Nuclear Data Sheets最新文献

Evaluated spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented for ³⁰F, ³⁰Ne, ³⁰Na, ³⁰Mg, ³⁰Al, ³⁰Si, ³⁰P, ³⁰S, ³⁰Cl, and ³⁰Ar. The recommended values for the level energies and their percentage decay modes, level lifetimes, γ energies, γ branching ratios, transition probabilities, etc. are presented. Among these nuclides, ³⁰F is unobserved and most likely particle unbound. Additional experimental data are required for firm spin-parity assignments of the low-lying excited levels of ³⁰Ne. The most well studied nuclide is ³⁰Si followed by ³⁰P. The data for the most proton-rich nuclide ³⁰Ar are presented following the recent work of 2018Xu04 and 2015Mu13. This evaluation for A=30 supersedes the previous one, 2010Ba29.

The experimental reaction and decay studies producing nuclei in the A=230 mass chain have been reviewed. Data on elements from radon (Z=86) to americium (Z=95) are included, and level and decay schemes are presented for these nuclides. This work supersedes the previous evaluation for this mass chain (2012Br12).

Evidence suggests that the uncertainties reported in a widely referenced paper by Houtermans et al. in Int. J. Appl. Radiat. Isot. 31, 153 (1980) have been significantly underestimated, potentially by an order of magnitude. Up to the present date, this has had implications for the accuracy of the reference half-life and uncertainty values derived from evaluations of literature data. The current study aims to propose more realistic uncertainty values that can serve as a foundation for future re-evaluations. Additionally, it is suggested that similar corrections could be considered for other historical papers to ensure consistency across the field. Although the approach to rectifying old data may involve some degree of subjectivity, it offers a practical and effective way to incorporate the historical decay data until they can be replaced by more precise measurements accompanied by comprehensive uncertainty assessments.

The half-life of ¹³⁴Cs has been determined through 882 and 471 activity measurements of two sources over 12 years with a re-entrant ionisation chamber in a temperature-stabilised room. The data were aggregated from in total 204 565 and 99 486 ionisation current measurements with 0.057 % standard deviation. The decay curves adhere to the exponential-decay law, devoid of any cyclic perturbations at daily, monthly, and multi-annual scales, maintaining an exceptionally low standard deviation of 0.0003 % on the amplitude. A discernible annual cycle with an amplitude of 0.0051 (3) % was effectively mitigated to an insignificant level of 0.0009 (3) % by compensating the residuals proportionally to daily variations in ambient humidity. The study yielded a half-life value for ¹³⁴Cs of 754.200 (53) d or 2.06493 (14) a, with a relative standard uncertainty of 0.0070 %. The result obtained in this work can be recommended as a reference value, owing to its high statistical accuracy and conservative estimate of systematic errors.

Experimental nuclear structure and decay data are evaluated for 13 known nuclides of mass number A=63 (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se). Detailed evaluated level properties and related information are presented and recommended spectroscopic parameters are provided, combining all the data from various reactions and decays. No excited state has been observed for ⁶³Ti, ⁶³As and ⁶³Se, among which the first two nuclides have no halflife, decay modes and spin-parity being measured and reported yet. The ground-state spins and/or parities of ⁶³V, ⁶³Cr, ⁶³Mn, and ⁶³Ge still have not been definitely determined and information for excited states in these nuclides plus ⁶³Fe is limited. Information for ⁶³Ga is mostly from one measurement and no data for ⁶³Ge ε+β⁺ decay have been measured while this decay mode (%100) of the ⁶³Ge parent is known. The ⁶³Cu nuclide is the most extensively studied via more than 28 different reactions and decays, followed by ⁶³Zn and ⁶³Ni. Among all those nuclides, only ⁶³Cu has a complete radioactive decay scheme. This work supersedes earlier full evaluations of A=63 published by 2001Ba27, 1991Ki10, 1979Au10, and 1975Au03.

Evaluated nuclear structure and decay data for all nuclei with mass number A=202 (²⁰²Os, ²⁰²Ir, ²⁰²Pt, ²⁰²Au, ²⁰²Hg, ²⁰²Tl, ²⁰²Pb, ²⁰²Bi, ²⁰²Po, ²⁰²At, ²⁰²Rn, ²⁰²Fr and ²⁰²Ra), are presented. All available experimental data are compiled and evaluated, and best values for level and γ-ray energies, quantum numbers, lifetimes, γ-ray intensities and transition probabilities, as well as other nuclear properties, are recommended. Inconsistencies and discrepancies that exist in the literature are discussed. A number of computer codes (https://www-nds.iaea.org/public/ensdf_pgm/) developed by members of the NSDD network were used during the evaluation process. This work supersedes the earlier evaluation by F.G. Kondev (2007Ko42), published in Nuclear Data Sheets 108, 1471 (2007).

The evaluated spectroscopic data are presented for these nuclides: ²⁴⁹U, ²⁴⁹Np, ²⁴⁹Pu, ²⁴⁹Am, ²⁴⁹Cm, ²⁴⁹Bk, ²⁴⁹Cf, ²⁴⁹Es ²⁴⁹Fm, ²⁴⁹Md and ²⁴⁹No. This work supersedes the earlier full evaluation of A=249 published by 2011Ab07.

The experimental results published before September 2023 from the various reaction and decay studies leading to nuclides of Z=60 to Z=76, ¹⁶²Nd, ¹⁶²Pm, ¹⁶²Sm, ¹⁶²Eu, ¹⁶²Gd, ¹⁶²Tb, ¹⁶²Dy, ¹⁶²Ho, ¹⁶²Er, ¹⁶²Tm, ¹⁶²Yb, ¹⁶²Lu, ¹⁶²Hf, ¹⁶²Ta, ¹⁶²W, ¹⁶²Re ¹⁶²Os, in the A=162 mass chain have been reviewed. These data are summarized and presented, together with adopted level schemes and properties. This work is intended to supersede the previous evaluation of the A=162 nuclides by C.W.Reich (2007Re16), which was published in Nuclear Data Sheets 108, 1807 (2007).