Nuclear Data Sheets最新文献

This work represents an update of the previous evaluation of the nuclear data on the A=147 nuclides (2009Ni02). The experimental data from reaction and decay studies leading to the following nuclides have been reviewed: ¹⁴⁷I, ¹⁴⁷Xe, ¹⁴⁷Cs, ¹⁴⁷Ba, ¹⁴⁷La, ¹⁴⁷Ce, ¹⁴⁷Pr, ¹⁴⁷Nd, ¹⁴⁷Pm, ¹⁴⁷Sm, ¹⁴⁷Eu, ¹⁴⁷Gd, ¹⁴⁷Tb, ¹⁴⁷Dy, ¹⁴⁷Ho, ¹⁴⁷Er, ¹⁴⁷Tm. These data are presented, together with the adopted level schemes and their properties. ¹⁴⁷Pm nuclide and half-life of ¹⁴⁷Nd were evaluated by Balraj Singh (McMaster University; [email protected]). All the other nuclei were evaluated by Ninel Nica (Texas A&M University; [email protected]).

Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for ²¹³Hg, ²¹³Tl, ²¹³Pb, ²¹³Bi, ²¹³Po, ²¹³At, ²¹³Rn, ²¹³Fr, ²¹³Ra, ²¹³Ac, ²¹³Th, and ²¹³Pa. This evaluation for A=213 supersedes the earlier one by the same evaluator, M. S. Basunia (2007Ba19), published in Nuclear Data Sheets 108, 633 (2007).

One highlight of this evaluation is the following: In ²¹³Po, from ²⁰⁸Pb(¹⁸O,Xγ) study 2011As05 proposed revision of spin-parity assignments for 293 level: 7/2⁺ instead of (11/2⁺); 440 level: 11/2⁺ instead of (7/2⁺); 868 level: 9/2⁺ instead of (13/2⁺). New experiments are needed.

Evaluated nuclear structure and decay data are presented for 16 known A=126 nuclides (Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd). The A=126 mass chain was last evaluated by J. Katakura and K. Kitao, which was published in Nuclear Data Sheets 97, 765 (2002) (2002Ka66). In 2015, B. Singh evaluated the data of ¹²⁶Rh, ¹²⁶Pd and ¹²⁶Ag. The current work is an update of these previous evaluations. Experimental data from new publications since 2002Ka66 have been incorporated. Even when no new publications appeared, some previous datasets have been modified for new β-decay Q values and conversion coefficients. Adopted values for levels and gammas are based on data of various decays and reactions. Inconsistencies and discrepancies have been noted.

Experimental nuclear structure data from various reactions and decays are compiled and evaluated for all known nuclides with mass number A=48 (S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni). For each nuclide, detailed evaluated nuclear structure information is presented for each individual reaction and decay, and the best values combining all available data are recommended for spectroscopic properties, such as level energies, half-lives, γ-ray energies and intensities, decay radiations. No excited states have been identified in ⁴⁸S, ⁴⁸Cl, ⁴⁸Co and ⁴⁸Ni, among which the first three even have no measured ground-state half-lives and decay modes. For ⁴⁸Fe, a level scheme with a sequence of excited states was established for the first time from a recent one-neutron removal measurement by 2021Ya33. Data for excited states in ⁴⁸Ar, ⁴⁸K and ⁴⁸Mn remain limited; no decay scheme has been measured for ⁴⁸Ar and ⁴⁸K yet, while the decay scheme for ⁴⁸Ni is incomplete due to unobserved levels. ⁴⁸Ti is the most studied nuclide through various reactions and decays, followed by ⁴⁸V, ⁴⁰Ca, ⁴⁸Sc, and ⁴⁸Cr, among which no decay event to ⁴⁸Sc has been observed and the decay schemes for ⁴⁸V and ⁴⁸Cr are considered as incomplete. This work supersedes the previous full evaluations of A=48: 2006Bu08, 1993Bu04, 1985Al14, 1978Be01.

The ²³⁹Pu(n,f)/²³⁵U(n,f) cross-section ratio has been measured with the fission Time Projection Chamber (fissionTPC) from 100 keV to 100 MeV. The fissionTPC provides three-dimensional reconstruction of fission-fragment ionization profiles, allowing for a precise quantification of measurement uncertainties. The measurement was performed at the Los Alamos Neutron Science Center which provides a pulsed white source of neutrons. The data are recommended to be used as a cross-section ratio shape. A discussion of the status of the absolute normalization and comparisons to ENDF evaluations and previous measurements is included.

The evaluated experimental data are presented and evaluated for 13 known nuclides of mass 64 (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se). For each nuclide, the best values combining all available data are recommended for spectroscopic properties. No excited states have been identified in ⁶⁴Ti, ⁶⁴As, and ⁶⁴Se. Only one excited state in ⁶⁴V as an isomer, and three in ⁶⁴Cr have been identified. Data for excited states in ⁶⁴Mn, ⁶⁴Fe, and ⁶⁴Co remain limited. ⁶⁴Ni, ⁶⁴Cu, and ⁶⁴Zn are the most studied nuclides through various reactions and decays, followed by ⁶⁴Ga and ⁶⁴Ge. In the opinion of the evaluators, there are several incomplete or discrepant aspects of the high-spin portion of the level scheme for ⁶⁴Zn above ≈5 MeV excitation which need to be resolved in further experiments using large γ-detector arrays. The decay schemes of ⁶⁴Ti β⁻, ⁶⁴As ε and ⁶⁴Se ε are unknown, while very little information is available for ⁶⁴V β⁻ and ⁶⁴Cr β⁻. The decay schemes of ⁶⁴Mn β⁻, ⁶⁴Fe β⁻, ⁶⁴Co β⁻ and ⁶⁴Ge ε are somewhat better known, but still considered incomplete by evaluators. The decay scheme of ⁶⁴Ga ε decay is known in detail, however there is the possibility of additional levels populated above 4713 keV, as the Q(ε) value is 7171 keV. The β⁻, β⁺ and ε decay modes of ⁶⁴Cu are well known, as this radionuclide is of great importance in applications, for example, as a dosimeter for neutron flux determination in nuclear reactors, and as a radiopharmaceutical for positron emission tomography (PET). This work supersedes earlier full evaluations of A=64 by 2007Si04, 1996Si12, 1991Si03, 1979Ha35 and 1974Au04.