 228Pa α decay, and studies involving nuclear reactions are warranted since the level scheme of 224Ac presented in this evaluation is considered as incomplete due to the lack of confirmed information about multipolarities, mixing ratios and other spectroscopic details. Three new nuclides 224Bi, 224Po, and 224At are added in this revision, together with new in–beam γ–ray and Coulomb excitation data for 224Ra. Although, not much new experimental data have appeared since the previous evaluation (1997Ar05), extensive modifications have been made in almost all the datasets. This work supersedes the information presented in the previous NDS evaluations of A = 224: 1997Ar05, 1986Ma45 and 1976El05.