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 224 Bi, 224 Po, 224 At, 224 Rn, 224 Fr, 224 Pa and 224 U nuclei, only the ground-state information is known. Half-lives of ground states of 224 Bi and 224 Po have not yet been measured. The decay of 224 Rn to 224 Fr has been studied, but no decay scheme has been proposed. The decay of 224 Ac to 224 Ra is reported only in an abstract style conference proceedings. For a definite Jπ assignment for ground state of 224 Ac, a detailed study of this decay may be helpful. In the decay of 228 Pa to 224 Ac, authors of 1994Ah03 state that the lowest state observed in their work may not be the ground state. Thus an extensive study of 228 Pa α decay, and studies involving nuclear reactions are warranted since the level scheme of 224 Ac 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 224 Bi, 224 Po, and 224 At are added in this revision, together with new in-beam γ-ray and Coulomb excitation data for 224 Ra. 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. Cutoff Date: Literature available up to October 15, 2015, has been consulted. The bibliographic source is mainly the NSR database (2011Pr03) at Brookhaven National Laboratory webpage: www.nndc.bnl.gov/nsr/ General Policies and Organization of Material: see http://www.nndc.bnl.gov/nds/NDSPolicies.pdf. Acknowledgments:The current evaluation benefited from all the previous NDS evaluations stated above in addition to some of the A=228 and 220 NDS evaluations pertaining to α-decay chains. We thank Jagdish Tuli (NNDC,BNL) for a detailed review of this work, Murray Martin (ORNL) for his comments on the spin-parity assignment of 224 Ac g.s., and Joann Totans (NNDC,BNL) for sending us copies of several secondary references. General Comments:The statistical analysis of γ-ray data and deduced level schemes is carried out through computer codes available at data center in Brookhaven (www.nndc.bnl.gov). Theoretical conversion coefficients are from BrIcc computer code (2008Ki07) with "Frozen Orbitals" approximation, and with an implicit uncertainty of 1.4%, when not stated. All Q values are from 2012Wa38. In cases where averages have been taken, the assigned uncertainty in the recommended result is set so that it is not lower than the lowest uncertainty in a dataset that is being averaged.

Determination of 238U(n, γ) and 238U(n, f) reactions cross-section in the neutron emission spectrum of 241Am-Be source

“…Uncertainties in the sources' activities were below 5%. Standard decay data were taken from [21][22][23][24][25]. Decay data of fission and activation products were taken from [26] for 239 Np, [27] for 143 Ce, [23] for 133 I, [28] for 105 Ru, [29] for 134 Te/ 134 I, [30] for 91 Sr, [31] for 135 I, [32] for 92 Sr, and [33] for 115 In.…”

KATRIN background due to surface radioimpurities

“…The decay chain of 223 Ra includes four 𝛼-decays [17][18][19][20]. The 228 Th decay chain includes five 𝛼-decays [21][22][23][24][25]. The principal decay paths are shown in Eqs.…”

A comparative evaluation of calix[4]arene-1,3-crown-6 as a ligand for selected divalent cations of radiopharmaceutical interest

“…Properties of selected radiometal nuclides [21][22][23][24][25][26]. The ionic radii were reported in the literature for the coordination number VIII and the charge state 2+ (ref 27).…”